Advanced Colorectal Carcinoma Research Articles

Histology and its prognostic effect on KRAS-mutated colorectal carcinomas in Korea.

KRAS mutation is frequently identified in advanced colorectal carcinoma (CRC); however, its prognostic significance and the associated histological features have remained to be clarified. In the present study, the precise histological results and prognostic value of KRAS-mutated CRCs were investigated in patients from South Korea. A retrospective review of the results from KRAS mutation testing, as well as evaluation of the histology of 310 cases of CRC at various stages, were performed. Cross-tabulation and survival analysis were performed according to the KRAS status. Patients with KRAS mutation more frequently exhibited serrated and papillary architectures (P=0.009 and P=0.014, respectively). KRAS mutation was an independent unfavorable prognostic factor for overall survival (OS) according to multivariate analysis (P=0.001), whereas no association was observed with disease-free survival (DFS) (P=0.611). Of note, in the subgroup of KRAS-mutated carcinomas, the presence of a solid component on histology was associated with less favorable OS (P=0.032). Furthermore, among the wild type cases, patients with a micropapillary component had a worse OS than those who did not (P=0.018). However, no subgroup or specific histological features were associated with DFS. In summary, KRAS-mutated CRCs had a moderate association with particular histological features, and according to the KRAS mutational status, there was a certain degree of association between histology and prognosis.

Circulating tumour DNA-guided adjuvant chemotherapy in colorectal carcinoma

Approximately 20% of locoregional colorectal carcinoma (CRC) relapse after standard of care treatment. Therefore, it is necessary to personalize our adjuvant strategies and define this subgroup, which remains at high risk after treatment. Circulating tumour DNA (ctDNA) is cell-free DNA from apoptotic cancer cells, which carries the whole genome information of the primary tumour and has emerged as good candidate to guide our therapy decisions in the future. It was shown that high levels of ctDNA after adjuvant chemotherapy is a poor prognostic factor. Moreover, it was presented at ESMO 2019 in Barcelona that patients with advanced colorectal carcinomas and ctDNA-positive samples after surgery had a significantly decreased 2‑year disease-free survival in comparison to ctDNA-negative patients. That means, ctDNA could be a tool to select this high-risk subgroup in advanced CRC in order to prolong or intensify adjuvant chemotherapy and to avoid insufficient treatment.

Beyond Taxonomic Analysis of Microbiomes: A Functional Approach for Revisiting Microbiome Changes in Colorectal Cancer.

Colorectal cancer (CRC) is one of the most prevalent cancers in the world, especially in developed countries. In different studies, the association between CRC and dysbiosis of gut microbiome has been reported. However, most of these works focus on the taxonomic variation of the microbiome, which presents little, if any, functional insight about the reason behind and/or consequences of microbiome dysbiosis. In this study, we used a previously reported metagenome dataset which is obtained by sequencing 156 microbiome samples of healthy individuals as the control group (Co), as well as microbiome samples of patients with advanced colorectal adenoma (Ad) and colorectal carcinoma (Ca). Features of the microbiome samples have been analyzed at the level of species, as well as four functional levels, i.e., gene, KEGG orthology (KO) group, Enzyme Commission (EC) number, and reaction. It was shown that, at each of these levels, certain features exist which show significant changing trends during cancer progression. In the next step, a list of these features were extracted, which were shown to be able to predict the category of Co, Ad, and Ca samples with an accuracy of >85%. When only one group of features (species, gene, KO group, EC number, reaction) was used, KO-related features were found to be the most successful features for classifying the three categories of samples. Notably, species-related features showed the least success in sample classification. Furthermore, by applying an independent test set, we showed that these performance trends are not limited to our original dataset. We determined the most important classification features at each of the four functional levels. We propose that these features can be considered as biomarkers of CRC progression. Finally, we show that the intra-diversity of each sample at the levels of bacterial species and genes is much more than those of the KO groups, EC numbers, and reactions of that sample. Therefore, we conclude that the microbiome diversity at the species level, or gene level, is not necessarily associated with the diversity at the functional level, which again indicates the importance of KO-, EC-, and reaction-based features in metagenome analysis. The source code of proposed method is freely available from https://www.bioinformatics.org/mamed.

