Search

Purpose:No biomarker to personalize treatment in locally advanced rectal cancer (LARC) is currently available. We assessed in LARC whether a diagnostic biopsy-adapted immunoscore (ISB) could predict response to neoadjuvant treatment (nT) and better define patients eligible to an organ preservation strategy (“Watch-and-Wait”).Experimental Design:Biopsies from two independent cohorts (n1 = 131, n2 = 118) of patients with LARC treated with nT followed by radical surgery were immunostained for CD3+ and CD8+ T cells and quantified by digital pathology to determine ISB. The expression of immune-related genes post-nT was investigated (n = 64 patients). Results were correlated with response to nT and disease-free survival (DFS). The ISB prognostic performance was further assessed in a multicentric cohort (n = 73 patients) treated by Watch-and-Wait.Results:ISB positively correlated with the degree of histologic response (P < 0.001) and gene expression levels for Th1 orientation and cytotoxic immune response, post-nT (P = 0.006). ISB high identified patients at lower risk of relapse or death compared with ISB low [HR, 0.21; 95% confidence interval (CI), 0.06–0.78; P = 0.009]. Prognostic performance of ISB for DFS was confirmed in a validation cohort. ISB was an independent parameter, more informative than pre- (P < 0.001) and post-nT (P < 0.05) imaging to predict DFS. ISB combined with imaging post-nT discriminated very good responders that could benefit from organ preservation strategy. In the “Watch-and-Wait” cohort (n = 73), no relapse was observed in patients with ISB high (23.3%).Conclusions:ISB predicts response to nT and survival in patients with LARC treated by surgery. Its usefulness in the selection of patients eligible for a Watch-and-Wait strategy is strongly suggested.

Supplementary Figures

Supplementary Tables

In colorectal cancer, KRAS (exons 2, 3, and 4) and NRAS (exons 2, 3, and 4) mutations are associated with resistance to antiepidermal growth factor receptor monoclonal antibodies, and BRAF mutation is a molecular marker of poor prognosis. KRAS exon 2 and BRAF-mutated colorectal cancers have well-known distinct clinicopathological characteristics. Comparison of tumors with different RAS status (exons 2, 3, and 4 of KRAS and NRAS) based on their clinicopathological characteristics has never been established. All colorectal cancer patients with RAS and BRAF testing from 2011 to 2015 were included in this observational retrospective study. Patient and tumor characteristics were collected and correlation with RAS and BRAF status was evaluated. A total of 1735 patients with colorectal cancer were included. RAS-mutated colorectal cancers (n=1002), compared with RAS wild-type colorectal cancers (n=733), were significantly associated with male gender, classical adenocarcinoma subtype, well/moderately differentiated tumors, and microsatellite stable phenotype. KRAS codon 13-mutated colorectal cancers (n=171), compared with RAS wild-type colorectal cancers, more frequently presented classical adenocarcinoma subtype and microsatellite stable phenotype. In comparison with other RAS mutations, KRAS exon 3-mutated colorectal cancers (n=23) were associated with mucinous/rare histological subtypes and, most likely to located in the rectum. KRAS exon 4-mutated colorectal cancers (n=33) were more frequently associated with mucinous/rare histological subtypes. There was no significant association between NRAS mutation (n=37) and clinicopathological features. Colorectal cancers are associated with different clinicopathological features according to the type of RAS mutation. Consequently, these particular characteristics must be considered when assessing the prognostic value of RAS status in colorectal cancer.

Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide and clinical outcome has improved substantially during the last two decades with targeted therapies. The immune system has a major role in cancers, especially the CD8 + T cells specific to tumor antigens. However, tumors can escape immune response by different mechanisms including upregulation of inhibitory immune checkpoint receptors, such as well-known Programmed cell Death protein-1 (PD-1)/Programmed cell Death Ligand 1 (PD-L1) interaction, leading CD8 + T cells to a state of anergy. Immunotherapy, with the so-called immune checkpoint inhibitors (CPIs), has recently been approved in treatment of multiple cancers due to its prolonged disease control and acceptable toxicities. The recent groundbreaking success involving anti-PD-1 CPIs in metastatic CRC with deficient mismatch repair system (dMMR) is promising, with several trials ongoing. Major challenges are ahead in order to determine how, when and for which patients we should use these CPIs in CRC.This review highlights some promises and challenges concerning personalized immunotherapy in CRC. First results and ongoing breakthrough trials are presented. The crucial role of biomarkers in selecting patient is also discussed.As of now, dMMR and POLE mutations (DNA polymerase ε) with ultramutator phenotype are the most powerful predictive biomarkers of CPI efficacy. The most challenging issue is pMMR mCRC and determination of how to convert a 'nonimmunogenic' neoplasm into an 'immunogenic' neoplasm, a combination of CPIs with radiation or MEK inhibitor probably being the most relevant strategy. Next-generation sequencing (NGS) assays to quantify mutational load could be more reliable predictive biomarkers of CPIs efficacy than PD-L1 expression or immune scores.

Purpose: No biomarker to personalize treatment in locally advanced rectal cancer (LARC) is currently available. We assessed in LARC whether a diagnostic biopsy-adapted immunoscore (ISB) could predict response to neoadjuvant treatment (nT) and better define patients eligible to an organ preservation strategy (“Watch-and-Wait”). Experimental Design: Biopsies from two independent cohorts (n1 = 131, n2 = 118) of patients with LARC treated with nT followed by radical surgery were immunostained for CD3+ and CD8+ T cells and quantified by digital pathology to determine ISB. The expression of immune-related genes post-nT was investigated (n = 64 patients). Results were correlated with response to nT and disease-free survival (DFS). The ISB prognostic performance was further assessed in a multicentric cohort (n = 73 patients) treated by Watch-and-Wait. Results: ISB positively correlated with the degree of histologic response (P < 0.001) and gene expression levels for Th1 orientation and cytotoxic immune response, post-nT (P = 0.006). ISB high identified patients at lower risk of relapse or death compared with ISB low [HR, 0.21; 95% confidence interval (CI), 0.06–0.78; P = 0.009]. Prognostic performance of ISB for DFS was confirmed in a validation cohort. ISB was an independent parameter, more informative than pre- (P < 0.001) and post-nT (P < 0.05) imaging to predict DFS. ISB combined with imaging post-nT discriminated very good responders that could benefit from organ preservation strategy. In the “Watch-and-Wait” cohort (n = 73), no relapse was observed in patients with ISB high (23.3%). Conclusions: ISB predicts response to nT and survival in patients with LARC treated by surgery. Its usefulness in the selection of patients eligible for a Watch-and-Wait strategy is strongly suggested.

International audience; Background: DNA mismatch repair system deficiency (dMMR) is found in 15% of colorectal cancers (CRCs). Two methods are used to determine dMMR, immunohistochemistry (IHC) of MMR proteins and molecular testing of microsatellite instability (MSI). Only studies with a low number of patients have reported rates of discordance between these two methods, ranging from 1% to 10%.Materials and methods: Overall, 3228 consecutive patients with CRCs from two centers were included. Molecular testing was carried out using the Pentaplex panel and IHC evaluated four (MLH1, MSH2, MSH6, and PMS2; cohort 1; n = 1085) or two MMR proteins (MLH1 and MSH2; cohort 2; n = 2143). The primary endpoint was the rate of discordance between MSI and MMR IHC tests.Results: Fifty-one discordant cases (1.6%) were initially observed. Twenty-nine out of 51 discordant cases were related to IHC misclassifications. In cohort 1, after re-reading IHC and/or carrying out new IHC, 16 discordant cases were reclassified as nondiscordant. In cohort 2, after the addition of MSH6/PMS2 IHC and re-examination, 13 were reclassified as nondiscordant. In addition, 10 misclassifications of molecular tests were identified. Finally, only 12 discordant cases (0.4%) remained: 5 were proficient MMR/MSI and 7 were dMMR/microsatellite stable.Conclusions: Our study confirmed the high degree of concordance between MSI and MMR IHC tests. Discordant cases must be reviewed, and if needed, tests must be repeated and analyzed by an expert team.

