Complete pathological response after chemotherapy or immune checkpoint inhibitors in deficient MMR metastatic colorectal cancer: Results of a retrospective multicenter study.

About 5% of the patients with metastatic colorectal cancers (mCRC) present microsatellite instability (MSI)/deficient mismatch repair system (dMMR). While metastasectomy is known to improve overall and progression-free survival in mCRC, specific results in selected patients with dMMR/MSI mCRC are lacking. Our study aimed to describe metastasectomy results, characterize histological response and evaluate pathological complete response (pCR) rate in patients with dMMR/MSI mCRC. We retrospectively reviewed data from all consecutive patients with dMMR/MSI mCRC who underwent surgical metastasectomy between January 2010 and June 2021 in 17 French centers. Primary outcome was to assess the pCR rate defined by tumor regression grade (TRG) 0. Secondary endpoints included relapse-free survival (RFS) and overall survival (OS), and explored TRG as predictive factor for RFS and OS. Among the 88 patients operated, 109 metastasectomies were performed in 81 patients after neoadjuvant treatment [chemotherapy ± targeted therapy (CTT): 69, 85.2%; immunotherapy (ICI): 12, 14.8%], and pCR was achieved in 13 (16.1%) patients. Among the latter, pCR rate were 10.2% in the patients having received CTT (N = 7) and 50.0% in the patients treated with ICI (N = 6). Radiological response did not predict TRG. With a median follow-up of 57.9 (IQR 34.2-81.6) months, median RFS was 20.2 (15.4-not reached) months, median OS was not reached. Major pathological responses (TRG0 + TRG1) were significantly associated with longer RFS (HR 0.12, 95% CI 0.03-0.55; P = .006). The pCR rate of 16.1% achieved with neoadjuvant treatment in patients with dMMR/MSI mCRC is consistent with previously reported rates in pMMR/MSS mCRC. Immunotherapy showed better pCR rate than chemotherapy ± targeted therapy. Further prospective trials are needed to validate immunotherapy as neoadjuvant treatment in resectable/potentially resectable dMMR/MSI mCRC and identify predictive factors for pCR.

Circulating DNA changes are predictive of disease progression after transarterial chemoembolization.

Transarterial chemoembolization (TACE) is used to treat patients with unresectable hepatocellular carcinoma (HCC). We evaluated the clinical impact of a-fetoprotein (AFP) and circulating cell-free and tumor DNA (cfDNA and ctDNA) changes around the TACE procedure. Our prospective monocentric study enrolled consecutive patients treated with TACE, with samples collected at baseline (D - 1), Day 2 (D + 2) and 1 month (M + 1) after TACE. cfDNA was quantified by the fluorometric method, and ctDNA was quantified by digital polymerase chain reaction designed for two hotspot TERT mutations. Computerized tomography scans or magnetic resonance imaging were performed at M + 1 every 3 months following TACE and independently reviewed. The objective was to identify thresholds of cfDNA, ctDNA and AFP changes associated with progressive disease (PD) using receiver operating characteristic curves. Thirty-eight patients were included from March 2018 to March 2019. All markers significantly increased from D - 1 to D + 2 (P < .005), and cfDNA and ctDNA significantly decreased from D + 2 to M + 1 (P < .0001). The analysis of changes from D - 1 to M + 1 identified thresholds at +31.4% for cfDNA and 0% for ctDNA that were significantly associated with PD at M + 1 (44.4% [>+31.4%] vs 3.8% [≤+31.4%] and 50.0% [>0%] vs 5.0% [≤0%], respectively). No significant threshold was identified for AFP. Using a score combining cfDNA and ctDNA, the patients were classified into high- or low-risk PD groups at M + 1, with PD rates of 80.0% vs 4.3% (P = .001) and median progression-free survival times of 1.3 vs 10.3 months (P = .002). Our study suggests that cfDNA and ctDNA increases around the TACE procedure and are associated with therapeutic failure.

FOLFIRI plus BEvacizumab or aFLIbercept after FOLFOX-bevacizumab failure for COlorectal cancer (BEFLICO): An AGEO multicenter study.