Development of Promitil®, a lipidic prodrug of mitomycin c in PEGylated liposomes: From bench to bedside.

Several liposome products have been approved for the treatment of cancer. In all of them, the active agents are encapsulated in the liposome water phase passively or by transmembrane ion gradients. An alternative approach in liposomal drug delivery consists of chemically modifying drugs to form lipophilic prodrugs with strong association to the liposomal bilayer. Based on this approach, we synthesized a mitomycin c-derived lipidic prodrug (MLP) which is entrapped in the bilayer of PEGylated liposomes (PL-MLP, Promitil®), and activated by thiolytic cleavage. PL-MLP is stable in plasma with thiolytic activation of MLP occurring exclusively in tissues and is more effective and less toxic than conventional chemotherapy in various tumor models. PL-MLP has completed phase I clinical development where it has shown a favorable safety profile and a 3-fold reduction in toxicity as compared to free mitomycin c. Clinical and pharmacokinetic studies in patients with advanced colo-rectal carcinoma have indicated a significant rate of disease stabilization (39%) in this chemo-refractory population and significant prolongation of median survival in patients attaining stable disease (13.9months) versus progressive disease patients (6.35months). The pharmacokinetics of MLP was typically stealth with long T½ (~1day), slow clearance and small volume of distribution. Interestingly, a longer T½, and slower clearance were both correlated with disease stabilization and longer survival. This association of pharmacokinetic parameters with patient outcome suggests that arrest of tumor growth is related to the enhanced tumor localization of long-circulating liposomes and highlights the importance of personalized pharmacokinetic evaluation in the clinical use of nanomedicines. Another important area where PL-MLP may have an added value is in chemoradiotherapy, where it has shown a strong radiosensitizing effect in animal models based on a unique mechanism of enhanced prodrug activation and encouraging results in early human testing.

Association of pre-surgery to pre-radiotherapy lymphocyte counts ratio with disease-free survival in rectal cancer patients receiving neoadjuvant concurrent chemoradiotherapy

BackgroundColorectal cancer is the fourth most common cancer globally and neoadjuvant concurrent chemoradiotherapy (nCRT) and surgery are the standard treatments for locally advanced colorectal carcinoma. This study investigated the association between dynamic changes in absolute lymphocyte counts (ALCs) and disease-free survival (DFS) in rectal cancer patients receiving nCRT and identified factors associated with these changes.MethodsWe retrospectively examined 34 patients with locally advanced rectal cancer who received nCRT followed by surgery and adjuvant chemotherapy. The association between ALCs and DFS and that between ALCs and downstaging were analyzed and potential clinical- and treatment-related factors related to dynamic changes in ALCs were subsequently evaluated. The patient eligibility criteria were as follows: pathologically confirmed rectal adenocarcinoma, clinical stages II–III, ≥ 18 years of age, and so on. Pre-RTL was defined as ALCs obtained before the initiation of nCRT and pre-SL was defined as ALCs obtained before surgery. We measured pre-SL to pre-RTL ratio (pre-SLR), DFS, and ALCs.ResultsThe median ALC declined significantly during nCRT. A lower pre-SLR was associated with poorer DFS with statistical significance in Kaplan–Meier (p = 0.007), univariate regression (hazard ratio [HR] = 6.287, 95% confidence interval [CI] 1.374–28.781, p = 0.018), and multivariable regression (HR = 7.347, 95% CI 1.595–33.850, p = 0.011) analyses. Neither patient characteristics nor treatment-related factors were related to downstaging. The pelvic bone marrow (PBM) volume receiving at least 30 Gy (V30) was significantly associated with pre-SLR in the univariate (HR = 5.760, 95% CI 1.317–25.187, p = 0.020) and multivariable (HR = 5.760, 95% CI 1.317–25.187, p = 0.020) regression analyses.LimitationsOur study had several limitations. The sample size was small and the study was performed in a selected population, which may limit the generalization of the findings.ConclusionsRadiotherapy had a profound impact on the change in ALCs. A lower pre-SLR was significantly associated with poorer DFS in rectal cancer patients receiving nCRT. The V30 of PBM was a predictor of pre-SLR.

