PARP inhibitor era in ovarian cancer treatment: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Ovarian cancer is the eighth leading cause of cancer-related death among women, characterized by late diagnosis and a high relapse rate. In randomized controlled trials, we aimed to evaluate the efficacy and safety of PARP inhibitors (PARPi) in treating advanced ovarian cancer.

METHODS

This review was registered on PROSPERO (CRD42021283150), included all phase II and phase III randomized controlled trials (RCTs) assessing the effect of PARPi on ovarian cancer until the 13th of April, 2022. The main outcomes were progression- free survival (PFS), overall survival (OS), and adverse events (AEs). Pooled hazard ratios (HRs), and risk ratios (RRs) were calculated with 95% confidence intervals (95% CI). The random-effects model was applied in all analyses.

RESULTS

In the meta-analysis, 16 eligible RCTs were included, with a total of 5,815 patients. In recurrent ovarian cancer, PARPi maintenance therapy showed a significant PFS benefit over placebo in the total population (HR 0.34, CI 0.29-0.40), BRCA mutant (HR 0.24, CI 0.18-0.31), germline BRCA mutant (HR 0.23, CI 0.18-0.30), and BRCA wild-type cases (HR 0.50, CI 0.39-0.65). PARPi monotherapy also improved PFS (HR 0.62, CI 0.51-0.76) compared with chemotherapy in BRCAm patients with recurrent ovarian cancer. The use of PARPi maintenance therapy resulted in an improvement in PFS over placebo in newly-diagnosed cancers in the overall population (HR 0.46, CI 0.30-0.71) and the BRCAm population (HR 0.36, CI 0.29-0.44). Although the risk of severe AEs was increased by PARPi therapy compared to placebo in most settings investigated, these side effects were controllable with dose modification, and treatment discontinuation was required in the minority of cases.

CONCLUSIONS

PARPis are an effective therapeutic option for newly-diagnosed and recurrent ovarian cancer. Despite a minor increase in the frequency of serious adverse effects, they are generally well tolerated.

[Comparison of progression-free and overall survival between endometrial cancer patients treated with laparoscopic and open surgical techniques]

Introduction: Recently published unfavourable results of endoscopic radical surgery for early-stage cervical cancer compared to open surgery raises the need for auditing treatment results of endoscopic staging surgery for endometrial cancer. Aim: Comparison of progression-free and overall survival (PFS and OS) between endometrial cancer patients treated with laparoscopic (LSC) and open surgical techniques. Method: Retrospective analysis was performed to compare clinicopathological and survival data of endometrial cancer patients who had either laparoscopic or open staging surgery between 2013 and 2019 at the Gynaecological Oncology Unit of the University of Debrecen, Hungary. Distribution of the most relevant prognostic factors were compared with χ² and t-tests. Frequencies of progressive disease and disease-specific deaths were compared in the Cox-model, while progression-free and overall survival curves were compared with the Kaplan-Meier method. Results: The frequency of endometrioid, serous papillary, mixed Müllerian, adenosquamous and other histological types in the laparoscopic and open groups were similar (p = 0.3356). The frequency of grade 1, 2 and 3 tumours in the endoscopic and open groups showed significant differences (p = 0.0036). Pathological stage-distribution (IA, IB, II, IIIA, IIIB, IIIC1, IIIC2) of endoscopic cases and open cases was also statistically different (p = 0.0048). The mean number of removed lymph-nodes was higher in the open surgery group (14.3 vs. 9,3, p<0.0001). The frequency of recurrence did not show significant difference between the two groups, in contrast to the frequency of disease-specific deaths (2/120 vs. 29/345, p = 0.01; 2/120 vs. 17/345, p = 0.12). In the Cox-model, progression-free survival and overall survival showed a hazard ratio favouring laparoscopic surgery, however, the range of 95% confidence intervals showed no statistical significance (PFS LSC vs. open: HR = 0.36, 95% CI = 0.084-1.538; OS LSC vs. open: HR = 0.603, 95% CI = 0.135-2.693). Conclusion: Progression-free and overall survival of endoscopically staged endometrial cancer is not worse than those of patients staged with open surgery. Orv Hetil. 2020; 161(10): 382-388.