The impact of body mass index on survival and surgical outcomes in ovarian cancer: insights from the MITO trials
Epithelial ovarian cancer accounts for approximately 80% of ovarian cancer cases. Although obesity is not a primary risk factor for its onset, a high body mass index may worsen prognosis and survival. This may result from chronic inflammation, metabolic and hormonal changes, and increased treatment toxicity and surgical complications associated with obesity. This study is a post-hoc analysis of data from 3 MITO (Multicenter Italian Trials in Ovarian Cancer) clinical trials (MITO-2, MITO-7, and MITO16/MaNGO), involving 2040 patients with epithelial ovarian cancer. The effects of body mass index on progression-free survival, overall survival, and surgical outcomes were evaluated. Statistical analyses included Cox regression models to assess the risk of progression and mortality in relation to body mass index, while also accounting for baseline clinical variables. Additionally, regression analysis was conducted to examine the association between body mass index and surgical outcomes, with mixed cumulative-link models used to analyze categories of post-operative residual tumor. Higher body mass index was significantly associated with poorer progression-free survival (p = .02) and overall survival (p = .001). Extreme obesity, in particular, increased the risk of disease progression and mortality, with adjusted hazard ratios of 1.47 (95% confidence interval [CI] 1.13 to 1.92) for progression-free survival and 1.69 (95% CI 1.20 to 2.38) for overall survival. Additionally, higher body mass index correlated with worse surgical outcomes, including a greater likelihood of residual tumor. This effect was significant across body mass index categories: overweight (odds ratio [OR] 1.29, 95% CI 1.07 to 1.56), obese (OR 1.43, 95% CI 1.09 to 1.93), and extremely obese (OR 1.73, 95% CI 1.15 to 2.60). The evidence supports the hypothesis that elevated body mass index negatively affects prognosis in patients with advanced ovarian cancer. Weight management represents a crucial component for improving clinical outcomes and quality of life in these patients. Future therapeutic strategies should ideally incorporate multi-disciplinary approaches, such as pre-habilitation, to optimize treatment tolerance and promote better post-operative recovery.
