Low probability of disease cure in advanced ovarian carcinomas before the PARP inhibitor era

Harnessing immune cells to leverage PARP inhibitors

Homologous-recombination deficiency in DNA repair characterizes a unique group of cancers that are vulnerable to PARP inhibitors and cytotoxic chemotherapy. In this issue of Cell, Luo et al., demonstrated that this genetic attribute in cancer cells may reprogram tumor immune microenvironment and show promise of targeting effector-Treg cells.

Prognostic Role of CA-125 Elimination Rate Constant (KELIM) in Patients with Advanced Epithelial Ovarian Cancer Who Received PARP Inhibitors

BACKGROUND

This multicenter retrospective study aimed to investigate the prognostic value of the CA-125 elimination rate constant K (KELIM) in EOC patients who received platinum-based chemotherapy followed by PARP inhibitors, in either upfront or interval treatment settings.

METHODS

Between July 2019 and November 2022, we identified stage III-IV EOC patients who underwent primary or interval cytoreductive surgery and received olaparib or niraparib. Individual KELIM values were assessed based on validated kinetics and classified into favorable and unfavorable cohorts.

RESULTS

In a study of 252 patients undergoing frontline maintenance therapy with olaparib or niraparib, favorable KELIM (≥1) scores were associated with a higher PFS benefit in the primary cytoreductive surgery (PCS) cohort (hazard ratio (HR) for disease progression or death 3.51, 95% confidence interval (CI); 1.37-8.97, p = 0.009). Additionally, within the interval cytoreductive surgery (ICS) cohort, a favorable KELIM score (≥1) significantly increased the likelihood of achieving complete resection following cytoreductive surgery, with 59.4% in the favorable KELIM group compared to 37.8% in those with unfavorable KELIM.

CONCLUSIONS

A favorable KELIM score was associated with improved PFS in patients with advanced EOC undergoing PCS. Furthermore, in the ICS cohort, a favorable KELIM score increased the probability of complete cytoreduction.

Clinical impact of CA-125 ELIMination rate constant K (KELIM) on surgical strategy in advanced serous ovarian cancer patients

OBJECTIVES

The modeled CA-125 elimination constant K (KELIM) is a pragmatic early marker of tumor chemosensitivity in ovarian cancer patients treated with neoadjuvant chemotherapy before interval surgery. The primary objective of this study was to assess the prognostic value of KELIM regarding the feasibility of complete surgery, and secondary objectives were to assess the prognostic value of KELIM for the risk of a platinum resistant relapse, progression free survival, and overall survival.

METHODS

The study was based on a retrospective cohort of 284 patients treated for an advanced serous high grade ovarian cancer, International Federation of Gynecology and Obstetrics (FIGO) stages III-IV, with neoadjuvant chemotherapy, followed by interval surgery, in a comprehensive cancer center. CA-125 concentrations at baseline and during neoadjuvant chemotherapy were collected. The KELIM predictive value regarding the tumor radiological response rate, likelihood of complete surgery, risk of subsequent platinum resistant relapse, progression free survival, and overall survival were assessed with univariate and multivariate tests.

RESULTS

In 232 patients, KELIM was an independent and major predictor of the probability of complete surgery and survival. The final logistic regression model, including KELIM (odds ratio (OR) 0.36, 95% confidence interval (CI)0.16 to 0.73, p=0.006) and complete surgery (no vs yes, OR 0.29, 95% CI 0.15 to 0.53, p<0.001), highlighted the complementary impact of chemosensitivity and surgical outcome relative to the complete surgery. In the multivariate analysis, KELIM and complete surgery were significantly associated with a lower risk of early relapse. In the case of an unfavorable KELIM, when surgical efforts allowed complete cytoreduction, median overall survival was similar to that reported in the case of a favorable KELIM (46.3 months (range 34.6-60.3) vs 46.5 months (range 40.6-68.7), respectively).

CONCLUSION

Primary tumor chemosensitivity, assessed by the modeled CA-125 KELIM, calculated during neoadjuvant chemotherapy, is a major parameter to consider for decision making regarding interval surgery. Complementary to the RECIST score and laparoscopy, this non-invasive tool, available online, helps tailor the interval surgery strategy according to patient tumor chemosensitivity.

