Bevacizumab in recurrent ovarian cancer: could it be particularly effective in patients with clear cell carcinoma?

Treatment of recurrent ovarian carcinoma is a challenge, particularly for the clear cell (CCC) subtype. However, there is a preclinical rationale that these patients could achieve a benefit from antiangiogenic therapy. To assess this hypothesis, we used the growth modulation index (GMI), which represents an intrapatient comparison of two successive progression-free survival (PFS).

We conducted a retrospective real-world study performed on 34 patients with recurrent ovarian cancer, treated with bevacizumab-containing regimens from January 2009 to December 2017. The primary endpoint was GMI. An established cut-off > 1.33 was defined as a sign of drug activity.

73.5% of patients had high-grade serous ovarian carcinoma (HGSOC), and 17.7% had CCC; 70.6% of patients received carboplatin/gemcitabine/bevacizumab, and 29.4% received weekly paclitaxel/bevacizumab. According to histological subtype, the overall response rate and median PFS were 52% and 14 months for HGSOC and 83.3% and 20 months for CCC, respectively. The overall population median GMI was 0.99; it was 0.95 and 2.36 for HGSOC and CCC, respectively. CCC subtype was significantly correlated with GMI > 1.33 (odds ratio 41.67; 95% confidence interval 3.6-486.94; p = .03).

Adding bevacizumab to chemotherapy in recurrent CCC is associated with a remarkable benefit in this cohort. The efficacy of antiangiogenic drugs in CCC warrants further prospective evaluation.