An Innovative and Accurate Next-Generation Sequencing-Based Microsatellite Instability Detection Method for Colorectal and Endometrial Tumors.

The detection of microsatellite instability (MSI) and mismatch repair (MMR) deficiency has become mandatory for most tumors in recent years, owing to the development of immune checkpoint inhibitors as a highly effective therapy for MMR deficiency/MSI tumors. The timely and efficient detection of MSI is valuable, and new methods are increasingly being developed. To date, MMR assessment has been performed using immunohistochemistry of the 4 MMR proteins and/or microsatellite stability/MSI using PCR, mostly using the pentaplex panel. The implementation of next-generation sequencing (NGS) for MSI analysis would improve the effectiveness at a lower cost and in less time. This study describes the development of 8 new microsatellites combined with a classification algorithm, termed "Octaplex CaBio-MSID" (for Cancérologie Biologique MSI Detection tool), to assess MSI using NGS. A series of 303 colorectal cancer and 88 endometrial cancer samples were assessed via MSI testing using NGS using the Octaplex CaBio-MSID algorithm. The sensitivity and specificity of Octaplex CaBio-MSID were 98.4% and 98.4% for colorectal cancers, and 89.3% and 100% for endometrial cancers, respectively. This new NGS-based MSI detection method outperforms previously published methods (ie, Idylla [Biocartis], OncoMate MSI Dx [Promega], and Foundation One CDx [Roche Foundation Medicine]). Although highly efficient, Octaplex CaBio-MSID requires validation in a larger independent series of different tumor types.

Genetic counselling referral practices for patients with pancreatic adenocarcinoma: A French retrospective multicentre observational cohort study (CAPANCOGEN).

BACKGROUND/OBJECTIVES: Genetic counselling (GC) is a key step in the identification of inherited germline mutations. However, the oncogenetic practices are poorly described for pancreatic adenocarcinoma (PA) in Europe. The CAPANCOGEN study aimed to describe the GC referral practices in France and assess the implementation of international guidelines in patients with PA. METHODS: Information about GC referrals with PA was collected in 13 French centres from September 2019 to October 2021. In the 5 largest centres, personal and familial histories of cancers and diseases associated with a higher risk of germline mutations were collected in 460 patients, according to international, American, European and French GC referral guidelines. Univariate and multivariate logistic regression analysis were performed to identify the factors influencing GC referral. RESULTS: Among 833 patients, a total of 100 patients (12%) had an indication of GC according to local multidisciplinary tumour board meetings (MTBM). Among these patients, 41% did not undergo GC. The median time between MTBM and GC was 55 days (IQR: 14.5-112). Among 460 patients with collected personal and familial history, 31.5% were not referred to a GC despite an existing indication. In multivariate logistic regression analysis, suspected CDKN2A (p = 0.032) or BRCA mutation (p < 0.001), familial pancreatic cancer history (p < 0.001) and controlled disease with first-line platinum-based chemotherapy (p < 0.001) increased the referral rate. Conversely, older age (p = 0.002) and a locally advanced PA (p = 0.045) decreased the risk of GC referral. CONCLUSIONS: GC referral is inadequate despite valuable information in patients' medical files.

Risk factors for biliary stent infections in malignant biliary obstruction secondary to unresectable malignancies.

