Correlation between TXNRD1/HO-1 expression and response to neoadjuvant chemoradiation therapy in patients with esophageal squamous cell carcinoma

Background Thioredoxin reductase 1 (TXNRD1) and heme oxygenase-1 (HO-1) are both involved in the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway and play key roles in antioxidant responses. In patients with esophageal squamous cell carcinoma (ESCC), the correlation between the expression of these two proteins and the therapeutic response to neoadjuvant chemoradiation therapy (NACRT), as well as the difference in their expression after chemoradiotherapy, remains unknown. Methods Proteins involved in the Nrf2 pathway were immunolocalized in carcinoma cells in ESCC patients on NACRT with 5-fluorouracil and cisplatin, followed by esophagectomy. The 8-hydroxydeoxyguanosine (8-OHdG) levels were used to quantify reactive oxygen species. The changes in immunoreactivity before and after NACRT (Δ) were assessed. Results Tumor reduction following NACRT was significantly attenuated in pre-therapeutic biopsy specimens associated with high HO-1 status. TXNRD1Δ, HO-1Δ, and 8-OHdGΔ were significantly different in the ineffective and effective groups. The overall survival was significantly lower in high Nrf2 and TXNRD1 groups. In addition, high TXNRD1 expression was an independent prognostic factor in the multivariate analysis of overall survival. Conclusions The study findings indicate that HO-1 status in pre-therapeutic biopsy specimens could predict response to NACRT, and TXNRD1 status could predict overall survival of ESCC patients.

Comparative analysis of long-term oncologic outcomes for minimally invasive and open Ivor Lewis esophagectomy after neoadjuvant chemoradiation: a propensity score matched observational study

Background Locally advanced esophageal carcinoma is typically treated with neoadjuvant chemoradiation and esophagectomy (trimodality therapy). We compared the long-term oncologic outcomes of minimally invasive Ivor Lewis esophagectomy (M-ILE) cohort with a propensity score weighted cohort of open Ivor Lewis esophagectomy (O-ILE) cases after trimodality therapy. Methods This is a retrospective review of 223 patients diagnosed with esophageal carcinoma who underwent neoadjuvant chemoradiation followed by M-ILE or O-ILE from April 2009 to February 2019. Inverse probability of treatment weighting (IPTW) adjustment was used to balance the baseline characteristics between study groups. Kaplan–Meier survival curves were calculated for overall survival and recurrence-free survival comparing the two groups. Multivariate Cox proportional hazards regression models were used to determine predictive variables for overall and recurrence-free survival. Results The IPTW cohort included patients with esophageal carcinoma who underwent M-ILE (n = 142) or O-ILE (n = 68). The overall rate of postoperative adverse events was not significantly different after IPTW adjustment between the O-ILE and M-ILE trimodality groups (53.4% vs. 39.2%, p = 0.089). The 3-year overall survival (OS) for the M-ILE group was 59.4% (95% CI: 49.8–67.8) compared to 55.7% (95% CI: 39.2–69.4) for the O-ILE group (p = 0.670). The 3-year recurrence-free survival for the M-ILE group was 59.9% (95% CI: 50.2–68.2) compared to 61.6% (95% CI: 41.9–76.3) for the O-ILE group (p = 0.357). A complete response to neoadjuvant chemoradiation was significantly predictive of improved OS and RFS. Conclusion The overall and recurrence-free survival rates for M-ILE were not significantly different from O-ILE for esophageal carcinoma after trimodality therapy. Complete response to neoadjuvant chemoradiation was predictive of improved overall and recurrence- free survival.

