Are peritoneal biopsies important?

Garcia-Soto and associates carried out a retrospective review of patients who presented to their institution over a 16-year period. These women had ovarian cancer that was believed to be grossly confined to the ovary. All underwent comprehensive surgical staging by gynecologic oncologists; the procedures were performed in accordance with the Gynecologic Oncology Group staging manual. The researchers report how many patients’ cancers were upstaged due to diagnosis of metastatic disease contained in peritoneal, adhesion, and omental biopsies. They also provide information regarding metastatic disease to lymph nodes and other organs. Their ultimate goal was to determine the significance of routine omentectomy and peritoneal biopsies as part of a comprehensive staging procedure.

Of the 86 patients who met the study criteria, 29% (25/86) were given upstaged diagnoses after surgical staging, and 60% (15/25) of these were upstaged due to positive biopsies of the peritoneum, adhesions, or omentum. This subset represented 17% (15/86) of all study participants. Twenty percent (5/25) of patients with upstaged disease—or 6% (5/86) of all participants—had upstaged diagnoses due to disease found in biopsies of the peritoneum and adhesions. When correlated with other clinical factors, grade 3 disease and the presence of ascites were also correlated with a diagnosis of occult metastatic disease; the presence of positive cytology was not.

Sampling tissue that appears normal

While 17% of the participants’ disease was upstaged due to results from biopsies of the peritoneum, adhesions, and omentum, it is unknown whether the adhesions actually looked suspicious. In 2011, a similar study of 122 patients found that disease was upstaged in 16% (19/122) of patients due to findings from biopsies of the peritoneum and adhesions; an additional 5 patients’ disease was upstaged when microscopic disease was detected in the omentum. The incidence of positive disease is fairly similar between these 2 studies. However, Shroff and colleagues determined that 11% (13/122) of positive peritoneal biopsies were found in evidently abnormal tissue, whereas discovery of disease in normal-looking peritoneal tissue was less common (5% or 6/122). As one might expect, the yield from biopsies of suspicious areas was higher, but the authors of both studies concluded that it is still worthwhile to biopsy normal-appearing areas.

In discussing the Garcia-Soto study, Journal Club members thought that it would have been educational to know specifically how biopsies were obtained and whether these samples were from areas that looked suspicious or were apparently normal. It would have been informative to understand what surgical findings led to biopsies that were positive for disease. Another concern was that there had been no gynecologic pathology review. Study patients were treated over a long period of time and most likely, there were different pathologists reviewing specimens. Entities such as endosalpingiosis can be confused with metastatic disease and a gynecologic pathology review to insure uniformity of diagnoses would have been reassuring.

No changes for now

In summary, we will probably not change our surgical staging procedure in the near future. The work by Garcia-Soto and colleagues showed that positive biopsies led to upstaging. Their findings support the practice of sampling the peritoneum, adhesions, and omentum in women who have cancers that appear to be confined to the ovaries. Biopsies are easy to perform and pose little risk to the patient. Until ample data indicate otherwise, comprehensive surgical staging should continue in this population.