BACKGROUND: Palliative biliary drainage in patients with unresectable malignant biliary obstruction (MBO) frequently leads to biliary stent infection (BI), which could impact medical care. The aim of this study was to assess the risk factors for BI occurrence in patients after stenting procedure and the impact of BI on patient survival. METHODS: All consecutive patients hospitalized from 2014 to 2018 for MBO and biliary stenting were retrospectively included. Demographic, clinical, and microbiological characteristics of each BI episode during a 1-year follow-up were described. Documented BI was defined as the association of BI episode and confirmed blood stream infection (BSI). Univariate and multivariate analyses were performed to evaluate risk factors for the first BI occurrence. RESULTS: Among 180 patients, 56% were men (mean age of 69±12), and 54% have pancreatic cancer, 16% biliary cancer, 2% hepatic cancer, and 28% lymph node or metastatic compression; metallic stent was placed in 92%. A total of 113 BI episodes occurred in 74 patients, 55% of the first episodes occurring within 3 months after stenting. BI was documented in 56% of the episodes. Enterobacteriaceae were the most frequent pathogens found, while no yeasts were documented. Mortality rate in patients with BI was 64%. Multivariate analysis showed a significant difference in BI occurrence for two criteria: WHO score 3-4 (OR=8.79 [1.79-42.89]; p=0.007) and transpapillary stenting location (OR=3.72 [1.33-10.44]; p=0.013). CONCLUSION: Since transpapillary stenting is a risk factor for BI, preserving the papilla as much as possible is a priority so as to avoid BI.

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.

Cetuximab, docetaxel, and cisplatin versus platinum, fluorouracil, and cetuximab as first-line treatment in patients with recurrent or metastatic head and neck squamous-cell carcinoma (GORTEC 2014-01 TPExtreme): a multicentre, open-label, randomised, phase 2 trial.

BACKGROUND: Results from a phase 2 trial of the TPEx chemotherapy regimen (docetaxel-platinum-cetuximab) showed promising results, with a median overall survival of 14·0 months in first-line recurrent or metastatic head and neck squamous-cell carcinoma (HNSCC). We therefore aimed to compare the efficacy and safety of the TPEx regimen with the standard of care EXTREME regimen (platinum-fluorouracil-cetuximab) in this setting. METHODS: This was a multicentre, open-label, randomised, phase 2 trial, done in 68 centres (cancer centres, university and general hospitals, and private clinics) in France, Spain, and Germany. Eligible patients were aged 18-70 years with histologically confirmed recurrent or metastatic HNSCC unsuitable for curative treatment; had at least one measurable lesion according to Response Evaluation Criteria in Solid Tumors version 1.1; and had an Eastern Cooperative Oncology Group (ECOG) performance status of 1 or less. Participants were randomly assigned (1:1) using the TenAlea website by investigators or delegated clinical research associates to the TPEx regimen or the EXTREME regimen, with minimisation by ECOG performance status, type of disease evolution, previous cetuximab treatment, and country. The TPEx regimen consisted of docetaxel 75 mg/m2 and cisplatin 75 mg/m2, both intravenously on day 1, and cetuximab on days 1, 8, and 15 (intravenously 400 mg/m2 on day 1 of cycle 1 and 250 mg/m2 weekly subsequently). Four cycles were repeated every 21 days with systematic granulocyte colony-stimulating factor (G-CSF) support at each cycle. In case of disease control after four cycles, intravenous cetuximab 500 mg/m2 was continued every 2 weeks as maintenance therapy until progression or unacceptable toxicity. The EXTREME regimen consisted of fluorouracil 4000 mg/m2 on day 1-4, cisplatin 100 mg/m2 on day 1, and cetuximab on days 1, 8, and 15 (400 mg/m2 on day 1 of cycle 1 and 250 mg/m2 weekly subsequently) all delivered intravenously. Six cycles were delivered every 21 days followed by weekly 250 mg/m2 cetuximab as maintenance therapy in case of disease control. G-CSF support was not mandatory per the protocol in the EXTREME regimen. The primary endpoint was overall survival in the intention-to-treat population; safety was analysed in all patients who received at least one dose of chemotherapy or cetuximab. Enrolment is closed and this is the final analysis. This study is registered at ClinicalTrials.gov, NCT02268695. FINDINGS: Between Oct 10, 2014, and Nov 29, 2017, 541 patients were enrolled and randomly assigned to the two treatment regimens (271 to TPEx, 270 to EXTREME). Two patients in the TPEx group had major deviations in consent forms and were not included in the final analysis. Median follow-up was 34·4 months (IQR 26·6-44·8) in the TPEx group and 30·2 months (25·5-45·3) in the EXTREME group. At data cutoff, 209 patients had died in the TPEx group and 218 had died in the EXTREME group. Overall survival did not differ significantly between the groups (median 14·5 months [95% CI 12·5-15·7] in the TPEx group and 13·4 months [12·2-15·4] in the EXTREME group; hazard ratio 0·89 [95% CI 0·74-1·08]; p=0·23). 214 (81%) of 263 patients in the TPEx group versus 246 (93%) of 265 patients in the EXTREME group had grade 3 or worse adverse events during chemotherapy (p<0·0001). In the TPEx group, 118 (45%) of 263 patients had at least one serious adverse event versus 143 (54%) of 265 patients in the EXTREME group. 16 patients in the TPEx group and 21 in the EXTREME group died in association with adverse events, including seven patients in each group who had fatal infections (including febrile neutropenia). Eight deaths in the TPEx group and 11 deaths in the EXTREME group were assessed as treatment related, most frequently sepsis or septic shock (four in each treatment group). INTERPRETATION: Although the trial did not meet its primary endpoint, with no significant improvement in overall survival with TPEx versus EXTREME, the TPEx regimen had a favourable safety profile. The TPEx regimen could provide an alternative to standard of care with the EXTREME regimen in the first-line treatment of patients with recurrent or metastatic HNSCC, especially for those who might not be good candidates for up-front pembrolizumab treatment. FUNDING: Merck Santé and Chugai Pharma.

