Case report: Pathological complete response induced by immunochemotherapy in a case of Pulmonary Sarcomatoid Carcinoma staged IIIA-N2.

Pulmonary sarcomatoid carcinoma (PSC) represents a rare and highly aggressive variant of lung cancer, characterized by its recalcitrance to conventional therapeutic modalities and the attendant dismal prognosis it confers. Recent breakthroughs in immunotherapy have presented novel prospects for PSC patients; nevertheless, the utility of neoadjuvant/conversional immunotherapy in the context of PSC remains ambiguous. In this report, we present a middle-aged male presenting with Stage III PSC, notable for its high expression of the programmed death-ligand 1 (PD-L1), initially deemed as non-resectable for sizeable tumor mass and multiple lymph nodes metastases. The patient underwent a transformation to a resectable state after a regimen of three cycles of platinum-based chemotherapy plus immunotherapy. Following definitive surgical resection, the individual realized a pathological complete response (pCR), culminating in a significant prolongation of event-free survival (EFS). This case underscores the viability of employing immunochemotherapy as a neoadjuvant/conversional strategy for chosen cases of PSC.

Neoadjuvant Chemotherapy in Locally Advanced Sinonasal Teratocarcinosarcoma a Rare Malignancy: An Audit From an Academic Tertiary Care Centre in India.

AIMS: Sinonasal teratocarcinosarcomas (SNTCS) are rare sinonasal malignancies, the incidence of which is less than 1% of all tumors. There is limited data available on SNTCS's, often as case reports and small case series. The management of SNTCS is complicated because of its location, locally aggressive biology, difficulty in achieving complete resection, and limited data on chemotherapy in these malignancies. This audit was performed to understand the role of neoadjuvant chemotherapy (NACT) in SNTCS's, its ability to downstage the disease, achieve complete resection, and impact on long-term survival outcomes. METHODS: This was a retrospective analysis of a prospectively maintained database approved by the Institutional Ethics Committee (IEC). The baseline characteristics, the extent of tumor, Kadish stage, NACT regimen, and adverse events were extracted from the Electronic Medical Records and the patient's case file. Patients with baseline extensive/inoperable disease were referred for NACT from the multidisciplinary joint clinic followed by response assessment (RECIST v1.1). Patients underwent skull-base surgery if respectable post-completion of NACT, however, if deemed unresectable were treated with non-surgical modalities or palliative therapies. RESULTS: The data of 27 patients were evaluated from the year 2015-2022. The median age was 42 years (IQR:30-56) and 85.2% (n = 23) were males. The ECOG-PS was 0-1 in 88.8% (n = 24) patients. All 27 patients received NACT in view of extensive disease at presentation. 74.1% (n = 20) patients received Cisplatin-Etoposide and 25.9% (n = 7) received other chemotherapy regimens. The median number of chemotherapy cycles was 2(IQR:2-3). 96.3% patients (n = 26) completed the planned NACT cycles. 70.4% (n = 19) patients achieved a partial response in post-NACT imaging. 77.8% (n = 18) underwent surgery, 18.5% (n = 5) received CTRT, and 7.4% (n = 2) received definitive-RT alone. The median PFS and OS of the cohort was 19months (95%CI:12.0-25.6) and 23months (95%CI:5.94-40.06) respectively. CONCLUSION: NACT is safe, feasible, and effective with significant response rates, leading to effective downstaging, resectability and improved survival in patients with locally advanced SNTCS's.

A phase 2 trial of zanidatamab in HER2-overexpressed advanced endometrial carcinoma and carcinosarcoma (ZW25-IST-2).