After failure of first line FOLFOX-bevacizumab for metastatic colorectal cancer (mCRC), adding either bevacizumab or aflibercept to second-line FOLFIRI increases survival compared to FOLFIRI alone. In this French retrospective multicentre cohort, we included patients with a mCRC treated with either FOLFIRI-aflibercept or FOLFIRI-bevacizumab. The primary endpoint was overall survival (OS), and secondary endpoints were progression-free survival (PFS), disease control rate (DCR: CR + PR + SD) and safety. We included 681 patients from 36 centers, 326 and 355 in the aflibercept and bevacizumab groups, respectively. Median age was 64.2 years and 45.2% of patients were men. Most patients had RAS-mutated tumors (80.8%) and synchronous metastases (85.7%). After a median follow up of 31.2 months, median OS was 13.0 months (95% CI: 11.3-14.7) and 10.4 months (95% CI: 8.8-11.4) in the bevacizumab and aflibercept groups, respectively (P < .0001). Median PFS was 6.0 months (95% CI: 5.4-6.5) and 5.1 months (95% CI: 4.3-5.6) (P < .0001). After adjustment on age, PS, PFS of first line, primary tumor resection, metastasis location and RAS/BRAF status, bevacizumab was still associated with better OS (HR: 0.71, 95% CI: 0.59-0.86, P = .0003). FOLFIRI-bevacizumab combination was associated with longer OS and PFS, and a better tolerability, as compared to FOLFIRI-aflibercept after progression on FOLFOX-bevacizumab.

Prognostic factors of BRAF V600E colorectal cancer with liver metastases: a retrospective multicentric study.

BACKGROUND: BRAF V600E-mutant colorectal cancers (CRCs) are associated with shorter survival than BRAF wild-type tumors. Therapeutic decision-making for colorectal liver metastases (CRLM) harboring this mutation remains difficult due to the scarce literature. The aim was to study a large cohort of BRAF V600E-mutant CRLM patients in order to see if surgery extend overall survival among others prognostic factors. METHODS: BRAF V600E-mutant CRCs diagnosed with liver-only metastases, resected or not, were retrospectively identified between April 2008 and December 2017, in 25 French centers. Clinical, molecular, pathological characteristics and treatment features were collected. Overall survival (OS) was defined as the time from CRLM diagnosis to death from any cause. Cox proportional hazard models were used for statistical analysis. RESULTS: Among the 105 patients included, 79 (75%) received chemotherapy, 18 (17%) underwent upfront CRLM surgery, and 8 (8%) received exclusive best supportive care. CRLM surgery was performed in 49 (46.7%) patients. CRLM were mainly synchronous (90%) with bilobar presentation (61%). The median OS was 34 months (range, 28.9-67.3 months) for resected patients and 10.6 (6.7-12.5) months for unresected patients (P < 0.0001). In multivariate analysis, primary tumor surgery (hazard ratio (HR) = 0.349; 95% confidence interval (CI) 0.164-0.744, P = 0.0064) and CRLM resection (HR = 0.169; 95% CI 0.082-0.348, P < 0.0001) were associated with significantly better OS. CONCLUSIONS: In the era of systemic cytotoxic chemotherapies, liver surgery seems to extend OS in BRAF V600E-mutant CRCs with liver only metastases historical cohort.

Heterogeneity of Mismatch Repair Status and Microsatellite Instability between Primary Tumour and Metastasis and Its Implications for Immunotherapy in Colorectal Cancers.

Deficient mismatch repair system (dMMR)/microsatellite instability (MSI) is found in about 5% of metastatic colorectal cancers (mCRCs) with a major therapeutic impact for immune checkpoint inhibitor (ICI) use. We conducted a multicentre study including all consecutive patients with a dMMR/MSI mCRC. MSI status was determined using the Pentaplex panel and expression of the four MMR proteins was evaluated by immunohistochemistry (IHC). The primary endpoint was the rate of discordance of dMMR/MSI status between primary tumours and paired metastases. We included 99 patients with a dMMR/MSI primary CRC and 117 paired metastases. Only four discrepancies (3.4%) with a dMMR/MSI primary CRC and a pMMR/MSS metastasis were initially identified and reviewed by expert pathologists and molecular biologists. Two cases were false discrepancies due to human or technical errors. One discordant case could not be confirmed due to the low level of tumour cells. The last case had a confirmed discrepancy with a dMMR/MSI primary CRC and a pMMR/MSS peritoneal metastasis. Our study demonstrated a high concordance rate of dMMR/MSI status between primary CRCs and their metastases. The analysis of one sample, either from the primary tumour or metastasis, with consistent dMMR and MSI status seems to be sufficient prior to treatment with ICI.