Lymphovascular and Perineural Invasions Are Independently Associated with Advanced Colorectal Carcinoma

Background: Lymphovascular invasion (LVI) and perineural invasion (PNI) are relatively common in various malignancies including colorectal cancers and have been shown to have prognostic significance. Objectives: The aim of this study was to identify the clinical and pathological variables associated with LVI and PNI in patients with colorectal carcinoma, who have been treated at Milad General Hospital in Tehran, Iran. Methods: The records of the patients with the diagnosis of colorectal carcinoma, who had undergone an operation at Milad General Hospital (Tehran, Iran) between 2012 and 2017, were reviewed. All patients, whose pathology reports and treatment records were available at Milad Hospital, were included. Relevant demographic, pathological, and surgical data, including age, gender, tumor location, maximum tumor size, pathologic Tumor, Node, Metastasis (TNM) stage, and grade and number of removed lymph nodes were extracted from the medical records. Results: In total, 547 patients (374 cases of colon cancer and 173 cases of rectal cancer) enrolled in the study. The prevalence of LVI and PNI was 16.4% and 30.7%, respectively. LVI and PNI were found to be associated with higher tumor grade, higher T-stage, and higher overall stage. Conclusions: Colorectal carcinomas with positive LVI or PNI are more likely to have a higher grade, higher T-stage, and higher overall stage, and PNI is an independent factor for advanced disease.

Prognostic Value of CDX2 and Villin Expression in Advanced Stage Colorectal Carcinoma.

To determine the frequency of expression of CDX2 and Villin in a subsection of advanced stage primary colorectal cancers and detect its association with tumour differentiation, lymph node metastasis, invasion and survival. A descriptive study. Ortadogu Private Hospital, Adana, Turkey, from January 2012 to March 2017. Formalin-fixed, paraffin-embedded tissue specimens were obtained from 70 patients who underwent surgery for colorectal carcinoma. Inclusion criteria were patients who underwent surgery with stage 3 and stage 4 colorectal cancer. The exclusion criteria were patients who had recurrent colorectal cancer and/or accompanying cancer in another region. Immunohistochemical technique was used for the localisation of CDX2 and Villin in colorectal cancer tissues. The catagorical variables between the groups was analysed by using the Chi-square test or Fisher Exc. test. Overall survival time was defined as the years elapsed between date of after operation and death as a result of disease (or the last follow-up date). Overall survival was analysed using the Wald test, and the log-rank test was used to examine their relationship when different parameters were applied. The survival curve was plotted using the standard Kaplan-Meier methodology. Values of p <0.05 were considered statistically significant. Both CDX2 and Villin had relation with gender (p=0.045, p=0.016), male and female expression of CDX2 was n=31 (67.4%), n=15 (32.6%), respectively and Villin was n=34 (68.0%), n=16 (32.0%), respectively; age (p=0.804, p=0.791), had no relation with tumor site (p=0.131, p=0.921) and histologic grade (p=0.209, p=0.579) and lymph node metastasis (p=0.063, p=0.392) and perineural invasion (p=0.476, p=0.053) and lymphovasculer invasion (p=0.080, p=0.791) and overall survival ( p=0.121, hep=0.059). CDX2 and Villin were not associated with any of the clinicopathologic parameters. Overall survival analysis also did not show a significant association with immunoexpression of these molecules and survival. CDX2 and Villin might not be useful as a prognostic factor in advanced stage colorectal carcinoma.

Identification of Eph receptor signaling as a regulator of autophagy and a therapeutic target in colorectal carcinoma.