OBJECTIVE: HER2 overexpression is associated with decreased overall survival in metastatic endometrial cancer. Trastuzumab with chemotherapy has demonstrated efficacy for first-line management of advanced HER2+ endometrial carcinoma, but HER2-directed therapy in the recurrent setting is limited. Zanidatamab (ZW25), a humanized, bispecific antibody that simultaneously binds the 2 distinct HER2 epitopes bound by trastuzumab and pertuzumab, has demonstrated safety and activity in HER2+ tumors. Here, we report the results of a phase 2, open-label study evaluating the efficacy and safety of zanidatamab in patients with HER2+ metastatic endometrial carcinoma/carcinosarcoma who received prior treatment. METHODS: We enrolled 16 patients with HER2+ endometrial carcinoma/carcinosarcoma after progression on ≤2 lines of therapy on a single-arm phase 2 study of zanidatamab. The primary endpoint was overall response rate (ORR; complete or partial response) by Response Evaluation Criteria in Solid Tumors version 1.1. HER2 immunohistochemistry and fluorescence in situ hybridization (FISH) were performed on pretreatment samples. Intratumor HER2 genetic heterogeneity was assessed. RESULTS: This study did not meet its primary efficacy endpoint. Although a clinical benefit rate of 37.5% was observed by 24 weeks, only 1 patient achieved a partial response (ORR, 6.2%). Eight patients had HER2 intratumor heterogeneity or lacked HER2 amplification by FISH. Decreased HER2 expression on repeat pretreatment samples was observed in 3 (75%) of 4 patients evaluated. CONCLUSIONS: We observed a low response rate to zanidatamab in recurrent HER2+ endometrial carcinoma/carcinosarcoma, which may be driven by downregulation of HER2 expression. Repeat HER2 testing should be considered prior to second-line HER2-directed therapy. CLINICALTRIALS: govidentifier: NCT04513665.

Genomic and Molecular Characteristics of Ovarian Carcinosarcoma.

Ovarian carcinosarcoma (OCS) is a rare malignancy with a poor prognosis. It is a biphasic tumor with malignant epithelial and mesenchymal components. A few mutations commonly seen in cancer have been identified in OCS, including TP53, PIK3CA, c-myc, ZNF217, ARID1A, and CTNNB1. Some OCS tumors have shown vascular endothelial growth factor positivity and limited HER2 expression. There is evidence of homologous recombination deficiency in OCS. This malignancy can be categorized as copy number high but has not been shown to have a high tumor mutational burden. There are mixed findings regarding the presence of biomarkers targeted by immune checkpoint inhibitors in OCS. For treatments other than systemic chemotherapy, the data available are largely based on in vitro and in vivo studies. In addition, there are case reports citing the use of poly-ADP ribose polymerase inhibitors, vascular endothelial growth factor inhibitors, and immunotherapy with varying degrees of success. This review paper will discuss the molecular and genomic characteristics of OCS, which can guide future treatment strategies.

A case of ovarian carcinosarcoma with a germline pathogenic variant of BRCA2 involving a perforated appendix with an abscess.

We report a case of rare and aggressive ovarian carcinosarcoma with a germline pathogenic BRCA2 variant. A patient with a history of breast cancer who developed an inflammatory ovarian tumor with peritonitis carcinomatosis involving the appendix suffered from cachexia. Following three cycles of weekly paclitaxel and carboplatin chemotherapy, emergency surgery was required owing to sepsis. Bilateral salpingo-oophorectomy, total hysterectomy, appendectomy, and small intestine adhesiolysis were performed. Histologically, the tumor comprised an admixture of carcinomatous and sarcomatous components, with involvement of the appendix, which had caused perforation and abscess formation. The final diagnosis was ovarian carcinosarcoma with a germline pathogenic BRCA2 variant, c.658_659del (p.Val220fs). The patient responded completely to adjuvant chemotherapy. A combination of chemotherapy and surgery might be beneficial to patients with ovarian carcinosarcoma and germline pathogenic BRCA2 variants with a poor general condition. This is the first report of ovarian carcinosarcoma with a germline pathogenic BRCA2 variant that responded favorably to chemotherapy.

Bladder carcinosarcoma treated by cystectomy and adjuvant chemotherapy with good outcomes: a case report.

BACKGROUND: Primary carcinosarcoma of the bladder is a rare and highly aggressive tumor, representing less than 1% of all bladder neoplasms. There is no specific treatment guideline has for carcinosarcoma of the bladder, and majority of published patients was treated exclusively by surgery. CASE PRESENTATION: We report a case of 65-year-old Moroccan man, presented with macroscopic hematuria, pollakiuria and painful urination. Histological analysis showed a biphasic epithelial and mesenchymal proliferation, with invasion of lamina propria and muscularis, compatible with diagnosis of bladder carcinosarcoma. The patient was treated with cystectomy and adjuvant chemotherapy based on gemcitabin-cisplatin, 18 months after treatment, patient still free of recurrence. CONCLUSION: Carcinosarcoma of the urinary bladder is a rare and aggressive tumor regardless treatment. A multidisciplinary management based on radical cystectomy and combined adjuvant treatments can improve prognosis. In this work, we suggest to propose adjuvant chemotherapy whenever possible.

