Cancer


We have already discussed the role of calcium in the prevention of colon cancer. This has been a very significant finding given the fact that over half the population is marginally deficient in calcium due to insufficient daily intake. Patients with low selenium intake are also at risk for developing colon cancer and breast cancer, as well as lung cancer.
Polyps are growths that can occur in the rectum and colon. These can be easily removed, but they often recur. About 20 percent of all polyps transform into cancer, so it is important to try to prevent their recurrence once they have been resected. The recurrence of polyps was examined in one study sponsored by the Ludwig Institute for Cancer Research in Toronto, Canada. After surgical resection of polyps in 200 people who were then deemed free of all other polyps, one group of 100 patients was given a daily supplement of 400 milligrams of vitamin С and 400 IU of vitamin E. The other group received a placebo. After two years of treatment, a slight reduction of polyp recurrences was noted in the patient group receiving the vitamin supplementation.
Another similar study at six different research centers in the United States involved 865 people. They too had resected polyps and were deemed free of polyps at the time they were enrolled in the program. One group received supplements of vitamins С and E; the second group received beta-carotene; the third group got vitamins С and E as well as beta-carotene; and the fourth group got a placebo. This trial is still ongoing, but the results thus far are encouraging and show some promise, since the people who received vitamins С and E plus beta-carotene had a decreased recurrence rate.
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Heightened public awareness and an improved prognosis for cancer victims have made the cancer experience less threatening and isolating than it once was. While you may hear of some stories of recovering cancer patients experiencing job discrimination and being unable to obtain health or life insurance, these cases are decreasing in number. Several states have even enacted legislation to prevent insurance companies from canceling policies or from instituting other forms of discrimination. Health insurance can be obtained through large employers. Because large employers spread the insurance risk among many employees, insurance companies accept all new employees without underwriting.
On the personal side, assistance for the cancer patient is more readily available than ever before. Cancer support groups, cancer information workshops, and low-cost medical consultation are just a few of the forms of assistance now offered in many communities. Breast cancer activists learned a great deal from the success of the AIDS activists who pressured Congress to provide funds for AIDS research. The National Breast Cancer Coalition and other grass-roots groups have lobbied to increase cancer research dollars. Their efforts have been paying off. Government funding has increased substantially over the past decade. The battle for funds continues.
Increasing efforts in cancer research, improvements in diagnostic equipment, and advances in treatment provide hope for the future.
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Electrical sources like power cables emit alternating electromagnetic fields at very low frequencies. For many years there was no special concern that these might be associated with cancer. However, in 1979 an epidemiological study was published by Drs Wertheimer and Leeper suggesting that children who lived within a short distance of alternating electromagnetic fields were at increased risk of some cancers. This observation has generated a vast amount of discussion, research and investment in research into the possible harmful effects of electromagnetic fields. The work is incomplete and it is hard to draw conclusions. Indeed, our colleague Professor Ray Cartwright, in an article in the British Journal of Cancer, concluded ‘it is not surprising that some confusion exists in the minds of the scientific community and the general public as to the reality of these risks’.
Briefly, most of the scientific evidence, although not yet conclusive, suggests that the risk, if it exists, is small. The energy emitted by these low-frequency electrical sources is at the low end of the electromagnetic (EM) spectrum, much below that of radio waves or ultraviolet rays. Electromagnetic fields are not ionizing and do not even produce heat. There has not been much work in the laboratory, but such work as has been done does not show any consistent evidence of cancer causation by electromagnetic irradiation from electrical sources. Wertheimer and Leeper produced the only evidence which causes concern. They looked at the incidence of childhood leukaemia in relation to electromagnetic fields and said that it was higher in children who had a high exposure to EM fields. Since then, studies have looked at occupations where there is believed to be an excess of exposure to electrically generated electromagnetic irradiation. Such occupations include those of linesmen, power-station workers, telecommunication workers, electrical engineers, nuclear-shipyard electricians, radio and television repairers and assembly-line workers. On balance, the studies suggest there may be a small excess risk of leukaemia in these workers but it is difficult to link this conclusively to electromagnetic irradiation. There is no good, conclusive evidence that they are actually exposed to more electromagnetic irradiation than the general population and it is quite possible that they are exposed to other leukaemagens (leukaemia-inducing agents) such as chemicals in the workplace. Studies which have attempted to reproduce the observations of a link between childhood leukaemia and overhead power cables have, in general, been unconvincing but are continuing. The results of these investigations are very difficult to interpret because the studies are small and the documentation of the actual exposure to electromagnetic irradiation as a result of the power lines is rather imprecise.