CEA, CA19-9, circulating DNA and circulating tumour cell kinetics in patients treated for metastatic colorectal cancer (mCRC).

BACKGROUND: We previously reported that CEA kinetics are a marker of progressive disease (PD) in metastatic colorectal cancer (mCRC). This study was specifically designed to confirm CEA kinetics for predicting PD and to evaluate CA19-9, cell-free DNA (cfDNA), circulating tumour DNA (ctDNA) and circulating tumour cell (CTC) kinetics. METHODS: Patients starting a chemotherapy (CT) with pre-treatment CEA > 5 ng/mL and/or CA19.9 > 30 UI/mL were prospectively included. Samples were collected from baseline to cycle 4 for CEA and CA19-9 and at baseline and the sixth week for other markers. CEA kinetics were calculated from the first to the third or fourth CT cycle. RESULTS: A total of 192 mCRC patients were included. CEA kinetics based on the previously identified >0.05 threshold was significantly associated with PD (p < 0.0001). By dichotomising by the median value, cfDNA, ctDNA and CA19-9 were associated with PD, PFS and OS in multivariate analysis. A circulating scoring system (CSS) combining CEA kinetics and baseline CA19-9 and cfDNA values classified patients based on high (n = 58) and low risk (n = 113) of PD and was independently associated with PD (ORa = 4.6, p < 0.0001), PFS (HRa = 2.07, p < 0.0001) and OS (HRa = 2.55, p < 0.0001). CONCLUSIONS: CEA kinetics alone or combined with baseline CA19-9 and cfDNA are clinically relevant for predicting outcomes in mCRC. TRIAL REGISTRATION NUMBER: NCT01212510.

Risk of early progression according to circulating ESR1 mutation, CA-15.3 and cfDNA increases under first-line anti-aromatase treatment in metastatic breast cancer.

BACKGROUND: Endocrine therapy is recommended as a first-line treatment for hormone receptor-positive metastatic breast cancer (HR+MBC) patients. No biomarker has been validated to predict tumor progression in that setting. We aimed to prospectively compare the risk of early progression according to circulating ESR1 mutations, CA-15.3, and circulating cell-free DNA in MBC patients treated with a first-line aromatase inhibitor (AI). METHODS: Patients with MBC treated with a first-line AI were prospectively included. Circulating biomarker assessment was performed every 3 months. The primary objective was to determine the risk of progression or death at the next follow-up visit (after 3 months) in case of circulating ESR1 mutation detection among patients treated with a first-line AI for HR+MBC. RESULTS: Overall, 103 patients were included, and 70 (68%) had progressive disease (PD). Circulating ESR1 mutations were detected in 22/70 patients with PD and in 0/33 patients without progression (p < 0.001). Among the ESR1-mutated patients, 18/22 had a detectable mutation prior to progression, with a median delay of 110 days from first detection to PD. The detection of circulating ESR1 mutations was associated with a 4.9-fold (95% CI 3.0-8.0) increase in the risk of PD at 3 months. Using a threshold value of 25% or 100%, a CA-15.3 increase was also correlated with progression (p < 0.001 and p = 0.003, respectively). In contrast to ESR1, the CA-15.3 increase occurred concomitantly with PD in most cases, in 27/47 (57%) with a 25% threshold and in 21/25 (84%) with a 100% threshold. Using a threshold value of either 25% or 100%, cfDNA increase was not correlated with progression. CONCLUSION: The emergence of circulating ESR1 mutations is associated with a 4.9-fold increase in the risk of early PD during AI treatment in HR+MBC. Our results also highlighted that tracking circulating ESR1 mutations is more relevant than tracking CA-15.3 or cfDNA increase to predict progression in this setting. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02473120. Registered 16 June 2015-retrospectively registered after one inclusion (first inclusion 1 June 2015).

Prognosis and chemosensitivity of deficient MMR phenotype in patients with metastatic colorectal cancer: An AGEO retrospective multicenter study.

