Disruptive Innovation

Seminar By Clayton M. Christensen

* When you are wildly successful you are doomed.

* Companies often fail because of the very management practices that have allowed them to become industry leaders. Because these practices make it extremely difficult for them to develop the disruptive technologies that ultimately steal away their markets. (Technology means the processes by which an organization transforms labor, capital, materials, and information into products and services of greater value. This concept of technology therefore extends beyond engineering and manufacturing to encompass a range of marketing, investment, and managerial processes. Innovation refers to a change in one of these technologies).

* Well-managed companies are excellent at developing the sustaining technologies that improve the performance of their products in the ways that matter to their customers. This is because their management practices are biased toward: Listening to customers, Investing aggressively in technologies that give those customers what they say they want, Seeking higher margins, Targeting larger markets rather than smaller ones.

* Disruptive technologies, however, are distinctly different from sustaining technologies. These technologies change the value proposition in a market. When they first appear, they almost always offer lower performance in terms of the attributes that mainstream customers care about. But disruptive technologies have other attributes that a few fringe (generally new) customers value. They are typically cheaper, smaller, simpler and frequently more convenient to use. Therefore they open up new markets. Further because with experience and sufficient investment, the developers of disruptive technologies will always improve their products’ performance, they are eventually able to take over the older markets. This is because they are able to deliver sufficient performance on the old attributes, and they add some new ones.

* Good theories are statements of what causes what and why. Most managers are not aware of good theories. Their analysis is based on data. And data refers to the past. And therefore to guide their actions in the future, with or without data, they have to rely on randomness. Because they do not have recourse to a good theory. This is the case with innovation.

* Flight became possible only after people came to understand the relevant natural laws and principles that defined how the world worked: the law of gravity, Bernoulli’s principle, and the concepts of lift, drag, and resistance. When people then designed flying systems that recognized or harnessed the power of these laws and principles, rather than fighting them, they were able to fly to heights and distances that were previously unimaginable.

* Another aspect of ‘Innovation’ is that it changes according to the various needs of constituencies. Just like a piece of legislation being passed through Parliament. The innovation may be different from the original idea because it has been shaped and morphed in order to mirror the economic model of the company.

* There are 10 questions which we need to get right for creating new businesses.

1. How can we beat the competition? (Business Model)
2. Which customers should we target? (Resource)
3. What products will our customers want to buy? (Resource)
4. How should we distribute to and communicate with our customers? (Process)
5. Which things should our company do, and which should our partners and suppliers do? (Process)
6. How can we avoid commoditization? (Business Model)
7. Who should be on our management team? (Resource)
8. What is the best organizational structure for this business? (Process)
9. How can we know when to change course? (Business Model)
10. Whose investment capital will help, and whose will hurt? (Resource)

* The Disruptive Innovation Theory states that there are 2 trajectories. One trajectory represents the pace of technological progress or how products and services are getting better over time. The other trajectory relates to how much of improvement can the customer utilize or absorb.

* In the initial phase any new product or service is not good enough for anything but gradually as it improves it gets too good for everything. Intel when it introduced its first chip it was not found good enough but through gradual improvement it became too good at everything.

* In a stable business incumbent companies nearly always win because they play catch-up with the progress of technology and use it to increase their profits.

* Innovations that disrupt usually emerge at the low cost end of the business. In the 70s and 80s, 'Digital' was the most admired company having gone from zero to $16 billions in 16 years. However, in 1988 it collapsed and with it every mini-computer company collapsed. Why? The mini-computer companies were making around a 45% margin and with innovations in mini-computers they were predicting a 60 % margin. So DEC had to adopt a set of values that essentially dictated, “If it generates 50% gross margins or more, it’s good business. If it generates less than 40% margins, it’s not worth doing.” At the same time one found that the Personal Computer which was a disruptive technology was earning a margin of 40% which would move down towards 20%. Digital entered the Personal Computer market 4 times and each time found that it could not achieve the profitability it had in the mini-computer business. Good companies find it easy to move up but difficult to move down.