Those currently investigating this problem in North America and Europe will try even harder to tease out the answers. This will take years, and will cost the power industry and government large sums of money. There will be much more speculation but. at present, the scientific evidence seems to point to the following conclusion drawn by Ray Cartwright in his recent article: ‘We are thus looking forward to many more years of speculation surrounding the supposed adverse health effects of electromagnetic fields at very low frequencies with respect to leukaemia, despite the fact that our present scientific knowledge points at the very best to a minute risk of electromagnetic fields verging on the point of non-existence.’
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CANCER AND RADIATION HAZARDS: ELECTROMAGNETIC FIELDSElectrical sources like power cables emit alternating electromagnetic fields at very low frequencies. For many years there was no special concern that these might be associated with cancer. However, in 1979 an epidemiological study was published by Drs Wertheimer and Leeper suggesting that children who lived within a short distance of alternating electromagnetic fields were at increased risk of some cancers. This observation has generated a vast amount of discussion, research and investment in research into the possible harmful effects of electromagnetic fields. The work is incomplete and it is hard to draw conclusions. Indeed, our colleague Professor Ray Cartwright, in an article in the British Journal of Cancer, concluded ‘it is not surprising that some confusion exists in the minds of the scientific community and the general public as to the reality of these risks’.Briefly, most of the scientific evidence, although not yet conclusive, suggests that the risk, if it exists, is small. The energy emitted by these low-frequency electrical sources is at the low end of the electromagnetic (EM) spectrum, much below that of radio waves or ultraviolet rays. Electromagnetic fields are not ionizing and do not even produce heat. There has not been much work in the laboratory, but such work as has been done does not show any consistent evidence of cancer causation by electromagnetic irradiation from electrical sources. Wertheimer and Leeper produced the only evidence which causes concern. They looked at the incidence of childhood leukaemia in relation to electromagnetic fields and said that it was higher in children who had a high exposure to EM fields. Since then, studies have looked at occupations where there is believed to be an excess of exposure to electrically generated electromagnetic irradiation. Such occupations include those of linesmen, power-station workers, telecommunication workers, electrical engineers, nuclear-shipyard electricians, radio and television repairers and assembly-line workers. On balance, the studies suggest there may be a small excess risk of leukaemia in these workers but it is difficult to link this conclusively to electromagnetic irradiation. There is no good, conclusive evidence that they are actually exposed to more electromagnetic irradiation than the general population and it is quite possible that they are exposed to other leukaemagens (leukaemia-inducing agents) such as chemicals in the workplace. Studies which have attempted to reproduce the observations of a link between childhood leukaemia and overhead power cables have, in general, been unconvincing but are continuing. The results of these investigations are very difficult to interpret because the studies are small and the documentation of the actual exposure to electromagnetic irradiation as a result of the power lines is rather imprecise.Those currently investigating this problem in North America and Europe will try even harder to tease out the answers. This will take years, and will cost the power industry and government large sums of money. There will be much more speculation but. at present, the scientific evidence seems to point to the following conclusion drawn by Ray Cartwright in his recent article: ‘We are thus looking forward to many more years of speculation surrounding the supposed adverse health effects of electromagnetic fields at very low frequencies with respect to leukaemia, despite the fact that our present scientific knowledge points at the very best to a minute risk of electromagnetic fields verging on the point of non-existence.’*83\194\4*

Since we know ionizing radiation can cause cancer we must minimize the risk to the general population and concentrate particularly on those for whom there is special concern, such as workers in the radiation industry. In general, the science of radiation protection is now well developed. The historical examples of occupational exposure, like the painters of watch faces mentioned above, serve as chilling warnings of the consequences of relaxing radiation protection, but in general most workers in the radiation industry are working at levels of exposure which are associated with only negligible increases in cancer risk. There is no cause for complacency and even more strict radiation protection regulations are now being imposed. The new regulations in the United Kingdom for substances hazardous to health will help to document, strengthen and enforce the regulations.