Mismatch repair-deficient (dMMR) and/or microsatellite instability-high (MSI) colorectal cancers (CRC) represent about 5% of metastatic CRC (mCRC). Prognosis and chemosensitivity of dMMR/MSI mCRC remain unclear. This multicenter study included consecutive patients with dMMR/MSI mCRC from 2007 to 2017. The primary endpoint was the progression-free survival (PFS) in a population receiving first-line chemotherapy. Associations between chemotherapy regimen and survival were evaluated using a Cox regression model and inverse of probability of treatment weighting (IPTW) methodology in order to limit potential biases. Overall, 342 patients with dMMR/MSI mCRC were included. Median PFS and overall survival (OS) on first-line chemotherapy were 6.0 and 26.3 months, respectively. For second-line chemotherapy, median PFS and OS were 4.4 and 21.6 months. Longer PFS (8.1 vs. 5.4 months, p = 0.0405) and OS (35.1 vs. 24.4 months, p = 0.0747) were observed for irinotecan-based chemotherapy compared to oxaliplatin-based chemotherapy. The association was no longer statistically significant using IPTW methodology. In multivariable analysis, anti-VEGF as compared to anti-EGFR was associated with a trend to longer OS (HR = 1.78, 95% CI 1.00-3.19, p = 0.0518), whatever the backbone chemotherapy used. Our study shows that dMMR/MSI mCRC patients experienced short PFS with first-line chemotherapy with or without targeted therapy. OS was not different according to the chemotherapy regimen used, but a trend to better OS was observed with anti-VEGF. Our study provides some historical results concerning chemotherapy in dMMR/MSI mCRC in light of the recent nonrandomized trials with immune checkpoint inhibitors.

Intra-arterial hepatic beads loaded with irinotecan (DEBIRI) with mFOLFOX6 in unresectable liver metastases from colorectal cancer: a Phase 2 study.

BACKGROUND: Chemo-embolisation with drug-eluting beads loaded with irinotecan (DEBIRI) increased survival as compared with intravenous irinotecan in chemorefractory patients with liver-dominant metastases from colorectal cancer (LMCRC). First-line DEBIRI with systemic chemotherapy may increase survival and secondary resection. METHODS: In the FFCD-1201 single-arm Phase 2 study, patients with untreated, non-resectable LMCRC received DEBIRI plus mFOLFOX6. Four courses of DEBIRI were performed alternating right and left lobe or two sessions with both lobes treated during the same session. RESULTS: Fifty-seven patients were enrolled. Grade 3-5 toxicities were more frequent when both lobes were treated during the same session (90.5% versus 52.8%). Nine-month PFS rate was 53.6% (95% CI, 41.8-65.1%). The objective response rate (RECIST 1.1) was 73.2%, and the secondary R0 surgery was 33%. With a median follow-up of 38.3 months, median OS was 37.4 months (95% CI, 25.7-45.8), and median PFS 10.8 months (95% CI, 8.2-12.3). CONCLUSIONS: Front-line DEBIRI + mFOLFOX6 should not be recommended as the hypothesised 9-month PFS was not met. However, high response rate, deep responses, and prolonged OS encourage further evaluation in strategies integrating biologic agent, in particular in patients with secondary surgery as the main goal. CLINICAL TRIAL REGISTRATION: NCT01839877.

CA19.9 decrease >15% is a predictor of favourable outcome in patients treated for advanced pancreatic carcinoma: analysis of two independent cohorts.

BACKGROUND: Although carbohydrate antigen 19.9 (CA19.9) is widely used in pancreatic adenocarcinoma (PA), no consensual cut-off value of CA19.9 decrease has been established for treatment monitoring. METHODS: This was a retrospective study including patients with a baseline CA19.9 ≥ 37 UI/ml and with locally advanced or metastatic PA from two French centers. CA19.9 measurements were performed at baseline and first CT-scan evaluation. The aim was to use a training set to determine the best cut-off of CA19.9 decrease for predicting progressive disease (PD) and to analyze its performance in an independent validation cohort. RESULTS: A total of 95 and 93 patients were included in the training and validation sets, respectively. A ≤15% CA19.9 decrease was the best cut-off for predicting PD with a sensitivity (Se) = 68% and a specificity (Sp) = 90%. In the validation set, this threshold was associated with Se = 76% and Sp = 83%. A >15% CA19.9 decrease was significantly associated with improved PFS (median 8.3 versus 3.1 months, p < 0.0001) and OS (median 14 versus 7.2 months, p < 0.0001). A >15% CA19.9 decrease was also identified as a factor independently associated with OS (HRa = 0.25, 95% CI:0.14-0.44). CONCLUSIONS: A CA 19.9 decrease >15% is a favourable predictor of outcome in patients treated for advanced PA.

