Trends in the Incidence and Survival Rates of Primary Ovarian Clear Cell Carcinoma Compared to Ovarian Serous Carcinoma in Korea

Changes in the tumor immune microenvironment during disease progression in clear cell ovarian cancer

OBJECTIVE

The tumor immune microenvironment in ovarian clear cell carcinoma has not been clearly defined. We analyzed the immunological changes from treatment-naive to recurrence to correlate them with clinical outcomes.

METHOD

We compared the changes in immune infiltration of advanced-stage ovarian clear cell carcinoma samples before treatment and at the time of recurrence via immunohistochemistry (Programmed Cell Death-ligand 1 (PD-L1), cluster of differentiation 8 (CD8+), forkhead box P3 (Foxp3+)), tumor-infiltrating lymphocytes (TIL), and next-generation sequencing (54 patients). We analyzed the association between platinum sensitivity status and tumor immune microenvironment.

RESULTS

Immunohistochemistry revealed significantly increased PD-L1 (p=0.048) and CD8+T cells (p=0.022) expression levels after recurrence. No significant differences were observed in TIL density or Foxp3+T cells. There was no significant correlation between TIL, PD-L1, CD8+T cell, and Foxp3+T cell levels in treatment-naive tumors and survival outcomes. The most common genomic alterations were PIK3CA (41.7%) and ARID1A (41.7%) mutations. There were no differences in the immunological changes or survival outcomes according to PIK3CA and ARID1A mutations. Patients with recurrent platinum-sensitive disease showed higher TIL expression levels. There were no significant differences in PD-L1, CD8+T cells, or Foxp3+T cells between platinum-sensitive and platinum-resistant diseases.

CONCLUSION

We characterized the tumor immune microenvironment in patients with advanced-stage ovarian clear cell carcinoma. PD-L1 and CD8+T cell expression significantly increased after recurrence. Whether this could be used to select patients for immunotherapy in the recurrence setting should be investigated.

Aberrant SWI/SNF Complex Members Are Predominant in Rare Ovarian Malignancies-Therapeutic Vulnerabilities in Treatment-Resistant Subtypes

SWI/SNF (SWItch/Sucrose Non-Fermentable) is the most frequently mutated chromatin-remodelling complex in human malignancy, with over 20% of tumours having a mutation in a SWI/SNF complex member. Mutations in specific SWI/SNF complex members are characteristic of rare chemoresistant ovarian cancer histopathological subtypes. Somatic mutations in ARID1A, encoding one of the mutually exclusive DNA-binding subunits of SWI/SNF, occur in 42-67% of ovarian clear cell carcinomas (OCCC). The concomitant somatic or germline mutation and epigenetic silencing of the mutually exclusive ATPase subunits SMARCA4 and SMARCA2, respectively, occurs in Small cell carcinoma of the ovary, hypercalcaemic type (SCCOHT), with SMARCA4 mutation reported in 69-100% of SCCOHT cases and SMARCA2 silencing seen 86-100% of the time. Somatic ARID1A mutations also occur in endometrioid ovarian cancer (EnOC), as well as in the chronic benign condition endometriosis, possibly as precursors to the development of the endometriosis-associated cancers OCCC and EnOC. Mutation of the ARID1A paralogue ARID1B can also occur in both OCCC and SCCOHT. Mutations in other SWI/SNF complex members, including SMARCA2, SMARCB1 and SMARCC1, occur rarely in either OCCC or SCCOHT. Abrogated SWI/SNF raises opportunities for pharmacological inhibition, including the use of DNA damage repair inhibitors, kinase and epigenetic inhibitors, as well as immune checkpoint blockade.

A first-in-human phase I study of TAS-117, an allosteric AKT inhibitor, in patients with advanced solid tumors

PURPOSE

TAS-117 is a highly potent and selective, oral, allosteric pan-AKT inhibitor under development for advanced/metastatic solid tumors. The safety, clinical pharmacology, pharmacogenomics and efficacy were investigated.

METHODS

This phase I, open-label, non-randomized, dose-escalating, first-in-human study enrolled patients with advanced/metastatic solid tumors and comprised three phases (dose escalation phase [DEP], regimen modification phase [RMP], and safety assessment phase [SAP]). The SAP dose and regimen were determined in the DEP and RMP. Once-daily and intermittent dosing (4 days on/3 days off, 21-day cycles) were investigated. The primary endpoints were dose-limiting toxicities (DLTs) in Cycle 1 of the DEP and RMP and incidences of adverse events (AEs) and adverse drug reactions (ADRs) in the SAP. Secondary endpoints included pharmacokinetics, pharmacodynamics, pharmacogenomics, and antitumor activity.

RESULTS

Of 66 enrolled patients, 65 received TAS-117 (DEP, n = 12; RMP, n = 10; SAP, n = 43). No DLTs were reported with 24-mg/day intermittent dosing, which was selected as a recommended dose in SAP. In the SAP, 98.5% of patients experienced both AEs and ADRs (grade ≥ 3, 67.7% and 60.0%, respectively). In the dose range tested (8 to 32 mg/day), TAS-117 pharmacokinetics were dose proportional, and pharmacodynamic analysis showed a reduction of phosphorylated PRAS40, a direct substrate of AKT. Four patients in the SAP had confirmed partial response.