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.

Temozolomide Alone or Combined with Capecitabine for the Treatment of Advanced Pancreatic Neuroendocrine Tumor.

BACKGROUND: The combination of capecitabine (CAP) with temozolomide (TEM) chemotherapy in advanced pancreatic neuroendocrine tumors (PanNET) relies on limited evidence. We compared TEM-CAP to TEM alone in patients with advanced PanNET. METHODS: Consecutive patients with advanced PanNET treated with TEM or TEM-CAP between 2004 and 2017 in three expert centers were included. Progression-free survival (PFS), tolerance, tumor response, and overall survival were compared between the two groups. Propensity-based analyses were performed to reduce confounding bias due to the nonrandomized setting. RESULTS: TEM and TEM-CAP were administered to 38 patients and 100 patients, respectively, with a median age of 58 years. The patients in the TEM group more often had hormonal syndromes (p = 0.03), a longer median delay to diagnosis (p = 0.001), and a higher number of pretreatment lines (p < 0.001). The performance status was 0 in 58% versus 65% of the patients, and tumor's median Ki-67 index was 8% versus 11%, respectively. Tolerance was similar, except that there were more cases of asthenia in the TEM group (p = 0.017) and more cases of hand-foot syndrome in the TEM-CAP group (p = 0.025). The objective response rate was 34% versus 51% (p = 0.088). The raw median PFS was similar with TEM and with TEM-CAP (21.4 vs. 19.8 months, p = 0.84). Although CAP tended to decrease the risk of progression in Cox multivariate analysis (HR 0.65, p = 0.12), it had no effect after adjustment for the propensity score (HR 1.06, p = 0.80). CONCLUSIONS: TEM-CAP might not prolong PFS but might achieve a higher response rate than TEM alone. Hence, TEM-CAP might be preferred when tumor shrinkage is the main therapeutic objective. Otherwise, TEM might be adequate for patients with an impaired performance status or in case of extrahepatic metastases.

Comparison of Temozolomide-Capecitabine to 5-Fluorouracile-Dacarbazine in 247 Patients with Advanced Digestive Neuroendocrine Tumors Using Propensity Score Analyses.