Circulating ESR1 mutations at the end of aromatase inhibitor adjuvant treatment and after relapse in breast cancer patients.

BACKGROUND: Detection of circulating ESR1 mutations is associated with acquired resistance to aromatase inhibitor (AI) in metastatic breast cancer. Until now, the presence of circulating ESR1 mutations at the end of adjuvant treatment by AI in early breast cancer had never been clearly established. In this context, the aim of the present study was to evaluate the circulating ESR1 mutation frequency at the end of adjuvant treatment and after relapse. METHODS: This monocentric retrospective study was based on available stored plasmas and included all early breast cancer patients who completed at least 2 years of AI adjuvant treatment and experienced a documented relapse after the end of their treatment. Circulating ESR1 mutations (D538G, Y537S/N/C) were assessed by droplet digital PCR in plasma samples taken at the end of adjuvant treatment, at time of relapse and at time of progression under first line metastatic treatment. RESULTS: A total of 42 patients were included, with a median adjuvant AI exposure of 60 months (range 41-85). No circulating ESR1 mutation was detectable at the end of AI adjuvant therapy. At first relapse, 5.3% of the patients (2/38) had a detectable circulating ESR1 mutation. At time of progression on first-line metastatic treatment, 33% of the patients (7/21) under AI had a detectable circulating ESR1 mutation compared to none of the patients under chemotherapy (0/10). The two patients with a detectable ESR1 mutation at relapse were treated by AI and had an increase of their variant allele fraction at time of progression on first-line metastatic treatment. CONCLUSIONS: Circulating ESR1 mutation detection at the end of AI-based adjuvant treatment is not clinically useful. Circulating ESR1 mutation could be assessed as soon as first relapse to guide interventional studies.

Copy number variations in DCC/18q and ERBB2/17q are associated with disease-free survival in microsatellite stable colon cancer.

We conducted a prospective study to assess the prognostic impact of selected copy number variations (CNVs) in Stage II-III microsatellite stable (MSS) colon cancer. A total of 401 patients were included from 01/2004 to 01/2009. The CNVs in 8 selected target genes, DCC/18q, EGFR/7p, TP53/17p, BLK/8p, MYC/8q, APC/5q, ERBB2/17q and STK6/20q, were detected using a quantitative multiplex polymerase chain reaction of short fluorescent fragment (QMPSF) method. The primary end-point was the impact of the CNVs on the 4-year disease-free survival (DFS). The recurrence rate at 4 years was 20.9%, corresponding to 14% Stage II patients versus 31% Stage III patients (p < 0.0001). The 4-year DFS was significantly decreased in patients with a loss at DCC/18q (p = 0.012) and a gain at ERBB2/17q (p = 0.041). The multivariate analysis demonstrated that Stage III, a loss at DCC/18q and a gain at ERBB2/17q were independent factors associated with DFS. A combination of DCC/18q and ERBB2/17q was also associated with relapse, with the hazard ratio increasing from 1 to 2.4 (95% confidence interval (CI), 1.5-4.1) and 3.1 (95% CI, 1.2-8.4) in the presence of 0, 1 or 2 alterations, respectively (p = 0.0013). CNVs in DCC/18q and ERBB2/17q are significantly associated with DFS in Stage II-III MSS colon cancer.

Diagnostic value of CA19.9, circulating tumour DNA and circulating tumour cells in patients with solid pancreatic tumours.

BACKGROUND: The direct comparison of CA19.9, circulating tumour cells (CTCs) and circulating tumour DNA (ctDNA) using endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has never been performed for the diagnosis of solid pancreatic tumours (SPTs). METHODS: We included 68 patients with a SPT referred for EUS-FNA. CTCs were analysed using size-based platform and ctDNA using digital PCR. The sensitivity, specificity, negative and positive predictive values were evaluated for each marker and their combination. RESULTS: SPTs corresponded to 58 malignant tumours (52 pancreatic adenocarcinoma (PA) and 6 others) and 10 benign lesions. The sensitivity and specificity for PA diagnosis were 73% and 88% for EUS-FNA, 67% and 80% for CTC, 65% and 75% for ctDNA and 79% and 93% for CA19.9, respectively. The positivity of at least 2 markers was associated with a sensitivity and specificity of 78% and 91%, respectively. CtDNA was the only marker associated with overall survival (median 5.2 months for ctDNA+ vs 11.0 months for ctDNA-, P=0.01). CONCLUSIONS: CA19.9 alone and in combination with ctDNA and/or CTC analysis may represent an efficient method for diagnosing PA in patients with SPTs. Further studies including a larger cohort of patients with both malignant and benign lesions will be necessary to confirm these promising results.

