The changing distribution and survival of colorectal carcinoma: an epidemiological study in an area of northern Italy

Abstract

This study analyses the inter-relations of anatomical tumour location, gender, age and incidence rates for colorectal cancer from 1978 to 1999 in an area of northern Italy: the Parma district. Data were obtained from the Parma Cancer Registry. Age-adjusted incidence rates were analysed by gender, age and colorectal cancer subsites. In addition, 5 year observed survival rates were determined. In the Parma area, the incidence of colorectal cancer is rising. We have observed a true increase in the rate of the age standardized incidence of right colon cancer, linked to an increased incidence of left colon cancer, while the incidence of rectal cancer has remained constant. The frequency of right-sided colon cancer was higher in aged patients, and in women. Age-standardized relative survival of patients after diagnosis of colorectal cancer between 1992 and 1996 was found to be significantly higher than age-standardized relative survival after diagnosis between 1978 and 1982. In the Parma area there has been an increased incidence of right colon cancer, linked to an increased incidence of left colon cancer, while the incidence of rectal cancer has remained constant. We feel that this shift, whatever the reason for it, has important implications for the choice of screening techniques.