ATR inhibitor, camonsertib, dose optimization in patients with biomarker-selected advanced solid tumors (TRESR study).

BACKGROUND: Camonsertib is a selective oral inhibitor of ataxia telangiectasia and Rad3-related (ATR) kinase with demonstrated efficacy in tumors with DNA damage response gene deficiencies. On-target anemia is the main drug-related toxicity typically manifesting after the period of dose-limiting toxicity evaluation. Thus dose/schedule optimization requires extended follow-up to assess prolonged treatment effects. METHODS: Long-term safety/tolerability and antitumor efficacy of three camonsertib monotherapy dose levels/schedules were assessed in the TRESR study dose-optimization phase: 160 mg once daily (QD) 3 days on/4 off (160 3/4; the preliminary recommended phase II dose [RP2D]) and two step-down groups of 120 mg QD 3/4 (120 3/4) and 160 mg QD 3/4, 2 weeks on/1 off (160 3/4, 2/1w). Safety endpoints included incidence of treatment-related adverse events (TRAEs), dose modifications, and transfusions. Efficacy endpoints included overall response rate, clinical benefit rate, progression-free survival, and circulating-tumor-DNA (ctDNA)-based molecular response rate. RESULTS: The analysis included 119 patients: 160 3/4 (n = 67), 120 3/4 (n = 25), and 160 3/4, 2/1w (n = 27) treated up to 117.1 weeks as of the data cutoff. The risk of developing grade 3 anemia was significantly lower in the 160 3/4, 2/1w group compared with the preliminary RP2D group (HR = 0.23, 2-sided P = .02), translating to reduced transfusion and dose reduction requirements. The intermittent weekly schedule did not compromise antitumor activity. CONCLUSION: The 160 3/4, 2/1w dose was established as an optimized regimen for future camonsertib monotherapy studies offering significantly reduced anemia incidence without any compromise to efficacy.

Correlating the KELIM (CA125 elimination rate constant K) score and the chemo-response score as predictors of chemosensitivity in patients with advanced ovarian carcinoma.

BACKGROUND: The objective of this study is to assess the correlation between the pre-operative CA125 Elimination rate constant K(KELIM) score and the intraoperative chemo-response score (CRS) in patients with advanced high grade serous ovarian cancer(HGSC) treated with neoadjuvant chemotherapy(NACT). METHODS: This is a retrospective cohort study of patients with Stage III-IV HGSC treated with NACT from March 2010 to December 2019 at Princess Margaret Cancer Center, Toronto, Canada. KELIM scores were calculated based on the tool devised by You et al. available online. CRS was assessed using an established 3-tier scoring system. An association analysis was performed to determine if the KELIM score assessed during NACT can predict CRS score at the time of interval cytoreductive surgery(ICS). RESULTS: 172 patients were included in this analysis. Patients with CRS 1-2 had a lower median Platinum Free Interval(PFI) (9.24 vs 13.64 months, p = 0.005), lower median progression free survival(PFS) (14.99 vs 20.29 months, p = 0.003) and lower 5-year overall survival(OS) (63.8% vs 69.7%, p = 0.54) compared to patients with CRS3. Among patients with CRS 1-2(n = 115), 68.7% had KELIM <1, while 56.2% of patients with CRS3 had KELIM ≥1(56.2%), p = 0.0017, suggesting a correlation between the KELIM and CRS scores. Furthermore, patients with KELIM ≥1 and CRS3 had significantly higher PFS compared to other groups(median PFS 28.27 months vs 17.66 months for KELIM ≥1/CRS 1/2; 17.13 months for KELIM <1/CRS 3; and 14.53 months for KELIM <1/CRS 1-2, p = 0.003). CONCLUSION: The biochemical KELIM score correlated with the surgical pathologic CRS score and may predict pathological response to chemotherapy. This information can be utilized to tailor and personalize treatment in patients with advanced ovarian malignancy.

Novel Molecular Targets in Endometrial Cancer: Mechanisms and Perspectives for Therapy.

