ABSTRACT
Cancer is the most challenging health-care problem of the developed countries at the end of the twentieth century. This is best illustrated by figures concerning some of the most common neoplasms in these countries, namely breast and colon cancer. Lung cancer is excluded from this discussion, because the main cause of lung cancers-smoking-is well known and the rise in non-smoking policies will, hopefully, result in the decline of this neoplasm. In breast cancer, unfortunately, this is not so: in the United States of America alone about 46000 women are expected to die of it in 1993. The overall mortality rates have, over the years, unfortunately remained almost static because the advances in the detection and prevention of cancer have been offset by the increased incidence of the disease (Anonymous, 1993). A similarly bleak picture must be drawn for cancer of the colon: annually 20000 deaths are reported in the UK. If treated surgically, approximately 50 per cent of the patients survive five years, but if the crude survival rate is taken into account, it drops to approximately 20-25 per cent (Schumacher et al., 1994). An equally pessimistic picture can be drawn for many other solid neoplasms.
