NEW ORLEANS – When complete resection of advanced-stage, epithelial ovarian cancer is not possible, surgical resection that leaves a small volume of residual tumor at a single site produces significantly better outcomes than leaving minimal residual cancer at multiple sites, according to a review of 510 patients at two U.S. centers.
“In the past, we separated these patients based on whether they had a complete resection, R0 disease, or had 1 cm or less of residual disease” regardless of the number of sites with this small amount of residual tumor. The third category was patients with more than 1 cm of residual tumor at one or more sites, explained Dr. Manning-Geist in an interview. “What we did was break down the patients with 1 cm or less of residual tumor into those with one site or multiple sites. This is the first reported study to use number of sites” as a clinical characteristic for analysis in this context.
The message from the findings is that, while the goal of debulking surgery in patients with advanced epithelial ovarian cancer is complete tumor resection, if that can’t be achieved, the next goal is to leave residual tumor at just a single site, she concluded. A question that remains is whether primary debulking surgery is preferable to neoadjuvant treatment followed by interval debulking surgery. In the results Dr. Manning-Geist presented, patients who underwent primary debulking had better outcomes than those with neoadjuvant therapy followed by interval debulking, but these two subgroups also had different clinical characteristics.
The study used data from 510 patients with stage IIIC or IV epithelial ovarian cancer treated at either Brigham and Women’s or Massachusetts General Hospital during 2010-2015. The study cohort included 240 patients who underwent primary debulking surgery and 270 who first received neoadjuvant chemotherapy and then underwent interval debulking surgery. The patients who received neoadjuvant therapy were, on average, older (65 years vs. 63 years), had a higher prevalence of stage IV disease (44% vs. 16%), and had a higher prevalence of tumors with serous histology (93% vs. 77%), compared with patients who underwent primary debulking.
Complete tumor resections occurred in 39% of the primary debulking patients and in 64% of those who received neoadjuvant therapy; residual disease of 1 cm or less at one site occurred in 17% and 13%, respectively; minimal residual disease at multiple sites remained in 28% and 17% respectively; and the remaining patients had residual disease of more than 1 cm in at least one site, 16% and 6% respectively.
For this analysis, Dr. Manning-Geist and her associates considered residual disease at any of seven possible sites: diaphragm, upper abdomen, bowel mesentary, bowel serosa, abdominal peritoneum, pelvis, and nodal. Even if multiple individual metastases remained within one of these sites after surgery, it was categorized as a single site of residual disease.