ESGO-ESMO-ESP consensus conference recommendations on ovarian cancer: pathology and molecular biology and early, advanced and recurrent disease

The European Society of Gynaecological Oncology, the European Society for Medical Oncology (ESMO) and the European Society of Pathology held a consensus conference (CC) on ovarian cancer on 15-16 June 2022 in Valencia, Spain. The CC panel included 44 experts in the management of ovarian cancer and pathology, an ESMO scientific advisor and a methodologist. The aim was to discuss new or contentious topics and develop recommendations to improve and harmonise the management of patients with ovarian cancer. Eighteen questions were identified for discussion under four main topics: (i) pathology and molecular biology, (ii) early-stage disease and pelvic mass in pregnancy, (iii) advanced stage (including older/frail patients) and (iv) recurrent disease. The panel was divided into four working groups (WGs) to each address questions relating to one of the four topics outlined above, based on their expertise. Relevant scientific literature was reviewed in advance. Recommendations were developed by the WGs and then presented to the entire panel for further discussion and amendment before voting. This manuscript focuses on the recommendation statements that reached a consensus, their voting results and a summary of evidence supporting each recommendation.

Real-world Study on the Effect of PARPi as Maintenance Therapy on Platinum Sensitivity after First- and Second-line Chemotherapy in Patients with Recurrent High-grade Serous Epithelial Ovarian Cancer

BACKGROUND

This study investigated the effect of poly(ADP-ribose) polymerase inhibitors (PARPi) as maintenance therapy after first- and second-line chemotherapy on platinum sensitivity in patients with recurrent high-grade serous epithelial ovarian cancer (rHGSOC).

METHODS

This study retrospectively analyzed 172 patients with rHGSOC treated at Zhejiang Cancer Hospital and Jiaxing Maternity and Child Health Care Hospital between January 2017 and December 2021. The 1st-PARPi group comprised patients who received a PARPi as maintenance therapy after first-line chemotherapy (n=23), and the 1st-control group comprised those who did not (n = 105). Similarly, the 2nd-PARPi group comprised patients not given a PARPi in their first-line treatment (n = 30), and the 2nd-control group comprised those who were given a PARPi (n = 89).

RESULTS

Among the 23 patients in the 1st-PARPi group and the 105 patients in the 1st-control group, nine and 99 were platinum-sensitive, and 14 and six were platinum-resistant, respectively (hazard ratio [HR]: 14.46, P < 0.0001). Among the 30 patients in the 2nd-PARPi group and 89 patients in the 2nd-control group, 10 and 71 were platinum-sensitive, and 20 and 18 were platinumresistant, respectively (HR: 4.37, P < 0.0001). Age, stage, residual tumor, the courses of platinumbased chemotherapy, and breast cancer susceptibility gene mutations were not associated with platinum sensitivity when using a PARPi as maintenance therapy after first- and second-line chemotherapy.

CONCLUSION

Patients with rHGSOC using a PARPi were more likely to be platinum-sensitive and develop platinum resistance independent of PARPi duration. Care should be taken when using a PARPi as maintenance therapy after first- and second-line chemotherapy.

Survival and modelled cancer antigen-125 ELIMination rate constant K score in ovarian cancer patients in first-line before poly(ADP-ribose) polymerase inhibitor era: A Gynaecologic Cancer Intergroup meta-analysis

BACKGROUND

In patients with advanced ovarian cancer, the modelled CA-125 ELIMination rate constant K (KELIM) is an early indicator of the tumour intrinsic chemosensitivity. We assessed the prognostic and surrogate values of KELIM with respect to those of surgery outcome (based on post-operative residual lesions) in the Gynaecologic Cancer Intergroup (GCIG) individual patient data meta-analysis MAOV (Meta-Analysis in OVarian cancer) built before the emergence of poly(ADP-ribose) polymerase (PARP) inhibitors.

METHODS

The dataset was split into learning and validation cohorts (ratio 1:2). The individual modelled KELIM values were estimated, standardised by the median value, then scored as unfavourable (<1.0) or favourable (≥1.0). Overall survival (OS) and progression-free survival (PFS) analyses were performed with a two-step meta-analytic approach and surrogacy through a two-level meta-analytic model.

RESULTS

KELIM was assessed in 5884 patients from eight first-line trials (learning, 1962; validation, 3922). A favourable KELIM score was significantly associated with longer OS (validation set, median, 78.8 versus 28.4 months, hazard-ratios [HR] 0.46, 95% confidence interval [CI], 0.41-0.50, C-index 0.68), and longer PFS (validation set, median 30.5 versus 9.8 months, HR 0.49, 95% CI, 0.45-0.54, C-index 0.68), as were International Federation of Gynaecology and Obstetrics (FIGO) stage and debulking surgery outcome. Three prognostic groups were identified based on the surgery outcome and KELIM score, with large differences in OS (105.1, ∼45.0, and 22.1 months) and PFS (58.1, ∼15.0, and 8.0 months). Surrogacy for OS and for PFS was not established.

CONCLUSION

KELIM is an independent prognostic biomarker for survival, complementary to surgery outcome, representing a new determinant of first-line treatment success.