Endometrial cancer (EC) has a high epidemiological impact with incidence and mortality rising worldwide. In recent years, the integration of the pathologic and molecular classification has provided relevant information to understand the heterogeneity in the biology of EC, which led to the evolution in the management of patients. Currently, therapeutic breakthroughs have been made in advanced EC to improve oncologic outcomes, with efforts to include patient reported outcomes. Precision and personalized medicine are under way in EC exploring different combination approaches to target cross-talk pathways, cancer cell microenvironment, and metabolic vulnerabilities and improve drug delivery. Yet, collaborative efforts are needed to face the challenges in practice by refining patient selection, ideal biomarker identification, and de-escalation of therapies according to emerging molecular and genomic features of EC.

HER2-low and Overexpression in Mucinous Ovarian Cancer: Analysis of ASCO/CAP and ToGA Immunohistochemical Scoring.

Mucinous ovarian carcinoma is an uncommon malignancy characterized by resistance to chemotherapy and poor survival in the metastatic setting. HER2 amplification is a frequent late event in carcinogenesis, yet the incidence of HER2-low in mucinous ovarian carcinoma is unknown. Further, the optimal method for determining overexpression in these tumors is not established. We sought to assess the ASCO/CAP and ToGA trial scoring methods for HER2 IHC with correlation to FISH, p53, and mismatch repair protein status and to determine the incidence of HER2-low in mucinous ovarian carcinoma. A total of 29 tumors from 23 patients were included. Immunohistochemistry for HER2, p53, MLH1, PMS2, MSH2, and MSH6 was performed. Scoring was performed according to the ASCO/CAP and ToGA trial criteria. HER2 FISH was performed and scored according to the ASCO/CAP criteria. The proportion of HER2-low, defined as 1+ or 2+ staining with negative FISH, was determined. Using ASCO/CAP, 26% demonstrated 3+ while 35% demonstrated 2+ staining. Using ToGA, 30% demonstrated 3+ while 57% demonstrated 2+ staining. By FISH, 26% were positive for HER2 amplification. Both systems captured all FISH-positive cases; the use of ASCO/CAP resulted in fewer equivocal and false-positive cases. Among HER2-negative cases, 88% were HER2-low. Aberrant p53 expression was detected in 55% of cases; mismatch repair deficiency was not identified in any cases. ASCO/CAP guidelines are accurate and resource-effective in determining HER2 overexpression in mucinous ovarian carcinoma. HER2-low is common in these tumors; further studies to determine the role of HER2-targeted therapy including antibody-drug conjugates are indicated.

High grade adverse event reporting and enrolment in gynecologic oncology clinical trials.

OBJECTIVE: The primary objective is to assess factors associated with treatment related high grade (CTCAE grade ≥ 3) adverse event (AE) reporting among participants in gynecologic oncology clinical trials. METHODS: All AEs recorded in the Princess Margaret Clinical Trial adverse event database between 01/2016 and 12/2018 were evaluated. Gynecologic oncology clinical trials assessing systemic therapy were included. Inferential statistics on risk factors of related grade ≥ 3 adverse event reporting and GEE logistic models with Odds Ratios (OR) were performed. Multivariable analysis adjusting for age, clinical trial phase, sponsor, and therapy type. RESULTS: The gynecology cancer clinical trials accrued 317 unique patients (359 nested on trials) in 42 systemic therapy trials. In the period, 17,175 related AEs were reported in the gynecological cancer trials, 7.4% were grade ≥ 3. On multivariable analysis, no odds differences of grade ≥ 3 related AEs were detected according to study phase. Patients in immunotherapy clinical trials had lower odds of related grade ≥ 3 AEs than patients on targeted or other therapy (adjusted OR [aOR] 0.43; 95% CI 0.24-0.75). There was greater odds of related grade ≥ 3 AEs in clinical trials assessing combination vs single therapeutics (aOR 2.26, 95% CI 1.34-3.80). Patients aged ≥65 (aOR 1.77; 95% CI 1.08-2.89) had greater odds of related grade ≥ 3 AEs than patients aged 50 to 65 years. When compared to other disease sites, the odds of having a grade  ≥ 3 related AE reported in gynecology clinical trials was no different. CONCLUSIONS: In this cohort, factors influencing the odds of related grade ≥ 3 AE reporting in gynecologic trials included type of therapy and age. The study phase did not correlate with odds of high-grade AE reporting.