Cell-Free DNA in Metastatic Colorectal Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: Circulating DNA can be detected and quantified in the blood of cancer patients and used for detection of tumor-specific genetic alterations. The clinical utility has been intensively investigated for the past 10 years. The majority of reports focus on analyzing the clinical potential of tumor-specific mutations, whereas the use of total cell-free DNA (cfDNA) quantification is somehow controversial and sparsely described in the literature, but holds important clinical information in itself. The purpose of the present report was to present a systematic review and meta-analysis of the prognostic value of total cfDNA in patients with metastatic colorectal cancer (mCRC) treated with chemotherapy. In addition, we report on the overall performance of cfDNA as source for KRAS mutation detection. MATERIALS AND METHODS: A systematic literature search of PubMed and Embase was performed by two independent investigators. Eligibility criteria were (a) total cfDNA analysis, (b) mCRC, and (c) prognostic value during palliative treatment. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed, and meta-analysis applied on both aggregate data extraction and individual patients' data. RESULTS: Ten eligible cohorts were identified, including a total of 1,076 patients. Seven studies used quantitative polymerase chain reaction methods, two BEAMing [beads, emulsification, amplification, and magnetics] technology, and one study digital droplet polymerase chain reaction. The baseline levels of cfDNA was similar in the presented studies, and all studies reported a clear prognostic value in favor of patients with lowest levels of baseline cfDNA. A meta-analysis revealed a combined estimate of favorable overall survival hazard ratio (HR) in patients with levels below the median cfDNA (HR = 2.39, 95% confidence interval 2.03-2.82, p < .0001). CONCLUSION: The total cfDNA levels are high in patients with mCRC and bear strong prognostic information, which should be tested prospectively by using a predefined cut-off value based on normal values in healthy cohorts. Finally, the potential use of cfDNA for detection of tumor-specific mutations was emphasized in a large individual patients' data meta-analysis. IMPLICATIONS FOR PRACTICE: Reliable prognostic markers could help to guide patients and treating physicians regarding the relevance and choice of systemic therapy. Small fragments of circulating cell-free DNA (cfDNA) can be measured in a simple blood sample. This report presents the first meta-analysis of the prognostic value of total cfDNA measurement in patients with metastatic colorectal cancer. Data from 1,076 patients confirmed that patients with the lowest pre-treatment levels of cfDNA had a significantly higher chance of longer survival than those with higher levels. Cell-free DNA analysis can also be used for detection of tumor-specific mutations, and hold potential as a valuable tool in colorectal cancer treatment.

Short report: Monitoring ESR1 mutations by circulating tumor DNA in aromatase inhibitor resistant metastatic breast cancer.

Acquired estrogen receptor gene (ESR1) mutations have been recently reported as a marker of resistance to aromatase inhibitors in hormone receptor positive metastatic breast cancer. We retrospectively considered seven patients treated for metastatic breast cancer with available samples from the primary tumor before any treatment, cryopreserved metastasis removed during progression and concomitant plasmas. All these seven patients were in disease progression after previous exposure to aromatase inhibitors for at least 6 months, and were assessed for ESR1 mutations detection in tumor and circulating DNA. For these patients, Sanger sequencing identified four metastases with clear ESR1 mutation and one possible, whereas digital PCR identified six mutated metastases. Then, under blind conditions and using digital PCR, corresponding circulating ESR1 mutations were successfully detected in four of these six metastatic breast cancer patients. Moreover, in two patients with serial blood samples following treatments exposure, the monitoring of circulating ESR1 mutations clearly predicted disease evolution. In the context of high interest for ESR1 mutations, our results highlight that these acquired recurrent mutations may be tracked in circulating tumor DNA and may be of clinical relevance for metastatic breast cancer patient monitoring.

