Circulating tumor DNA in patients with locally advanced rectal cancer treated with multimodal treatment.

Background: The management of locally advanced rectal cancer (LARC) relies on a multimodal approach. Neither instrumental work-up nor molecular biomarkers are currently available to identify a risk-adapted strategy. Objectives: We aim to investigate the role of circulating tumor DNA (ctDNA) and its clearance at different timepoints during chemo-radiotherapy (CRT) and correlate them with clinical outcomes. Design: Between November 2014 and November 2019, we conducted a monocentric prospective observational study enrolling consecutive patients with LARC managed with neoadjuvant standard CRT (capecitabine and concomitant pelvic long-course radiotherapy), followed by consolidation capecitabine in selected cases and surgery. Methods: Blood samples for ctDNA were obtained at pre-planned timepoints. We evaluated the correlation of baseline variant allele frequency (VAF) with pathologic complete response (pCR) down-staging, node regression (pN0), event-free survival (EFS), and overall survival (OS). Results: Among 112 screened patients, 61 were enrolled. In all, 38 (62%) had a positive ctDNA at baseline with VAF > 0 and 23 had negative ctDNA (VAF = 0). Among patients with negative ctDNA, 30% had a complete response, while only 13% of positive ctDNA patients had pCR [odds ratio (OR) 0.35 (95% confidence interval (CI): 0.10-1.26), p = 0.11]. Similarly, 96% and 74% of pN0 were observed among negative and positive ctDNA patients, respectively [OR 0.13 (95% CI: 0.02-1.07), p = 0.058]. The presence of a baseline VAF > 0 was associated with a trend toward a lower EFS compared with VAF = 0 patients [hazard ratio (HR) = 2.30, 95% CI: 0.63-8.36, p = 0.21]. Within the limitations of small sample size, no difference in OS was observed according to the baseline ctDNA status (HR = 1.18, 95% CI: 0.35-4.06, p = 0.79). Conclusion: Within the limitations of a reduced number of patients, patients with baseline negative ctDNA seem to show a higher probability of pN0 status and a trend toward improved EFS. Prospective translational studies are required to define the role of ctDNA analysis in the multimodal treatment of LARC.

Immunotherapy in the neoadjuvant treatment of gastrointestinal tumors: is the time ripe?

Immune checkpoint inhibitors (ICIs) revolutionized the management of mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) gastrointestinal (GI) cancers. Based on notable results observed in the metastatic setting, several clinical trials investigated ICIs as neoadjuvant treatment (NAT) for localized dMMR/MSI-H GI cancers, achieving striking results in terms of clinical and pathological responses and creating the opportunity to spare patients from neoadjuvant chemotherapy and/or radiotherapy and even surgical resection. Nevertheless, these impressive findings are mainly derived from small proof of concept phase II studies and there are still several open questions to address. Moreover, dMMR/MSI-H represents a limited subgroup accounting for less than 10% of GI cancers. Consequently, many efforts have been produced to investigate neoadjuvant ICIs also in mismatch repair-proficient/microsatellite stable (MSS) cancers, considering the potential synergistic effect in combining immune-targeted agents with standard therapies such as chemo and/or radiotherapy. However, results for combining ICIs to the standard of care in the unselected population are still unsatisfactory, without improvements in event-free survival in esophago-gastric adenocarcinoma for the addition of pembrolizumab to chemotherapy, and sometimes limited benefit in patients with locally advanced rectal cancer. Therefore, a major challenge will be to identify among the heterogenous spectrum of this disease, those patients that could take advantage of neoadjuvant immunotherapy and deliver the most effective treatment. In this review we discuss the rationale of NAT in GI malignancies, summarize the available evidence regarding the completed trials that evaluated this treatment strategy in both MSI-H and MSS tumors. Finally, we discuss ongoing studies and future perspectives to render neoadjuvant immunotherapy another arrow in the quiver for the treatment of locally advanced GI tumors.

Anti-EGFR Rechallenge in Patients With Refractory ctDNA RAS/BRAF wt Metastatic Colorectal Cancer: A Nonrandomized Controlled Trial.

