Research progress of PARP inhibitor monotherapy and combination therapy for endometrial cancer.

2021 ◽  
Vol 22 ◽  
Author(s):  
Ke Shen ◽  
Li Yang ◽  
Fei-Yan Li ◽  
Feng Zhang ◽  
Lei-Lei Ding ◽  
...  

: Endometrial cancer is one of the three most common malignant tumors in the female reproductive system. Advanced and recurrent endometrial cancers have poor prognoses and lack effective treatments. Poly(ADP-ribose) polymerase (PARP) inhibitors have been applied to many different types of tumors, and they can selectively kill tumor cells that are defective in homologous recombination repair. Endometrial cancer is characterized by mutations in homologous recombination repair genes; accordingly, PARP inhibitors have achieved positive results in off-label treatments of endometrial cancer cases. Clinical trials of PARP inhibitors as monotherapies and within combination therapies for endometrial cancer are ongoing. For this review, we searched PubMed with "endometrial cancer" and "PARP inhibitor" as keywords, and we used "olaparib", "rucaparib", "niraparib" and "talazoparib" as search terms in clinicaltrials.gov for ongoing trials. The literature search ended in October 2020, and only English-language publications were selected. Multiple studies confirm that PARP inhibitors play an important role in killing tumor cells with defects in homologous recombination repair. Its combination with immune checkpoint inhibitors, PI3K/AKT/mTOR pathway inhibitors, cell cycle checkpoint inhibitors, and other drugs can improve the treatment of endometrial cancer.

Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 254
Author(s):  
Jenny-Maria Jönsson ◽  
Maria Bååth ◽  
Ida Björnheden ◽  
Irem Durmaz Sahin ◽  
Anna Måsbäck ◽  
...  

Serous endometrial cancer (SEC) resembles high-grade serous ovarian cancer (HGSOC) genetically and clinically, with recurrent copy number alterations, TP53 mutations and a poor prognosis. Thus, SEC patients may benefit from targeted treatments used in HGSOC, e.g., PARP inhibitors. However, the preclinical and clinical knowledge about SEC is scarce, and the exact role of defective DNA repair in this tumor subgroup is largely unknown. We aimed to outline the prevalence of homologous recombination repair deficiency (HRD), copy-number alterations, and somatic mutations in SEC. OncoScan SNP arrays were applied to 19 tumors in a consecutive SEC series to calculate HRD scores and explore global copy-number profiles and genomic aberrations. Copy-number signatures were established and targeted sequencing of 27 HRD-associated genes was performed. All factors were examined in relation to HRD scores to investigate potential drivers of the HRD phenotype. Ten of the 19 SEC tumors (53%) had an HRD score > 42, considered to reflect an HRD phenotype. Higher HRD score was associated with loss of heterozygosity in key HRD genes, and copy-number signatures associated with non-BRCA1/2 dependent HRD in HGSOC. A high number of SECs display an HRD phenotype. It remains to be elucidated whether this also confers PARP inhibitor sensitivity.


Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2249
Author(s):  
Sandra van Wilpe ◽  
Sofie H. Tolmeijer ◽  
Rutger H. T. Koornstra ◽  
I. Jolanda M. de Vries ◽  
Winald R. Gerritsen ◽  
...  

Homologous recombination repair deficiency (HRD) can be observed in virtually all cancer types. Although HRD sensitizes tumors to DNA-damaging chemotherapy and poly(ADP-ribose) polymerase (PARP) inhibitors, all patients ultimately develop resistance to these therapies. Therefore, it is necessary to identify therapeutic regimens with a more durable efficacy. HRD tumors have been suggested to be more immunogenic and, therefore, more susceptible to treatment with checkpoint inhibitors. In this review, we describe how HRD might mechanistically affect antitumor immunity and summarize the available translational evidence for an association between HRD and antitumor immunity across multiple tumor types. In addition, we give an overview of all available clinical data on the efficacy of checkpoint inhibitors in HRD tumors and describe the evidence for using treatment strategies that combine checkpoint inhibitors with PARP inhibitors.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e17550-e17550
Author(s):  
Ignacio Romero ◽  
Ana Oaknin ◽  
Zaida Garcia-Casado ◽  
Raul Marquez ◽  
Alfonso Yubero Esteban ◽  
...  