[Contributions of molecular biology to the management of colorectal cancer]. / Apports de la biologie moléculaire dans la prise en charge du cancer colorectal.

CONTRIBUTIONS OF MOLECULAR BIOLOGY TO THE MANAGEMENT OF COLORECTAL CANCER. Colorectal cancer (CRC) is a major public health problem affecting almost 43.000 people a year and causing 17.000 deaths. Advances in molecular biology have made it possible to identify some of the mechanisms involved in colorectal carcinogenesis and tumor proliferation. Some molecular alterations are now routinely investigated to adapt follow-up and therapeutic decisions in both localized and metastatic CRC.

BIOLOGIE MOLÉCULAIRE ET PRISE EN CHARGE DU CANCER COLORECTAL. Le cancer colorectal (CCR) est un problème de santé publique majeur qui touche près de 43 000 personnes par an et cause 17 000 décès. Les progrès de la biologie moléculaire ont permis d'identifier certains des mécanismes impliqués dans la carcinogenèse colorectale et la prolifération tumorale. Certaines altérations moléculaires sont désormais recherchées en pratique courante pour adapter le suivi et la décision thérapeutique dans les CCR localisés et métastatiques.

Ampullary tumors: French Intergroup Clinical Practice Guidelines for diagnosis, treatments and follow-up (TNCD, SNFGE, FFCD, UNICANCER, GERCOR, SFCD, SFED, ACHBT, AFC, SFRO, RENAPE, SNFCP, AFEF, SFP, SFR).

BACKGROUND: Management of ampullary tumors (AT) is challenging because of a low level of scientific evidence. This document is a summary of the French intergroup guidelines regarding the management of AT, either adenoma (AA) or carcinoma (AC), published in July 2023, available on the website of the French Society of Gastroenterology (SNFGE) (www.tncd.org). METHODS: A collaborative work was conducted under the auspices of French medical, endoscopic, oncological and surgical societies involved in the management of AT. Recommendations are based on recent literature review and expert opinions and graded in three categories (A, B, C), according to quality of evidence. RESULTS: Accurate diagnosis of AT requires at least duodenoscopy and EUS. All patients should be discussed in multidisciplinary tumor board before treatment. Surveillance may only be proposed for small AA in familial adenomatous polyposis. For AA, endoscopic papillectomy is the preferred option only if R0 resection can be achieved. When not possible, surgical papillectomy should be considered. For AC beyond pT1a N0, pancreaticoduodenectomy is the procedure of choice. Adjuvant monochemotherapy (gemcitabine, 5FU) may be proposed. For aggressive tumors (pT3/T4, pN+, R1, poorly differentiated AC, pancreatobiliary differentiation) with high risk of recurrence, 6 months polychemotherapy (CAPOX/FOLFOX for the intestinal subtype and mFOLFIRINOX for the pancreatobiliary or the mixed subtype) may be a valid alternative. Clinical and radiological follow up is recommended for 5 years. CONCLUSIONS: These guidelines help to homogenize and highlight unmet needs in the management of AA and AC. Each individual case should be discussed by a multidisciplinary team.

Relative dose intensity of first-line triplet chemotherapy in metastatic colorectal cancer.

PURPOSE: Relative dose intensity (RDI) is a measurement of chemotherapy (CT) dose defined as the actual dose received divided by the standard calculated dose during a set period. The study objective was to assess the impact of a RDI ≥ 80% on response and survival of patients treated in first line CT by FOLFOXIRI or FOLFIRINOX ± Bevacizumab (BV) for an unresectable metastatic colorectal cancer (mCRC). MATERIALS AND METHODS: It was a retrospective, non-interventional, multicenter study calculating RDI from the first cycles of CT to the first CT-scan evaluation (CT-scan1). Objective response and disease control rates (ORR and DCR), progression-free survival (PFS) and overall survival (OS) were compared between patients with RDI ≥ 80% and <80% and results were adjusted for age, gender, ECOG, tumor location, number of metastatic sites, RAS and BRAF status, the CT regimen, the use of BV, the delay from C1 to CT scan1. RESULTS: Among 152 screened patients, 100 met inclusion criteria, with a mean (± standard deviation) age at 59.0 (± 10.7) years. The ECOG performance status was 0-1 in 96 (96%) patients; metastases were synchronous in 95 (95%), RAS and BRAF were mutated in 60 (60%) and 22 (22%), respectively. ORR was observed in 51 (51%) at CT-scan1 with median PFS and OS of 10.5 and 21.9 months, respectively. A RDI ≥ 80% was observed in 44 (44%) patients without impact on ORR (ORa: 1.04, 95% CI: 0.37 to 2.89, p = 0.94) but was significantly associated to improved PFS and OS with HRa 0.50 (95%CI: 0.29 to 0.87, p = 0.013) and 0.52 (95% CI: 0.29 to 0.91, p = 0.023), respectively. CONCLUSION: Our results suggest a low level of FOLFOXIRI or FOLFIRINOX +/- BV exposure in first-line mCRC is associated with a significant trend on PFS and OS.