Importance: The available evidence regarding anti-epidermal growth factor receptor (EGFR) inhibitor rechallenge in patients with refractory circulating tumor DNA (ctDNA) RAS/BRAF wild-type (wt) metastatic colorectal cancer (mCRC) is derived from small retrospective and prospective studies. Objective: To evaluate the efficacy of anti-EGFR rechallenge in patients with refractory ctDNA RAS/BRAF wt mCRC. Design, Setting, and Participants: This nonrandomized controlled trial used a pooled analysis of individual patient data from patients with RAS/BRAF wt ctDNA mCRC enrolled in 4 Italian trials (CAVE, VELO, CRICKET, and CHRONOS) and treated with anti-EGFR rechallenge between 2015 and 2022 (median [IQR] follow-up, 28.1 [25.8-35.0] months). Intervention: Patients received anti-EGFR rechallenge therapy, including cetuximab plus avelumab, trifluridine-tipiracil plus panitumumab, irinotecan plus cetuximab, or panitumumab monotherapy. Main Outcomes and Measures: Overall survival (OS), progression-free survival (PFS), overall response rate (ORR), and disease control rate (DCR) were calculated. Exploratory subgroup analysis evaluating several clinical variables was performed. Safety was reported. Results: Overall, 114 patients with RAS/BRAF wt ctDNA mCRC (median [IQR] age, 61 [29-88] years; 66 men [57.9%]) who received anti-EGFR rechallenge as experimental therapy (48 received cetuximab plus avelumab, 26 received trifluridine-tipiracil plus panitumumab, 13 received irinotecan plus cetuximab, and 27 received panitumumab monotherapy) were included in the current analysis. Eighty-three patients (72.8%) had received 2 previous lines of therapy, and 31 patients (27.2%) had received 3 or more previous lines of therapy. The ORR was 17.5% (20 patients), and the DCR was 72.3% (82 patients). The median PFS was 4.0 months (95% CI, 3.2-4.7 months), and the median OS was 13.1 months (95% CI, 9.5-16.7 months). The subgroup of patients without liver involvement had better clinical outcomes. The median PFS was 5.7 months (95% CI, 4.8-6.7 months) in patients without liver metastasis compared with 3.6 months (95% CI, 3.3-3.9 months) in patients with liver metastasis (hazard ratio, 0.56; 95% CI, 0.37-0.83; P = .004). The median OS was 17.7 months (95% CI, 13-22.4 months) in patients without liver metastasis compared with 11.5 months (95% CI, 9.3-13.9 months) in patients with liver metastasis (hazard ratio, 0.63; 95% CI, 0.41-0.97; P = .04). Treatments showed manageable toxic effects. Conclusions and Relevance: These findings suggest that anti-EGFR rechallenge therapy has promising antitumor activity in patients with refractory ctDNA RAS/BRAF wt mCRC. Within the limitation of a subgroup analysis, the absence of liver metastases was associated with significant improved survival. Trial Registration: ClinicalTrials.gov Identifiers: NCT02296203; NCT04561336; NCT03227926; NCT05468892.

The role of anti-EGFR rechallenge in metastatic colorectal cancer, from available data to future developments: A systematic review.

Despite recent molecular and immunological advancements, prognosis of metastatic colorectal cancer (mCRC) patients remains poor. In this context, several retrospective and phase II studies suggested that after failure of an upfront anti-EGFR based regimen, a subset of patients can still benefit from further anti-EGFR blockade. Several translational studies involving circulating tumor DNA (ctDNA) analysis demonstrated that cancer clones harboring mutations driving anti-EGFR resistance, which can arise under anti-EGFR agents selective pressure, often decay after anti-EGFR discontinuation potentially restoring sensitivity to this therapeutic strategy. Accordingly, several retrospective analyses and a recent prospective trial demonstrated that ctDNA RAS and BRAF wild-type mCRC patients are those benefitting the most from anti-EGFR rechallenge. Indeed, in molecularly selected patients, anti-EGFR rechallenge strategy achieved up to 30 % response rate, with a progression free survival longer than 4 months and an overall survival longer than 1 year, which favorably compared with other standard therapeutic options available for heavily pretreated patients. Anti-EGFR is also well tolerated with no unexpected toxicities compared to the upfront setting. However, several open questions remain to be addressed towards a broader applicability of anti-EGFR strategy in the everyday clinical practice such as the identification of the best rechallenge regimen, the right placement in mCRC therapeutic algorithm, the best ctDNA screening panel. In our systematic review, we revised available data from clinical trials assessing anti-EGFR rechallenge activity in chemo-refractory mCRC patients, discussing as well potential future scenarios and development to implement this therapeutic approach. Particularly, we discussed the role of ctDNA as a safe, timely and comprehensive tool to refine patient's selection and the therapeutic index of anti-EGFR rechallenge.

Immune-checkpoint inhibitors in anal squamous cell carcinoma: a systematic review and meta-analysis.

