Introduction: Epithelial ovarian cancer (EOC) is the fourth most common malignancy among Malaysian women. This study aims to evaluate the outcomes of EOC, fallopian tube cancer and primary peritoneal serous carcinoma (PPSC) between a centre managed by both clinical oncologists and gynaecologic oncologists, Institut Kanser Negara (IKN) and a centre managed solely by gynaecologic oncologists, Hospital Ampang (HA).
Materials and methods: This retrospective cohort study involved data review of all the newly diagnosed patients with EOC, fallopian tube cancer and PPSC who received treatment in IKN and HA from January 2015 to December 2019, with follow-up continuing until December 2022. The primary outcome is overall survival (OS) and the secondary outcome is progression free survival (PFS) rates; estimated using the Kaplan-Meier method and compared using the logrank test. Another secondary outcome is to determine the prognostic factors affecting the OS of patients from these two cohorts using Cox regression analysis.
Results: A total of 256 patients from both centres were recruited (106 and 150 patients from IKN and HA respectively) and at the time of diagnosis, more than half of the patients were diagnosed with advanced stage disease (67.5% and 62% from IKN and HA respectively). The median OS for patients with EOC was significantly longer for HA compared to IKN (69 months vs 39 months, p < 0.042). There was no significant difference in the median PFS for both centres. Furthermore, when the comparison was made based on the disease staging, there was no difference in the median OS and median PFS. Multivariate analysis identified that patients aged between 41 and 60 years (Hazard ratio [HR]: 2.83; 95% CI: 1.11, 7.25, p = 0.030), patients with medical illness (HR 1.51; 95% CI: 1.04, 2.21, p = 0.033), patients with advanced-stage disease (HR: 3.63; 95% CI: 2.20, 6.00, p < 0.001) and patients with ECOG ≥ 1 (HR: 2.00; 95%CI: 1.38, 2.91, p < 0.001) as independent risk factors for adverse outcome. Meanwhile, optimal surgery is found to be a protective factor (HR 0.60; 95% CI: 0.41, 0.89, p = 0.011). Patients with optimal surgery had reduced the risk of adverse outcome.
Conclusion: Our findings confirmed that the median OS was significantly longer for patients with EOC in HA compared to IKN. However, there was no significant difference in the median OS based on the disease staging; therefore, we could not establish the non-inferiority outcome between the two centres. Furthermore, there was no significant difference in median PFS for both centres. This could be due to small sample size to be able to detect any difference. In addition, it could also be contributed by the different treatment options available and unequal volume of patients treated in both centres. Thus, further study with larger sample size and longer time period is needed to provide better guidance and treatments for the patients.