e17550 Background: In epithelial ovarian cancer (EOC), the identification of mutations in homologous recombination repair (HRR) genes on tumor is prognostic, predictive of response to PARP inhibitors, and a tool to identify individuals at genetic cancer risk. The aim of this study is to compare the concordance between two laboratories in identifying and classifying genetic variants in HRR genes. Methods: In a multicentre ambispective series of unselected, non mucinous EOC of all stages formalin-fixed and paraffin embedded tumors were collected. These samples underwent the same mutational analysis of 15 HRR genes ( ATM, BARD1, BRCA1, BRCA2, BRIP1, CDK12, CHEK1, CHEK2, FANCL, PALB2, PPP2R2A, RAD51B, RAD51C, RAD51D, RAD54L) in two different Laboratories (Lab1, Lab2) that used their own validated multi-gene NGS panels. Variant allele frequency (VAF) threshold was 5% for single nucleotide polymorphism and 10% for indels. Large rearrangements were not analyzed. Variants were classified into three categories based on ACMG criteria: non-mutated (class 1-2), Variants of Uncertain Significance (VUS: class 3) and likely pathogenic/pathogenic (class 4-5). Results: A total of 81 cases were sent for the analysis. One had low DNA quality and therefore 80 cases were finally studied (85% high grade serous and 74% FIGO stage III-IV). Results reported by Lab1 and Lab2 (lab1/Lab2) were the following: 21/19 (26%/24%) cases had BRCA1/2 mutations, 7/8 (8.7%/10%) mutations on other HRR genes including two in ATM and RAD51D, one in CHEK1, CHEK2, and FANCL and one RAD51C reported in Lab2 only while the rest were either VUS 23/27 (29%/34%) or non-mutated 29/26 (36%/33%). Concordance between laboratories in classifying patients was 93.75% (kappa coefficient 0.86). Discrepancies (DC) on variants were classified into arbitrary categories, namely 0= complete concordance, category 1 meaning DC in detection assumed to be due to tumor heterogeneity (VAF nearby the threshold) or technique (1A), or caused by laboratories performance and avoidable (1B) and the category 2 identified DC in interpretation without clinical relevance (2A) or clinically relevant (2B), the results of total number of variants are shown in table. Overall, regarding clinically relevant DC in HRR genes, 9 DC in variants were observed including six 2B, two 1A and one 1B and they affect 5 (6.3%) patients since some were overlapping. Conclusions: In our EOC series the concordance of two Laboratories in the identification of clinically relevant HRR mutations on tumor is high but discrepancies in interpretation remain a challenge that needs further harmonization.[Table: see text]


2020 ◽  
Vol 295 (37) ◽  
pp. 12946-12961
Author(s):  
Soichiro S. Ito ◽  
Yosuke Nakagawa ◽  
Masaya Matsubayashi ◽  
Yoshihiko M. Sakaguchi ◽  
Shinko Kobashigawa ◽  
...  

The anticancer agent 5-fluorouracil (5-FU) is cytotoxic and often used to treat various cancers. 5-FU is thought to inhibit the enzyme thymidylate synthase, which plays a role in nucleotide synthesis and has been found to induce single- and double-strand DNA breaks. ATR Ser/Thr kinase (ATR) is a principal kinase in the DNA damage response and is activated in response to UV– and chemotherapeutic drug–induced DNA replication stress, but its role in cellular responses to 5-FU is unclear. In this study, we examined the effect of ATR inhibition on 5-FU sensitivity of mammalian cells. Using immunoblotting, we found that 5-FU treatment dose-dependently induced the phosphorylation of ATR at the autophosphorylation site Thr-1989 and thereby activated its kinase. Administration of 5-FU with a specific ATR inhibitor remarkably decreased cell survival, compared with 5-FU treatment combined with other major DNA repair kinase inhibitors. Of note, the ATR inhibition enhanced induction of DNA double-strand breaks and apoptosis in 5-FU–treated cells. Using gene expression analysis, we found that 5-FU induced the activation of the intra-S cell-cycle checkpoint. Cells lacking BRCA2 were sensitive to 5-FU in the presence of ATR inhibitor. Moreover, ATR inhibition enhanced the efficacy of the 5-FU treatment, independently of the nonhomologous end-joining and homologous recombination repair pathways. These findings suggest that ATR could be a potential therapeutic target in 5-FU–based chemotherapy.


2020 ◽  
Vol 30 (5) ◽  
pp. 684-694
Author(s):  
Rebecca Arend ◽  
Shannon Neville Westin ◽  
Robert L Coleman

Most women with ovarian cancer experience disease relapse, presenting numerous treatment challenges for clinicians. Maintenance therapy in the relapsed setting aims to extend the time taken for a cancer to progress, thus delaying the need for additional treatments. Four therapies are currently approved in the USA for secondline maintenance treatment of platinum sensitive, recurrent ovarian cancer: one antivascular endothelial growth factor agent (bevacizumab) and three poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors (olaparib, niraparib, and rucaparib). In addition to efficacy, maintenance therapies must have a good tolerability profile and no significant detrimental impact on quality of life, as patients who receive maintenance are generally free from cancer related symptoms. Data from key bevacizumab trials (OCEANS, NCT00434642; GOG-0213, NCT00565851; MITO16B, NCT01802749) and PARP inhibitor trials (Study 19, NCT00753545; SOLO2, NCT01874353; NOVA, NCT01847274; ARIEL3, NCT01968213) indicate that bevacizumab and the PARP inhibitors are effective in patients with platinum sensitive, recurrent ovarian cancer but differ in their tolerability profiles. In addition, the efficacy of PARP inhibitors is dependent on the presence of homologous recombination repair deficiency, with patients with the deficiency experiencing greater responses from treatment compared with those who are homologous recombination repair proficient. Allowing for caveats of cross trial comparisons, we advise that clinicians account for the following points when choosing whether and when to administer a secondline maintenance treatment for a specific patient: presence of a homologous recombination repair deficient tumor; the patient’s baseline characteristics, such as platelet count and blood pressure; mode of administration of therapy; and consideration of future treatment options for thirdline and later therapy.


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