INTRODUCTION: Squamous cell carcinoma of the anus (SCCA) is a rare tumor. While most patients with locally advanced disease are cured with chemo-radiotherapy, about a quarter eventually experience metastatic recurrence. Standard treatment for advanced disease is chemotherapy, but recently evidence on the activity of immunotherapy has been reported. We performed a systematic review and meta-analysis of prospective trials testing immune-checkpoint inhibitors (ICIs) in patients with SCCA. OBJECTIVE: We aimed to evaluate the overall response rate (ORR) and the disease control rate (DCR) of ICIs in patients with advanced SCCA. METHODS: We systematically searched PubMed, Embase, and Scopus, through December 31, 2022, for prospective trials assessing ICIs in patients with advanced SCCA. The primary and secondary endpoints were respectively ORR and DCR. RESULTS: Six prospective trials were included in the analysis, one of which was randomized. Overall, seven treatment arms and 347 patients have been analyzed. Five treatment arms tested ICIs as monotherapy and two arms examined ICIs in combination with cetuximab and bevacizumab, respectively. The pooled ORR was 13% (95%CI, 10%-17%), with a DCR of 57% (95%CI, 40%-74%). Results did not change in a sensitivity analysis, which excluded the two treatment arms testing the combination of ICIs with other drugs. CONCLUSIONS: The efficacy of ICIs in SCCAs is low. Combination strategies with targeted drugs or chemotherapy might represent a better therapeutic strategy for these patients. Further studies are awaited to identify resistance mechanisms to ICIs and optimize their efficacy.

Tumour-specific mesorectal excision for rectal cancer: Systematic review and meta-analysis of oncological and functional outcomes.

BACKGROUND: Tumour-specific mesorectal excision (TSME) practice for rectal cancer only relies on small retrospective studies. This study aimed to perform a systematic review and meta-analysis to assess the oncological and functional outcomes of TSME practice. METHODS: A systematic review protocol was drawn to include all the studies that compared partial versus total mesorectal excision (PME vs TME) practised for rectal adenocarcinoma up to 16 cm from the anal verge. A systematic literature search was conducted on EMBASE-Medline, Pubmed and Cochrane Library. Reports were screened for the study's outcomes: oncological radicality, postoperative anastomotic leak risk and functional outcomes. Included studies were appraised for risk-of-bias and meta-analysed. Evidence was rated with the GRADE approach. RESULTS: Twenty-seven studies were included, consisting of 12325 patients (PME n = 4460, 36.2%; TME n = 7865, 63.8%). PME was performed for tumours higher than 10 cm from the anal verge in 54.5% of patients. There was no difference between PME and TME in circumferential resection margin positivity (OR 1.31, 95%CI 0.43-3.95, p = 0.64; I2 = 38%), and local recurrence risk (HR 1.05, 95%CI 0.52-2.10, p = 0.90; I2 = 40%). The postoperative leak risk (OR 0.42, 95%CI 0.27-0.67, p < 0.001; I2 = 60%) and the major low anterior resection syndrome risk (OR 0.34, 95%CI 0.28-0.40, p < 0.001; I2 = 0%) were lower after PME surgery. No difference was found in urinary incontinence (OR 0.68, 95%CI 0.13-3.67, p = 0.66) and urinary retention after early catheter removal (OR 2.00, 95%CI 0.24-16.51, p = 0.52). CONCLUSIONS: Evidence from this meta-analysis shows that TSME for rectal cancer has good oncological results and leads to the best-fitted functional results possible for the patient's condition.

Panitumumab plus trifluridine/tipiracil as anti-EGFR rechallenge therapy in patients with refractory RAS wild-type metastatic colorectal cancer: Overall survival and subgroup analysis of the randomized phase II VELO trial.

The randomized phase II VELO trial showed that the addition of panitumumab to trifluridine/tipiracil significantly improves progression-free survival (PFS) as compared to trifluridine/tipiracil in third-line therapy in patients with refractory RAS wild-type (WT) metastatic colorectal cancer (mCRC). With longer follow-up, final overall survival results and posttreatment subgroup analysis are presented. Sixty-two patients with refractory RAS WT mCRC were randomly assigned to receive, as third-line therapy, trifluridine/tipiracil alone (arm A) or in combination with panitumumab (arm B). Primary endpoint was PFS; secondary endpoints included overall survival (OS) and overall response rate (ORR). Median OS was 13.1 months (95% CI 9.5-16.7) in arm A compared to 11.6 months (95% CI 6.3-17.0) in arm B (HR: 0.96, 95% CI 0.54-1.71, P = .9). To evaluate the impact of subsequent lines of treatment, subgroup analysis was performed for the 24/30 patients in arm A, that received fourth-line therapy after disease progression. Median PFS was 4.1 months (95% CI 1.44-6.83) for 17 patients treated with anti-EGFR rechallenge as compared to 3.0 months (95% CI 1.61-4.31) for seven patients that received other therapies (HR: 0.29, 95% CI 0.10-0.85, P = .024). Median OS from the start of fourth-line treatment was 13.6 months (95% CI 7.2-20), and 5.1 months (95% CI 1.8-8.3) for patients treated with anti-EGFR rechallenge vs other therapies, respectively (HR: 0.30, 95% CI 0.11-0.81, P = .019). Final results of the VELO trial support the role of anti-EGFR rechallenge in the continuum of care of patients with RAS/BRAF WT mCRC.