[Clinicopathological and gene mutation characteristics of uterine carcinosarcoma].

To explore the clinicopathological characteristics, immunophenotype, diagnosis and differential diagnosis of uterine carcinosarcoma (UCS), and to explore the gene mutation characteristics and tumor mutation burden (TMB) of UCS. The clinical imaging, pathomorphological data and immunohistochemical expression of 4 cases of UCS, which were archived in the Department of Pathology of the Second Affiliated Hospital of Soochow University from January 2021 to May 2022 were retrospectively analyzed. All exon groups of 4 cases of UCS were sequenced. All the 4 patients were female, aged 47-81 years. The maximum diameter of the tumor was 4.0-13.0 cm, and the boundary was unclear. Microscopically, the tumor was composed of malignant epithelium and sarcoma. Immunohistochemistry showed that the epithelial components of 4 patients expressed broad-spectrum cytokeratin (AE1/E3), the sarcoma components expressed Vimentin, PAX8, ER, PR were expressed to varying degrees, and Ki-67 positive index was high (60%-90%). There were 3 p53 missense mutations, 1 nonsense mutation, 4 MLH1, PMS2, MSH2, MSH6 were positive and PD-L1 was negative. The sequencing results of the whole exon group of 4 UCS patients showed that TP53, BCL9L, BRD4, CLTCLI, PSMD1I, PLEC genes showed a high mutation ratio, which was 3/4, 2/4, 2/4, 2/4, 2/4, 2/4, respectively. TMB analysis showed that the TMB of 4 cases of UCS was<5 mut/Mb. UCS is a rare and highly malignant endometrial tumor. The sequencing results of the whole exon group suggested that TP53, BCL9L, BRD4 and other genes had high mutation rates, suggesting that the occurrence and development of UCS may be closely related to Wnt signaling pathway. Molecular typing indicated that 3 cases of UCS were of high copy number type/p53 mutation type, and 1 case had POLD1 mutation. Microsatellite stability, low PD-L1 expression and TMB results suggested that UCS patients have no obvious advantage in immunotherapy.

An Unconventional Regimen of Carboplatin and Paclitaxel in Metastatic Colorectal Carcinosarcoma: A Case Report and Review of Literature.

Colorectal carcinosarcoma is an exceedingly rare subtype of colorectal cancer that displays the histological and molecular features of both mesenchymal and epithelial tumors. Due to its rarity, there are no guidelines regarding the systemic treatment of this disease. This report describes a case of a 76-year-old woman with colorectal carcinosarcoma with extensive metastatic burden treated with carboplatin and paclitaxel. After four cycles of chemotherapy, the patient had an excellent clinical and radiographical response to treatment. To the best of our knowledge, this is the first report addressing the use of carboplatin and paclitaxel in this disease. We reviewed seven published case reports of metastatic colorectal carcinosarcoma where various systemic treatments were offered. Remarkably, there are no previously published reports where even a partial response was noted, which underscores the aggressiveness of this disease. While further studies are required to validate our experience and assess long-term outcomes, this case suggests an alternative treatment regimen for metastatic colorectal carcinosarcoma.

The survival impact of adjuvant radiotherapy and chemotherapy in patients with non-endometrioid endometrial carcinomas: a PSM-IPTW analysis based on SEER database.

PURPOSE: To investigate outcomes of adjuvant treatments for non-endometrioid endometrial carcinomas (NEEC), as previous studies are limited by its rarity and heterogeneity. PATIENTS AND METHODS: Patients with endometrial serous carcinoma (SC), clear cell carcinoma (CCC) and carcinosarcoma were identified between 2004 and 2018 from SEER database. Propensity score matching (PSM) along with inverse probability treatment weighting (IPTW) technique were employed to balance confounding factors. Multivariate, exploratory subgroup and sensitivity analyses were conducted to evaluate the impact of adjuvant treatment on overall survival (OS) and cause-specific survival (CSS). RESULTS: The cohort comprised 5577 serous, 977 clear cell, and 959 carcinosarcomas. Combined chemotherapy and radiotherapy (CRT), chemotherapy alone, and radiotherapy alone were respectively administered in 42.21%, 47.27% and 10.58% of the whole cohort. Prior to adjusting, chemotherapy plus brachytherapy yielded the most beneficial effect among various strategies. After PSM-IPTW adjustment, CRT still demonstrated beneficial effect on OS and CSS. Subgroup analysis indicated CRT improved survival among various TNM stages, particularly with uterine carcinosarcoma. In the sensitivity analyses for serous histology, brachytherapy with or without chemotherapy appeared to benefit stage I-II patients. In stage III-IV SC patients, chemotherapy plus brachytherapy was still associated with improved survival outcomes. When nodal metastases were identified, additional external beam radiotherapy (EBRT) to CT was more utilized with survival improvement. CONCLUSION: In NEEC patients, combined CRT yielded beneficial effects than any single mode. Both chemotherapy and brachytherapy promoted survival in early stage SC patients. Late stage SC patients may benefit from chemotherapy plus either EBRT or brachytherapy.

