CANCER OF CORPUS II—HISTOLOGY AND EXTENSIONThe majority of uterine cancers have a relatively well-differentiated glandular architecture. In general, of course, the more anaplastic tumors may be expected to grow more rapidly and to metastasize earlier than do the more mature adenocarcinomas. The differentiation between well-differentiated uterine adenocarcinoma and atypical, adenomatous hyperplasia of the endometrium is not simple, and often ﬁxed and stained rather than frozen sections must be obtained before submitting the patient to the treatment established for an ascertained malignancy.
Squamous epithelium commonly coexists with the glandular elements of endometrial carcinoma. Historically, the term adenoacanthoma was used to describe a well-differentiated tumor and adenosquamous carcinoma to describe a more anaplastic carcinoma with squamous elements. The term adenocarcinoma with squamous elements is now used with a description of the degree of differentiation of both the glandular and squamous components. Uterine papillary serous carcinomas are a highly virulent histologic subtype of endometrial carcinomas (5% to 10% of cases). These tumors histologically resemble papillary serous carcinoma elsewhere in the body (e.g., ovary). Clear-cell carcinomas of the endometrium are less common (<5%), and histologi-cally they are similar to clear-cell adenocarcinomas of the ovary, cervix, and vagina. Clear-cell tumors tend to develop in postmenopausal women and carry a worse prognosis. Survival rates of 39% to 55% have been reported, versus 65% or better for endometrial carcinoma.
Successful therapy primarily depends on the surgical extirpation of the disease while it is conﬁned to the uterus. Unfortunately, many of these patients are not good surgical risks owing to chronic or intercurrent afﬂictions common to the sixth and seventh decades of life. Primary treatment consists of surgical exploration with hysterectomy, bilateral salpingo-oophorectomy, cytologic examination of the abdomen and diaphragm, and paraaortic node sampling. For patients with signiﬁ- cant medical comorbidities, radiation therapy alone can be used, though at a cost in efﬁcacy. Postoperative radiation to the vaginal cuff reduces local recurrence. Distant metastatic disease is treated with high-dose progestins, cisplatin, and doxorubicin (Adriamycin). The use of adjuvant radiation therapy in women with disease limited to the uterus based on systematic surgical staging is controversial. For patients with stage I, grade 1 tumors, postoperative radiation (vaginal brachy- therapy and/or external beam irradiation) may be considered if there is deep myometrial invasion to the outer one-third or if there is any invasion and the surgical staging was limited.
The treatment of stage II disease is less well deﬁned. Three therapeutic options have been employed: primary operation (radical hysterectomy and pelvic node dissection), primary radiation (intrauterine and vaginal implant and external irradiation) followed by an operation (extrafascial hysterectomy), and simple hysterectomy followed by external beam irradiation. Most patients with stage II disease are treated with a combination of radiation and extrafascial hysterectomy, resulting in 5-year survival rates that approach 75%.
Patients with stage III and IV endometrial cancer have a high risk of hematogenous and lymphatic spread of their cancer outside of the pelvis. Therefore, systemic therapy plays a key role in the management of these patients. Both hormonal and cytotoxic agents have activity in patients with advanced endometrial cancer. In addition, there continues to be a role for radiation therapy to gain local control or to treat pelvic disease. Following treatment, patients should be monitored by follow-up Pap smears from the vaginal cuff every 3 months for 2 years, then every 6 months for 3 years, and then yearly. A chest radiograph should be obtained annually. Ten percent of recurrences will occur more than 5 years after initial diagnosis.
Death results from distant metastases to vital organs more commonly in endometrial carcinoma than in cervical neoplasms. These distant metastases are unquestionably bloodborne. Local obstruction of the ureters is rare.