Thromboembolic Risk in Prostate Cancer Patients Treated with PARP Inhibitors: A Systematic Review and Meta-analysis

BACKGROUND

Poly (ADP-ribose) polymerase inhibitors (PARPi) have been associated with thrombotic events, although the association with thrombosis risk in different cancers remains poorly defined.

METHODS

This meta-analysis included phase II and phase III clinical trials in which patients with metastatic prostate cancer were treated with PARPi either as monotherapy or in combination. The primary endpoints were the rates of thromboembolic events in prostate cancer patients.

RESULTS

A total of 2210 and 1662 patients with prostate cancer were compared in the PARP inhibitor and control groups, respectively. 96 (4.3%) and 37 (2.2%) patients had thrombosis in the PARPi and control groups, respectively. PARPi had a statistically significant increased risk of thrombosis in prostate cancer patients (Odds Ratio (OR)=1.98, 95% CI: 1.06-3.70, P=0.030).

CONCLUSION

The heightened thrombotic risk associated with PARPi treatment in prostate cancer emphasizes the need for comprehensive management protocols to effectively reduce the risk and ensure safer outcomes.

The benefit of treatment beyond progression with immune checkpoint inhibitors: a multi-center retrospective cohort study

OBJECTIVE

Treatment beyond progression (TBP) with immune checkpoint inhibitors (ICIs) is an evolving field due to the limitations of conventional imaging in response evaluation. However, real-life data on the benefit of TBP is scarce, especially from the limited resource settings and patients treated in the later lines. Therefore, we aimed to investigate the survival benefit of TBP with ICIs in patients with advanced tumors from a limited resource setting.

METHODS

For this multi-center retrospective cohort study, we included 282 patients treated with ICIs and had radiological progression according to RECIST 1.1 criteria. We evaluated post-progression survival according to the use of TBP (TBP and non-TBP groups) with univariate and multivariate analyses.

RESULTS

The cohort's median age was 61, and 84.4% were treated in the second or later lines. 82 (29.1%) of 282 patients continued on ICIs following the initial progression. In multivariate analyses, patients in the TBP group had improved post-progression survival compared to non-TBP (13.18 vs. 4.63 months, HR: 0.500, 95% CI: 0.349-0.717, p < 0.001). The benefit of the TBP was independent of the tumor type, treatment line, and age. Furthermore, TBP with ICIs remained associated with improved post-progression survival (HR: 0.600, 95% CI: 0.380-0.947, p = 0.028) after excluding the patients with no further treatment after progression in the non-TBP arm.

CONCLUSIONS

In this study, we observed that patients receiving ICIs beyond progression had considerably longer survival. Continuation of ICIs after progression should be considered a reasonable management option for patients with advanced cancer, specifically for patients with limited alternative options.