Genetic variations of the A13/A14 repeat located within the EGFR 3' untranslated region have no oncogenic effect in patients with colorectal cancer.

BACKGROUND: The EGFR 3' untranslated region (UTR) harbors a polyadenine repeat which is polymorphic (A13/A14) and undergoes somatic deletions in microsatellite instability (MSI) colorectal cancer (CRC). These mutations could be oncogenic in colorectal tissue since they were shown to result into increased EGFR mRNA stability in CRC cell lines. METHODS: First, we determined in a case control study including 429 CRC patients corresponding to different groups selected or not on age of tumor onset and/or familial history and/or MSI, whether or not, the germline EGFR A13/A14 polymorphism constitutes a genetic risk factor for CRC; second, we investigated the frequency of somatic mutations of this repeat in 179 CRC and their impact on EGFR expression. RESULTS: No statistically significant difference in allelic frequencies of the EGFR polyA repeat polymorphism was observed between CRC patients and controls. Somatic mutations affecting the EGFR 3'UTR polyA tract were detected in 47/80 (58.8%) MSI CRC versus 0/99 microsatellite stable (MSS) tumors. Comparative analysis in 21 CRC samples of EGFR expression, between tumor and non malignant tissues, using two independent methods showed that somatic mutations of the EGFR polyA repeat did not result into an EGFR mRNA increase. CONCLUSION: Germline and somatic genetic variations occurring within the EGFR 3' UTR polyA tract have no impact on CRC genetic risk and EGFR expression, respectively. Genotyping of the EGFR polyA tract has no clinical utility to identify patients with a high risk for CRC or patients who could benefit from anti-EGFR antibodies.

Prognostic value of Lynch syndrome, BRAFV600E , and RAS mutational status in dMMR/MSI-H metastatic colorectal cancer in a pooled analysis of Dutch and French cohorts.

BACKGROUND: Current knowledge on prognostic biomarkers (especially BRAFV600E /RAS mutations) in metastatic colorectal cancer (mCRC) is mainly based on mCRC patients with proficient mismatch repair (pMMR) tumors. It is uncertain whether these biomarkers have the same prognostic value in mCRC patients with deficient mismatch repair (dMMR) tumors. METHODS: This observational cohort study combined a population-based Dutch cohort (2014-2019) and a large French multicenter cohort (2007-2017). All mCRC patients with a histologically proven dMMR tumor were included. RESULTS: In our real-world data cohort of 707 dMMR mCRC patients, 438 patients were treated with first-line palliative systemic chemotherapy. Mean age of first-line treated patients was 61.9 years, 49% were male, and 40% had Lynch syndrome. BRAFV600E mutation was present in 47% of tumors and 30% harbored a RAS mutation. Multivariable regression analysis on OS showed significant hazard rates (HR) for known prognostic factors as age and performance status, however showed no significance for Lynch syndrome (HR: 1.07, 95% CI: 0.66-1.72), BRAFV600E mutational status (HR: 1.02, 95% CI: 0.67-1.54), and RAS mutational status (HR: 1.01, 95% CI: 0.64-1.59), with similar results for PFS. CONCLUSION: BRAFV600E and RAS mutational status are not associated with prognosis in dMMR mCRC patients, in contrast to pMMR mCRC patients. Lynch syndrome is also not an independent prognostic factor for survival. These findings underline that prognostic factors of patients with dMMR mCRC are different of those with pMMR, which could be taken into consideration when prognosis is used for clinical decision-making in dMMR mCRC patients and underline the complex heterogeneity of mCRC.