INTRODUCTION: Although chemotherapy combining 5-fluorouracil (5FU)-dacarbazine (DTIC) or temozolomide (TEM)-capecitabine (CAP) is extensively used in patients with neuroendocrine tumors (NET), they were never compared. We compared their tolerance and efficacy in advanced NET. METHODS: We evaluated the records of consecutive patients with pancreatic or small-intestine advanced NET who received 5FU-DTIC or TEM-CAP between July 2004 and December 2017 in 5 French centers. Tolerance, tumor response and progression-free survival (PFS) were compared. Factors associated with PFS were analyzed using Cox multivariate regression model. To reduce the confounding bias of the nonrandomized design, PFS was compared using propensity score analyses. RESULTS: Ninety-four (5FU-DTIC) patients and 153 (TEM-CAP) patients were included. Pancreatic NET represented 82.3% of cases and 17.1, 61.8 and 10.9% of patients had G1, G2 or G3 NET respectively. Progression at baseline was reported in 92.7% of patients with available data. Grades 3-4 adverse events occurred in 24.7 and 8.5% of TEM-CAP and 5FU-DTIC patients respectively (p = 0.002). The overall response rate was 38.3 and 39.2% respectively (p = 0.596). Median PFS on raw analysis was similar to 5FU-DTIC and TEM-CAP (13.9 vs. 18.3 months, respectively p = 0.86). TEM-CAP was associated with an increased risk of progression on the raw multivariate analysis (hazard ratio [HR] 1.90, 95% CI [1.32-2.73], p = 0.001) and when adjusted on propensity score (HR 1.65, 95% CI [1.18-2.31], p = 0.004). CONCLUSION: PFS may be longer with 5FU-DTIC than TEM-CAP in patients with advanced NET. Although patients often prefer oral chemotherapy, 5FU-DTIC is a relevant alternative. A randomized comparison is needed to confirm these results.

[French national standard for the treatment of squamous cell carcinoma of upper aero-digestive tract - General principles of treatment]. / Référentiel national de traitement des carcinomes épidermoïdes des voies aérodigestives supérieures ­ Principes généraux de traitement.

OBJECTIVES: The management of upper aerodigestive tract cancers is a complex specialty. It is essential to provide an update to establish optimal care. At the initiative of the INCa and under the auspices of the SFORL, the scientific committee, led by Professor Béatrix Barry, Dr. Gilles Dolivet, and Dr. Dominique De Raucourt, decided to develop a reference framework aimed at defining, in a scientific and consensus-based manner, the general principles of treatment for upper aerodigestive tract cancers applicable to all sub-locations. METHODOLOGY: To develop this framework, a multidisciplinary team of practitioners was formed. A systematic analysis of the literature was conducted to produce recommendations classified by grades, in accordance with the standards of the French National Authority for Health (HAS). RESULTS: The grading of recommendations according to HAS standards has allowed the establishment of a reference for patient care based on several criteria. In this framework, patients benefit from differentiated care based on prognostic factors they present (age, comorbidities, TNM status, HPV status, etc.), conditions of implementation, and quality criteria for indicated surgery (operability, resectability, margin quality, mutilation, salvage surgery), as well as quality criteria for radiotherapy (target volume, implementation time, etc.). The role of medical and postoperative treatments was also evaluated based on specific criteria. Finally, supportive care must be organized from the beginning and throughout the patients' care journey. CONCLUSION: All collected data have led to the development of a comprehensive framework aimed at harmonizing practices nationally, facilitating decision-making in multidisciplinary consultation meetings, promoting equality in practices, and providing a state-of-the-art and reference practices for assessing the quality of care. This new framework is intended to be updated every 5 years to best reflect the latest advances in the field.

Circulating tumor DNA in unresectable pancreatic cancer is a strong predictor of first-line treatment efficacy: The KRASCIPANC prospective study.

