Cancers in an aging population with severe motor and intellectual disabilities: a single-center retrospective cohort study.

[OBJECTIVE] To investigate the characteristics of cancers in aging individuals with severe motor and intellectual disabilities (SMID).

[METHODS] This is a retrospective cohort study conducted at a single center. Clinical records of 186 individuals residing in the SMID ward between January 2002 and December 2022 were reviewed. For colorectal cancer, which showed high incidence, statistical comparisons were performed with an age- and sex-matched non-cancer control group.

[RESULTS] Among 48 recorded deaths, cancer was the most common cause (13 cases, 27 %; median age at death, 57 years), followed by pneumonia (12 cases, 25 %; median age at death, 51 years). Among the 20 patients diagnosed with cancers (affecting 22 organs), colorectal cancer accounted for eight cases (36 %) and breast cancer for six cases (27 %). The standardized incidence ratios for both cancers exceeded 1. Colorectal cancer incidence was significantly associated with frequent gross hematochezia and the number of preceding years with positive fecal occult blood test results, as well as marginally with the frequency of enemas. Four patients with colorectal cancer underwent surgery, and three were alive at the end of the study period.

[CONCLUSION] As individuals with SMID age, cancer has become a leading cause of death. The incidence rates of colorectal and breast cancers exceed those in the general population. It is justifiable to apply the same screening protocols to this population as in the general population, but strategies to enhance diagnostic specificity and reduce the invasiveness of confirmatory tests are desirable. Surgical treatment for colorectal cancer may improve the survival outcomes.