There are Public Health programmes which could prevent cancers developing or increase the probability that a cancer may be cured Early detection is an important factor in reducing the death rate from cancer, whether it is achieved by personal actions or through participation in organised public health programmes. Awareness of different visual body signs or symptoms that could easily be observed by anyone and that are possibly related to cancer is important. It is unequivocally established that cancer survival is better for early, localised disease than for the later stage, advanced forms of the disease. Thus, the earlier in the process that a cancer can be diagnosed and treated then the better this is for the patient. Potential symptoms of cancer should not be ignored, but should serve as a clear warning for the individual to consult his or her doctor for advice. The signs and symptoms described in Table 10 are not specific for cancer. When any one is present, the individual should see a doctor. Much effort has gone into cancer screening and the development of methods for finding cancers at an earlier stage in their development and increasing the prospects of a cure. It is possible to make recommendations based on the available evidence.
:: Women from 50 years of age should participate in breast screening. This should be within programmes with quality control procedures in compliance with European Union Guidelines for Quality Assurance in Mammography Screening.
Mammography can detect breast tumours at a clinically undetectable stage. The results of the early randomised trials of mammographic screening demonstrated the value of this technique and led to the introduction of organised national programmes of screening in several countries in 1986–8. Reports from seven trials involving over half a million women subsequently indicated a reduction in mortality from breast cancer of about 25% in women invited to be screened. The reduction of mortality in those actually attending screening is about one third.
There is now considerable evidence that breast cancer screening with mammography is effective in reducing mortality from breast cancer. An overview of the Swedish trials reported relative risks of death of 0.71 in the group randomised to receive an offer of screening, with 95% confidence internal 0.57–0.89 for women aged 50–59 years at entry. Results for women ages 60–69 were almost identical. When applied to a population, a well-organised programme with a good compliance should lead to a reduction in breast cancer mortality of at least 20% in women aged over 50.
The value of screening women aged under 50 years is uncertain. No trials have had large enough statistical power to analyse these women separately. What recommendations should be made for mammographic screening of women aged between 40 and 49 is an important question that cannot currently be answered; over 40% of the years of life lost due to breast cancer diagnosed before the age of 80 years are attributable to cases presenting symptomatically at ages 35–49 years, frequently an age of considerable social responsibility.
Swedish workers have recently conducted an overview of four of their trials. The conclusions indicate that the benefit of breast screening, in terms of a reduction in breast cancer mortality of 21%, persisted for a median time of 15.8 years. In addition to this overview, two working groups have been convened. A working group of the International Agency for Cancer Research (IARC) met in Lyon on 5–12 March 2002 and consisted of 24 experts from 11 countries. The quality of the seven trials was assessed and it was concluded that screening by mammography reduced mortality from breast cancer in women of 50–69 years of age. In women who participated in screening programmes this reduction was estimated at 35%. For women of 40–49 years, evidence for a reduction in mortality was too limited to reach a conclusion. The evidence is insufficient to recommend performing routine breast self-examination as a method of screening.
Forty years of clinical trials, the contribution of hundreds of scientists and health workers and the dedication of hundreds of thousands of women to participate in studies lasting for decades has resulted in adequate evidence to support the efficacy of mammographic screening for breast cancer, which now allows its transfer to the arena of public health care . Doctors and women should be assured that participation in organised screening programmes with high quality control standards is of benefit, provided appropriate investigation and treatment is available. European Guidelines for Quality Control in Mammographic Screening have been developed and are widely employed throughout Europe.
Special efforts should be made to encourage screening among the more deprived members of communities. It is important not to over-emphasise the benefit of screening, and to appreciate that mammographic screening is but one step in the total care of women with the disease. As had been shown by long-term established programmes in the UK, Sweden, Finland and The Netherlands recognition of the importance of the multidisciplinary team in the assessment of mammographic abnormalities spread into the symptomatic sector leading to the development of integrated multidisciplinary breast care centres. Staffed by dedicated surgeons, radiologists and pathologists working alongside breast care nurses, counselling and other support personnel, these centres offer the necessary care for women with breast cancer.