Colon cancer patients with a serious psychiatric disorder present with a more advanced cancer stage and receive less adjuvant chemotherapy - A Nationwide Danish Cohort Study.

Background: Psychiatric patients with colorectal cancer may have delayed diagnosis and be oncologically undertreated.

Methods: The Danish Colorectal Cancer Group database comprised 25,194 colorectal cancer patients (CRC), (colon cancer (CC, n = 16,641), rectal cancer (RC, n = 8553)), having an operation in 2007-2013, were alive at least 30 days after operation, of which 422 have had at least one hospital contact for a serious psychiatric disorder; ICD-10: DF20-29: primary psychotic disorders, or DF30-39: affective disorders (exposed) in a period of 3650-120 days before the operation date. Pearson chi-squared test for cancer stage was calculated. Odds Ratio (OR) with 95% confidence interval (CI) for having had a palliative vs an intended curative aim of the operative treatment for CRC patients (cohort 1), and for having an oncological treatment for each cancer site CC or RC (cohort 2 and 3) in patients with and without a psychiatric history was estimated. We adjusted the OR for: age, gender, comorbidity index, cancer stage, socio-economic position group, and educational level.

Results: A higher cancer stage at the time of operation in patients with psychiatric disorders compared with patients without such a history was seen and may possibly point towards a delay in the diagnosis or in the treatment of CC in patients with psychiatric disorders. They also had decreased adjusted OR for having an oncological treatment, OR 0.55, 95% CI (0.40-0.76)), which was not explained by cancer stage. For patients with RC no difference was seen.

Conclusions: Attention for CC patients with pre-existing serious psychiatric disorders is recommended.