Vitamin D Supplementation and Adherence to World Cancer Research Fund (WCRF) Diet Recommendations for Colorectal Cancer Prevention: A Nested Prospective Cohort Study of a Phase II Randomized Trial.

Vitamin D and a healthy diet, based on World Cancer Research Fund (WCRF) recommendations, are considered key elements for colorectal cancer (CRC) prevention. In a CRC case-control study, we observed that CRC cases were often significantly Vitamin D deficient while subjects following WCRF recommendations significantly decreased their risk of developing CRC. We conducted a randomized phase-II trial (EudraCT number-2015-000467-14) where 74 CRC patients showed differences in response to Vitamin D supplementation, 2000 IU in average per day, according to gender and microbiota. The aim of this nested study is to correlate Vitamin D (supplementation, serum level and receptor polymorphisms), circulating biomarkers, and events (polyp/adenoma, CRC relapse and other cancers) in concomitant to WCRF recommendation adherence. Vitamin D supplementation did not modulate circulating biomarkers or follow-up events. FokI and TaqI VDR were associated with 25-hydroxyvitamin D (25OHD) levels. Patients following the WCRF recommendations had significantly lower leptin, significantly lower IL-6 (only in females), and significantly lower risk of events (HR = 0.41, 95%CI: 0.18-0.92; p = 0.03; median follow-up 2.6 years). Interestingly, no WCRF adherents had significantly more events if they were in the placebo (p < 0.0001), whereas no influence of WCRF was observed in the Vitamin D arm. While one-year Vitamin D supplementation might be too short to show significant preventive activity, a healthy diet and lifestyle should be the first step for preventive programs.

Panitumumab Plus Trifluridine-Tipiracil as Anti-Epidermal Growth Factor Receptor Rechallenge Therapy for Refractory RAS Wild-Type Metastatic Colorectal Cancer: A Phase 2 Randomized Clinical Trial.

Importance: Current third-line therapies for patients with metastatic colorectal cancer (MCRC) have limited efficacy. Rechallenge with epidermal growth factor receptor (EGFR) inhibitors for RAS wild-type (WT) MCRC may be valuable for these patients. Objective: To compare the anti-EGFR monoclonal antibody panitumumab plus standard-of-care trifluridine-tipiracil with trifluridine-tipiracil alone as third-line therapy for RAS WT MCRC. Design, Setting, and Participants: This phase 2 randomized clinical trial (RCT) was conducted in 7 Italian centers from June 2019 to April 2022. Patients with refractory RAS WT MCRC who had a partial or complete response to first-line chemotherapy plus an anti-EGFR monoclonal antibody and an anti-EGFR drug-free interval of 4 or more months during second-line therapy were included. Interventions: Patients were randomized 1:1 to receive panitumumab plus trifluridine-tipiracil or trifluridine-tipiracil alone. Main Outcomes and Measures: The primary end point was progression-free survival (PFS). Circulating tumor DNA (ctDNA) extended sequence variation analysis was performed in a subgroup of patients. Results: Of 62 included patients, 31 received panitumumab plus trifluridine-tipiracil (19 [61.3%] male; median age, 65 years [range, 39-81 years]) and 31 received trifluridine-tipiracil alone (17 [54.8%] male; median age, 66 years [range, 32-82 years]). The primary end point was met. Median PFS was 4.0 months (95% CI, 2.8-5.3 months) in the panitumumab plus trifluridine-tipiracil arm vs 2.5 months (95% CI, 1.4-3.6 months) in the trifluridine-tipiracil only (hazard ratio [HR], 0.48; 95% CI, 0.28-0.82; P = .007). Pretreatment plasma RAS/BRAF WT ctDNA identified patients obtaining prolonged clinical benefit with panitumumab plus trifluridine-tipiracil compared with trifluridine-tipiracil, with PFS rates at 6 months of 38.5% vs 13.0% and at 12 months of 15.4% vs 0%. A ctDNA liquid-biopsy extended mutation analysis by FoundationOne Liquid CDx (profiling 324 genes) was performed in a subgroup of patients with baseline plasma RAS/BRAF WT ctDNA; in 15 of 23 patients (65.2%) whose tumors were WT for KRAS, NRAS, BRAFV600E, EGFR, ERBB2, MAP2K1, and PIK3CA, median PFS was 6.4 months (95% CI, 3.7-9.2 months). Within this group of 15 patients, 2 (13.3%) had partial response, 11 (73.3%) had stable disease, and 2 (13.3%) had disease progression as best response. Conclusions and Relevance: In this RCT, third-line treatment with the anti-EGFR monoclonal antibody panitumumab plus the standard-of-care trifluridine-tipiracil resulted in improved PFS compared with treatment with trifluridine-tipiracil alone among patients with refractory RAS WT MCRC. The findings support the clinical utility of liquid biopsy-guided anti-EGFR rechallenge therapy for refractory RAS WT MCRC. Trial Registration: ClinicalTrials.gov Identifier: NCT05468892.

