Impact of older age on clinicopathological and prognostic features of colon cancer in postmenopausal women.

To clarify the clinicopathological features of colorectal cancer in older people, systematic studies considering age, sex, and the tumor locus is needed. We focused on colon cancer in postmenopausal women (<70 years, n = 68 vs. ≥70 years, n = 85), and examined the effect of age on clinicopathological features. Rates of medullary carcinoma /mucinous carcinoma were higher and pathological stages at diagnosis were less advanced in patients ≥70 years compared with <70 years. Matching pathological stages, no significant difference in disease-free interval was observed according to age; however, disease-specific survival (DSS) was poorer in patients ≥70 years than <70 years, being significantly different in stage IV cases. Regarding post-metastasis/recurrence (met/rec) cases, chemotherapy and surgery for metastasis were less frequent in those aged ≥70 years than <70 years. Post-met/rec DSS was poorer in ≥70 years, those with microsatellite instability, and those without surgery for met/rec than in each counterpart; however, post-met/rec chemotherapy exhibited no effect. Multivariate analyses revealed that an older age and no surgery for metastasis were independent predictors of disease-specific death. These findings remained after excluding stage IV cases. Older age was a potent risk factor of rapid disease-specific death after met/rec.