NEW YORK (Reuters Health) - Otherwise healthy women with advanced-stage epithelial ovarian cancer who undergo primary cytoreductive surgery (PCS) have improved survival compared with those who receive neoadjuvant chemotherapy (NACT), according to Boston-based researchers.
For the study, online November 17 in JAMA Oncology, Dr. J. Alejandro Rauh-Hain of Massachusetts General Hospital and colleagues analyzed retrospective data on close to 23,000 women diagnosed between 2003 and 2011 and treated at hospitals in the U.S.
All were aged 70 years or less, were likely candidates for either treatment, had stage IIIC or IV disease and a Charlson comorbidity index of 0. Overall, 86.4% received PCS and 13.6% underwent NACT.
The researchers used propensity-score matching to compare nearly 3,000 patients treated with NACT with similar patients who received PCS. Over a median follow-up of more than 56 months, overall survival was 37.3% in the PCS patients and 32.1 months in the NACT group, a significant difference.
"This difference," Dr. Rauh-Hain told Reuters Health by email, "was robust to large differences in two potential unobserved confounders, high disease burden and BRCA status."
However, he added, "the lower survival in women who received neoadjuvant chemotherapy could be explained by differences in another unobserved confounder, limited performance status, if the rates are higher in patients who underwent neoadjuvant chemotherapy versus primary cytoreductive surgery."
Commenting on the findings by email, Dr. Robert E. Bristow of the University of California, Irvine, told Reuters Health, "The authors are to be commended for their efforts to circumvent many of the limitations of using retrospective data to address this question by employing the statistical technique of propensity-score analysis. Nevertheless, there remain important prognostic variables that are not possible to adjust for in a retrospective database, such as the proficiency of the operating surgeon and the amount of residual disease following surgery."
Dr. Bristow, who is professor and chair in the Department of Obstetrics and Gynecology, added that it is interesting that the favorable survival effect for the primary surgery cohort was more pronounced in patients with stage IIIC disease and those treated during the later time interval (2010-2011).
These observations, he said, underscore both "the need for continued study to more precisely define specific subgroups of patients most likely to benefit (and by comparison not to benefit) from the oftentimes extensive procedure required in the primary surgery approach to achieve minimal residual disease" and "the evolving understanding over time that with regard to residual disease, 'less is more'- subsequent survival is inversely proportional to the maximal diameter of disease residuum."
More study is also needed of "the synergistic effect between effective surgery, removing all or most disease, and emerging adjuvant therapeutic approaches (e.g. intraperitoneal or regional therapy)," he said.