Clinical and epidemiological factors associated with suicide in colorectal cancer

While increased suicidal tendencies among cancer patients have been well documented, this study aims to examine suicide rates and factors associated with suicide specifically in patients with colorectal cancer (CRC).

Patients diagnosed with CRC between the years of 1988–2010 were selected from the Surveillance, Epidemiology, and End Result (SEER) database. Comparisons with the general population were done using the National Center for Disease Control registry.

One thousand three hundred eighty-one suicides among 884,529 patients were identified, with a standardized mortality ratio (SMR) of 1.53 (95% CI, 1.13–1.33) compared to the general population. No statistically significant difference in suicide rate was found with respect to age, marital status, socio-economic status, surgical intervention, histologic subtype, or stage at diagnosis. Within the CRC population, Whites were significantly more likely to commit suicide than non-Whites (OR, 2.28; 95% CI, 1.89–2.75; P < 0.001), and males were significantly more likely than females (OR, 5.635; 95% CI, 4.85–6.54; P < 0.001). Most suicides occurred in patients with distal lesions in the sigmoid/rectosigmoid junction (P < 0.001). SMRs for CRC patients were 4.24 for females (95% CI, 3.69–4.86), 1.35 for males (95% CI, 1.28–1.43), 0.38 for African-Americans (95% CI, 0.28–0.52), 1.77 for Whites (95% CI, 1.68–1.87), and 0.90 for other races (95% CI, 0.72–1.12).

Identification of risk factors associated with suicide among patients with CRC is an important step in developing screening strategies and management of psychosocial stressors. These results could be helpful in formulating a comprehensive suicide risk scoring system for screening all cancer patients.