* When one looks at the Steel industry one finds that Integrated Steel Mills dominated all segments of the market. The lowest segment of this market was the steel used for concrete reinforcement which was termed as the ‘Rebar’ segment. When the Mini-steel Mill entered this segment, the ‘Rebar’steel, which they made was much below quality but as they improved they had the cost advantage which the large Integrated steel plants could not match. The Integrated Steel Mills gave up this segment to the Mini-Steel plants and concentrated on the higher quality and more profitable segments of ‘Angle iron’ steel. The same story was repeated by the Mini-Steel Mills also moving up the chain, at first creating a below quality product and then improving and getting the large Integrated Steel Mills to relinquish this segment and concentrate on the next more profitable segment which was ‘Structural Steel’. Again the same story was repeated and the Integrated Steel Mills relinquished the ‘Structural Steel’ segment to the Mini-Steel Mills and concentrated on the most profitable segment which was ‘Sheet Steel’. The same story was played out and ultimately all but one Integrated Steel Mill closed down.

* The lesson from this is that one needs to define the fight in such a way that the existing giant wants to run away from you rather than fight you. Disrupt them by taking a piece of the market they are motivated to run away from. Enter from the low cost end of the market and target non-customers.

* One sees the same game played out in the automobile industry. GM and Ford never entered the small low cost car market. It didn’t make sense to enter. Just like it didn’t make sense for the Integrated Steel Mills to remain in the low end of the market. Toyota came in and disrupted them and moved up the value chain. Today, Toyota has a Lexus at the premium end.

* One sees that in the 60s,70s and 80s Japan grew rapidly by following this strategy. In every industry they entered at the low end and then moved up the value chain. By the 90s, they had done this in every industry. And, therefore by the 90s in every industry they were at the high end. And there is relatively no growth in the high end and therefore for 15 years they have experienced stagnation. In US, one has the facility of venture capital which encourages one to go back to the low end of the market and create market disruption all over again. But in Japan, they don’t have a culture of venture capital.

* In Innovation the creation of new products or services will give one a temporary benefit. But the creation of a new process will give one more staying power.

* Within the same business it is difficult to find the leader in the sustaining wave as well as in the emergent wave. In order to capitalize on the emergent wave the leader usually creates another business.

* IBM was able to remain atop its industry when minicomputers disrupted mainframes because it competed in the minicomputer market with a different business unit. And when the personal computer emerged, IBM addressed that disruption by creating an autonomous business unit in Florida.

* Originally Department Stores were more involved with selling Hardware. As Discount stores entered the Hardware segment, Department stores moved into Clothing and relinquished the Hardware segment. Soon Discount stores moved into clothing and other segments and gradually the Department stores started shutting down. Today, only 9 Department Stores remain out of an original number of 315.

* At the highest end of the market there is too much capacity and therefore mergers take place.

* IBM had a better operating system than Microsoft and a better processor than Intel. IBM could easily have entered the Personal Computer market but still continued in the mainframe business and outsourced the operating systems and processors. We need to question whether it is always good to outsource.

* Integrated firms compete on the basis of functionality and reliability. But as the market needs change to desiring improved speed, responsiveness and customization, the structure moves from being Integrated to being Modular.

* Interdependent or integrated architectures optimize performance, in terms of functionality and reliability. These architectures are proprietary because each company will develop its own interdependent design to optimize performance in a different way. A modular interface is a clean one. Modular components fit and work together in well-understood and highly defined ways. A modular architecture specifies the fit and function of all elements so completely that it doesn’t matter who makes the components or subsystems, as long as they meet the specifications.

* IBM as the most integrated competitor in the mainframe computer industry, held a 70% market share but made 95% of the industry’s profits: It had proprietary products, strong cost advantages and high entry barriers. For the same reasons, from the 50s through the 70s, General Motors with about 55% of US automobile market, garnered 80% of the industry’s profits. Most of the firms which were suppliers to IBM and General Motors, in contrast had to make do with subsistence profits year after year. These firms’ experiences are typical. Making highly differentiable products with strong cost advantages creates these circumstances of dominance.

* When this circumstance changes- when the dominant profitable companies overshoot what their mainstream customers can use- then this game can no longer be played, and the tables begin to turn. Customers will not pay still- higher prices for products they already deem too good. Before long modularity rules, and commoditization sets in. When the relevant dimensions of your product’s performance are determined not by you but by the subsystems that you procure from your suppliers, it becomes difficult to earn anything more than subsistence returns in a product category that used to make a lot of money. When your world becomes modular, you’ll need to look elsewhere in the value chain to make any serious money.

