Head to head / Dr. Barchana, do Israelis protect themselves against cancer?
“In recent years we have seen an increase in the incidence of cancer in Israel. Take skin cancer: Next week we will hold Skin Cancer Awareness Week, in preparation for summer. We recently found that 100 more new cases were diagnosed in 2008 than in 2007, for a total of 1,300 new cases. That is a moderate increase, related partly to population growth but also to people becoming sick as a result of exposure to the sun’s ultraviolet rays. Despite increased awareness of skin cancer we still anticipate a moderate increase in its incidence.
“We can see an improvement in the behavior of Israelis as a result of the warnings about skin cancer, new laws, awnings over public swimming pools. Today children engage in outdoor activities and hikes only with hats and sunscreen. The results of these actions may become evident only over time and are still not evident on the ground. You must remember that cancer is a disease that progresses slowly, and behavioral changes will be seen only over time.
“Already now one third of Israelis who are diagnosed with skin cancer are diagnosed at an early stage, before the disease has spread. That is excellent news, because in these situations the survival rate in Israel after five years is 100 percent, compared to 84 percent of people with skin cancer that is diagnosed in the invasive stage. Despite this achievement, two-thirds of Israelis with skin cancer − about 700 to 800 per year − are diagnosed in the stage when skin cancer has spread, and their chances of surviving the disease are lower.”
Barchana, 53, has been heading of the National Cancer Registry in the Ministry of Health for 16 years. All cases of cancer diagnosed in Israel are reported to the registry, which conducts quantitative studies and recommends means of prevention. Barchana, an epidemiologist, is also on the faculty of the School of Public Health of the University of Haifa and practices family medicine with the Meuhedet Health Fund.
How dangerous is Israel for skin cancer?
“Very dangerous. Australia has the highest incidence of skin cancer in the world, followed by the Scandinavian countries and Israel. When you take light-skinned people and put them in a desert climate, in a sunny country, that’s the result. In addition we are now seeing the results of the 1970s and 1980s fashion of prolonged beach sunbathing. Even today, when direct exposure to the sun has declined, the tanned look is still in fashion, and some people use tanning beds that are just as dangerous for developing skin cancer as sun exposure because of the ultraviolet rays in the tanning salons.”
Is the National Cancer Registry proving its worth?
“The purpose of the national registry is to serve as a national database for analyzing morbidity trends, both for research and for public health assessments. We’re succeeding on that level, because a great deal of cancer research is being done in Israel, and recently we are seeing updates to the ‘basket’ of subsidized health services based on the registry database, and a recommendation to include a new cancer treatment in the basket is being discussed. When a new drug is introduced it is budgeted according to the number of patients who are supposed to receive it, based on the registry data.”
You have been accused of avoiding examining possible cancer clusters, of multiple cases in a specific place such as a street, school or neighborhood. Is that true?
“Patients’ homes as registered with the Interior Ministry are included in the registry. The only data not included is the individual exposures of patients, for example exposure to dangerous substances in the workplace or smoking. As far as cumulative cases are concerned, technically speaking we sometimes see a collection of cases of cancer in a specific region, but there is a scientific limitation to determining exceptional accumulation of cases of morbidity. For example, if in a certain kibbutz we saw five new cancer patients a year over the past five years, all in all 25 cases of cancer, we still can’t talk about a surplus of cases.
“Or for example in a school in Kiryat Gat where a number of children were diagnosed with cancer. This is a school that serves a large area, so we cannot determine if the collection of cases really is exceptional. Every year 28,000 new cancer patients are identified, so cancer patients are diagnosed daily, about 75 patients a day. So if we found 14 cases in a place where 12 are expected, we cannot determine that this is a surplus.”
So will the cancer registry succeed in locating a high concentration of cancer cases in the wake of a silent exposure to dangerous substances in the country?
“The answer to the question is complex, and depends on the size of the population exposed and the type of cancer. For example, we recently received a report about a chemical firm in the Haifa Bay area that manufactures a substance that is harmful to the liver and could cause liver cancer with industrial exposure. So we looked at the cases of liver cancer in the residential area near the factory − and this is a relatively large area − and we found six cases in 20 years. We cannot draw any conclusions from these findings. Once there was a news report about a street in Jerusalem with a number of cancer patients. So even if six or seven people were diagnosed with cancer in one year, it would be hard to draw any conclusion about dangerous exposure on that street.”
What is the most dangerous cancer in Israel?
“It depends how you define dangerous, but the most significant cancer in terms of the number of patients, female patients to be exact, is breast cancer. Every year about 4,000 Israeli women are diagnosed with breast cancer, and 900 die from the disease. One of every eight Israeli women is liable to have breast cancer during her lifetime. As with skin cancer, if the disease is detected in the early stage the chances of being cured increase to 90 percent. Therefore it is important to constantly raise public awareness of the dangers, and to call for action to ensure early detection.”