[An exceptional venous pattern in a patient with cancer]. / Een vrouw met kanker en een opvallende venetekening.

A 71-year-old female was treated with carboplatin and paclitaxel for an endometrial carcinosarcoma. The patient demonstrated an unusual type 1 allergic reaction on carboplatin, which started with an erythematous urticarial venous pattern proximal from the venous catheter with carboplatin.

Primary maxillary sinus carcinosarcoma with multidisciplinary management: a case report with 4 years follow-up and literature review.

BACKGROUND: Primary maxillary sinus carcinosarcoma (CS) is an extremely rare malignant tumor characterized by biphasic histologic components, lack of standardized treatment, high recurrence rate, and poor prognosis. This paper presents a case of primary maxillary sinus CS and its treatment. CASE PRESENTATION: A 39-year-old female patient complained of right facial pain and maxillary teeth numbness on March 21, 2018. Computed tomography examination revealed a malignant mass with osteolytic destruction. Preoperative biopsy suggested sarcomatoid carcinoma or CS. A total right maxillectomy under general anesthesia was performed on April 12, 2018. The final staging was T3N0M0 (ACJJ 2019). Postoperative radiotherapy and chemotherapy were performed. On May 26, 2018, the patient received the first cycle of doxorubicin plus ifosfamide. Two days before radiotherapy, the patient received an intra-oral prosthesis. From June 20, 2018, to August 22, 2018, the patient received concurrent chemoradiotherapy: radiotherapy (60 Gy in 30 fractions) and the second cycle of doxorubicin. Then, the patient received four cycles of doxorubicin plus ifosfamide. The patient was followed for 39 months with no evidence of disease. CONCLUSION: Using multidisciplinary therapy, clinical-stage T3N0M0 (ACJJ 2019) maxillary sinus CS may achieve a good prognosis.

Ovarian and uterine carcinosarcomas are sensitive in vitro and in vivo to elimusertib, a novel ataxia-telangiectasia and Rad3-related (ATR) kinase inhibitor.

BACKGROUND: Carcinosarcoma of the ovary (OCS) and uterus (UCS) are rare highly aggressive malignancies. Ataxia-telangiectasia-and-Rad3-related (ATR) kinase and homologous recombination play a pivotal role in DNA damage repair. Homologous recombination deficiency (HRD) has been demonstrated in >30% of OCS/UCS. We investigated the preclinical activity of elimusertib, a selective ATR kinase inhibitor, against carcinosarcoma (CS) cell lines and xenografts. METHODS: Sensitivity to elimusertib was evaluated in vitro against nine whole exome-sequenced (WES) primary CS cell lines and in vivo against HRD CS xenografts. Western blots were performed to determine baseline ATR and p-ATR protein expression in CS, and ATR pathway downstream effectors and apoptosis markers in CS HRD cell lines after Elimusertib treatment. RESULTS: Out of the 9 CS cell lines, 3 harbored HRD and 6 homologous recombination proficient (HRP) features. Most of CS (i.e., 7/9 = 85%) were found to be sensitive to Elimusertib in vitro. Among the 5 primary CS cell lines with a high-grade pure serous epithelial component, HRD cell lines were more sensitive to elimusertib than HRP tumors (mean IC50 ± SEM HRD CS = 61.3 nM ±15.2 vs HRP = 361.6 nM ±24.4 (p = 0.01)). Baseline ATR and p-ATR protein expression was higher in HRD CS cell lines. Elimusertib showed tumor growth inhibition in HRD CS xenografts (p < 0.0001) and increased overall animal survival (p < 0.0001). Western blot demonstrated dose-dependent inhibition of ATR, p-ATR and its downstream effector p-CHK1, and a dose-dependent increase in caspase-3 expression. CONCLUSIONS: Elimusertib is preclinically active in vitro and in vivo against primary CS cell lines and xenografts, respectively. CS models harboring HRD or with pure/mixed endometrioid histology demonstrated higher sensitivity to ATR inhibition. Clinical trials with elimusertib in CS patients are warranted.