BACKGROUND: There is no robust predictor of response to chemotherapy (CT) in unresectable pancreatic adenocarcinomas (UPA). The objective of the KRASCIPANC study was to analyze the kinetics of cell-free DNA (cfDNA)/circulating tumor DNA (ctDNA) as a predictor of response to CT in UPA. METHODS: Blood samples were collected just before first CT and at day 28. The primary endpoint was the kinetics of KRAS-mutated ctDNA by digital droplet PCR between D0 and D28 as a predictor of progression-free survival (PFS). RESULTS: We analyzed 65 patients with a KRAS-mutated tumor. A high level of cfDNA and KRAS-mutated ctDNA at D0, as well as the presence of KRAS-mutated ctDNA at D28, were strongly associated with lower centralized disease control rate (cDCR), shorter cPFS and OS in multivariate analysis. A score combining cfDNA level at diagnosis ≥ or <30 ng/mL and presence or not of KRAS-mutated ctDNA at D28 was an optimal predictor of cDCR (OR=30.7, IC95% 4.31-218 P=.001), PFS (HR=6.79, IC95% 2.76-16.7, P<.001) and OS (HR=9.98, IC95% 4.14-24.1, P<.001). CONCLUSION: A combined score using cfDNA level at diagnosis and KRAS-mutated ctDNA at D28 is strongly associated with patient survival/response to chemotherapy in UPA. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04560270.

Safety of FOLFIRI + Durvalumab +/- Tremelimumab in Second Line of Patients with Advanced Gastric Cancer: A Safety Run-In from the Randomized Phase II Study DURIGAST PRODIGE 59.

Efficacy of immune checkpoint inhibitors (ICI) as monotherapy in 2nd line treatment for gastric or gastro-oesophageal junction (GEJ) adenocarcinoma is low, with no evaluation of efficacy and safety of ICI combined with chemotherapy. The DURIGAST PRODIGE 59 study is a randomised, multicentre, phase II study designed to assess the efficacy and safety of the combination of FOLFIRI + Durvalumab +/- Tremelimumab as 2nd line treatment of patients with advanced gastric/GEJ adenocarcinoma. Here, we report data from the safety run-in phase with FOLFIRI Durvalumab (arm A) or FOLFIRI Durvalumab and Tremelimumab (arm B). Among the 11 patients included, 63.6% experienced at least one grade 3-4 adverse events (AEs) related to the treatment, most frequently neutropenia (36.4%). There was only one immune-related AE (grade 2 hyperthyroidism). Ten serious AEs were described among six patients, but only two were related to the treatment, due to the chemotherapy. One seizure epilepsy related to a brain metastasis was observed, but was not related by the investigator to the treatment. However, the Independent Data Monitoring Committee recommended brain imaging at inclusion. This safety run-in phase demonstrates an expected safety profile of FOLFIRI with Durvalumab +/- Tremelimumab combination allowing the randomised phase II.

Impact of the COVID-19 pandemic on disease stage and treatment for patients with pancreatic adenocarcinoma: A French comprehensive multicentre ambispective observational cohort study (CAPANCOVID).

BACKGROUND: The COVID-19 pandemic caused major oncology care pathway disruption. The CAPANCOVID study aimed to evaluate the impact on pancreatic adenocarcinoma (PA) - from diagnosis to treatment - of the reorganisation of the health care system during the first lockdown. METHODS: This multicentre ambispective observational study included 833 patients diagnosed with PA between September 1, 2019 and October 31, 2020 from 13 French centres. Data were compared over three periods defined as before the outbreak of COVID-19, during the first lockdown (March 1 to May 11, 2020) and after lockdown. RESULTS: During the lockdown, mean weekly number of new cases decreased compared with that of pre-pandemic levels (13.2 vs. 10.8, -18.2%; p = 0.63) without rebound in the post-lockdown period (13.2 vs. 12.9, -1.7%; p = 0.97). The number of borderline tumours increased (13.6%-21.7%), whereas the rate of metastatic diseases rate dropped (47.1%-40.3%) (p = 0.046). Time-to-diagnosis and -treatment were not different over periods. Waiting neoadjuvant chemotherapy in resectable tumours was significantly favoured (24.7%-32.6%) compared with upfront surgery (13%-7.8%) (p = 0.013). The use of mFOLFIRINOX preoperative chemotherapy regimen decreased (84.9%-69%; p = 0.044). After lockdown, the number of borderline tumours decreased (21.7%-9.6%) and advanced diseases increased (59.7%-69.8%) (p = 0.046). SARS-CoV-2 infected 39 patients (4.7%) causing 5 deaths (12.8%). CONCLUSION: This cohort study suggests the existence of missing diagnoses and of a shift in disease stage at diagnosis from resectable to advanced diseases with related therapeutic modifications whose prognostic consequences will be known after the planned follow-up. TRIAL REGISTRATION: Clinicaltrials.gov NCT04406571.