Intensity-modulated radiotherapy and cisplatin-based chemotherapy for anal cancer: long-term outcomes at a single institution.

PURPOSE: To evaluate oncological outcomes and late toxicities in a retrospective series of patients with locally-extended anal squamous cell carcinoma (ASCC), treated with curative Intensity Modulated Radiotherapy (IMRT) and chemotherapy. METHODS: ASCC patients who underwent chemo-radiotherapy with IMRT from 2010 to 2020 were included. Oncological outcomes were assessed in terms of overall survival (OS), disease-free survival (DFS), colostomy-free survival (CFS) and event-free survival (EFS). Late toxicity was detected according to CTCAE v.5.0 and RTOG late radiation morbidity scoring system. RESULTS: Ninety-five patients were included. Most patients (83%) received chemotherapy with oral Fluoropyrimidine plus Cisplatin. The median follow-up was 5.5 years. The OS was 85.2%, 82.1% and 79.3% at 3, 5 and 8 years, respectively. The DFS was 73.1%, 70%, and 65.3% at 3, 5 and 8 years, respectively; 3, 5 and 8 years CFS was 86.2%, 84.3% and 84.3%, respectively. The EFS was 71%, 67.9% and 63.1%, at 3, 5 and 8 years, respectively. On univariable analysis, a statistically significant lower OS was found for patients with T3-T4 stage (HR = 4.58, p = 0.005) and overall treatment time (OTT) ≥ 47 days (HR = 3.37, p = 0.038). A statistically significant lower DFS was reported for patients with T3-T4 stage (HR = 2.72, p = 0.008) and Serum Squamous Cell Carcinoma Antigen (SCC) value post-RT > 1.5 (HR = 2.90, p = 0.038.). Ten severe late toxicity (≥ G3) events were reported in 8 patients (8.6%). CONCLUSIONS: Our data confirm IMRT concomitant with a Cisplatin-based chemotherapy as an effective treatment of ASCC, ensuring acceptable long-term toxicities and good oncological outcomes.

Pretreatment Plasma Circulating Tumor DNA RAS/BRAF Mutational Status in Refractory Metastatic Colorectal Cancer Patients Who Are Candidates for Anti-EGFR Rechallenge Therapy: A Pooled Analysis of the CAVE and VELO Clinical Trials.

Rechallenge with anti-EGFR drugs represents a promising strategy in refractory RAS/BRAF wild-type (WT) metastatic colorectal cancer (mCRC). We performed the pooled analysis of the CAVE and VELO studies to evaluate the percentage of patients with WT circulating tumor DNA (ctDNA) tumors and the association of mutational status with time from the last anti-EGFR drug administration. At baseline, 97/129 patients had RAS/BRAF WT plasma ctDNA, while 32/129 had RAS/BRAF mutated plasma ctDNA. Median anti-EGFR drug-free interval was 10.6 (CI 95%, 8.9-13.4) months in the plasma RAS/BRAF mutant group as compared to 13.0 (CI 95%, 11.1-16.6) months in RAS/BRAF WT group (p = 0.169). To investigate the time window of the RAS/BRAF mutant cancer cell clone disappearance, descriptive analysis using different time points was performed. No difference in the proportion of patients whose baseline plasma ctDNA was RAS/BRAF WT or mutated was found between 4 and 18 months since the last administration of anti-EGFR drugs. In contrast, 38/44 of patients with anti-EGFR drug-free interval of 18 months or more displayed a ctDNA RAS/BRAF WT status. Taken together, these results shows that the length of anti-EGFR free interval is not a sufficient criterion for patient selection, supporting the role of liquid biopsies for improving treatment efficacy.

