The prevalence of colorectal cancer in Italy

Aims: To analyze the prevalence of colorectal cancer (CRC) in different areas of Italy by age, interval since diagnosis and disease stage at diagnosis, and to estimate the prevalence of CRC. These data provide estimates of patient demand on health resources. Patients and methods: Eleven Italian cancer registries (CRs) provided data on 33,740 patients observed for up to 15 years. For the 1,829 cases from the specialized colorectal cancer registry of Modena we analyzed prevalence by Dukes' stage and family history. PREVAL software produced observed prevalence figures by time from diagnosis; to determine the total prevalence, correction factors were applied to the observed data. Results: At the end of 1992, five-year CRC prevalence was high (close to 200 per 100,000) in Geneva, Parma, Romagna and Firenze, and low (around 75 per 100,000) in the southern areas of Latina and Ragusa. For all CRs, 86 patients per 100,000 population were alive up to 2 years from diagnosis and 77 per 100,000 between 2 and 5 years from diagnosis. The 5-year prevalence of patients diagnosed with Dukes' B or C (high risk of recurrence and requiring postoperative surveillance) was 152 per 100,000; that of Dukes' A patients 36 per 100,000 (considered cured after surgery and not requiring intensive follow-up or care); that of unstaged patients plus those with distant metastasis at diagnosis was 28 per 100,000 at 5 years (requiring palliative care but not follow-up). The 12-year prevalence of HNPCC was 23 per 100,000, or about 7% of the total; for such patients knowledge of the long-term prevalence is important because they are diagnosed young and are at high risk of multiple tumor development. Conclusions: 70% of the prevalent patients diagnosed within 5 years prior to the prevalence date were likely to require care for cancer recurrence, while 13% of the prevalent cases required care for distant metastases.