The risk of nuclear accident or the deliberate use of nuclear radiation in warfare remains with us. Minimizing this risk is perhaps one of the most crucial roles of government in cancer prevention.
If exposure to large doses of irradiation, in occupations or accidents or warfare, are now avoidable, the focus of radiation protection comes down to the low doses of irradiation which are present in everyday life.
At present, little can be done about the exposure to natural irradiation in the environment. It probably contributes a relatively small amount to the total cancer risk and certainly is very much less important than major factors like smoking or diet. Medical exposure to ionizing radiation in diagnostic X-rays should be kept to a minimum. Hew techniques and new machines are aimed at minimizing dose levels and reducing the amount of tissue X-rayed. It is pretty clear that, within these technical limitations, the benefits of irradiation are much greater than the risk of increased cancer, if any, at such low doses.
People should not, however, have X-rays too frequently. Dental X-rays should not be given to people with normal and healthy teeth and gums more often than once every two years. It is important to wear a special apron when having a dental X-ray and your dentist will provide this for you. It is particularly important to avoid the irradiation of the unborn child and babies in the first year of life. All doctors are concerned to minimize the use of X-rays in pregnancy and in early life, and X-rays should only be used when there is a very clear need for the information that they generate.
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PREVENTION OF RADIATION-INDUCED CANCERSince we know ionizing radiation can cause cancer we must minimize the risk to the general population and concentrate particularly on those for whom there is special concern, such as workers in the radiation industry. In general, the science of radiation protection is now well developed. The historical examples of occupational exposure, like the painters of watch faces mentioned above, serve as chilling warnings of the consequences of relaxing radiation protection, but in general most workers in the radiation industry are working at levels of exposure which are associated with only negligible increases in cancer risk. There is no cause for complacency and even more strict radiation protection regulations are now being imposed. The new regulations in the United Kingdom for substances hazardous to health will help to document, strengthen and enforce the regulations.The risk of nuclear accident or the deliberate use of nuclear radiation in warfare remains with us. Minimizing this risk is perhaps one of the most crucial roles of government in cancer prevention.If exposure to large doses of irradiation, in occupations or accidents or warfare, are now avoidable, the focus of radiation protection comes down to the low doses of irradiation which are present in everyday life.At present, little can be done about the exposure to natural irradiation in the environment. It probably contributes a relatively small amount to the total cancer risk and certainly is very much less important than major factors like smoking or diet. Medical exposure to ionizing radiation in diagnostic X-rays should be kept to a minimum. Hew techniques and new machines are aimed at minimizing dose levels and reducing the amount of tissue X-rayed. It is pretty clear that, within these technical limitations, the benefits of irradiation are much greater than the risk of increased cancer, if any, at such low doses.People should not, however, have X-rays too frequently. Dental X-rays should not be given to people with normal and healthy teeth and gums more often than once every two years. It is important to wear a special apron when having a dental X-ray and your dentist will provide this for you. It is particularly important to avoid the irradiation of the unborn child and babies in the first year of life. All doctors are concerned to minimize the use of X-rays in pregnancy and in early life, and X-rays should only be used when there is a very clear need for the information that they generate.*80\194\4*