Observational Study on Antibody Response to COVID-19 Vaccines in PAtients with Gastro-Entero-PanCreatic Cancers and NeuroendocrIne NeoplAsms on Systemic TreatmEnts (VACCINATE).

The coronavirus disease-19 (COVID-19) pandemic dramatically impacted oncological patients' care. Since the introduction of vaccines and the demonstration of their benefit on frail patients, COVID-19 vaccinations were indicated to also be beneficial to oncological population. However, data about the impact of anticancer-treatments and the timing between vaccinations and systemic therapy delivery were not available. We aimed to evaluate potential factors influencing the outcome of the COVID-19 vaccination in cancer patients. We prospectively collected data of patients undergoing the COVID-19 vaccination with gastro-entero-pancreatic and neuroendocrine neoplasms, treated at our institute, between 03/2021 and 12/2021. We enrolled 46 patients, 63.1% males; at the time of data collection, 86.9% had received two-doses of Pfizer-BioNTech and the rest had received the Moderna vaccine. All patients obtained a subsequent immune-response. Chemotherapy seems to determinate a significantly lower antibody response after vaccination compared to the other anti-cancer agents (p = 0.004). No significant effect on immune-response was reported for both vaccinations performed ≤7 vs. >7 days from the last systemic treatment (p = 0.77) and lymphocytes count (p = 0.11). The findings suggest that the optimal timing for COVID-19 vaccination and lymphocytes count are not the issue, but rather that the quality of the subset of lymphocytes before the vaccination determine the efficacy level of immune-response in this population.

Colorectal cancer, Vitamin D and microbiota: A double-blind Phase II randomized trial (ColoViD) in colorectal cancer patients.

BACKGROUND: Several studies suggest a role of gut microbiota in colorectal cancer (CRC) initiation and progression. Vitamin D (vitD) blood levels are also inversely correlated with CRC risk and prognosis. However, these factors' interplay remains unknown. METHODS: 74 CRC patients after standard treatment were randomized to 1-year 2000 IU/day vitD or placebo.  Baseline and post-treatment fecal microbiota for shotgun metagenomics sequencing was collected. Coda-lasso and Principal Component Analysis were used to select and summarize treatment-associated taxa and pathways. Associations between vitD and taxa/pathways were investigated with logistic regression. Mediation analysis was performed to study if treatment-associated taxa mediated the effect of supplementation on 25(OH)D levels. Cox proportional-hazards model was used for disease-free survival (DFS). RESULTS: 60 patients were analyzed. Change in alpha diversity (Shannon: p = 0.77; Simpson: p = 0.63) and post-treatment beta diversity (p = 0.70) were comparable between arms. Post-treatment abundances of 63 taxa and 32 pathways differed between arms. The 63 taxa also mediated the effect of supplementation on 25(OH)D (p = 0.02). There were sex differences in vitD levels, microbiota and pathways. Pathways of essential amino acids' biosynthesis were more abundant in supplemented women. Fusobacterium nucleatum presence at baseline was associated with worse DFS (p = 0.02). Those achieving vitD sufficiency (25(OH)D≥30 ng/ml) had lower post-treatment abundances (p = 0.05). Women were more likely to have F. nucleatum post-treatment (p = 0.02). CONCLUSIONS: VitD supplementation may contribute shaping the gut microbiota and the microbiota may partially mediate the effect of supplementation on 25(OH)D. The observed sex-specific differences highlight the necessity of including sex/gender as a variable in microbiome studies.

Temozolomide Treatment Alters Mismatch Repair and Boosts Mutational Burden in Tumor and Blood of Colorectal Cancer Patients.

The majority of metastatic colorectal cancers (mCRC) are mismatch repair (MMR) proficient and unresponsive to immunotherapy, whereas MMR-deficient (MMRd) tumors often respond to immune-checkpoint blockade. We previously reported that the treatment of colorectal cancer preclinical models with temozolomide (TMZ) leads to MMR deficiency, increased tumor mutational burden (TMB), and sensitization to immunotherapy. To clinically translate these findings, we designed the ARETHUSA clinical trial whereby O6-methylguanine-DNA-methyltransferase (MGMT)-deficient, MMR-proficient, RAS-mutant mCRC patients received priming therapy with TMZ. Analysis of tissue biopsies and circulating tumor DNA (ctDNA) revealed the emergence of a distinct mutational signature and increased TMB after TMZ treatment. Multiple alterations in the nucleotide context favored by the TMZ signature emerged in MMR genes, and the p.T1219I MSH6 variant was detected in ctDNA and tissue of 94% (16/17) of the cases. A subset of patients whose tumors displayed the MSH6 mutation, the TMZ mutational signature, and increased TMB achieved disease stabilization upon pembrolizumab treatment. SIGNIFICANCE: MMR-proficient mCRCs are unresponsive to immunotherapy. We provide the proof of concept that inactivation of MMR genes can be achieved pharmacologically with TMZ and molecularly monitored in the tissue and blood of patients with mCRC. This strategy deserves additional evaluation in mCRC patients whose tumors are no longer responsive to standard-of-care treatments. See related commentary by Willis and Overman, p. 1612. This article is highlighted in the In This Issue feature, p. 1599.

