7. The retroperitoneal spaces should be explored to evaluate the pelvic and paraaortic lymph nodes. The retroperitoneal dissection is performed by incision of the peritoneum over the psoas muscles. This may be performed on the ipsilateral side only for unilateral tumors. Any enlarged lymph nodes should be resected and submitted for frozen section. If no metastases are present, a formal pelvic lymphadenectomy should be performed. The para-aortic area should be explored.
Metastases in apparent stage I and II epithelial ovarian cancer occur in as many as 3 in 10 patients whose tumors appear to be confined to the pelvis but who have occult metastatic disease in the upper abdomen or the retroperitoneal lymph nodes (110,133–140). In a literature review, occult metastases in such patients were found in biopsies of the diaphragm in 7.3%, biopsies of the omentum in 8.6%, the pelvic lymph nodes in 5.9%, the aortic lymph nodes in 18.1%, and in 26.4% of peritoneal washings (132).
The importance of careful initial surgical staging is emphasized by the findings of a cooperative national study in which 100 patients with apparent stage I and II disease were referred for subsequent therapy and underwent additional surgical staging (133). In this series, 28% of the patients initially believed to have stage I disease were upstaged and 43% of those believed to have stage II disease had more advanced lesions. A total of 31% of the patients were upstaged as a result of additional surgery, and 77% were reclassified as having actual stage III disease. Histologic grade was a significant predictor of occult metastasis. Sixteen percent of the patients with grade 1 lesions were upstaged, compared with 34% with grade 2 disease and 46% with grade 3 disease.
Borderline Tumors The principal treatment of borderline (low malignant potential) ovarian tumors is surgical resection of the primary tumor. There is no evidence that either subsequent chemotherapy or radiation therapy improves survival. When a frozen section determines that the histology is borderline, premenopausal patients who desire preservation of ovarian function may undergo a conservative operation, a unilateral oophorectomy (3,141). In a study of patients who underwent unilateral ovarian cystectomy only for apparent stage I borderline serous tumors, Lim-Tan et al. found that this conservative operation was safe, with only 8% of the patients developing recurrences 2 to 18 years later, all with curable disease confined to the ovaries (141). Recurrence was associated with positive margins of the removed ovarian cyst. Thus, hormonal function and fertility can be maintained (3,141). For patients who had an oophorectomy or cystectomy and a borderline tumor is documented later in the permanent pathology, no additional immediate surgery is necessary.
Stage I After a comprehensive staging laparotomy, only a minority of women will have local disease (FIGO stage I). There are over 20,000 women diagnosed yearly with epithelial ovarian cancer in the United States, and nearly 4,000 of these have disease confined to the ovaries (1,142). The prognosis for these patients depends on the clinical–pathologic features, as outlined below. Because of this emphasis on the importance of surgical staging, the rate of lymph node sampling increased in the United States, with a study showing that for women with stages I and II disease, the percentage having lymph nodes sampled increased from 38% to 59% from 1991 to 1996 (143).