Proportionate increase in incidence of colorectal cancer at an age below 40 years: An observation

Aim: Colorectal cancer is particularly a disease affecting individuals above 40 years of age and 90% of cases occur in persons over the age of 50. Genetic and familial factors, viz, HNPCC and FAP, contribute to less than 20% and environmental or acquired factors are the cause of the rest. The aim of this study is to find out the relative proportion of patients < 40 years of age affected by this disease, registered in our institute.
Materials and Methods: Colorectal cancers registered in the calendar years of 2003 and 2004 in our institute were analyzed in this study. Data from Population Based Cancer Registry (P.B.C.R.) for Bangalore, Mumbai, Delhi and Chennai for the year 1988 were taken for comparison.
Results: The results show that our institute's figures exceed the generally accepted figure for 'incidence of the disease below the age of 40 years' by less than 10% of both the total incidence of the disease and those of P.B.C.R. for Bangalore, Mumbai and Chennai. The corresponding figure for females in Delhi P.B.C.R. shows a little similarity to our institute's figure.
Conclusion: This observation indicates a changing pattern of colorectal cancer occurrence. This change may be a regional one or may be a result of genetic or environmental changes.