Advanced colorectal carcinoma is currently incurable, and new therapies are urgently needed. We report that phosphotyrosine‐dependent Eph receptor signaling sustains colorectal carcinoma cell survival, thereby uncovering a survival pathway active in colorectal carcinoma cells. We find that genetic and biochemical inhibition of Eph tyrosine kinase activity or depletion of the Eph ligand EphrinB2 reproducibly induces colorectal carcinoma cell death by autophagy. Spautin and 3‐methyladenine, inhibitors of early steps in the autophagic pathway, significantly reduce autophagy‐mediated cell death that follows inhibition of phosphotyrosine‐dependent Eph signaling in colorectal cancer cells. A small‐molecule inhibitor of the Eph kinase, NVP‐BHG712 or its regioisomer NVP‐Iso, reduces human colorectal cancer cell growth in vitro and tumor growth in mice. Colorectal cancers express the EphrinB ligand and its Eph receptors at significantly higher levels than numerous other cancer types, supporting Eph signaling inhibition as a potential new strategy for the broad treatment of colorectal carcinoma.

Meta-analysis of the role of colonoscopy after an episode of left-sided acute diverticulitis.

BackgroundRoutine colonoscopy was traditionally recommended after acute diverticulitis to exclude coexistent malignancy. Improved CT imaging may make routine colonoscopy less required over time but most guidelines still recommend it. The aim of this review was to assess the role of colonoscopy in patients with CT‐proven acute diverticulitis.MethodsPubMed and Embase were searched for studies reporting the prevalence of advanced colorectal neoplasia (ACN) or colorectal carcinoma in patients who underwent colonoscopy within 1 year after CT‐proven left‐sided acute diverticulitis. The prevalence was pooled using a random‐effects model and, if possible, compared with that among asymptomatic controls.ResultsSeventeen studies with 3296 patients were included. The pooled prevalence of ACN was 6·9 (95 per cent c.i. 5·0 to 9·4) per cent and that of colorectal carcinoma was 2·1 (1·5 to 3·1) per cent. Only two studies reported a comparison with asymptomatic controls, showing comparable risks (risk ratio 1·80, 95 per cent c.i. 0·66 to 4·96). In subgroup analysis of patients with uncomplicated acute diverticulitis, the prevalence of colorectal carcinoma was only 0·5 (0·2 to 1·2) per cent.ConclusionRoutine colonoscopy may be omitted in patients with uncomplicated diverticulitis if CT imaging is otherwise clear. Patients with complicated disease or ongoing symptoms should undergo colonoscopy.

Nanoparticulate delivery of irinotecan active metabolite (SN38) in murine colorectal carcinoma through conjugation to poly (2-ethyl 2-oxazoline)-b-poly (L-glutamic acid) double hydrophilic copolymer

SN-38 is the active metabolite of irinotecan, an FDA-approved chemotherapeutic agent indicated for colorectal carcinoma, which would not be clinically applicable due to its very poorly soluble and hydrolytic degradation properties. To overcome these limitations, it was proposed to conjugate SN38 to residing carboxylic acid residues in poly (2-ethyl 2-oxazoline) block poly (L-glutamic acid), inducing nano-assembly in aqueous medium. Following a series of reactions including poly (2-ethyl oxazoline) macro-initiated ring opening polymerization of N-carboxyanhydride, deprotection of benzyl group and chemical conjugation of SN38 via biodegradable ester linkage, the as-synthesized product was characterized by dynamic light scattering, ζ potential and transmission electron microscopy. The resulting particles presented about 90% loading efficiency with a mean size of 90 nm. Upon incubation with colorectal carcinoma CT26 cell line, higher association of SN-38 fluorescence and significantly more specific cytotoxicity was noticed for the SN38 conjugated particles than free drug. Therapeutic applicability of the as-synthesized product was evaluated in CT26 allograft tumor model in BALB/c mice, showing superior efficiency of the SN38 conjugated particles particularly in tumors with sizes larger than 200 mm3 than parent irinotecan and reduced mortality rate by 2.5 times. Conclusively, the poly (2-ethyl 2-oxazoline) decorated nano-conjugates of poly (L-glutamic acid) and SN38 can be regarded as a novel and potentially efficient drug delivery system for advanced colorectal carcinoma.