Tumor microenvironment before and after chemoradiation in locally advanced rectal cancer: Beyond PD-L1

Background: In rectal cancer treatment, neoadjuvant chemoradiation therapy (CRT) is the standard of care and reduces local failure rate. The tumor microenvironment (TME) is a complex entity comprising of tumor cells, immune cells and surrounding stroma and is closely associated with tumor growth and survival, response to antitumor therapies and also resistance to antitumor therapies. The purpose of this study is to assess the change in biomarkers associated with TME following standard neoadjuvant CRT in rectal cancer. Methods: We accessed archival tissue from rectal cancer patients treated with neoadjuvant CRT at Allegheny Health Network (AHN) facilities over the past 14 years. Pre-treatment and post-treatment biopsies were assayed for PD-L1, CD8+ T-cells, CXCL9, TIM-3, IDO-1, IFN-G, IL17RE, LAG-3, and OX40 in 41 patients. Results: We found statistically significant upregulation in multiple biomarkers namely CD8, IL17RE, LAG3 and OX40 post neoadjuvant CRT and a trend towards upregulation, although not statistically significant, in biomarkers PD-L1, CXCL9, TIM-3, IDO-1 and IFN-G expression. Conclusions: This data has broad implications, not only in rectal cancer but also in other malignancies, and provides a glimpse into the TME before and after neoadjuvant CRT. We hypothesize that the biomarkers which were noted to be upregulated could be used for development of therapeutic targeted drug therapy and designing appropriate clinical trials in an effort to achieve better response to neoadjuvant therapy, increasing pathological complete response rates and improved overall outcomes.

960 Randomized multicenter study of neoadjuvant chemoradiation therapy (CRT) alone or in combination with pembrolizumab in patients with resectable or borderline resectable pancreatic cancer

BackgroundPancreatic cancer (PC) is a challenging target for immunotherapy due to its immune-suppressive microenvironment. Neoadjuvant chemoradiation (CRT) can increase the presence of tumor-infiltrating lymphocytes (TILs). We hypothesized that the combination of CRT and pembrolizumab can further expand and activate TILs.MethodsPatients with resectable or borderline resectable PC were randomized 2:1 to the investigational treatment (Arm A) of pembrolizumab 200mg IV every 3 weeks concurrently with CRT (capecitabine 825 mg/m2 orally twice daily and radiation 50.4 Gy in 28 fractions over 28 days) or CRT only (Arm B) prior to surgical resection. The primary endpoints were safety and difference in TILs density between Arm A and B assessed using multiplexed immunofluorescence on resected tumor specimens. As a correlate analysis, single cell RNA-sequencing (scRNA-seq) was performed to quantify gene expression in T cells from tumors and peripheral blood, and to track expanded T cell clonotypes in these compartments (n=4 patients Arm A; n=3 patients Arm B). The study was amended after enrollment of 37 patients to allow FOLFIRINOX prior to CRT, given changes in standard of care.Results37 patients were enrolled (24 Arm A, 13 Arm B). After neoadjuvant therapy, 13 patients had unresectable disease (9 on A, 4 on B), and 24 patients underwent surgery and were evaluable for the TILs primary endpoint (17 arm A, 7 arm B). The mean difference (A-B) in CD8+ T cell density was 36 cells/mm2 (95% CI -85 to 157, stdev 130) (p 0.48). Additional analysis did not show significant differences in activated cytotoxic T cells, regulatory T cells, M1- or M2-like polarized macrophages, or granulocytes. The median recurrence free survival (RFS) was 18.2 months on Arm A and 14.1 on Arm B (p 0.41). Overall survival was 27.8 months on Arm A and 24.3 on Arm B (p 0.68) with a median follow up of 2.2 years. The most common grade 3 treatment-related toxicities were lymphopenia reported in 29% on Arm A and 31% on Arm B, respectively followed by diarrhea in 8% on Arm A attributed to CRT. scRNA-seq revealed clonal expansion and expression of co-inhibitory markers among TIL subsets.ConclusionsThe combination of CRT and pembrolizumab is safe. Preliminary analysis shows that the addition of pembrolizumab to CRT has minimal effects on intratumoral densities of TILs and other immune cell populations. Single cell transcriptome analyses enable in-depth characterization of the functional responses of T cells to pembrolizumab in the setting of CRT.AcknowledgementsThis study was funded by MerckTrial RegistrationNCT02305186Ethics ApprovalThe study was conducted at 6 sites: University of Virginia, Dana Farber Cancer Institute, MD Anderson Cancer Center (MDACC), Mayo Clinic, Hartford Healthcare Cancer Center, and University of Miami. Written informed consent was provided by the study participants and the protocol was approved by the relevant local IRBs in each site.