Doctors gaining ground in battle against cancer

DOCTORS are winning the fight against cancer but progress is slow and the greatest reductions in deaths have come from lifestyle changes rather than through new treatments.

A report by Sir Richard Doll, one of the world's leading cancer epidemiologists, calls for extended screening programmes for early diagnosis and specialist clinics to maximise the benefits of existing treatments.

Better health education on diet, avoidance of sunburn and 'intensive efforts' to reduce the use of tobacco were also neccessary, he said. He renewed his attack on the Government for declining to ban tobacco advertising.

In a wide-ranging review of the 22 most common cancers and the changes in incidence and death rates since the 1970s, Sir Richard concluded that 'major advances are few and far between'. Future progress relies on 'effective application of the knowledge we now have of the main means to avoid the disease'.

There is cause for cautious optimism, according to the report in the Journal of Clinical Oncology. The death rate has fallen in both sexes under 55 years of age, and in men up to 65, since the late 1950s. Substantial increases have occurred only in men over 75 and in women aged between 60 and 69.

However, the situation for individual cancers is complex, with some lymphatic system cancers, testicular and prostate cancers, and kidney cancer in women, showing an increase which is difficult to explain.

The greatest progress in cancer treatment has been made in the under-15s, with a fall in the death rate of more than 40 per cent. But improved treatment has its own problems, Sir Richard said, with side-effects including stunted growth, infertility, and an increased risk of cancer in later life.

Among adults, the biggest change has occurred in stomach cancer, where the death rate has been halved, probably due to increased consumption of fresh fruit and vegetables, a decrease in salt-preserved foods and the use of refrigeration to preserve foods.

The number of deaths from colorectal cancer has also fallen, due to better surgical treatment, a reduction of saturated fat in the diet and an increase in green and yellow vegetables and dietary fibre.

The second biggest change was the reduction in lung cancer as cigarette smoking has fallen. But Sir Richard, who discovered the link between lung cancer and smoking, said he was 'disturbed by reports that the Department of Trade and Industry is forcing a reluctant Minister for Health' to vote against an EC directive which restricts tobacco advertising.

For breast cancer, better drug treatment is likely in the coming years. The drug tamoxifen has been shown to bring about an 11 per cent increase in survival rates, while the 'most exciting' data for the drug shows the benefits of use for after surgery to prevent recurrence.

There has been no change in the incidence and death rate due to leukaemia and cancers of the brain and central nervous system.

Melanoma, a skin cancer, has increased dramatically because of increased exposure to sunlight and sunburn in childhood.

The risk of testicular cancer is at least three times greater now than it was in the 1930s - although death rate is falling - although doctors do not know why; and the death rates from ovarian and womb cancer have fallen, due to improved treatments and the protective effect of the contraceptive pill.

Sir Richard said that it was too soon to tell what impact 'cancer hazards' such as asbestos in buildings, pesticide residues in food, dioxins in waste and nuclear installations and electric power lines would have on incidence of the disease.