An increased incidence of endometrial cancer has also been found in association with tamoxifen treatment of breast cancer, perhaps related to the estrogenic effect of tamoxifen on the endometrium. Because of this increase, patients on tamoxifen should have follow-up pelvic examinations and should be examined if there is any abnormal uterine bleeding. The pattern of spread is partially dependent on the degree of cellular differentiation. In patients with poorly differentiated tumors, myometrial invasion occurs much more frequently. Myometrial invasion is frequently a harbinger of lymph node involvement and distant metastases and is often independent of the degree of differentiation.
Metastatic spread occurs in a characteristic pattern.
Spread to the pelvic and para-aortic nodes is common. Distant metastases can occur and most commonly involve the lungs, inguinal and supraclavicular nodes, liver, bones, brain, and vagina. Another factor found to correlate with extrauterine and nodal spread of tumor is involvement of the capillary-lymphatic space on histopathologic examination. I disease become possible by careful operative staging. I, grade 1 carcinomas of favorable histologic type.