* When one looks at IBM and Intel one finds that because the architecture of IBM was integrated it did not enter the components segment even though it had the capability of doing so. There was less profit in that segment. But when the market expectations shifted to more speed, customization and responsiveness then Intel opened up its architecture and entered every computer and thus created a modular structure. Intel now solved problems that absorbed IBM’s engineers. And, thus commoditized IBM’s engineers. A similar scene was witnessed in the case of Compaq outsourcing to Flextronics and ultimately Flextronics the circuit board manufacturer commoditizing Compaq. The irony is that if Compaq had not outsourced it would have been killed earlier. But because it outsourced it was killed later.

* As the low cost entrants move forward up the value chain, they trivialize what is left behind so that very little value can be added after disruption.

* Implant makers have commoditized doctors who are surgeons for, say, ‘hip and knee’. The implant makers have created ‘fool proof and idiot simple’ solutions. Diagnostics have commoditized physicians. Once one has been diagnosed precisely one can then be given standardized therapy. Bloomberg has commoditized Wall Street analysts.

* Low end disruption or low end businesses address over served customers. That is when existing products and services are ‘too good’ and hence overpriced relative to the value existing customers seek. Wal-Mart is a low end disruptive innovation. It began by offering customers a low-priced, relatively straight-forward product. These customers were over-served.

* Disruptive innovations enable a larger population of less-skilled, less wealthy people to do things in a more convenient, lower-cost setting, which historically could only be done by specialists in less convenient settings.

* A new disruption brings in a new population which are mainly non-consumers.

* The low cost advantage of India is temporary but the number of non-customers is huge.

* The transistor disrupted the vacuum tube. The vacuum tube manufacturers concentrated on desktop radios and floor standing TVs and kept on trying to improve their vacuum tubes for these products. While this was happening Sony created the transistor radio which was a pocket radio which was not of a good quality but was targeted to non-users who were teenagers. Sony didn’t sell to Parents. Sony then came out with the portable TV with the transistor. Again it was competing with non-consumption. Soon the vacuum tubes just got sucked out by the transistor using devices. The vacuum tube improvements were being crammed into the space where one would certainly fail.

* Similarly voice-recognition software was being developed by IBM and was being crammed into the space of the Word processor. In the meanwhile, this software was launched in toy robots with simple standard phrases being used and in chat rooms. Not very sophisticated but gradually improving over time. Disruption of new technology is accepted more by non-customers.

* IBM needed to make the voice-recognition software more cost-effective and increase its performance. This is not so achievable in the upper segment as it is in the low end segment. Among non-customers one doesn’t have to spend so much money to be successful.

* Billions of dollars are being spent to make the use of solar energy more widespread among current users of electricity in the urban area. No matter how much improvement one makes in solar panels its adoption in the urban areas will not be much. The expectations are too high. Whereas in Mongolia 40% of population lives in tents. They have no access to electricity. The adoption of solar panels is a tremendous success here. They are non-consumers.

* Linux is a modular architecture. It cannot compete head-on with Microsoft which is an interdependent architecture. So, Linux creates a web-centric use which is a new space. It will disrupt by fuelling web-centric computing. There are problems in the software today but gradually it will improve.

* Not only products and companies get disrupted but whole channels get disrupted. Vacuum tubes were being sold through appliance stores. When Sony started developing its transistors the same appliance stores were refusing to keep them. At the very same time K-Mart and Wal-Mart were coming up and they decided to sell Sony’s transistors and thus disrupted the whole channel of appliance stores.

* In new markets rules don’t apply. Rules like IRR, ROI etc. Patterns need to be seen and which customers one is serving. One needs to go after non-customers.

* The rule of shareholder value is no longer valid. In 60s, it was valid because the average time a share was held was 6 years. Now it is 60 days. Shareholders have become speculators. Therefore, the long-term value of the firm is the goal and not increasing shareholder value.

* If existing managers are taught how the world works they can use disruption effectively.

