The big 'C'
published: Wednesday | February 26, 2003
By Eulalee Thompson, Staff Reporter
SINCE SCIENTISTS have not yet put their fingers on the cause of the big 'C' - cancer - national strategies to prevent or control the disease in
populations, for the most part, merely hold a promise.
Strong associations between certain risk factors and the development of cancer, have been emerging though mainly from observational epidemiologic studies. Lifestyle and dietary modifications and avoiding suspected carcinogens are preventive strategies recommended by the World Health Organisation (WHO) for inclusion in national cancer control programmes along with nipping abnormal growth in the bud through cancer screening.
Jamaica's cancer control programme is not an integrated global one, instead, Dr. Deanna Ashley, director, Health Promotion & Protection, says that she and her team have designed national prevention programmes around selected cancers such as tobacco-related (lung) and cervical cancers, where the evidence is clear for intervention.
"We have chosen to take the ones that we can manage first and we think that we can get good results. We have a not yet built a national programme for breast and prostate cancers as those need more information...we need to understand more on the epidemiology and causal factors before we can decide on a prevention strategy because we don't want to build a programme only on treatment," she said.
Some researchers have been pointing to a link between prostate cancer and diet; new research published last October in the Journal of the National Cancer Institute indicates that breast self-examination alone is not adequate as a preventive tool and controversy still surrounds the use of mammograms.
Over 30 years of work on tobacco smoke have produced fairly conclusive evidence of the burden of tobacco-induced cancer. A strong association between tobacco use and cancers of many sites have been consistently confirmed in hundreds of epidemiologic studies. The WHO, in fact, recommends that every country give immediate priority to tobacco control in its fight against cancer, citing tobacco use in all forms as being responsible for about 30 per cent of all cancer deaths in developed countries and a rapidly rising proportion in developing countries.
"The no-smoking campaign has many spin-off benefits; it impacts a range of cancers and other chronic diseases such as heart disease. To change behaviour to encourage people to stop smoking is the strategy," Dr. Ashley.
In terms of cervical cancer, she said that it is clear that early diagnosis, through PAP smears and treatment can reduce the risk of serious health outcomes and death.
On the issue of the role of diet in cancer risk analysis, the U.S National Cancer Institute (NCI) indicates that consuming fruits and vegetables has generally been found in epidemiologic studies to be associated with reduced risk for a number of different cancers but the specific active components in these foods are not known.
Other cancer risk factors include alcohol use, physical inactivity and being fat. Alcohol consumption has been associated with increased risk of oral, pharynx, oesophageal; inactivity has been associated with increased risk of colon, breast and possibly other cancers and being overweight has been associated with colon, breast, endometrial and possibly other cancers.
Suspected environmental carcinogens include exposure to ionising radiation and ultraviolet radiation, certain occupational and chemical exposures such as aniline dyes in bladder cancer and benzene in leukaemia.
Dr. Ashley said that cancer prevention must however, be placed in the context of chronic diseases prevention since many of factors - diet, physical inactivity, smoking, obesity - which affect cancer risk, also impact other chronic diseases such as cardiovascular disease and diabetes.