Table Speech


“Secrets of Cancer”

November 17, 2010

Mr. Keiichi Nakagawa
Associate Professor,
The University of Tokyo Hospital

 Today, one in two Japanese becomes a “cancer” patient. 350,000 people die from cancer every year, accounting for a third of the total mortality. I had a chance to be on a TV show the other day. During the show, the MC stated “I am always afraid of cancer as I regard it as an incurable disease.” I made a comment that “cancer is no longer incurable, as 60% of cancer patients get cured today. Cancer is more a lifestyle-related illness, thus prevention halves the risk of becoming cancer patients. Also, early detection leads to complete cure. This is why regular cancer checkup is crucial. The alarming fact is that the number of people receiving checkups in Japan is the lowest among developed nations.”

 Some of you might believe in the superstition that cancer is hereditary. Although cancer is a disease of the genes, it is not basically hereditary. Some of you might avoid eating burnt food to prevent cancer, yet the most important prevention in our daily life is to quit smoking.

 Death causes in Japan have shifted. Tuberculosis was the top before and during the War. Stroke replaced TB after the War up to the 1980s. Today, stroke is decreasing while heart disease is on an increase. The point is that most of the diseases have gone past their worst numbers, thanks to medical advancement. Cancer, however, is the only disease showing constant increase in Japan before and after the War. What is more is that Japan is the only country among 7 developed nations that has an increasing number of cancer deaths.

 Now, we need to understand the nature of cancer. In short, cancer cell is an “immortal cell generated by its own error in copying.” Our body consists of 60 trillion cells, of which 600 billion die each day. New cells are supplemented by cell division. In other words, 600 billion times of copying take place. As a natural outcome, errors do happen, generating the immortal cancer cells. Thanks to lymphocyte, cancer cells are detected as foreign substance and killed every day, which keeps us from becoming cancer patients.

 Cancer cells only survive in the body from where they were generated.Immune cells kill cancer cells only by recognizing them as foreign substances. As cancer cells originate from one’s own cells, they are similar in nature with immune cells, making detection hard and imperfect. Cancer cells start to increase from ages 30-40. Unfortunately immune strength weakens as one gets older, making cancer detection harder and harder.

 Cancer is the phenomena of aging. It is inevitable that Japan has the largest number of cancer patients, as the Japanese people enjoy the longest life expectancy at birth (83 years for males and 86 years for females). In other words, people did not live long enough to become cancer patients in earlier times, when life expectancy was about 35-40 years.

 Now how can we prevent dying from cancer? Even an ideal cancer-free lifestyle cannot eliminate the risk completely, and your chance to have cancer remains at around 30%. Suppose there are 10 risk factors of cancer, smoking accounts for 3, while lack of vegetables/fruits or excessive salt intake and meat consumption accounts for another 3. Now, what is the remaining 4? The answer is luck. Yet, we cannot just rely on mere luck. This is why cancer check-ups for early detection play a significant role.

 If cancer patients start suffering from pain, cancers have already metastasized to the bones in 80% of the cases. Metastasized cancer is incurable. As early-stage cancer does not show any symptoms, it is crucial to take regular check-ups. It takes 15 years for one overlooked breast cancer cell to develop into a 1cm-cell. Yet, it takes only 5 years for a 1cm-cancer to become 5cm-large.

 Even medical specialists, including myself, cannot diagnose a cell less than 1cm-large. Early-stage cancer is defined as 2cm-large or less. It takes 1.5 years for a 1cm-cancer to become 2cm-large. In theory, check-ups taken once in every 1.5 years will guarantee 100% detection. In short, regular check-up is the only way to diagnose early-stage cancer. There are two types of check-ups, resident’s check-up and occupational field check-up. Regular check-up is most effective, especially for cervical cancer, colorectal cancer and breast cancer. 84% of the Americans and 79% of the British take cervical cancer check-ups, while the percentage is as low as 21% in Japan. As a result, in Japan, you get diagnosed with cancer only after having some symptoms at the advanced or terminal stage, in most cases.

 Surgical operation, radiation and chemotherapy are the three treatments proved to be scientifically effective for cancers. Japan is the only country where most of the patients go to surgeons for operations. The department of surgery undertakes cancer treatments in Japan today, making operations the mainstream and thus, making the level of treatments by radiation or chemotherapy the lowest among the seven developed nations.

 Japan is again an exceptional country regarding the usage of pain-killers that control the intense pain caused by cancers. Its usage in Japan is one twentieth of that in the US, based on the common knowledge that “drugs shorten one’s life.”

 Although Japan has the world’s largest number of cancer patients, various countermeasures are still underdeveloped. It is my sincere wish that early diagnosis will prevail as well as treatment methods will be improved.