CONCLUSION

Oral doses of TAS-117 once daily up to 16 mg/day and intermittent dosing of 24 mg/day were well tolerated. TAS-117 pharmacokinetics were dose proportional at the doses evaluated. Antitumor activity may occur through AKT inhibition.

TRIAL REGISTRATION

jRCT2080222728 (January 29, 2015).

Exploration and prognostic analysis of two types of high-risk ovarian cancers: clear cell vs. serous carcinoma: a population-based study

BACKGROUND

Ovarian clear cell carcinoma (OCCC) is a rare pathological histotype in ovarian cancer, while the survival rate of advanced OCCC (Stage III-IV) is substantially lower than that of the advanced serous ovarian cancer (OSC), which is the most common histotype. The goal of this study was to identify high-risk OCCC by comparing OSC and OCCC, with investigating potential risk and prognosis markers.

METHODS

Patients diagnosed with ovarian cancer from 2009 to 2018 were identified from the Surveillance, Epidemiology, and End Results (SEER) Program. Logistic and Cox regression models were used to identify risk and prognostic factors in high-risk OCCC patients. Cancer-specific survival (CSS) and overall survival (OS) were assessed using Kaplan-Meier curves. Furthermore, Cox analysis was employed to build a nomogram model. The performance evaluation results were displayed using the C-index, calibration plots, receiver operating characteristic (ROC) curve, and decision curve analysis (DCA). Immunohistochemically approach was used to identify the expression of the novel target (GPC3).

RESULTS

In the Cox analysis for advanced OCCC, age (45-65 years), tumor numbers (total number of in situ/malignant tumors for patient), T3-stage, bilateral tumors, and liver metastases could be defined as prognostic variables. Nomogram showed good predictive power and clinical practicality. Compared with OSC, liver metastases had a stronger impact on the prognosis of patients with OCCC. T3-stage, positive distant lymph nodes metastases, and lung metastases were risk factors for developing liver metastases. Chemotherapy was an independent prognostic factor for patient with advanced OCCC, but had no effect on CSS in patients with liver metastases (p = 0.0656), while surgery was significantly related with better CSS in these patients (p < 0.0001) (p = 0.0041). GPC3 expression was detected in all tissue sections, and GPC3 staining was predominantly found in the cytoplasm and membranes.

CONCLUSION

Advanced OCCC and OCCC with liver metastases are two types of high-risk OCCC. The constructed nomogram exhibited a satisfactory survival prediction for patients with advanced OCCC. GPC3 immunohistochemistry is expected to accumulate preclinical evidence to support the inclusion of GPC3 in OCCC targeted therapy.

Impact of bevacizumab and secondary cytoreductive surgery on survival outcomes in platinum-sensitive relapsed ovarian clear cell carcinoma: A multicenter study in Korea

OBJECTIVE

This study investigated survival outcomes for platinum-sensitive relapsed ovarian clear cell carcinoma (OCCC) by treatment method.

METHODS

OCCC patients with platinum-sensitive recurrence that received secondary treatment at five institutions between July 2007 and June 2021 were included. Patient characteristics and survival outcomes were compared according to the use of bevacizumab (BEV) during second-line chemotherapy and secondary cytoreductive surgery (CRS).

RESULTS

138 patients were included. The BEV (n = 36) and non-BEV (n = 102) groups had similar initial FIGO stages and proportions of secondary CRS. The BEV group showed improved progression-free survival (PFS; median, 15.4 vs. 7.5 months; P = 0.042) and overall survival (OS; P = 0.043) compared to the non-BEV group. In multivariate analyses, BEV was identified as an independent prognostic factor for PFS (adjusted hazard ratio [aHR], 0.571; 95% confidence interval [CI], 0.354-0.921; P = 0.022) and OS (aHR, 0.435; 95%CI, 0.195-0.970; P = 0.042). The secondary CRS group (n = 42) had early-stage disease at diagnosis more frequently (P = 0.009) and multi-site metastasis (P < 0.001) at recurrence less frequently than the no surgery group (n = 96). The secondary CRS group showed significantly better PFS (median, 33.7 vs. 7.2 months; P < 0.001) and OS (P < 0.001). Secondary CRS was associated with a significantly improved PFS (aHR, 0.297; 95% CI, 0.183-0.481; P < 0.001) and OS (aHR, 0.276; 95% CI, 0.133-0.576; P = 0.001). The BEV and non-BEV groups showed similar PFS and OS among the patients who underwent secondary CRS. In contrast, the BEV group showed improved PFS and OS among patients who did not undergo surgery.

CONCLUSIONS

The use of BEV during second-line chemotherapy and secondary CRS may improve PFS and OS in patients with platinum-sensitive relapsed OCCC. Further prospective studies are warranted.