PD-1/PD-L1 blockade, a novel strategy for targeting metastatic colorectal cancer: A systematic review and meta-analysis of randomized trials.

Currently, standard treatment of patients with metastatic colorectal cancer (mCRC) comprises chemotherapy (CT) and/or biological therapy (BT) and/or best supportive care (BSC). The present study performed a meta-analysis on five phase II-III randomized clinical trials, which compared CT/BT/BSC as the control arm with the immune checkpoint inhibitors (ICIs) anti-programmed cell death protein 1 (PD-1) or its ligand (PD-L1) alone or in combination with cytotoxic T lymphocyte antigen 4 or mitogen activated protein kinase kinase inhibitors as the experimental arm, to evaluate whether a standard approach could be overcome using the novel target therapy strategy. Pooled hazard ratio (HR) for progression-free survival was 0.95 in favor of the experimental arm [95% confidence interval (CI), 0.74-1.22; P=0.68]. Heterogeneity was significant: Cochran's Q, 21.0; P=0.0082; I2 index, 76%. Pooled HR for overall survival was 0.88 in favor of the experimental arm (95% CI, 0.75-1.02; P=0.08). Heterogeneity was not significant (Cochran's Q, 6.0; P=0.31; I2 index, 16%). The present meta-analysis demonstrated a trend toward the improvement of survival by PD-1/PD-L1 blockade in mCRC. Further homogeneous studies are necessary to strengthen these results, beyond the known benefits of ICIs in deficient mismatch repair/high microsatellite instability tumors.

Small-size (40 µm) Beads Loaded with Irinotecan in the Treatment of Patients with Colorectal Liver Metastases.

PURPOSE: The purpose of this study was to investigate survival outcomes and safety after chemoembolization using irinotecan-loaded small-size beads (DEB-IRI) in patients with colorectal liver metastases unresponsive to standard chemotherapy. MATERIALS AND METHODS: Between December 2013 and August 2019, fifty-five patients (32 males, median age 64.5 years) with pretreated colorectal liver metastases unresponsive to standard chemotherapy underwent 197 chemoembolization procedures (mean 3.6 ± 2.3 SD per patient). Thirty patients (30/55; 55%) had extrahepatic disease metastatic to the lungs, lymph nodes or peritoneum. Local tumor control was evaluated at 3, 6, 9 and 12 months. Median overall survival, survival rates at 1 and 2 year and adverse events were evaluated. RESULTS: Local tumor control was achieved in 32/55 (58%), 12/55 (22%), 4/55 (7%) and 2/55 (4%) patients at 3, 6, 9 and 12 months, respectively. Median overall survival was 9.9 months (95% CI: 6.2-14.2 months) with 1- and 2-year survival rates of 45% and 15%, respectively. A total of 30 (15%) G1-G3 treatment-related adverse events occurred across all embolization procedures. No severe treatment-related adverse events occurred. CONCLUSION: Chemoembolization using irinotecan-loaded small-size beads is a safe and effective procedure as a salvage treatment in patients with colorectal liver metastases, showing good results in terms of liver-specific progression free survival and overall survival.

Personality Factors in Colorectal Cancer: A Systematic Review.

Background: The role of personality in cancer incidence and development has been studied for a long time. As colorectal cancer (CRC) is one of the most prevalent cancer types and linked with lifestyle habits, it is important to better understand its psychological correlates, in order to design a more specific prevention and intervention plan. The aim of this systematic review is to analyze all the studies investigating the role of personality in CRC incidence. Methods: All studies on CRC and personality up to November 2020 were scrutinized according to the Cochrane Collaboration and the PRISMA statements. Selected studies were additionally evaluated for the Risk of Bias according to the Newcastle-Ottawa Scale (NOS). Results: Eight studies met the inclusion criteria and were eventually included in this review. Two main constructs have been identified as potential contributors of CRC incidence: emotional regulation (anger) and relational style (egoism). Conclusion: Strong conclusions regarding the influence of personality traits on the incidence of CRC are not possible, because of the small number and the heterogeneity of the selected studies. Further research is needed to understand the complexity of personality and its role in the incidence of CRC and the interaction with other valuable risk factors.