Early changes in tumor-naive cell-free methylomes and fragmentomes predict outcomes in pembrolizumab-treated solid tumors.

Early kinetics of circulating tumor DNA (ctDNA) in plasma predict response to pembrolizumab, but typically requires sequencing of matched tumor tissue or fixed gene panels. We analyzed genome-wide methylation and fragment length profiles using cell-free methylated DNA immunoprecipitation and sequencing (cfMeDIP-seq) in 204 plasma samples from 87 patients before and during treatment with pembrolizumab from a pan-cancer phase II investigator-initiated trial (INSPIRE). We trained a pan-cancer methylation signature using independent methylation array data from The Cancer Genome Atlas to quantify a cancer-specific methylation (CSM) and fragment length score (FLS) for each sample. CSM and FLS are strongly correlated with tumor-informed ctDNA levels. Early kinetics of CSM predict overall survival and progression-free survival, independently of tumor type, PD-L1, and tumor mutation burden. Early kinetics of FLS are associated with overall survival independently of CSM. Our tumor-naïve mutation-agnostic ctDNA approach integrating methylomics and fragmentomics could predict outcomes in patients treated with pembrolizumab.

Development of a Practical Nomogram for Personalized Anemia Management in Patients Treated with Ataxia Telangiectasia and Rad3-related Inhibitor Camonsertib.

PURPOSE: Camonsertib is a highly selective and potent inhibitor of ataxia telangiectasia and Rad3-related (ATR) kinase. Dose-dependent anemia is a class-related on-target adverse event often requiring dose modifications. Individual patient risk factors for the development of significant anemia complicate the selection of a "one-size-fits-all" ATR inhibitor (ATRi) dose and schedule, possibly leading to suboptimal therapeutic doses in patients at low risk of anemia. We evaluated whether early predictors of anemia could be identified to ultimately inform a personalized dose-modification approach. PATIENTS AND METHODS: On the basis of preclinical observations and a mechanistic understanding of ATRi-related anemia, we identified several potential factors to explore in a multivariable linear regression modeling tool for predicting hemoglobin level ahead of day 22 (cycle 2) of treatment. RESULTS: In patients treated with camonsertib monotherapy (NCT04497116), we observed that hemoglobin decline is consistently preceded by reticulocytopenia, and dose- and exposure-dependent decreases in monocytes. We developed a nomogram incorporating baseline and day 8 hemoglobin and reticulocyte values that predicted the day 22 hemoglobin values of patients with clinically valuable concordance (within 7.5% of observations) 80% of the time in a cross-validation performance test of data from 60 patients. CONCLUSIONS: The prediction of future hemoglobin decrease, after a week of treatment, may enable a personalized, early dose modification to prevent development of clinically significant anemia and resulting unscheduled dose holds or transfusions.

Clinical Validation of Human Papilloma Virus Circulating Tumor DNA for Early Detection of Residual Disease After Chemoradiation in Cervical Cancer.

PURPOSE: Most cervical cancers are caused by human papilloma virus (HPV), and HPV circulating tumor DNA (ctDNA) may identify patients at highest risk of relapse. Our pilot study using digital polymerase chain reaction (dPCR) showed that detectable HPV ctDNA at the end of chemoradiation (CRT) is associated with inferior progression-free survival (PFS) and that a next-generation sequencing approach (HPV-seq) may outperform dPCR. We aimed to prospectively validate HPV ctDNA as a tool for early detection of residual disease. METHODS: This prospective, multicenter validation study accrued patients with stage IB-IVA cervical cancer treated with CRT between 2017 and 2022. Participants underwent phlebotomy at baseline, end of CRT, 4-6 weeks post-CRT, and 3 months post-CRT for HPV ctDNA levels. Plasma HPV genotype-specific DNA levels were quantified using both dPCR and HPV-seq. The primary end point was 2-year PFS. RESULTS: With a median follow-up of 2.2 (range, 0.5-5.5) years, there were 24 PFS events among the 70 patients with HPV+ cervical cancer. Patients with detectable HPV ctDNA on dPCR at the end of CRT, 4-6 weeks post-CRT, and 3 months post-CRT had significantly worse 2-year PFS compared with those with undetectable HPV ctDNA (77% v 51%, P = .03; 82% v 15%, P < .001; and 82% v 24%, P < .001, respectively); the median lead time to recurrence was 5.9 months. HPV-seq showed similar results as dPCR. On multivariable analyses, detectable HPV ctDNA on dPCR and HPV-seq remained independently associated with inferior PFS. CONCLUSION: Persistent HPV ctDNA after CRT is independently associated with inferior PFS. HPV ctDNA testing can identify, as early as at the end of CRT, patients at high risk of recurrence for future treatment intensification trials.

