Gender difference in the incidence of colorectal cancer is well known and has been supported by various epidemiologic studies. In Korea, women have lower incidence of colorectal cancer and adenoma, and the incidence in men has recently increased. Hormone replacement therapy in menopausal women is preventive of colorectal cancer but can cause cardiovascular diseases and breast cancer. Estrogen exerts diverse effects through estrogen receptors, ERalpha and ERbeta. ERbeta is associated with anti-proliferation and apoptosis. The ratio of ERalpha/ERbeta is important in the protection and tumorigenesis of colorectal cancer. Therefore ERbeta modulation has been investigated for preventing or treating colorectal cancer and avoiding adverse effects of estrogen at the same time. In addition, the gender-difference in the incidence of colorectal cancer should be taken into account when making guidelines on colorectal surveillance for Korean population.
Adenoma/diagnosis/epidemiology/mortality ; Colorectal Neoplasms/*diagnosis/epidemiology/mortality ; Estradiol Dehydrogenases/metabolism ; Estrogen Receptor alpha/metabolism ; Estrogen Receptor beta/metabolism ; Estrogens/*metabolism ; Humans ; Sex Factors

BACKGROUND/AIMS: Since pancreatic endocrine tumors (PET) are rare and heterogeneous diseases, their survival and prognosis are not well known. Due to recent advances in CT/MRI technology, incidentalomas of the pancreas are detected with increasing frequency. This study presents results of clinical manifestations of PET and predictive factors associated with survival. METHODS: From year 1990 through 2006, medical records of 98 patients (56 men, 42 women) who were diagnosed as PET pathologically at Seoul National University Hospital were reviewed retrospectively. RESULTS: Ages ranged from 17 to 76 years (mean 51.6+/-1.3 years) with a mean follow-up of 3.6+/-0.4 years (range 0-10.1 years). Overall 5-year survival rate was 68.1%, and 5-year survival rate of the patients who had distant metastases at initial diagnosis was 43.9%. Functioning tumors [hazard ratio (HR) 0.229, 95% confidence interval (CI) 0.056-0.943, p=0.041] and lymph node or liver metastases (HR 5.537, 95% CI 2.106-14.555, p<0.001) were the significant prognostic factors associated with survival rate. However, tumor size and pathology showed no significant association with survival. CONCLUSIONS: Because small and pathologically benign nature do not predict good prognosis in PET, aggressive treatment such as curative resection would be considered initially even in the case of incidental PET.
Adenoma, Islet Cell/*diagnosis/epidemiology/*mortality ; Adolescent ; Adult ; Aged ; Combined Modality Therapy ; Female ; Follow-Up Studies ; Humans ; Liver Neoplasms/diagnosis/secondary ; Lymph Nodes/pathology ; Male ; Middle Aged ; Multivariate Analysis ; Pancreatic Neoplasms/*diagnosis/epidemiology/*mortality ; Predictive Value of Tests ; Prognosis ; Retrospective Studies ; Survival Rate ; Tomography, X-Ray Computed ; Treatment Outcome