Long term survival in 200 patients with advanced stage of colorectal carcinoma and diabetes mellitus - a single institution experience.

BackgroundDiabetes mellitus (DM) and DM related comorbidities may initiate difficulties during cancer specific treatment and may have an impact on cancer management and outcome. The aim of our study was to find out if DM in patients with advanced colorectal carcinoma (CRC) is associated with cancer-specific or overall survival.Patients and methodsThis study included 200 consecutive patients (131 males, 69 females, mean age 63 years) with elective CRC surgery at the Institute of Oncology Ljubljana and DM was found in 39 (19.5%) of them. Even 64% of patients had Stage 3 or 4 disease, so neo-adjuvant chemotherapy (CTX) and/or radiotherapy (RT) were carried out in 59% of cases. Data about gender, age, body mass index, presence of DM, American Society of Anesthesiologists (ASA) physical status score, stage of disease and postoperative complications were collected prospectively. Cancer-specific survival and overall survival were compared by log-rank test.ResultsPatients with DM had a higher ASA score, BMI, the illness marker, rate of massive bleeding, blood transfusion and longer hospital stay than those without DM. The mean follow-up period was 4.75 years. All causes mortality in patients with DM and without DM was 23% and 27%, respectively. Three-year cancer-specific survival in patients with DM and without DM was 85% and 89%, respectively (p = 0.68). Three-year overall survival in patients with DM and without DM was 82% and 84%, respectively (p = 0.63).ConclusionsThe presence of DM was not associated with tumor stage, disease-specific survival or overall survival in patients with advanced CRC.

Analysis of DNA Damage Response Gene Alterations and Tumor Mutational Burden Across 17,486 Tubular Gastrointestinal Carcinomas: Implications for Therapy.

Alterations in the DNA damage response (DDR) pathway confer sensitivity to certain chemotherapies, radiation, and other DNA damage repair targeted therapies. BRCA1/2 are the most well-studied DDR genes, but recurrent alterations are described in other DDR pathway members across cancers. Deleterious DDR alterations may sensitize tumor cells to poly (ADP-ribose) polymerase inhibition, but there are also increasing data suggesting that there may also be synergy with immune checkpoint inhibitors. The relevance of DDR defects in gastrointestinal (GI) cancers is understudied. We sought to characterize DDR-defective GI malignancies and to explore genomic context and tumor mutational burden (TMB) to provide a platform for future rational investigations. Tumor samples from 17,486 unique patients with advanced colorectal, gastroesophageal, or small bowel carcinomas were assayed using hybrid-capture-based comprehensive genomic profiling including sequencing of 10 predefined DDR genes: ARID1A, ATM, ATR, BRCA1, BRCA2, CDK12, CHEK1, CHEK2, PALB2, and RAD51. TMB (mutations per megabase [mut/Mb]) was calculated from up to 1.14 Mb of sequenced DNA. Clinicopathologic features were extracted and descriptive statistics were used to explore genomic relationships among identified subgroups. DDR alterations were found in 17% of cases: gastric adenocarcinoma 475/1,750 (27%), small bowel adenocarcinoma 148/666 (22%), esophageal adenocarcinoma 467/2,501 (19%), and colorectal cancer 1,824/12,569 (15%). ARID1A (9.2%) and ATM (4.7%) were the most commonly altered DDR genes in this series, followed by BRCA2 (2.3%), BRCA1 (1.1%), CHEK2 (1.0%), ATR (0.8%), CDK12 (0.7%), PALB2 (0.6%), CHEK1 (0.1%) and RAD51 (0.1%). More than one DDR gene alteration was found in 24% of cases. High microsatellite instability (MSI-H) and high TMB (TMB-H, ≥20 mut/Mb) were found in 19% and 21% of DDR-altered cases, respectively. Of DDR-altered/TMB-H cases, 87% were also MSI-H. However, even in the microsatellite stable (MSS)/DDR-wild-type (WT) versus MSS/DDR-altered, TMB-high was seen more frequently (0.4% vs. 3.3%, P < .00001.) Median TMB was 5.4 mut/Mb in the MSS/DDR-altered subset versus 3.8 mut/Mb in the MSS/DDR-WT subset (P ≤ .00001), and ATR alterations were enriched in the MSS/TMB-high cases. This is the largest study to examine selected DDR defects in tubular GI cancers and confirms that DDR defects are relatively common and that there is an association between the selected DDR defects and a high TMB in more than 20% of cases. Microsatellite stable DDR-defective tumors with elevated TMB warrant further exploration. Deleterious DNA damage response (DDR) alterations may sensitize tumor cells to poly (ADP-ribose) polymerase inhibition, but also potentially to immune checkpoint inhibitors, owing to accumulation of mutations in DDR-defective tumors. The relevance of DDR defects in gastrointestinal (GI) cancers is understudied. This article characterizes DDR-defective GI malignancies and explores genomic context and tumor mutational burden to provide a platform for future rational investigations.

