A controlled cohort study of long-term income in colorectal cancer patients.

Purpose: The study aims to investigate long-term development in annual labor income (ALI) among patients with colorectal cancer (CRC) compared to individually matched cancer-free controls.

Methods: In a register-based cohort study based on data from Norwegian national registries, 752 patients diagnosed with CRC 1992-1996 at the age 45-54 years were observed annually up to 10 years post-diagnosis. Also, 752 individually matched controls were observed correspondingly. The relationship of CRC and ALI development was modeled by linear mixed model statistics.

Results: CRC was associated with reduced ALI in females in the year of diagnosis, irrespective of extent of disease. From the year after diagnosis and onwards, ALI decreased in female patients and controls, most strongly in females with distant CRC, and also in males with regional and distant CRC. Five years after diagnosis, mean ALI was reduced by 22 % in females and 6 % in males with localized CRC. Corresponding numbers were 21 % in females and 11 % in males with regional CRC and 6 % reduction in female and less than 1 % reduction in male controls. After adjustment for post-diagnostic disability pension and days of employment, ALI developed similarly in male patients and controls, whereas CRC remained associated with reduced ALI in the year of diagnosis in females and throughout observation in females with distant CRC.

Conclusion: Except for males with localized cancer, CRC was associated with negative development in ALI in both sexes, varying by extent of disease. The work ability and income status of female CRC patients and males with metastasing disease should be checked during follow-up.