Trends and outcomes of surgical treatment for ovarian cancer in older adults in Japan

ObjectiveThe prognostic implications of surgical outcomes in older adults with ovarian cancer remain unclarified. This study aimed to describe temporal trends in surgical management and examine the association between surgical outcomes and survival among older patients with ovarian cancer.MethodsThis population-based retrospective study analyzed data from the Osaka Cancer Registry from patients diagnosed with ovarian cancer between 2004 and 2018. During this period, 10,033 women were diagnosed with malignant ovarian tumors in Osaka Prefecture, of whom 7,285 were classified as epithelial ovarian malignancies. Among them, 1,441 patients aged ≥70 years were identified. After excluding 39 patients with unknown surgical outcomes and 40 with insufficient chemotherapy data, 1,365 patients were included. Based on the surgical outcomes, patients were classified as having complete resection with no residual tumor, residual macroscopic tumor-present, or no surgery. Disease extent was categorized as localized, regional, or distant. Overall survival was assessed using univariate and multivariate models.ResultsThe proportion of patients managed without surgery increased over the study period, from 20.9% in 2004–2007 to 29.0% in 2016–2018, although this trend did not reach statistical significance (p = 0.11). This shift was most evident among patients with advanced disease (p < 0.001), indicating a temporal change in surgical management among older patients. A stepwise survival gradient was observed according to surgical outcome. The 5-year overall survival rates were 63.9%, 27.9%, and 9.9% for complete resection, residual macroscopic tumor, and no surgery, respectively. Compared with complete resection, the hazard ratios for mortality were 2.63 (95% CI, 2.22–3.10) for residual macroscopic tumor and 5.37 (95% CI, 4.55–6.34) for no surgery. In multivariate analysis, surgical outcome remained associated with overall survival after adjustment for available clinical variables.ConclusionIn this registry-based cohort of patients aged ≥70 years, the proportion of patients managed without surgery increased over time, particularly among those with advanced disease, and receipt of surgery was associated with longer overall survival. However, as comorbidity and frailty data were unavailable in the registry, residual confounding related to treatment selection cannot be excluded.