HAVOC: Small-scale histomic mapping of cancer biodiversity across large tissue distances using deep neural networks.

Intratumoral heterogeneity can wreak havoc on current precision medicine strategies because of challenges in sufficient sampling of geographically separated areas of biodiversity distributed across centimeter-scale tumor distances. To address this gap, we developed a deep learning pipeline that leverages histomorphologic fingerprints of tissue to create "Histomic Atlases of Variation Of Cancers" (HAVOC). Using a number of objective molecular readouts, we demonstrate that HAVOC can define regional cancer boundaries with distinct biology. Using larger tumor specimens, we show that HAVOC can map biodiversity even across multiple tissue sections. By guiding profiling of 19 partitions across six high-grade gliomas, HAVOC revealed that distinct differentiation states can often coexist and be regionally distributed within these tumors. Last, to highlight generalizability, we benchmark HAVOC on additional tumor types. Together, we establish HAVOC as a versatile tool to generate small-scale maps of tissue heterogeneity and guide regional deployment of molecular resources to relevant biodiverse niches.

Gestational trophoblastic neoplasia: does centralization of care impact clinical management?

OBJECTIVE: International societies advocate for gestational trophoblastic neoplasia referral to designated expert centers. This study assessed the impact of centralization of trophoblastic care on clinical outcomes. METHODS: A centralized program was implemented in 2018 at two affiliated academic hospitals, Princess Margaret Cancer Center and Mount Sinai Hospital. A retrospective analysis of patients treated between 2000 and 2022 was performed and the clinical outcomes were compared before (2000-2017) and after (2018-2022) centralization. Statistical analyses were performed with significance set as p<0.05. RESULTS: A total of 94 patients with trophoblastic neoplasia were included: 60 pre-centralization and 34 post-centralization, 79.8% low-risk and 18.1% high-risk. Centralization led to significant improvement for: (1) accurate score documentation (from 37.9% to 89.3%,); (2) contraception counseling (from 67.2% to 96.7%); (3) median time from diagnosis to chemotherapy (from 9 days to 1 day); and (4) incomplete follow-up (from 20.7% to 3.3%) (all p<0.05). First-line chemotherapy for low-risk neoplasia was dactinomycin in 47.9% and 87.0% pre- and post-centralization, respectively (p=0.005). The median number of chemotherapy cycles decreased from seven to four (p=0.01), and the median number of consolidation cycles increased from two to three (p<0.001). Serum human chorionic gonadotropin (hCG) levels of 10 000-100 000 IU/L were significantly associated with longer time to hCG normalization and higher risk of resistance to first-line chemotherapy compared with hCG levels <1000 IU/L. CONCLUSION: Centralization of trophoblastic neoplasia care leads to greater guideline compliance, faster chemotherapy initiation, fewer chemotherapy cycles with optimized consolidation, and enhanced surveillance completion. This supports the establishment of trophoblastic neoplasia expert centers.

Camonsertib in DNA damage response-deficient advanced solid tumors: phase 1 trial results.