* The way we segment markets makes new products fail. We usually segment markets according to product categories or customer categories. It’s usually an inside-out approach. We need to look outside-in. From a customer’s point of view he/she needs to get ‘jobs’ done or important problems solved. We need to find out what are the ‘jobs’ which are arising in the customer’s life and for which jobs will the product be hired.

* In the example of Milk Shakes purchased from a Mcdonald’s outlet the question one needs to ask is ‘What job arises that gets a milk shake hired?’ It was found that 40% bought milk shakes in the morning from the Mcdonald’s outlet. They did not consume it in the outlet and bought the milk shake alone. It was found that they used it as a nourishment and pastime while driving to work in the morning. So they had one hand on the wheel while the other hand held the milk shake. Competition for this ‘job’ therefore gets restated to include bananas, snickers, bagels etc. In the evening the same milk shake was being hired by parents who were saying ‘no’ to their children throughout the day and needed to alleviate their guilt by giving in to their children by buying them a milk shake in the evening. Once one understands the ‘jobs’ for which the product is hired one can now go on improving vis-à-vis the ‘job’ for which it is hired. For instance the morning milk shake could become more viscous and fruity while the evening milk shake could be packaged differently. Size of market now gets defined from the customer’s perspective.

* From this perspective one sees that the market is larger, one’s share smaller, the real competition is not in the product category, the growth potential is greater, and one understands the constraints under which non-customers operate.

* There are 3 levels of architecture where a job is concerned viz. What is the fundamental job or problem the customer is facing? This includes its functional, emotional and social dimensions. What are the experiences in purchase and use, which if all provided, would sum up to nailing the job perfectly? What are the products’ attributes, technologies, features etc. that are needed to provide the necessary experiences?

* Any company’s products get hired for 3 to 4 jobs. We need to catch customers right after they hired a product. We don’t ask ‘why’. We understand and write a case about the situation. We need to ask what the customer hired or did when in that same situation but didn’t hire your product. We then need to do research on what else is the product hired to do as well as find out what were the situations in which one made do with nothing. Understanding customers without understanding the jobs which arise for them, will give one a wrong direction.

* By understanding jobs we find for example that most people take photo-prints and look at them just once. They like to put them in an album but seldom look at them. From this perspective, the use of a digital camera is mainly restricted to the click and attach facility. What is the use of trying to get the customer to do editing which he/she is not interested in. A brand is not built through advertising. It is built around the jobs it is hired to do. If one has a job to do and the brand pops up in one’s mind then one will go out and hire it.

* The following steps need to be adopted:

1. Design a product that does a job well.
2. Create this brand that uniquely links the product to the job.
3. Trust that brand for that purpose.
4. Whenever that job space comes up the customer will hire that brand and talk about it.
5. Only then can advertising help to build it.

* 'Sawzall' helps to drill hole in wall. It is a brand built around this specific job. It’s share is more than 80%. Similarly, 'Holehawg' is another brand built around a product which is a right angle drill for plumbers. It’s share is again more than 80%. Both brands belong to Milwaukee. All the rest of Milwaukee’s brands have less than 10% share. Similarly Sony has Walkman and Play Station which are huge purpose brands while the other Sony brands have a much lesser share.

* Usually, companies have a proprietary end to end architecture. They are integrated. When the modular architecture takes off the coin flips. If Apple opens up its architecture then 'iTunes' will be in every iPod no matter who manufactures it just like Intel. Components become more important.

* Automobiles today struggle to sustain a premium through differentiation on some dimensions. If one looks at jobs which need to be done by cars then one can come up with the following possibilities viz. a gift to a loved one of the family which then necessitates creation of a package of experiences for that car. Or one can say that my car is my office. There are 20 million people who need to work out of their car. The car can then become a purpose brand. Customers will then be willing to pay a premium for the job the car is being hired for. In the automobile market one cannot have the attitude of one size fits all.

* Every brand today that is valuable started as a purpose brand. One can develop other product forms to do the same jobs or develop brands for different jobs.

