Impact of obesity on secondary cytoreductive surgery and overall survival in women with recurrent ovarian cancer

Highlights

• Examined epithelial ovarian cancer (EOC) patients undergoing secondary debulking

• Body mass index (BMI) correlated with survival at time of secondary cytoreduction

• Higher BMI associated with shorter overall survival in recurrent EOC

• Higher preoperative BMI not associated with suboptimal secondary tumor debulking

• BMI a prognostic factor for EOC patients undergoing secondary cytoreduction

Abstract

Objectives

Obesity may negatively influence tumor biology in women with epithelial ovarian cancers. To date, only body mass indices (BMI) determined at the time of diagnosis have correlated with clinical outcome. We hypothesized that obesity negatively affects survival throughout the disease course, and sought to determine the prognostic role of BMI at the time of secondary cytoreductive surgery (SCS) for recurrent ovarian cancer.

Methods

We performed a review of patients undergoing SCS for recurrent epithelial ovarian or peritoneal cancer between 1997 and 2012. We retrospectively reviewed data which were analyzed using Fisher's exact test, Kaplan–Meier survival, and Cox regression analysis. BMI was defined according to the National Institutes of Health's categorizations.

Results

We identified 104 patients; 2 were underweight, 46 were of ideal body weight, 32 were overweight, and 24 were obese. Overall, 90 patients underwent optimal resection and BMI did not correlate with ability to perform optimal SCS (p = 0.25). When examining BMI strata (underweight, ideal, overweight, and obese), we observed a statistical trend between increasing BMI and poor outcome; median survival was undetermined (greater than 50 months), 46 months, 38 months, and 34 months, respectively (p = 0.04). In a multivariate analysis, BMI was an independent predictor of survival (p = 0.02).

Conclusions

In this cohort of women undergoing SCS for recurrent ovarian cancer, BMI significantly and independently correlated with overall survival. This observation suggests an effect of excess weight on tumor biology and/or response to treatment that is prevalent throughout the disease course.

Introduction

Epithelial ovarian cancer remains a highly aggressive and fatal disease. This year alone it is expected that there will be 21,980 new cases of ovarian cancer diagnosed in the United States. Furthermore, 14,270 women will die from ovarian cancer, making it the fifth most fatal type of cancer death across all ages [1]. Of women diagnosed with ovarian cancer, greater than 70% of patients present with advanced stage disease and the five-year overall survival is approximately 30% [2]. The cornerstone of primary treatment for advanced stage disease involves both surgery and chemotherapy. Despite these interventions, recurrence is common with more than 60% of advanced stage patients developing recurrent disease [3]. Considering the dire natural history of ovarian cancer, the identification of prognostic factors – especially modifiable ones – is paramount. Age, stage of disease, histologic type, and residual tumor at the time of primary surgery are all established as prognostic factors with advanced ovarian carcinoma; however, these factors are non-modifiable [4], [5], [6]. Disease-free interval and complete secondary cytoreduction at time of recurrence are associated with increased median post-recurrence survival; these factors are, again, relatively unmodifiable [3].

Increasing obesity has been shown as an independent risk factor for an increase in all-cause mortality [7]. Furthermore, obesity is a well-established risk factor for many hormone-related cancers, including: breast, endometrial, colon, and prostate cancer [8]. The prognostic effect of obesity on epithelial ovarian cancer potentially has great implications considering the rising prevalence of obesity [9]. A recent meta-analysis was performed examining 10 studies on obesity and its prognostic effect on epithelial ovarian cancer. Due to the large amount of inter-study heterogeneity, no firm conclusion could be made [10]. Additionally, the studies examined body mass index in the upfront setting or prior to diagnosis without examining the possible effects of obesity throughout the disease course.

In this study, we hypothesize that obesity continues to play a role throughout the natural history of epithelial ovarian cancer and may adversely affect prognosis. Specifically, our objectives were to examine body mass index at the time of secondary cytoreduction and to determine any potential clinico-pathologic prognostic relationships.