Predictive biomarkers of response are essential to effectively guide targeted cancer treatment. Ataxia telangiectasia and Rad3-related kinase inhibitors (ATRi) have been shown to be synthetic lethal with loss of function (LOF) of ataxia telangiectasia-mutated (ATM) kinase, and preclinical studies have identified ATRi-sensitizing alterations in other DNA damage response (DDR) genes. Here we report the results from module 1 of an ongoing phase 1 trial of the ATRi camonsertib (RP-3500) in 120 patients with advanced solid tumors harboring LOF alterations in DDR genes, predicted by chemogenomic CRISPR screens to sensitize tumors to ATRi. Primary objectives were to determine safety and propose a recommended phase 2 dose (RP2D). Secondary objectives were to assess preliminary anti-tumor activity, to characterize camonsertib pharmacokinetics and relationship with pharmacodynamic biomarkers and to evaluate methods for detecting ATRi-sensitizing biomarkers. Camonsertib was well tolerated; anemia was the most common drug-related toxicity (32% grade 3). Preliminary RP2D was 160 mg weekly on days 1-3. Overall clinical response, clinical benefit and molecular response rates across tumor and molecular subtypes in patients who received biologically effective doses of camonsertib (>100 mg d-1) were 13% (13/99), 43% (43/99) and 43% (27/63), respectively. Clinical benefit was highest in ovarian cancer, in tumors with biallelic LOF alterations and in patients with molecular responses. ClinicalTrials.gov registration: NCT04497116 .

Identifying Mechanisms of Resistance by Circulating Tumor DNA in EVOLVE, a Phase II Trial of Cediranib Plus Olaparib for Ovarian Cancer at Time of PARP Inhibitor Progression.

PURPOSE: To evaluate the use of blood cell-free DNA (cfDNA) to identify emerging mechanisms of resistance to PARP inhibitors (PARPi) in high-grade serous ovarian cancer (HGSOC). EXPERIMENTAL DESIGN: We used targeted sequencing (TS) to analyze 78 longitudinal cfDNA samples collected from 30 patients with HGSOC enrolled in a phase II clinical trial evaluating cediranib (VEGF inhibitor) plus olaparib (PARPi) after progression on PARPi alone. cfDNA was collected at baseline, before treatment cycle 2, and at end of treatment. These were compared with whole-exome sequencing (WES) of baseline tumor tissues. RESULTS: At baseline (time of initial PARPi progression), cfDNA tumor fractions were 0.2% to 67% (median, 3.25%), and patients with high ctDNA levels (>15%) had a higher tumor burden (sum of target lesions; P = 0.043). Across all timepoints, cfDNA detected 74.4% of mutations known from prior tumor WES, including three of five expected BRCA1/2 reversion mutations. In addition, cfDNA identified 10 novel mutations not detected by WES, including seven TP53 mutations annotated as pathogenic by ClinVar. cfDNA fragmentation analysis attributed five of these novel TP53 mutations to clonal hematopoiesis of indeterminate potential (CHIP). At baseline, samples with significant differences in mutant fragment size distribution had shorter time to progression (P = 0.001). CONCLUSIONS: Longitudinal testing of cfDNA by TS provides a noninvasive tool for detection of tumor-derived mutations and mechanisms of PARPi resistance that may aid in directing patients to appropriate therapeutic strategies. With cfDNA fragmentation analyses, CHIP was identified in several patients and warrants further investigation.

A phase I study of the Wee1 kinase inhibitor adavosertib (AZD1775) in combination with chemoradiation in cervical, upper vaginal, and uterine cancers.