* Crest Fluoride is a disruptive technology because it prevents cavities. The advertising is associated with that job. If Crest is extended to other product forms like mouth rinse then the consumer gets confused. Because J&J also has mouth rinse. When P&G did that with Crest and applied it to many jobs it transformed it to an Endorser brand. P&G lost its leadership. JW Marriott created a hotel chain for conferences and company meetings. When there were other jobs like if one is just interested in a clean and inexpensive room then JW Marriott created another brand ‘Courtyard’. ‘Residence’ is another brand which is meant for the job of catering to those who get transferred. In this way one lessens the confusion.

* If you hire the product to do the job but it doesn’t do it then you will lose trust in it. If consumers don’t hire it for the wrong reason they will not lose trust in it.

* The dilemma is that one can’t prioritize low margin and high margin at the same time. Echo is a small low end car of Toyota. But it is sold through the same channel as other cars. One can therefore not prioritize ‘Echo’ because of the other bigger cars having bigger margins. When one is dealing with bigger margins one can't prioritize smaller margin products. One needs to grow faster to sustain the stock market. The bigger one gets one can’t prioritize emerging markets. Drugs coming out of R&D will be evaluated by Pfizer in terms of how much will they contribute to the growth of its current base of $5 billion revenues.

* When looking at disruptive innovations one needs to ask the following questions viz. Do they have the Resources? Will they have the right Processes? A process which is good at one thing may not be good at other things. Will the profit model (Business Model) allow them to prioritize medium range/low range products?

* For organic fibers, some years ago one needed to go to Dupont to find a molecule. One engaged in unstructured and exploratory exercises. But as others came into the field patterns emerged. One now didn’t feel the need to be an expert. When Quantum theory began to be used they found that they could predict properties even before the molecule was developed. So reverse engineering was indulged in.

* Original problem solving was embedded in the experts. And, there was a lot of experimentation. But, gradually patterns emerged which were recognized. One now knew how the world worked and created a set of rules.

* When it’s a new business one doesn’t know the right assumptions. In 93% of the cases, one finds that the strategy that leads to success is different from what the initial strategy was.

* One needs one strategy for sustenance and one for disruption. The questions and process adopted for the sustenance strategy is the following: Make assumptions, Build projections based upon assumptions, make decisions to invest based upon projections, implement the deliberate strategy. If one’s projections are going wrong one reexamines the assumptions. For instance, one assumes that based on a GDP growth of 7% one will achieve a certain revenue figure. If one’s projection is not being achieved one goes back and examines the assumption.

* For a Disruption innovation one indulges in Discovery– driven planning. The steps one follows are: One makes projections on a pilot basis. Now in this pilot what assumptions must prove true for the projections to happen? Implement the plan to learn– to test whether the critical assumptions are reasonable. Invest when the key assumptions prove valid.

* Be sure the brand is positioned on a job and move up the value chain as fast as possible.

* When one integrates with another company be sure it’s for resources and not for processes or profits.

* What matters is challenge, a desire to create history, burn one’s bridges, removing the escape buttons, and getting a breakthrough insight.

* Most leadership teams outsource insight. One cannot outsource insight. Grameen Bank in Bangla Desh was built on an insight which stated that people in rural area are not affected by a loss of money in as much as a loss of credibility and face. Small loans are therefore given to women with the community as collateral. This could not have come from outsourcing.

* All markets are ready but we just don’t have the ideas. We need to rethink the source of insight. We can’t source it from the same journals read by everyone. Big ideas don’t get killed; they just get diluted. We need to convert ideas into real time experiments. Just one idea is not enough. We need more and then roll them out as ‘fission’. We can’t execute new ideas with the previous mindset. We need to create escape velocity and avoid dilution.

* There is a disruption taking place in management education. Operating companies are starting their own universities. Today, there are 2000 corporate universities. Number of students applying to Harvard is coming down. Another thing is that everything is being uploaded onto to the Internet and is made foolproof and idiot simple for professors in corporate universities. In this way, professors in management institutes are getting commoditized. If this is done by Harvard then Harvard would make money because it would be providing the teacher with better material rather than targeting the end user.

* There are examples where incumbents killed entrants. Kodak came out with Easyshare targeted for girls. Where there is an emphasis on ‘Click and send by email’. It’s share jumped from 6% to 28% of the Digital Market. Fuji and Polaroid missed it.