Predictive and Prognostic Value of Microsatellite Instability in Gynecologic Cancer (Endometrial and Ovarian).

For endometrial cancer, a new classification is now available from ESMO, ESGO, and ESTRO based on clinical and molecular characteristics to determine adjuvant therapy. The contribution of molecular biology is major for this pathology mainly by the intermediary of deficient mismatch repair/microsatellite instability. Detection techniques for this phenotype have many peculiarities in gynecologic cancers (endometrial and ovarian) because it has been initially validated in colorectal cancer only. Endometrial cancer is the most common tumor with deficient mismatch repair, which is an important prognostic factor and a predictor of the benefit of adjuvant treatments. Concerning advanced stages, this phenotype is a theragnostic marker for using immunotherapy. Among ovarian cancer, microsatellite instability is less described in literature but exists, particularly in endometrioid type ovarian cancer. This review aims to provide an overview of the publications concerning deficient mismatch repair/microsatellite instability in endometrial and ovarian cancers, detection techniques, and clinical implications of these molecular characteristics.

Microsatellite Instability in Colorectal Cancers: Carcinogenesis, Neo-Antigens, Immuno-Resistance and Emerging Therapies.

A defect in the DNA repair system through a deficient mismatch repair system (dMMR) leads to microsatellite instability (MSI). Microsatellites are located in both coding and non-coding sequences and dMMR/MSI tumors are associated with a high mutation burden. Some of these mutations occur in coding sequences and lead to the production of neo-antigens able to trigger an anti-tumoral immune response. This explains why non-metastatic MSI tumors are associated with high immune infiltrates and good prognosis. Metastatic MSI tumors result from tumor escape to the immune system and are associated with poor prognosis and chemoresistance. Consequently, immune checkpoint inhibitors (ICI) are highly effective and have recently been approved in dMMR/MSI metastatic colorectal cancers (mCRC). Nevertheless, some patients with dMMR/MSI mCRC have primary or secondary resistance to ICI. This review details carcinogenesis and the mechanisms through which MSI can activate the immune system. After which, we discuss mechanistic hypotheses in an attempt to explain primary and secondary resistances to ICI and emerging strategies being developed to overcome this phenomenon by targeting other immune checkpoints or through vaccination and modification of microbiota.

Efficacy of Anti-EGFR in Microsatellite Instability Metastatic Colorectal Cancer Depending on Sporadic or Familial Origin.

Anti-epidermal growth factor receptor (EGFR) efficacy in patients with microsatellite instability (MSI) metastatic colorectal cancer (mCRC) according to sporadic vs familial origin is unknown. We retrospectively analyzed 128 patients with MSI mCRC treated with first-line chemotherapy ± anti-EGFR. Among them, 61 and 67 patients were respectively categorized as familial and sporadic based on mismatch repair protein immunostaining, BRAF mutational status, and MLH1 promoter methylation status. We observed that addition of anti-EGFR to chemotherapy was associated with a statistically significant improvement of progression-free survival for familial (median = 5.0 vs 10.2 months, hazard ratio [HR] = 0.47, 95% confidence interval [CI] = 0.23 to 0.94; P = .03) but not for sporadic (median = 4.4 vs 5.4 months, HR = 0.80, 95% CI = 0.39 to 1.60; P = .52) MSI mCRC patients. In multivariate analysis, the survival benefit of adding anti-EGFR to chemotherapy remained statistically significant for familial MSI cases (P = .04). These findings deserve to be confirmed in a prospective study and could help decision making in MSI mCRC without access or resistant to immunotherapy.

HSP110 as a Diagnostic but Not a Prognostic Biomarker in Colorectal Cancer With Microsatellite Instability.