OBJECTIVE: Wee1 kinase is a crucial regulator of the G2/M checkpoint which prevents entry of damaged DNA into mitosis. Adavosertib (AZD1775), a selective inhibitor of Wee1, induces G2 escape and increases cytotoxicity when combined with DNA damaging agents. We aimed to evaluate the safety and efficacy of adavosertib in combination with definitive pelvic radiotherapy and concurrent cisplatin in patients with gynecological cancers. METHODS: A multi-institutional, open-label phase I trial was designed to assess dose escalation (3+3 design) of adavosertib in combination with standard chemoradiation. Eligible patients with locally advanced cervical, endometrial or vaginal tumors were treated with a 5-week course of pelvic external beam radiation 45-50 Gy in 1.8-2 Gy daily fractions plus concurrent weekly cisplatin 40 mg/m2 and adavosertib 100 mg/m2 on days 1, 3 and 5 of each week during chemoradiation. The primary endpoint was to determine the recommended phase II dose of adavosertib. Secondary endpoints included toxicity profile and preliminary efficacy. RESULTS: Ten patients were enrolled (nine locally advanced cervical and one endometrial cancer). Two patients experienced a dose-limiting toxicity at dose level 1 (adavosertib 100 mg by mouth daily on days 1, 3 and 5), including one patient with grade 4 thrombocytopenia, and one with treatment hold >1 week due to grade 1 creatinine elevation and grade 1 thrombocytopenia. At dose level -1 (adavosertib 100 mg by mouth daily on days 3 and 5), one out of five patients enrolled had a dose-limiting toxicity in the form of persistent grade 3 diarrhea. The overall response rate at 4 months was 71.4%, including four complete responses. At 2 years follow-up, 86% of patients were alive and progression-free. CONCLUSION: The recommended phase II dose could not be determined due to clinical toxicity and early trial closure. Preliminary efficacy appears promising, yet selecting the adequate dose/schedule in combination chemoradiation warrants further investigation to limit overlapping toxicities.

Clinical parameters affecting survival outcomes in patients with low-grade serous ovarian carcinoma: an international multicentre analysis.

BACKGROUND: Women with low-grade ovarian serous carcinoma (LGSC) benefit from surgical treatment; however, the role of chemotherapy is controversial. We examined an international database through the Ovarian Cancer Association Consortium to identify factors that affect survival in LGSC. METHODS: We performed a retrospective cohort analysis of patients with LGSC who had had primary surgery and had overall survival data available. We performed univariate and multivariate analyses of progression-free survival and overall survival, and generated Kaplan-Meier survival curves. RESULTS: Of the 707 patients with LGSC, 680 (96.2%) had available overall survival data. The patients' median age overall was 54 years. Of the 659 patients with International Federation of Obstetrics and Gynecology stage data, 156 (23.7%) had stage I disease, 64 (9.7%) had stage II, 395 (59.9%) had stage III, and 44 (6.7%) had stage IV. Of the 377 patients with surgical data, 200 (53.0%) had no visible residual disease. Of the 361 patients with chemotherapy data, 330 (91.4%) received first-line platinum-based chemotherapy. The median follow-up duration was 5.0 years. The median progression-free survival and overall survival were 43.2 months and 110.4 months, respectively. Multivariate analysis indicated a statistically significant impact of stage and residual disease on progression-free survival and overall survival. Platinum-based chemotherapy was not associated with a survival advantage. CONCLUSION: This multicentre analysis indicates that complete surgical cytoreduction to no visible residual disease has the most impact on improved survival in LGSC. This finding could immediately inform and change practice.

Symptom screening with Targeted Early Palliative care (STEP) versus usual care for patients with advanced cancer: a mixed methods study.

PURPOSE: Although early palliative care is recommended, resource limitations prevent its routine implementation. We report on the preliminary findings of a mixed methods study involving a randomized controlled trial (RCT) of Symptom screening with Targeted Early Palliative care (STEP) and qualitative interviews. METHODS: Adults with advanced solid tumors and an oncologist-estimated prognosis of 6-36 months were randomized to STEP or symptom screening alone. STEP involved symptom screening at each outpatient oncology visit; moderate to severe scores triggered an email to a palliative care nurse, who offered referral to in-person outpatient palliative care. Patient-reported outcomes of quality of life (FACT-G7; primary outcome), depression (PHQ-9), symptom control (ESAS-r-CS), and satisfaction with care (FAMCARE P-16) were measured at baseline and 2, 4, and 6 months. Semi-structured interviews were conducted with a subset of participants. RESULTS: From Aug/2019 to Mar/2020 (trial halted due to COVID-19 pandemic), 69 participants were randomized to STEP (n = 33) or usual care (n = 36). At 6 months, 45% of STEP arm patients and 17% of screening alone participants had received palliative care (p = 0.009). Nonsignificant differences for all outcomes favored STEP: difference in change scores for FACT-G7 = 1.67 (95% CI: -1.43, 4.77); ESAS-r-CS = -5.51 (-14.29, 3.27); FAMCARE P-16 = 4.10 (-0.31, 8.51); PHQ-9 = -2.41 (-5.02, 0.20). Sixteen patients completed qualitative interviews, describing symptom screening as helpful to initiate communication; triggered referral as initially jarring but ultimately beneficial; and referral to palliative care as timely. CONCLUSION: Despite lack of power for this halted trial, preliminary results favored STEP and qualitative results demonstrated acceptability. Findings will inform an RCT of combined in-person and virtual STEP.