* By becoming so good hospitals overshot their patients with so much of care which these patients could not afford. So now if the technology is made available for these patients in outpatient clinics, doctors’ offices and homes of patients, there will be a new disruption. With nurses doing more sophisticated work the doctors are getting commoditized. The nurses become low cost high quality providers.

* Culture needs to shift from proof seeking to experimenting.

* A company relies on people as resources for innovation. But if it is to be sustainable then one needs to make it process dependent.

(Wherever one needed a more detailed explanation in order to clarify the concepts one has referred to the 2 books written by Clayton M. Christensen viz. ‘The Innovator’s Dilemma’, and ‘The Innovator’s Solution’. His latest book is ‘Seeing What’s Next’.)

Asbestos: Real Cause for Mesothelioma

Asbestos refers to a family of magnesium-silicate mineral fibers. In the past, asbestos was used widely for insulation because it does not conduct heat well and it is resistant to melting or burning. As the link between asbestos and mesothelioma has become well known, the use of this material has decreased. However, up to 8 million Americans may already have been exposed to asbestos.

According to the United States Environmental Protection Agency, as many as 733,000 schools and public buildings in the country contain asbestos insulation. As many as 10% to 15% of schools in the United States may contain asbestos insulation. People who may be at risk for occupational asbestos exposure include some miners, factory workers, insulation manufacturers, rail-road workers, ship builders, gas mask manufacturers and construction workers, particularly those involved with installing insulation. Several studies have shown that family members of people exposed to asbestos at work have an increased risk of developing mesothelioma, because asbestos fibers are carried home on the clothes of the workers.

There are 2 main forms of asbestos-- serpentine and amphiboles. Serpentine fibers are curly and pliable. Chrysotile is the only type of serpentine fiber and it is the most widely used form of asbestos. Amphiboles are thin, rod-like fibers of which there are 5 main types-crocidolite, amosite, anthrophylite, tremolite and actinolyte. Amphiboles (particularly crocidolite) are considered to be the most carcinogenic (cancer-causing). However, even the more commonly used chrysotile fibers have been associated with malignant (cancerous) mesotheliomas and should be considered dangerous as well.

It may be that asbestos causes cancer by physically irritating cells rather than by a chemical effect. When fibers are inhaled, most are cleared in the nose, throat, trachea or bronchi. Fibers are cleared by sticking to mucus inside the air passages and being coughed up or swallowed. The long, thin, fibers are less readily cleared, and they may reach the ends of the small airways and penetrate into the pleural lining of the lung and chest wall. These fibers may then directly injure mesothelial cells of the pleura, and eventually cause mesothelioma.

Asbestos fibers can also damage cells of the lung and result in asbestosis (formation of scar tissue in the lung), and lung cancer. The risk of lung cancer among people exposed to asbestos is increased by 7 times, compared with the general population. Indeed, asbestosis, mesothelioma and lung cancer are the 3 most frequent causes of death and disease among people with heavy asbestos exposure. Peritoneal mesothelioma, which forms in the abdomen, may result from coughing up and swallowing inhaled asbestos fibers. Cancers of the larynx, pancreas, esophagus, colon and kidney have also been linked to asbestos exposure, but the increased risk is not as great as with lung cancer.

Although the risk of developing mesothelioma rises with the amount of asbestos exposure, it is clear that genetic factors also play a role in determining who develops the disease. This explains why not all persons exposed to high levels of asbestos dust develop mesothelioma.

(Inputs from www.mesothelioma.com and www.mesothelioma.org)

Mesothelioma Strikes 3000 US Citizens Every Year

Mesothelioma is one of the deadliest diseases known to man, especially labor class persons. Average life span of an inflicted person from the time of diagnosis until death is less than 24 months. It’s a disease that strikes approximately 3,000 United States citizens every year. Disease affects men 3 to 5 times more often than women. It is less common in African Americans than in white Americans.

It is a disease that is almost 100% preventable; the only known cause is via exposure to the deadly mineral Asbestos. It comes from inhaling the particles of dust as the asbestos degrades; eating away at the lining of lungs and developing into a cancer.

Mesothelioma, which is also called Malignant mesothelioma, is an uncommon, but no longer rare, cancer that is difficult to diagnose and poorly responsive to therapy. It is the most serious of all asbestos-related diseases.