Determination of microsatellite instability (MSI) using molecular test and deficient mismatch repair (dMMR) using immunohistochemistry (IHC) has major implications on colorectal cancer (CRC) management. The HSP110 T 17 microsatellite has been reported to be more monomorphic than the common markers used for MSI determination. Large deletion of HSP110 T 17 has been associated with efficacy of adjuvant chemotherapy in dMMR/MSI CRCs. The aim of this study was to evaluate the interest of HSP110 deletion/expression as a diagnostic tool of dMMR/MSI CRCs and a predictive tool of adjuvant chemotherapy efficacy. All patients with MSI CRC classified by molecular testing were included in this multicenter prospective cohort (n = 381). IHC of the 4 MMR proteins was carried out. HSP110 expression was carried out by IHC (n = 343), and the size of HSP110 T 17 deletion was determined by PCR (n = 327). In the 293 MSI CRCs with both tests, a strong correlation was found between the expression of HSP110 protein and the size of HSP110 T 17 deletion. Only 5.8% of MSI CRCs had no HSP110 T 17 deletion (n = 19/327). HSP110 T 17 deletion helped to re-classify 4 of the 9 pMMR/MSI discordance cases as pMMR/MSS cases. We did not observe any correlation between HSP110 expression or HSP110 T 17 deletion size with time to recurrence in patients with stage II and III CRC, treated with or without adjuvant chemotherapy. HSP110 is neither a robust prognosis marker nor a predictor tool of adjuvant chemotherapy efficacy in dMMR/MSI CRC. However, HSP110 T17 is an interesting marker, which may be combined with the other pentaplex markers to identify discordant cases between MMR IHC and MSI.

PRODIGE 59-DURIGAST trial: A randomised phase II study evaluating FOLFIRI + Durvalumab ± Tremelimumab in second-line of patients with advanced gastric cancer.

Gastric or gastro-oesophageal junction (GEJ) adenocarcinomas present poor overall survival (OS). First-line chemotherapy regimen for patients with HER2-negative tumours is based on a doublet or triplet of fluoropyrimidine plus platinum salt ± taxane. Second-line chemotherapy (Docetaxel or Irinotecan) improves OS which nonetheless remains poor (around 5 months). The first results of immune checkpoint inhibitors (anti-PD-1) combined with chemotherapy in metastatic gastric and GEJ cancers were discordant in recent phase III trials. Data on dual-blockade (anti-PD-L1 or anti-PD-1 plus anti-CTLA-4) plus chemotherapy are lacking. DURIGAST is a randomised, multicenter, non-comparative, phase II study, evaluating safety and efficacy of FOLFIRI plus Durvalumab (anti-PD-L1) versus FOLFIRI plus Durvalumab and Tremelimumab (anti-CTLA-4) as second-line treatment of advanced gastric and GEJ adenocarcinoma. The primary objective is the rate of patients alive and without progression at 4 months. The main inclusion criteria are: patients with advanced gastric or GEJ adenocarcinoma, pre-treated with fluoropyrimidine + platinum salt ± taxane. Due to a lack of data on FOLFIRI, Durvalumab and Tremelimumab combination, a 2-step safety run-in phase has been performed before the randomised phase II. The safety run-in phase did not show any safety issue and the randomised phase II starts in September 2020.

Detection of Colorectal Cancer and Advanced Adenoma by Liquid Biopsy (Decalib Study): The ddPCR Challenge.