Endometrial carcinosarcoma.

Endometrial carcinosarcoma is a rare and aggressive high-grade endometrial carcinoma with secondary sarcomatous trans-differentiation (conversion theory). The clinical presentation and diagnostic work-up roughly align with those of the more common endometrioid counterpart, although endometrial carcinosarcoma is more frequently diagnosed at an advanced stage. Endometrial carcinosarcoma is not a single entity but encompasses different histological subtypes, depending on the type of carcinomatous and sarcomatous elements. The majority of endometrial carcinosarcomas are characterized by p53 abnormalities. The proportion of POLE and microsatellite instablity-high (MSI-H) is directly related to the epithelial component, being approximately 25% and 3% in endometrioid and non-endometrioid components.The management of non-metastatic disease is based on a multimodal approach with optimal surgery followed by (concomitant or sequential) chemotherapy and radiotherapy, even for early stages. Palliative chemotherapy is recommended in the metastatic or recurrent setting, with carboplatin/paclitaxel doublet being the first-line regimen. Although the introduction of immunotherapy plus/minus a tyrosine kinase inhibitor shifted the paradigm of treatment of patients with recurrent endometrial cancer, patients with endometrial carcinosarcoma were excluded from most studies evaluating single-agent immunotherapy or the combination. However, the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) approved the use of pembrolizumab and lenvatinib in endometrial cancer (all histotypes) after progression on chemotherapy and single-agent immunotherapy in MSI-H cancers. In the era of precision medicine, emerging knowledge on molecular endometrial carcinosarcoma is opening new promising therapeutic options for more personalized treatment. The present review outlines state-of-the-art knowledge and future directions for patients with endometrial carcinosarcoma.

Gastric carcinosarcoma with FGFR2 amplification under long-term control with pazopanib: a case report and literature review.

BACKGROUND: Gastric carcinosarcoma is most frequently diagnosed at an advanced stage when the tumor is generally large with invasion into other organs, lymph node metastasis, and distant metastasis. Standard chemotherapy has not been established, and surgery is the only curative treatment. Here, we present a case of postoperative recurrence of gastric carcinosarcoma under long-term tumor control with pazopanib. CASE PRESENTATION: A 77-year-old man was referred to our hospital because of nausea and vomiting. Computed tomography and upper gastrointestinal endoscopy revealed a type 1 tumor arising from the gastric antrum and extending into the duodenal bulb. He underwent distal gastrectomy (D2) with Roux-en-Y reconstruction. Histopathologically, the tumor had mixed adenocarcinoma and sarcoma components. According to the tumor-node-metastasis classification, the diagnosis was primary gastric carcinosarcoma pT1bN1M0 stage IB. Liver metastasis was detected 2 months after surgery; multiple lung metastases were detected 17 month after surgery. A genomic profiling test was performed using liver specimens as the patient became refractory to chemotherapy commonly used for gastric cancer, and the test revealed FGFR2 amplification along with TP53 R209*, AKT3 N127D, NOTCH1 A2036T, and POLD1 M161I. The patient was treated with pazopanib (800 mg/daily), and the tumor growth was controlled for 11 months. CONCLUSIONS: We report a case of postoperative recurrence of gastric carcinosarcoma under long-term tumor control with pazopanib. This case suggested that pazopanib may be effective in treating gastric carcinosarcoma.

The response of the canine mammary simple carcinoma and carcinosarcoma cells to 5-aminolaevulinic acid-based photodynamic therapy: An in vitro study.

