Incidence, therapy and prognosis of colorectal cancer in different age groups. A population-based cohort study of the Rostock Cancer Registry

Abstract

Purpose: Determination of frequency, treatment modalities used and prognoses of colorectal cancer in a population-specific analysis in relation to age.

Material and methods: In 1999 and 2000, 644/6,016 patients were documented as having colorectal carcinomas in the Cancer Registry of Rostock. 39 patients were excluded (16 cases: "in situ" carcinomas; 23 cases: insufficient data). Three age groups were formed: < 60 years, 60-74 years; > or = 75 years.

Results: The relative percentage of colorectal cancer increases with advanced age (< 60 years 7%; 60-74 years 12%, > or = 75 years 15%; p < 0.001). In older patients with stage III carcinomas, adjuvant treatment was done less frequently in accordance with the treatment recommendations (< 60 years 83-89%; 60-74 years 67-77%; > or = 75 years 29-36% according to stage and tumor localization); in stage IV, the use of chemotherapy was reduced (< 60 years 87.5-100%; 60-74 years 38-47%; > or = 75 years 33-37%). In the univariate analysis, age > or = 75 years (4-year survival rates: < 60 years 68 +/- 4.1%; 60-74 years 58 +/- 2.8%; > or = 75 years 38 +/- 3.7%), UICC stage and surgical treatment had a significant effect on prognosis. Adjuvant treatment had no significant effect on the whole population but on patients with UICC stage III and IV. In the multivariate analysis, however, the only independent prognostic parameters were age > or = 75 years (p = 0.001), performance of chemotherapy (colon cancer) or radiochemotherapy (rectal cancer; p = 0.004-0.001), and tumor stage (p = 0.045-0.001). Sex (p = 0.063) and age between 60 and 74 years (p = 0.067) had a borderline influence.

Conclusion: With increasing age, there is a departure in daily practice from the treatment recommendations. The patient's prognosis is dependent upon age (especially > or = 75 years), tumor stage, and therapy.