A layer of specialized cells called mesothelial cells lines the chest cavity, abdominal cavity and the cavity around the heart. These cells also cover the outer surface of most internal organs. Tissue formed by these cells is called mesothelium.

Mesothelium helps protect the organs by producing a special lubricating fluid that allows organs to move around. For example, this fluid makes it easier for the lungs to move inside the chest during breathing. Mesothelium of the chest is called the pleura and the mesothelium of the abdomen is known as the peritoneum. Mesothelium of the pericardial cavity is called the pericardium.

Mesothelioma was recognized as a tumor of the pleura, peritoneum and pericardium in the late 1700's. However it was not until much later, in 1960, that this particular type of tumor was described in more detail and even more importantly, its association with asbestos exposure was recognized. The first report linking mesothelioma to asbestos exposure was written by J.C.Wagner, and described 32 cases of workers in the "Asbestos Hills" in South Africa. Since than the relationship between mesothelioma and asbestos exposure has been confirmed in studies around the world.

Although the disease is much more commonly seen in 60-year old men, it has been described in women and early childhood as well. The cause of the disease is not so well understood in these latter two groups, but there is some evidence of possible asbestos exposure for some of these cases as well.

Malignant mesotheliomas are divided into 3 main types. About 50% to 70% of mesotheliomas are the epithelioid type. This type has the best prognosis (outlook for survival). The other two types are the sarcomatoid type (7%-20%), and the mixed/biphasic type (20%-35%). Treatment options for all 3 types are the same.

About three-fourths of mesotheliomas start in the chest cavity. They are known as pleural mesotheliomas. Another 10% to 20% begin in the abdomen. These are called peritoneal mesotheliomas. Pericardial mesotheliomas, those starting in the cavity around the heart, are very rare. The covering layer of the testicles is actually an out pouching of peritoneum into the scrotum. Mesotheliomas that affect this covering of the testicles are quite rare.

Asbestos exposure is the main cause of mesothelioma. After these fibers are breathed in, they travel to the ends of small air passages and reach the pleura where they cause physical damage to mesothelial cells that may result in cancer. In addition, they also cause injury to lung cells that can result in lung cancer and/or asbestosis (replacement of lung tissue by scar tissue). If swallowed, these fibers can reach the abdominal cavity where they have a role in causing peritoneal mesothelioma.

Beginning 15 years after the onset of exposure, about 6% of asbestos workers die of mesothelioma. In one study of asbestos insulation workers, the death rate from mesothelioma was 344 times higher than in the general population.

Early symptoms of mesotheliomas are not specific to the disease. People often ignore them or mistake them for common, minor ailments. Most people with mesothelioma have symptoms for only 2 to 3 months before they are diagnosed. About one-fourth have symptoms for at least six months prior to their diagnosis.

Over half of patients with pleural mesothelioma have pain in the lower back or at the side of the chest. Many report shortness of breath. A smaller percentage have trouble swallowing, cough, fever, sweating, fatigue, and weight loss. Other symptoms include hoarseness, coughing up blood, swelling of the face and arms, muscle weakness, and sensory loss.

Symptoms of peritoneal mesothelioma include abdominal pain, weight loss, nausea and vomiting. There may also be a hernia, fluid in the abdominal cavity or a mass in the abdomen.

A person with any of these symptoms who has been exposed to asbestos should see a doctor right away.

There are different types of mesothelioma. One of them is Pleural Mesothelioma. Pleural mesothelioma spreads within the chest cavity, sometimes involving the lung. Metastases can occur in any organ, including the brain, and are much more common than previously thought.

Peritoneal mesothelioma involves the abdominal cavity, infiltrating the liver, spleen or the bowel. As with pleural mesothelioma pain is the most common presenting complaint. In addition, due to fluid accumulation in the abdominal cavity (ascites), the abdomen appears enlarged. The patients experience nausea, vomiting, swelling of their feet, fever and difficulty in moving their bowels.

A rare form of mesothelioma is cystic mesothelioma of the peritoneum. Its prognosis is benign. Its occurrence has been described primarily in young women. However the diagnosis presents difficulties, requiring extensive electron microscopy and immunohistochemical studies.

(Inputs from www.mesothelioma.com and www.mesothelioma.org)