Colorectal Carcinomas Containing Hypermethylated MLH1 Promoter and Wild-Type BRAF/KRAS Are Enriched for Targetable Kinase Fusions.

Kinase fusions are rare and poorly characterized in colorectal carcinoma, yet they present unique opportunities for targeted therapy. In this study, we characterized kinase fusions from patients with advanced colorectal carcinoma who had MSK-IMPACT testing of their tumors between January 2014 and June 2018. Patients were analyzed for the presence of fusions, microsatellite instability (MSI), and RAS/BRAF mutations. Mismatch repair (MMR), IHC, and promoter hypermethylation status of MLH1 (MLH1ph) in microsatellite instability-high (MSI-H) colorectal carcinoma with fusions were investigated. Fusion transcripts were confirmed using a targeted RNA-seq panel assay. Of 2,314 colorectal carcinomas with MSK-IMPACT testing, 21 harbored kinase fusions. Overall 57% (12/21) of colorectal carcinoma fusions were MSI-H/MMR-D. Loss of MLH1 and MLH1ph was confirmed in all 12 and all 10 cases with available material, respectively. Fusions were present in 5% of MSI-H/MMR-D colorectal carcinoma compared with 0.4% of MSS/MMR-P colorectal carcinoma (P < 0.001) and 15% of MSI-H/MMR-D colorectal carcinoma with wild-type RAS/BRAF. Of 24 total MLH1-deficient colorectal carcinomas with MLH1ph and wild-type RAS/BRAF, 10 (42%) harbored kinase fusions. Kinase fusions in MSI-H colorectal carcinoma were associated with sporadic MLH1ph rather than with Lynch syndrome, and these patients may be eligible for kinase inhibitors, particularly following resistance or toxicity in response to immunotherapy. These findings identify a molecular subset of colorectal carcinoma with kinase fusions that may be responsive to kinase inhibitors.Significance: A high frequency of targetable kinase fusions in BRAF/RAS wild-type, MSI-H colorectal carcinoma offers a rationale for routine screening to identify patients with colorectal carcinoma with kinase fusions that may be responsive to kinase inhibitors.See related commentary by Valeri, p. 1041.

Metagenomic analyses of the gut microbiota associated with colorectal adenoma.

Recent studies have suggested an association between certain members of the Fusobacterium genus, especially F. nucleatum, and the progression of advanced colorectal carcinoma (CRC). We assessed such an association of the gut microbiota in Japanese patients with colorectal adenoma (CRA) or intramucosal CRC using colonoscopy aspirates. We analyzed samples from 81 Japanese patients, including 47 CRA and 24 intramucosal CRC patients, and 10 healthy subjects. Metagenomic analysis of the V3-V4 region of the 16S ribosomal RNA gene was performed. The linear discriminant analysis (LDA) effect size (LEfSe) method was used to examine microbial dysbiosis, revealing significant differences in bacterial abundances between the healthy controls and CRA or intramucosal CRC patients. In particular, F. varium was statistically more abundant in patients with CRA and intramucosal CRC than in healthy subjects. Here, we present the metagenomic profile of CRA and intramucosal CRC and demonstrate that F. varium is at least partially involved in the pathogenesis of CRA and intramucosal CRC.

