Endometrial Cancer Treatment (Professional)
General Information About Endometrial Cancer
Incidence and Mortality
Estimated new cases and deaths from endometrial (uterine corpus) cancer in the United States in 2013:
Cancer of the endometrium is the most common gynecologic malignancy and accounts for 6% of all cancers in women. It is a highly curable tumor. To detect endometrial cancer, a technique that directly samples the endometrial tissue is mandatory. The Pap smear is not reliable as a screening procedure in endometrial cancer, although a retrospective study found a strong correlation between positive cervical cytology and high-risk disease (i.e., high-grade tumor and deep myometrial invasion)  as well as an increased risk of nodal disease. The degree of tumor differentiation has an important impact on the natural history of this disease and on treatment selection. An increased incidence of endometrial cancer has been found in association with prolonged, unopposed estrogen exposure.[4,5] In contrast, combined estrogen and progesterone therapy prevents the increase in risk of endometrial cancer associated with unopposed estrogen use.[6,7] In some patients, an antecedent history of complex hyperplasia with atypia can be demonstrated. An increased incidence of endometrial cancer has also been found in association with tamoxifen treatment of breast cancer (NSABP-B-14), perhaps related to the estrogenic effect of tamoxifen on the endometrium.[8,9] 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. Well-differentiated tumors tend to limit their spread to the surface of the endometrium; myometrial extension is less common. 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.[10,11] Metastatic spread occurs in a characteristic pattern. Spread to the pelvic and para-aortic nodes is common. When distant metastasis occurs, it most commonly involves the following:
Another factor found to correlate with extrauterine and nodal spread of tumor is involvement of the capillary-lymphatic space on histopathologic examination. Three prognostic groupings of clinical stage I disease become possible by careful operative staging. Patients with grade 1 tumors involving only endometrium and no evidence of intraperitoneal disease (i.e., adnexal spread or positive washings) have a low risk (<5%) of nodal involvement. Patients with grade 2 or 3 tumors and invasion of less than 50% of the myometrium and no intraperitoneal disease have a 5% to 9% incidence of pelvic node involvement and a 4% incidence of positive para-aortic nodes. Patients with deep muscle invasion and high-grade tumors and/or intraperitoneal disease have a significant risk of nodal spread, 20% to 60% to pelvic nodes and 10% to 30% to para-aortic nodes. One study was directed specifically at stage I, grade 1 carcinomas of favorable histologic type. The authors identified the following four statistically significant adverse prognostic factors:
Another group identified aneuploidy and a high S-phase fraction as predictive of poor prognosis. A Gynecologic Oncology Group study related surgical-pathologic parameters and postoperative treatment to recurrence-free interval and recurrence site. For patients without extrauterine spread, the greatest determinants of recurrence were grade 3 histology and deep myometrial invasion. In this study, the frequency of recurrence was greatly increased with positive pelvic nodes, adnexal metastasis, positive peritoneal cytology, capillary space involvement, involvement of the isthmus or cervix, and, particularly, positive para-aortic nodes (includes all grades and depth of invasion). Of the cases with aortic node metastases, 98% were in patients with positive pelvic nodes, intra-abdominal metastases, or tumor invasion of the outer 33% of the myometrium.[16,17]
When the only evidence of extrauterine spread is positive peritoneal cytology, the influence on outcome is unclear. The value of therapy directed at this cytologic finding is not well founded.[18,19,20,21,22,23] The preponderance of evidence, however, would suggest that other extrauterine disease must be present before additional postoperative therapy is considered.
One report found progesterone receptor levels to be the single most important prognostic indicator of 3-year survival in clinical stage I and II disease. Patients with progesterone receptor levels higher than 100 had a 3-year disease-free survival of 93% compared with 36% for a level lower than 100. Only cervical involvement and peritoneal cytology were significant prognostic variables after adjusting for progesterone receptor levels. Other reports confirm the importance of hormone receptor status as an independent prognostic factor. Additionally, immunohistochemical staining of paraffin-embedded tissue for both estrogen and progesterone receptors has been shown to correlate with International Federation of Gynecology and Obstetrics grade as well as survival.[26,27,28] On the basis of these data, progesterone and estrogen receptors, assessed either by biochemical or immunohistochemical methods, should be included, when possible, in the evaluation of stage I and II patients. The following have also been found to be prognostic indicators of clinical outcome:
Other PDQ summaries containing information related to endometrial (uterine corpus) cancer include the following:
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