Randomized phase II trial of avelumab alone or in combination with cetuximab for patients with previously treated, locally advanced, or metastatic squamous cell anal carcinoma: the CARACAS study.

BACKGROUND: No standard therapies beyond first line are established for advanced squamous cell anal carcinoma (aSCAC). Earlier preliminary data suggest activity of epidermal growth factor receptor (EGFR) inhibition and programmed cell death ligand (PD-(L))1 blockade in patients with previously treated disease. Aim of this study was to explore activity and safety of avelumab with/without cetuximab in patients with aSCAC. METHODS: In this open-label, non-comparative, 'pick the winner', multicenter randomized phase II trial (NCT03944252), patients with aSCAC progressing after one or more lines of treatment were randomized 1:1 to the anti-PD-L1 agent avelumab alone (arm A) or combined with cetuximab (arm B). Overall response rate (ORR) was the primary endpoint. With one-sided α error set at 0.05 and power of 80%, at least 4 responses out of 27 patients per arm had to be observed to declare the study positive. Secondary endpoints were progression free survival (PFS), overall survival (OS), and safety. RESULTS: Thirty patients per arm were enrolled. Three patients in arm A and five in arm B achieved partial response: primary endpoint was reached in combination arm. ORR was 10% (95% CI 2.1 to 26.5) and 17% (95% CI 5.6 to 34.7) in arms A and B; disease control rate was 50% (95% CI 31.3 to 68.7) in arm A and 57 (95% CI 37.4-74.5) in arm B. At a median follow-up of 26.7 months (IQR 26.5-26.9), median PFS was 2.0 months (95% CI 1.8 to 4.0) in arm A and 3.9 (95% CI 2.1 to 5.6) in arm B. Median OS was 13.9 months (95% CI 7.7 to 19.4) in arm A and 7.8 (95% CI 6.2 to 11.2) in arm B. Acceptable safety profile was observed in both arms. CONCLUSIONS: CARACAS study met its primary endpoint in arm B, documenting promising activity of dual EGFR and PD-L1 blockade in aSCAC.

Optimizing Loco Regional Management of Oligometastatic Colorectal Cancer: Technical Aspects and Biomarkers, Two Sides of the Same Coin.

Colorectal cancer (CRC) is the third most common cancer worldwide and has a high rate of metastatic disease which is the main cause of CRC-related death. Oligometastatic disease is a clinical condition recently included in ESMO guidelines that can benefit from a more aggressive locoregional approach. This review focuses the attention on colorectal liver metastases (CRLM) and highlights recommendations and therapeutic locoregional strategies drawn from the current literature and consensus conferences. The different percutaneous therapies (radiofrequency ablation, microwave ablation, irreversible electroporation) as well as trans-arterial approaches (chemoembolization and radioembolization) are discussed. Ablation margins, the choice of the imaging guidance as well as characteristics of the different ablation techniques and other technical aspects are analyzed. A specific attention is then paid to the increasing role of biomarkers (in particular molecular profiling) and their role in the selection of the proper treatment for the right patient. In conclusion, in this review an up-to-date state of the art of the application of locoregional treatments on CRLM is provided, highlighting both technical aspects and the role of biomarkers, two sides of the same coin.

The Prognostic Value of the New Combined Hemo-Eosinophil Inflammation Index (HEI Index): A Multicenter Analysis of Anal Cancer Patients Treated with Concurrent Chemo-Radiation.

Anal squamous cell carcinoma (SCC) is a rare tumor, and bio-humoral predictors of response to chemo-radiation (CT-RT) are lacking. We developed a prognostic score system based on laboratory inflammation parameters. We investigated the correlation between baseline clinical and laboratory variables and disease-free (DFS) and overall (OS) survival in anal SCC patients treated with CT-RT in five institutions. The bio-humoral parameters of significance were included in a new scoring system, which was tested with other significant variables in a Cox's proportional hazard model. A total of 308 patients was included. We devised a prognostic model by combining baseline hemoglobin level, SII, and eosinophil count: the Hemo-Eosinophils Inflammation (HEI) Index. We stratified patients according to the HEI index into low- and high-risk groups. Median DFS for low-risk patients was not reached, and it was found to be 79.5 months for high-risk cases (Hazard Ratio 3.22; 95% CI: 2.04-5.10; p < 0.0001). Following adjustment for clinical covariates found significant at univariate analysis, multivariate analysis confirmed the HEI index as an independent prognostic factor for DFS and OS. The HEI index was shown to be a prognostic parameter for DFS and OS in anal cancer patients treated with CT-RT. An external validation of the HEI index is mandatory for its use in clinical practice.