Hi CrazyCat
At this point you need not worry--the decrement to OS seems to be associated with recurrent OV and then PARP treatment. But it also is associated with non-BRCA mutations with HRD negative. Where are you with either of these DNA/gene characteristics?
Re your comment from your oncologist: I read the research paper (on ENGOT-OV16/NOVA) and my oncologist substantiated that evidence on niraparib re OS versus PFS is not clear; PFS may be extended but OS may be less. The paper suggests flaws as your oncologist may have noted: 'Although the study was not powered for OS, was performed at a one-sided a-level of 0.025, and interpretation of OS is confounded by a high rate of crossover and missing data, these results warrant caution.' This is supported in the 'ASCO Guideline Rapid Recommendation Update' published August 30, 2022. It appears that the ASCO guidelines are well-scrutinized re supporting research. The recommendations state:
Recommendation 3.0. PARPi monotherapy maintenance (second-line or more) may be offered to patients with EOC
who have not already received a PARPi and who have responded to platinum-based therapy regardless of BRCA
mutation status; treatment is continued until progression of disease or toxicity despite dose reductions and best supportive care. Options include olaparib 300 mg every 12 hours, rucaparib 600 mg every 12 hours or niraparib
200-300 mg once daily. (Type: Evidence-based, benefits outweigh harms; Evidence quality: High; Strength of recommendation: Strong.) Maintenance treatment with niraparib for patients without germline or somatic BRCA
mutation should weigh potential PFS benefit against possible OS decrement. (Type: Evidence-based, benefits
outweigh harms; Evidence quality: Low; Strength of recommendation: Moderate.)
Recommendations 3.1/3.2. PARPi monotherapy should not be routinely offered to patients for the treatment of recurrent platinum sensitive EOC. (Type: Evidence-based, benefits outweigh harms; Evidence quality: Intermediate; Strength of recommendation: Moderate.) Evidence on PARPi use in this setting is evolving and data are continuing to emerge. Any decision to proceed with PARPi treatment in select populations (BRCA mutation, No prior PARPi use, Platinum Sensitive, Advanced Lines of Treatment) should be based on individualized patient and provider assessment of risks, benefits, and preferences.
Hope this is helpful.