BACKGROUND: In most countries, participation in colorectal cancer (CRC) screening programs with the immunological fecal occult blood test (iFOBT) is low. Mutations of RAS and BRAF occur early in colorectal carcinogenesis and "liquid biopsy" allows detection of mutated circulating tumor DNA (ctDNA). This prospective study aims to evaluate the performance of RAS and BRAF-mutated ctDNA in detecting CRC and advanced adenomas (AA). METHODS: One hundred and thirty patients who underwent colonoscopy for suspicion of colorectal lesion were included and divided into four groups: 20 CRC, 39 AA, 31 non-advanced adenoma and/or hyperplastic polyp(s) (NAA) and 40 with no lesion. Mutated ctDNA was analyzed by droplet digital PCR. RESULTS: ctDNA was detected in 45.0% of CRC, in 2.6% of AA and none of the NAA and "no-lesion" groups. All patients with stage II to IV mutated CRC had detectable ctDNA (n = 8/8). Among the mutated AA, only one patient had detectable ctDNA (4.3%), maybe due to limited technical sensitivity or to a low rate of ctDNA or even the absence ctDNA in plasma. Specificity and sensitivity of KRAS- and BRAF-mutated ctDNA for the detection of all CRC and AA were 100% and 16.9%, respectively. CONCLUSIONS: ctDNA had high sensitivity in detection of advanced mutated CRC but was unable to sensitively detect AA. ctDNA analysis was easy to perform and readily accepted by the population but requires combination with other circulating biomarkers before replacing iFOBT.

Microsatellite Instability: Diagnosis, Heterogeneity, Discordance, and Clinical Impact in Colorectal Cancer.

Tumor DNA mismatch repair (MMR) deficiency testing is important to the identification of Lynch syndrome and decision making regarding adjuvant chemotherapy in stage II colorectal cancer (CRC) and has become an indispensable test in metastatic tumors due to the high efficacy of immune checkpoint inhibitor (ICI) in deficient MMR (dMMR) tumors. CRCs greatly benefit from this testing as approximately 15% of them are dMMR but only 3% to 5% are at a metastatic stage. MMR status can be determined by two different methods, microsatellite instability (MSI) testing on tumor DNA, and immunohistochemistry of the MMR proteins on tumor tissue. Recent studies have reported a rate of 3% to 10% of discordance between these two tests. Moreover, some reports suggest possible intra- and inter-tumoral heterogeneity of MMR and MSI status. These issues are important to know and to clarify in order to define therapeutic strategy in CRC. This review aims to detail the standard techniques used for the determination of MMR and MSI status, along with their advantages and limits. We review the discordances that may arise between these two tests, tumor heterogeneity of MMR and MSI status, and possible explanations. We also discuss the strategies designed to distinguish sporadic versus germline dMMR/MSI CRC. Finally, we present new and accurate methods aimed at determining MMR/MSI status.

Targeted RNA-sequencing assays: a step forward compared to FISH and IHC techniques?

INTRODUCTION: ALK and ROS1 rearrangements are molecular targets of several tyrosine kinase inhibitors. RNA-sequencing approaches are regarded as the new standard for fusion gene detection, representing an alternative to standard immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) techniques. PATIENTS AND METHODS: We aimed to compare two recent amplicon-based RNA-sequencing techniques: FusionPlex® Alk Ret Ros1 v2 Kit (Archer® ) with FHS-003Z-12-Human Lung Cancer Panel (Qiagen® ) and assessed the accuracy of the data for therapy management. Thirty-seven formalin-fixed paraffin-embedded non-small cell carcinoma (NSCC) lesions initially explored by IHC and FISH were selected for RNA-sequencing analysis. RESULTS: Qiagen® and Archer® kits produced similar results and correctly identified 85.1% (23/27) and 81.5% (22/27) of IHC/FISH ALK- and ROS1-positive samples, respectively, and 100% (6/6) of the negative samples. With regard to the ambiguous IHC-positive/FISH-negative cases, RNA-sequencing confirmed 75% (3/4) of the FISH conclusion. Although not statistically significant, patients with common EML4-ALK variants presented shorter overall survival and progression-free survival compared with patients harboring rare variants. CONCLUSION: Our findings assessed the implementation of RNA-sequencing approaches to explore ALK and ROS1 rearrangements from formalin-fixed paraffin-embedded samples. We highlighted the similarities between Qiagen® and Archer® kits in terms of handling time, cost, and outcomes. We confirmed the feasibility of molecular testing in routine organization and its possible use not only as an alternative for standard IHC and FISH techniques, but as a supplementary technique helping to classify discrepant cases.