Differential Responses to Immune Checkpoint Inhibitors are Governed by Diverse Mismatch Repair Gene Alterations.

PURPOSE: The response to immune checkpoint inhibitors (ICI) in deficient mismatch repair (dMMR) colorectal cancer and endometrial cancer is variable. Here, we explored the differential response to ICIs according to different mismatch repair alterations. EXPERIMENTAL DESIGN: Colorectal cancer (N = 13,701) and endometrial cancer (N = 3,315) specimens were tested at Caris Life Sciences. Median overall survival (mOS) was estimated using Kaplan-Meier. The prediction of high-, intermediate-, and low-affinity epitopes by tumor mutation burden (TMB) values was conducted using R-squared (R2). RESULTS: Compared with mutL (MLH1 and PMS2) co-loss, the mOS was longer in mutS (MSH2 and MSH6) co-loss in all colorectal cancer (54.6 vs. 36 months; P = 0.0.025) and endometrial cancer (81.5 vs. 48.2 months; P < 0.001) patients. In ICI-treated patients, the mOS was longer in mutS co-loss in colorectal cancer [not reached (NR) vs. 36 months; P = 0.011). In endometrial cancer, the mOS was NR vs. 42.2 months; P = 0.711]. The neoantigen load (NAL) in mutS co-loss compared with mutL co-loss was higher in colorectal cancer (high-affinity epitopes: 25.5 vs. 19; q = 0.017, intermediate: 39 vs. 32; q = 0.004, low: 87.5 vs. 73; q < 0.001) and endometrial cancer (high-affinity epitopes: 15 vs. 11; q = 0.002, intermediate: 27.5 vs. 19; q < 0.001, low: 59 vs. 41; q < 0.001), respectively. R2 ranged from 0.25 in mutS co-loss colorectal cancer to 0.95 in mutL co-loss endometrial cancer. CONCLUSIONS: Patients with mutS co-loss experienced longer mOS in colorectal cancer and endometrial cancer and better response to ICIs in colorectal cancer. Among all explored biomarkers, NAL was higher in mutS co-loss and may be a potential driving factor for the observed better outcomes. TMB did not reliably predict NAL.

Inpatient management of hypercalcemia portends a poor prognosis among gynecologic oncology patients: A trigger to initiate hospice care?

We aim to describe survival outcomes of gynecologic oncology inpatients treated with intravenous bisphosphonates for hypercalcemia and develop a risk stratification model that predicts decreased survival to aid with goals of care discussion. In a single-center, retrospective cohort study of gynecologic oncology patients admitted for bisphosphonate therapy for hypercalcemia. Survival from hypercalcemia to death was assessed by Kaplan-Meier method and log-rank test. Univariate log-rank test and Cox proportional hazards modeling were used to develop a risk stratification model. Sixty-five patients were evaluable with a median follow-up of 83.5 months. Mean age was 59.2 years, 64.6% had recurrent disease, and 30.8% had ≥2 previous lines of chemotherapy. Median survival was 38 days. Our analysis identified four risk factors (RFs) [brain metastasis, >1 site of metastasis, serum corrected peak calcium >12.4 (mg/dL), and peak ionized calcium >5.97 (mg/dL)] that predicted survival and were used to build a risk stratification score. Sum of RFs included 35 patients with 1 RF, 11 had 2 RFs, and 19 had ≥3 RF. Median survival for 1, 2, or ≥ 3 RFs was 53, 28, and 26 days respectively (p = .009). Survival at 6 months was 28.6%, 18.2%, and 5.3% for each group respectively. Hospice enrollment was 26.2%, and did not vary by group (p = .51). Among gynecologic oncology patients, inpatient management of hypercalcemia with bisphosphonates portends poor prognosis. Individualized risk stratification may help guide end-of-life discussions and identify patients who may benefit most from hospice care.