Mutual associations between malignancy, age, gender, and subsite incidence of colorectal cancer.

ABSTRACT

BACKGROUND: A cross-sectional study was performed on a cohort of colorectal cancer (CRC) patients to reveal any influence of age, gender, and subsite on grades of malignancy. PATIENTS AND METHODS: Data from histopathological grading according to WHO criteria were pooled into groups of low-grade (well and moderately differentiated) and high-grade (poorly and undifferentiated) cancer and analyzed for associations. RESULTS: In general, women with CRC were significantly older than men (p<0.05). In particular, women with high-grade cancer in the proximal and distal colon had a median age of 75 years and were thus 10-15 years older (p<0.01 and p<0.05, respectively) than their male counterparts. In contrast, high-grade rectal cancer developed in both genders around the early age of 60 years. CONCLUSION: Women are protected from more aggressive cancer in the colon though not in the rectum until well after menopause. This likely reflects the differential sensitivity of the mucosa at these sites against the anticancer effects triggered by activation of estrogen receptor-beta.