Resume Introduction La collision tumorale est la rencontre de deux tumeurs provenant de deux sites topographiques distincts. Les cas de collisions metastatiques ganglionnaires sont exceptionnels. Nous rapportons le cas d’une collision metastatique ganglionnaire d’un carcinome urothelial et d’un adenocarcinome prostatique. Observation Un homme de 61 ans etait hospitalise pour une nephro-ureterectomie droite avec curage peri-ureteral. Il etait suivi depuis 2004 pour un adenocarcinome prostatique et traite par prostatectomie radicale puis radiotherapie 4 ans plus tard du fait d’une reascension du PSA. Dans le cadre du suivi, un carcinome urothelial du bas uretere a ete decouvert en 2014. L’analyse anatomopathologique du curage ganglionnaire montrait, dans un ganglion, une double metastase d’origine urotheliale et prostatique de type acinaire et ductal. L’etude immuno-histochimique incluant les anticorps CK7, CK20, PSA, GATA3, P63 a confirme le phenotype distinct des 2 proliferations tumorales. Discussion La collision metastatique d’un carcinome urothelial et d’un adenocarcinome prostatique a ete rapportee dans 4 cas seulement. Notre revue de la litterature montre que l’adenocarcinome prostatique precede toujours le carcinome urothelial. L’etude immuno-histochimique, lorsqu’elle est realisee, repose sur les CK7, CK20 et PSA. Elle peut etre completee dans un second temps par le GATA3, le recepteur aux androgenes et la P63.

Glioblastoma stem cells (GSCs) are believed to be involved in the mechanisms of tumor resistance, therapeutic failures, and recurrences after conventional glioblastoma therapy. Therefore, elimination of GSCs might be a prerequisite for the development of successful therapeutic strategies. ALK, ROS1, and MET are targeted by Crizotinib, a tyrosine kinase inhibitor which has been approved for treatment of ALK‐rearranged non–small‐cell lung cancer. In this study we investigated ALK, ROS1, and MET status in nine glioblastoma stem cell lines and tumors from which they arise. Fluorescent in situ hybridization (FISH), Sanger's direct sequencing, and immunohistochemistry were used to screen genomic rearrangements (or amplifications), genomic mutations, and protein expression, respectively. The immunohistochemical and FISH studies revealed no significant dysregulation of ROS1 in GSCs and associated tumors. Neither amplification nor polysomy of ALK was observed in GSC, but weak overexpression was detected by IHC in three of nine GSCs. Similarly, no MET amplification was found by FISH but three GSCs presented significant immunohistochemical staining. No ALK or MET mutation was found by Sanger's direct sequencing. In this study, we show no molecular rearrangement of ALK, ROS1, and MET that would lead us not to propose, as a valid strategy, the use of crizotinib to eradicate GSCs. However, MET was overexpressed in all GSCs with mesenchymal subtype and three GSCs presented an overexpression of ALK. Therefore, our study corroborates the idea that MET and ALK may assume a role in the tumorigenicity of GSC.

Tumor collision is the encounter of two tumors from two different topographical sites. Cases of metastatic lymph node collision are exceptional. We report the case of a metastatic lymph node collision of an urothelial carcinoma and a prostatic adenocarcinoma.A 61-year-old man was hospitalized for a right nephroureterectomy with peri-ureteral lymph node dissection. He was followed since 2004 for prostatic adenocarcinoma and treated with radical prostatectomy then radiation therapy 4 years later due to a new increase of PSA. In the follow-up, an urothelial carcinoma of the lower right ureter was discovered in 2014. Histological analysis of a peri-ureteral lymph node showed a double metastasis of urothelial and prostatic origin. The prostatic adenocarcinoma was composed of acinar and ductal subtypes. Immunohistochemical study including CK7, CK20, PSA, GATA3, P63 antibodies confirmed the distinct phenotype of the 2 tumors.Metastatic collision of urothelial carcinoma and prostatic adenocarcinoma has been reported in 4 cases only. Our review of literature shows that prostatic adenocarcinoma always precedes the urothelial carcinoma. Immunohistochemical study, when carried out for distinguishing both tumors, should include CK7, CK20 and PSA. GATA3, androgen receptor and P63 could be added in a second time.