Surgical Staging Of Ovarian Low Malignant Potential Tumors
Abstract & Commentary
Synopsis: Routine pelvic and para-aortic lymph node dissection is not necessary in the majority of women with ovarian low malignant potential tumors.
Source: Rao GG, et al. Obstet Gynecol. 2004. 104: 261-266.
Patients with ovarian tumors of low malignant potential have an excellent prognosis and few require adjuvant therapy. Although it is commonly preferred that patients identified intraoperatively with this neoplasm undergo formal surgical staging, the benefit of these additional procedures has been questioned given that few patients are treated on the basis of these biopsies. Rao and colleagues in a retrospective, multi-institutional study of borderline ovarian malignancies reviewed the outcomes of 248 women with ovarian tumors of low malignant potential in order to evaluate the benefits of surgical staging. Consecutive cases over a 20-year period were accessioned. Formal staging procedures were performed on approximately three-quarters of patients including 72% who had no visible intraperitoneal disease. Upstaging on the basis of these procedures occurred in 28% including a small fraction (6%) with retroperitoneal disease (all pelvic). None of the 314 paraortic nodes sampled contained disease.
After a median follow-up of more than 2 years, all but 15 (6%) patients are disease-free. No difference in recurrence rates were observed between those staged and those not staged. In addition, analysis of patterns of recurrence suggested no difference whether surgical staging was performed nor was there a difference in recurrence among stage III cases whether they received adjuvant chemotherapy or not. In a multivariate analysis of recurrence risks only 2 factors were independently predictive: lower gravidity and stage category (I vs II-IV). In addition, none of the 57 mucinous borderline tumors recurred or were upstaged. Rao et al conclude that survival of this class of neoplasms is excellent and routine pelvic and paraortic lymphadenectomy is unwarranted in the majority of patients.
Comment by Robert L. Coleman, MD
Surgical staging for all non-benign ovarian neoplasms is a practice endorsed by gynecologic oncologists throughout the world. A recent survey from the Society of Gynecologic Oncologists documented that 97% of respondents recommended formal surgical staging for all patients with ovarian tumors of low malignant potential (LMP). Although mounting data from retrospective and prospective trials suggest patients with these tumors do very well, a common reason to promote the additional surgery at the time of extirpation is to not miss staging an occult invasive tumor—a finding that may be underappreciated in frozen section analysis of a large pelvic mass.
Indeed, recent studies of frozen section report qualifications found invasive disease in 6 to 28% of cases of LMP tumors. The likelihood appears to be higher when an at least LMP was used to qualify the diagnosis compared to a rule out LMP. The current report, however, cannot provide confidence that staging is not required when the diagnosis is returned intraoperatively. Failure to gather that information in patients subsequently identified with bona fide invasive disease heralds the dilemma to either subject the patient to another operation or administer adjuvant chemotherapy to someone who may not need it. The report does confirm that in the majority of cases, LMP will be the final diagnosis for which surgical staging will add little except more blood loss and longer hospitalization. This is relevant in the not infrequent situation where a seemingly benign intraoperative ovarian masses was resected and LMP is returned on the final pathology report. While details of the pathology, wishes for future fertility along with intraoperative findings will be important in considering whether additional surgical staging is recommended, the current study would suggest most patients would benefit little from re-operation, particularly mucinous neoplasms. In all, it is prudent to preoperatively counsel patients with pelvic masses for the possibility of staging and to have appropriate consultation with a gynecologic oncologist when the diagnosis is returned intraoperatively.
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3. Menzin AW, et al. Gynecol Oncol. 2000;78:7-9.
Robert L. Coleman, MD, Dept. of Gynecologic Oncology, University of Texas Southwestern Medical Center, Dallas, TX is Associate Editor for OB/GYN Clinical Alert.