Safety of fertility sparing management in invasive mucinous ovarian carcinoma.

BACKGROUND: The aim of the study was to evaluate the safety of fertility-sparing surgery in invasive mucinous ovarian carcinomas (MOC). METHODS: Retrospective review was performed of MOCs diagnosed between 1999 and 2019 at two tertiary cancer centers. Pathology was reviewed to rule out metastasis from gastrointestinal tract. The demographics and survival outcomes were compared between women who underwent fertility-sparing surgery and those who underwent radical surgery (at least hysterectomy, bilateral salpingo-oophorectomy +/- staging). Cox proportional hazard models were constructed to evaluate the effect of fertility sparing surgery on survival. RESULTS: Of 134 with stage I disease, 42 (31%) underwent fertility-sparing surgery with unilateral salpingo-oophorectomy. Compared to women who underwent radical surgery, these women were younger with low grade, early-stage disease. Two patients (5%) in the fertility-sparing cohort experienced a recurrence and 1 of these 2 patients died due to disease progression. There was no difference in either OS or RFS between those that underwent fertility-sparing surgery and radical surgery. In a multivariable analysis adjusting for age and use of adjuvant chemotherapy, fertility-sparing surgery was not significantly associated with OS (HR 0.18; 95% CI 0.01-2.78) or RFS (HR 0.19; 95% CI 0.03-1.45). There were 4 patients (9%) with documented full-term delivery with median interval to conception of 11 months. CONCLUSIONS: Fertility-sparing surgery in stage I MOC is not associated with worse outcomes compared to radical surgery and is reasonable to offer to those with early stage disease who wish to retain fertility.

Fighting resistance: post-PARP inhibitor treatment strategies in ovarian cancer.

Poly (ADP-ribose) polymerase inhibitors (PARPis) represent a therapeutic milestone in the management of epithelial ovarian cancer. The concept of 'synthetic lethality' is exploited by PARPi in tumors with defects in DNA repair pathways, particularly homologous recombination deficiency. The use of PARPis has been increasing since its approval as maintenance therapy, particularly in the first-line setting. Therefore, resistance to PARPi is an emerging issue in clinical practice. It brings an urgent need to elucidate and identify the mechanisms of PARPi resistance. Ongoing studies address this challenge and investigate potential therapeutic strategies to prevent, overcome, or re-sensitize tumor cells to PARPi. This review aims to summarize the mechanisms of resistance to PARPi, discuss emerging strategies to treat patients post-PARPi progression, and discuss potential biomarkers of resistance.

Overcoming PARP inhibitor resistance in ovarian cancer.

Ovarian cancer (OC) is one of the most lethal tumors in women, mostly diagnosed at advanced stages. Standard of care is based on surgery and platinum-based chemotherapy which provides high rates of response, although most patients will relapse. Poly(ADP-ribose) polymerase inhibitors (PARPi) have recently been incorporated in the treatment strategy for high-grade OC, particularly for those with defects in DNA repair pathways (homologous repair deficiency (HRd)). However, some tumor cells may not respond and some others will develop mechanisms of resistance to adapt. The most known mechanism of PARPi resistance is the reversion of HRd to homologous repair proficiency driven by epigenetic and genetic changes. Ongoing research is exploring different agents that are trying to re-sensitize tumor cells,overcome or bypass resistance to PARPi. Current investigations are focused on agents that target replication stress and DNA repair pathways, improve drug delivery, and target other cross-talk pathways. A crucial challenge in practice will be to identify and select patients for the appropriate therapy or combination strategies. However, efforts are needed to decrease overlapping toxicity and define the correct schedule timing of dosing to maximize the therapeutic index.