BACKGROUNDS: Canine mammary gland tumors (CMGTs) are heterogeneous tumors and share many similar features with human breast cancer. Despite the improvement of current treatment options, new treatment modalities are required to effectively kill tumor cells without general toxicity in the treatment of CMGTs. Photodynamic therapy (PDT) is a promising method for cancer treatment. However, there is a limited study evaluating the therapeutic efficacy of PDT in the treatment of CMGTs. METHODS: In this context, we, for the first time, investigated the therapeutic potential of 5-aminolaevulinic acid (5-ALA) mediated PDT at 6 and 12 J/cm2 in two different subtypes [Tubulopapillary carcinoma (TPC) and carcinosarcoma (CS)] cells via different molecular analysis. The cytotoxic effects of 5-ALA/PDT on these cells were analyzed by intracellular PpIX level, WST-1 and ROS analysis. Furthermore, the underlying moleculer mechanism of 5-ALA/PDT mediated apoptotic effects on TPC and CS cells were evaluated Annexin V, AO/PI, RT-PCR and western blot analysis. RESULTS: The 5-ALA/PDT treatment upon irradiation considerably inhibited the viability of both TPC and CS cells (p<0.01) and caused apoptotic death through elevated ROS levels, the activation of Caspase-9, and Caspase-3, and the overexpression of Bax. However, the response of TPC and CS cells to 5-ALA/PDT was different. CONCLUSIONS: Our preliminary in vitro findings provide novel insights into the molecular mechanisms underlying 5-ALA/PDT mediated apoptosis in both TPC and CS cells. However, the therapeutic response of CMGT cells to 5-ALA/PDT is limited.

The role of multimodal adjuvant therapy for FIGO I-II carcinosarcoma of the uterus: a systematic review.

The uterine carcinosarcoma (UCS) is a rare entity with poor prognosis. Treatment of FIGO I-II UCS usually consists of surgery with or without adjuvant treatment. Due to the high metastatic potential, aggressive combined modality adjuvant treatment approaches, consisting of chemo- and radiotherapy, have been of interest. Our systematic review aims to compare survival, disease control and toxicity profiles in patients receiving adjuvant chemoradiation to other adjuvant strategies (e.g.observation, chemotherapy or radiotherapy). A total of ten studies were included for a combined cohort size of 6520 patients. Generally, the studies showed a trend towards improved disease control and survival in patients undergoing adjuvant multimodal treatment, although statistical significance was often not reached. Selection bias and non-randomized treatment allocation pose serious challenges to extrapolate these outcomes to clinical practice. We recommend additional prospective research on the role of adjuvant chemoradiation in FIGO I-II UCS.

Homologous recombination deficiency (HRD) signature-3 in ovarian and uterine carcinosarcomas correlates with preclinical sensitivity to Olaparib, a poly (adenosine diphosphate [ADP]- ribose) polymerase (PARP) inhibitor.

OBJECTIVES: Carcinosarcoma (CS) of the ovary and uterus are highly aggressive malignancies associated with poor survival. Poly(ADP-ribose)-polymerase inhibitors (PARPi) are targeted agents impairing DNA repair via homologous-recombination-deficiency (HRD) mechanisms. We used whole-exome-sequencing (WES) data from a cohort of fresh tumor samples of ovarian (OCS) and uterine carcinosarcoma (UCS), primary cell lines and xenografts to investigate the role for olaparib in CSs. METHODS: WES data from 73 CS samples (48 UCS and 25 OCS) were analyzed for HRD signatures. Olaparib activity was evaluated using cell-viability, cell-cycle, apoptosis and cytotoxicity assays against primary CS cell lines. Olaparib antitumor activity was tested in vivo against HRD CS xenografts. RESULTS: Signature-3 (i.e. HRD-related signature) was identified in 60% of OCS (15 of 25) vs 25% of UCS (12 of 48) (p = 0.005). CS cell lines harboring Signature-3/HRD (3 OCS/1 UCS) were significantly more sensitive to olaparib when compared to HRP cell lines (5 UCS/1 OCS) [mean IC50 ± SEM = 2.94 µM ± 0.07 vs mean ± SEM = 23.3 µM ± 0.09, (p = 0.02), respectively]. PARPi suppressed CS cell growth through cell cycle arrest in the G2/M phase and caused more apoptosis in HRD vs HRP primary tumors (p < 0.0001). In vivo, olaparib significantly impaired HRD CS xenografts tumor growth (p = 0.0008) and increased overall animal survival (p < 0.0001). CONCLUSIONS: OCS and UCS cell lines harboring HRD signature-3 were significantly more sensitive to olaparib in vitro and in vivo when compared to HRP CS. Clinical studies with PARPi in CS patients with a dominant signature 3 (HRD-related) are warranted.