Mismatch Repair Deficiency in Biliary Tract Cancer: Prognostic Implications and Correlation with Histology.

INTRODUCTION: Mismatch repair (MMR) deficiency represents a biomarker and therapeutic target in various neoplasms, but its role in biliary tract cancers (BTCs) remains misunderstood. METHODS: MMR status was retrospectively assessed using immunohistochemistry in 163-BTCs patients. We identified MMR proficiency (pMMR)/deficiency (dMMR) according to the loss of MMR proteins (MLH1, PMS2, MSH2, MSH6). The primary objective of the study was to assess the incidence of dMMR in BTCs; the secondary purpose was to explore its association with prognosis and clinical features. RESULTS: dMMR was recorded in 9 patients, and it was strongly associated with mucinous histology (p < 0.01). Regarding the prognostic effect, in 122-radically resected patients, disease-free survival (DFS) resulted significantly shorter in dMMR patients compared to pMMR patients (10.7 vs. 31.3 months, p = 0.025) and so did nodal status (48.2 vs. 15.3 months in N0 vs. N+) (p < 0.01). Moreover, dMMR confirmed its prognostic role in terms of DFS at multivariate analysis (p = 0.03), together with nodal status (p = 0.01), and resection margin (p = 0.03). In 103 M+ patients (encompassing 41 metastatic de novo and 62 recurred after surgery patients) there were not differences between dMMR and pMMR regarding survival analyses. CONCLUSIONS: dMMR status is strongly correlated with mucinous histology and represents an independent prognostic factor in terms of disease relapse in patients with resected BTC. IMPLICATIONS FOR PRACTICE: MMR may play an independent role in promoting an aggressive behaviour in patients with radically resected BTC. These results could be useful in improving the selection of patients after resection and, above all, should justify the evaluation of MMR status as a therapeutic target in BTC, especially in patients with atypical histology.

Efficacy and Safety of Chemotherapy after Immunotherapy in Patients with Advanced Non-Small-Cell Lung Cancer.

Background: There are currently few data about the safety and effectiveness of chemotherapy for patients with metastatic non-small-cell lung cancer (NSCLC) who have progressed from prior immunotherapy. Methods: Data from patients with consecutive stage IIIB-IV, ECOG performance status (PS) 0-2, non-small-cell lung cancer (NSCLC) treated with combination or single-agent chemotherapy following progression on an earlier immunotherapy regimen were retrospectively gathered. Recorded were baseline attributes, outcome metrics, and toxicities. The neutrophil/lymphocyte (N/L) ratio's predictive usefulness was examined through an exploratory analysis. Results: The analysis comprised one hundred subjects. The adeno/squamous carcinoma ratio was 77%/23%, the M/F ratio was 66%/34%, the ECOG PS was 0/1/≥2 47%/51%/2%, and the median PD-L1 expression was 50% (range 0-100). The median age was 67 (range 39-81) years. Prior immunotherapy included a single-agent treatment in 83% of cases, with pembrolizumab use being prevalent, and a median N/L ratio of four prior to chemotherapy. The overall median time-to-progression on previous immunotherapy was 6 months. After immunotherapy, just 33% of subjects underwent chemotherapy. A median of 4 (range 1-16) cycles of chemotherapy were administered; platinum doublets (primarily carboplatin) were delivered in only 31% of cases, vinorelbine accounted for 25%, taxanes for 25%, and gemcitabine for 8%. The median clinical benefit was 55%, while the overall response rate was 21%. The median overall survival was 5 months (range 1-22) and the median time to progression was 4 months (range 1-17). Subgroups with low and high N/L ratios were compared, but there was no discernible difference in survival. Conclusions: After immunotherapy, a small percentage of patients with advanced NSCLC had chemotherapy. Following immunotherapy advancement, chemotherapy demonstrated a moderate level of therapeutic effectiveness; no adverse concerns were noted. The effectiveness of chemotherapy following immunotherapy was not predicted by the baseline N/L ratio.

Primary Resistance to Immunotherapy-Based Regimens in First Line Hepatocellular Carcinoma: Perspectives on Jumping the Hurdle.

Immune checkpoint inhibitors (ICIs) are a key component of different stages of hepatocellular carcinoma (HCC) treatment, particularly in the first line of treatment. A lesson on the primary resistance which hampers their efficacy and activity was learned from the failure of the trials which tested them as first-line mono-therapies. Despite the combination of anti-PD(L)1 agents with anti-VEGF, anti CTLA4, or TKIs demonstrating relevant improvements in efficacy, the "doublets strategy" still shows room for improvement, due to a limited overall survival benefit and a high rate of progressive disease as best response. In this review, we discuss the results from the currently tested doublet strategies (i.e., atezolizumab+bevacizumab, durvalumab+tremelimumab with a mention to the newly presented ICIs/TKIs combinations), which highlight the need for therapeutic improvement. Furthermore, we examine the rationale and provide an overview of the ongoing trials testing the treatment intensification strategy with triplet drugs: anti-PD1+anti-CTLA4+anti-VEGF/TKIs and anti-PD1+anti-VEGF+alternative immunity targets. Lastly, we report on the alternative strategy to integrate ICIs into the new paradigm of immune therapeutics constituted by CAR-T and anti-cancer vaccines. This review provides up-to-date knowledge of ongoing clinical trials of the aforementioned strategies and critical insight into their mechanistic premises.