Incidence and molecular characteristics of deficient mismatch repair conditions across nine different tumors and identification of germline variants involved in Lynch-like syndrome.

BACKGROUND: Based on molecular characteristics, deficient DNA mismatch repair (dMMR) solid tumors are largely divided into three categories: somatically MLH1-hypermethylated tumors, Lynch syndrome (LS)-associated tumors, and Lynch-like syndrome (LLS)-associated tumors. The incidence of each of these conditions and the corresponding pathogenic genes related to LLS remain elusive. METHODS: We identified dMMR tumors in 3609 tumors from 9 different solid organs, including colorectal cancer, gastric cancer, small-bowel cancer, endometrial cancer, ovarian cancer, upper urinary tract cancer, urinary bladder cancer, prostate cancer, and sebaceous tumor, and comprehensively summarized the characterization of dMMR tumors. Characterization of dMMR tumors were performed as loss of at least one of MMR proteins (MLH1, MSH2, MSH6, and PMS2), by immunohistochemistry, followed by MLH1 promotor methylation analysis and genetic testing for MMR genes where appropriate. Somatic variant analysis of MMR genes and whole exome sequencing (WES) were performed in patients with LLS. RESULTS: In total, the incidence of dMMR tumors was 5.9% (24/3609). The incidence of dMMR tumors and the proportion of the three categorized dMMR tumors varied considerably with different tumor types. One to three likely pathogenic/pathogenic somatic MMR gene variants were detected in 15 out of the 16 available LLS tumors. One patient each from 12 patients who gave consent to WES demonstrated non-MMR germline variants affect function (POLQ or BRCA1). CONCLUSIONS: Our data regarding the LS to LLS ratio would be useful for genetic counseling in patients who are suspected to have LS, though the genetic backgrounds for the pathogenesis of LLS need further investigation.

Prevention of symptomatic pulmonary embolism for gynecologic malignancies with preoperative asymptomatic venous thromboembolism: GOTIC-VTE trial.

OBJECTIVE: In Japan, perioperative prophylaxis of pulmonary embolism (PE) in gynecologic cancer patients with preoperative asymptomatic venous thromboembolism (VTE) has not been well established yet. The GOTIC-VTE trial was a prospective, multi-center, single-arm clinical trial to investigate the prevention of postoperative symptomatic PE onset by seamless anticoagulant therapy from the preoperative period to 4 weeks after surgery instead of using intermittent pneumatic compression. METHODS: Anticoagulant therapy was started immediately after asymptomatic VTE diagnosis and stopped preoperatively according to the rules of each institution. Unfractionated heparin administration was resumed within 12 hours postoperatively, and this was followed by the switch to low-molecular-weight heparin and subsequently, edoxaban; this cycle was continued for 28 days. Primary outcome was the occurrence of symptomatic PE in 28 days postoperatively. Secondary outcomes were the incidence of VTE-related events in 28 days and 6 months postoperatively and protocol-related adverse events. RESULTS: Between February 2018 and September 2020, 99 patients were enrolled; of these, 82 patients were assessed as the full analysis set, including 58 for ovarian cancer, fallopian tube, or peritoneal cancer; 21 for endometrial cancer; and 3 for cervical cancer. No symptomatic PE was observed within 28 days postoperatively; two patients had bleeding events (major bleeding and clinically relevant nonmajor bleeding) and three had grade 3 adverse events (increased alanine transaminase, aspartate aminotransferase, or gamma-glutamyl transferase). CONCLUSION: The multifaceted perioperative management for gynecologic malignancies with asymptomatic VTE effectively prevented postoperative symptomatic PE. TRIAL REGISTRATION: JRCT Identifier: jRCTs031180124.

Intraperitoneal Carboplatin for Ovarian Cancer - A Phase 2/3 Trial.

BACKGROUND: Intraperitoneal chemotherapy has been shown to be effective at reducing mortality for patients with advanced epithelial ovarian cancer but is not widely used in practice. METHODS: We performed the Intraperitoneal Therapy for Ovarian Cancer with Carboplatin (iPocc) trial as an open-label, international, multi-institutional, randomized phase 2/3 clinical trial in women with newly diagnosed epithelial ovarian cancer who underwent laparotomy or laparoscopy. All patients received intravenous paclitaxel (80 mg/m2 on days 1, 8, and 15 of a 21-day cycle). In addition, patients in the control group received intravenous carboplatin (dose-dense intravenous paclitaxel plus intravenous carboplatin [dd-TCiv]), whereas patients in the experimental group received dose-dense intravenous paclitaxel plus intraperitoneal carboplatin (dd-TCip). The primary end point was progression-free survival (PFS). Secondary end points included overall survival, tumor response, treatment completion rate, and incidence of adverse events (AEs). RESULTS: Among 655 patients randomized to treatment, median (95% confidence interval [CI]) PFS was 20.7 (18.1 to 22.8) months for dd-TCiv (n=328) and 23.5 (20.5 to 26.9) months for dd-TCip (n=327; hazard ratio, 0.83; 95% CI, 0.69 to 0.99; P=0.04). The PFS benefit with dd-TCip was consistent in patients with different baseline characteristics, stage, size of residual tumor, age, and performance status. The treatment completion rates were 68.3 and 59.9% in the dd-TCiv and dd-TCip groups, respectively. The incidence of intraperitoneal catheter-related AEs in the dd-TCip group was 10.1%; there were no such AEs in the dd-TCiv group. CONCLUSIONS: In the first-line treatment of advanced epithelial ovarian cancer, intraperitoneal carboplatin resulted in a modest prolongation of PFS when given with dose-dense weekly paclitaxel regardless of residual tumor size, with no impact on noncatheter-related toxicities. (Funded by the Japan Agency for Medical Research and Development, and others; Japan Registry of Clinical Trials number, jRCTs031180141.)