Small bowel and rectal toxicity after pelvic radiotherapy : histopathological development, the influence of ageing and modulation by conformal treatment

Throughout history, cancer has been one of the major causes of death. It has been estimated that in the western world approximately one in three people will develop some kind of cancer during their lifetime, and one in five will die of it. Longevity is associated with prolonged exposure of somatic cells to environmental carcinogens leading to carcinogenesis in these ageing cells. Therefore, cancer is predominantly a disease related to old age. In The Netherlands, the number of persons over 85 years of age increased from 99.000 in 1976 to 203.000 in 1995 (an increase of 1O5 %). It is predicted that by the year 2015 the total population living in The Netherlands will have increased by 8.4%, from 15.4 million in 1994 to 16.7 million. However the proportion of the population more than 65 years of age is expected to grow much faster (45%), although the proportion of persons of 85 years and older will remain the same. In view of the demographic developments, the number of cancer cases can be expected to increase dramatically in the near future. Compared to 1994, for 2015 an increase varying from 30-60 % for cancer of the colon, prostate and breast has been predicted.