Olaparib plus bevacizumab first-line maintenance in ovarian cancer: final overall survival results from the PAOLA-1/ENGOT-ov25 trial

BACKGROUND

In the PAOLA-1/ENGOT-ov25 primary analysis, maintenance olaparib plus bevacizumab demonstrated a significant progression-free survival (PFS) benefit in newly diagnosed advanced ovarian cancer patients in clinical response after first-line platinum-based chemotherapy plus bevacizumab, irrespective of surgical status. Prespecified, exploratory analyses by molecular biomarker status showed substantial benefit in patients with a BRCA1/BRCA2 mutation (BRCAm) or homologous recombination deficiency (HRD; BRCAm and/or genomic instability). We report the prespecified final overall survival (OS) analysis, including analyses by HRD status.

PATIENTS AND METHODS

Patients were randomized 2:1 to olaparib (300 mg bid; up to 24 months) plus bevacizumab (15 mg/kg q3w; 15 months total) or placebo plus bevacizumab. Analysis of OS, a key secondary endpoint in hierarchical testing, was planned for ∼60% maturity or 3 years after the primary analysis.

RESULTS

After median follow-up of 61.7 and 61.9 months in the olaparib and placebo arms, respectively, median OS was 56.5 versus 51.6 months in the ITT (hazard ratio [HR]=0.92, 95% CI 0.76-1.12; P=0.4118). Subsequent poly(ADP-ribose) polymerase (PARP) inhibitor therapy was received by 105 (19.6%) olaparib patients versus 123 (45.7%) placebo patients. In the HRD-positive population, OS was longer with olaparib plus bevacizumab (HR=0.62, 95% CI 0.45-0.85; 5-year OS rate, 65.5% versus 48.4%); at 5 years, updated PFS also showed a higher proportion of olaparib plus bevacizumab patients without relapse (HR=0.41, 95% CI 0.32-0.54; 5-year PFS rate, 46.1% versus 19.2%). Myelodysplastic syndrome, acute myeloid leukemia, aplastic anemia, and new primary malignancy incidence remained low and balanced between arms.

CONCLUSIONS

Olaparib plus bevacizumab provided clinically meaningful OS improvement for first-line patients with HRD-positive ovarian cancer. These prespecified exploratory analyses demonstrated improvement despite a high proportion of patients in the placebo arm receiving PARP inhibitors post-progression, confirming the combination as one of the standards of care in this setting with the potential to enhance cure.

Benefit From Fractionated Dose-Dense Chemotherapy in Patients With Poor Prognostic Ovarian Cancer: ICON-8 Trial

PURPOSE

An international meta-analysis identified a group of patients with advanced epithelial ovarian cancer (EOC) with a very poor survival because of two unfavorable features: (1) a poor chemosensitivity defined by an unfavorable modeled CA-125 ELIMination rate constant K (KELIM) score <1.0 with the online calculator CA-125-Biomarker Kinetics, and (2) an incomplete debulking surgery. We assumed that patients belonging to this poor prognostic group would benefit from a fractionated densified chemotherapy regimen.

METHODS

The data set of ICON-8 phase III trial (ClinicalTrials.gov identifier: NCT01654146), where patients with EOC were treated with the standard three-weekly, or the weekly dose-dense, carboplatin-paclitaxel regimens and debulking primary surgery (immediate primary surgery [IPS] or delayed primary [or interval] surgery [DPS]), was investigated. The association between treatment arm efficacy, standardized KELIM (scored as favorable ≥1.0, or unfavorable <1.0), and surgery completeness was assessed by univariate/multivariate analyses in IPS and DPS cohorts.

RESULTS

Of 1,566 enrolled patients, KELIM was calculated with the online model in 1,334 with ≥3 CA-125 available values (85%). As previously reported, both KELIM and surgery completeness were complementary prognostic covariates, and could be combined into three prognostic groups with large OS differences: (1) good if favorable KELIM and complete surgery; (2) intermediate if either unfavorable KELIM or incomplete surgery; and (3) poor if unfavorable KELIM and incomplete surgery. Weekly dose-dense chemotherapy was associated with PFS/OS improvement in the poor prognostic group in both the IPS cohort (PFS: hazard ratio [HR], 0.50; 95% CI, 0.31 to 0.79; OS: HR, 0.58; 95% CI, 0.35 to 0.95) and the DPS cohort (PFS: HR, 0.53; 95% CI, 0.37 to 0.76; OS: HR, 0.57; 95% CI, 0.39 to 0.82).

CONCLUSION

Fractionated dose-dense chemotherapy might be beneficial for patients belonging to the poor prognostic group characterized by lower tumor chemosensitivity assessed with the online calculator CA-125-Biomarker Kinetics and incomplete debulking surgery. Further investigation in the future SALVOVAR trial is warranted.