CCTG CO.26 trial: A phase II randomized study of durvalumab (D) plus tremelimumab (T) and best supportive care (BSC) versus BSC alone in patients (pts) with advanced refractory colorectal carcinoma (rCRC).

481 Background: D is a human monoclonal antibody (mAb) that inhibits binding of programmed cell death ligand 1 (PD-L1) to its receptor. T is a mAb against the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). Targeting both PD-L1 and CTLA-4 may have additive/synergistic activity as the mechanisms of action of CTLA-4 and PD-L1 inhibition are non-redundant. This study evaluated whether combining PD-L1 and CTLA-4 inhibition would lead to improved pt survival vs BSC alone in rCRC. Methods: Pts with rCRC were randomized 2:1 to D+T vs BSC . Pts were eligible if they failed all standard regimens; containing a fluoropyrimidine, irinotecan and oxaliplatin (and an EGFR inhibitor if Ras wild type). Prior treatment (Tx) with anti-VEGF agents or TAS-102 was permitted but not mandatory. Tx consisted of D (1500 mg) D1 q 28 days and T (75 mg) D1 for first 4 cycles, and all appropriate supportive measures. Primary endpoint was overall survival (OS) and a two-sided p-value &lt; 0.10 was considered statistically significant. Results: Between August 2016 and June 2017, 180 pts were enrolled and 179 treated as randomized. Pt baseline characteristics were balanced. 85% of pts received ≥ 90% of planned doses of D and T. No pts with known defective mismatch repair (dMMR) tumors were enrolled. With a median (med) follow-up of 15.2 months (mo), the med OS was 6.6 mo for D+T and 4.1 mo for BSC (p = 0.07; Hazard ratio (HR): 0.72, 90% confidence interval (CI): 0.54–0.97). Med progression free survival was 1.8 mo and 1.9 mo respectively (HR 1.01, 90% CI 0.76–1.34; p=0.97). Disease control rate was 22.7% for D+T and 6.6% for BSC (p = 0.006). Grade 3/4 abdominal pain, fatigue, lymphocytosis and eosinophilia were significantly higher in D+T. At 16 weeks, there was significantly less deterioration on EORTC QLQ-C30 physical function for D+T. Confirmation of MMR status is ongoing. Conclusions: D+T significantly prolonged OS in pts with rCRC and preserved quality of life. Adverse events were more frequent with D+T. This is the first study showing that combined PD-L1 and CTLA-4 inhibition prolongs survival in pts with advanced refractory CRC not selected for dMMR. Clinical trial information: NCT02870920.

Anticancer response to disulfiram may be enhanced by co-treatment with MEK inhibitor or oxaliplatin: modulation by tetrathiomolybdate, KRAS/BRAF mutations and c-MYC/p53 status.

Ammonium tetrathiomolybdate (TTM) and disulfiram (DSF) are copper (Cu) chelators in cancer clinical trials partly because Cu chelation: a) restricts the activity of Cu-binding MEK1/2 enzymes which drive tumourigenesis by KRAS or BRAF oncogenic mutations and b) enhances uptake of oxaliplatin (OxPt), clinically used in advanced KRAS-mutant colorectal carcinomas (CRC). Whereas TTM decreases intracellular Cu trafficking, DSF can reach other Cu-dependent intracellular proteins. Since the use of individual or combined Cu chelation may help or interfere with anti-cancer therapy, this study investigated whether TTM modifies the response to DSF supplemented with: 1) UO126, a known MEK1/2 inhibitor; 2) other Cu chelators like neocuproine (NC) or 1, 10-o-phenanthroline (OPT) in wt p53 melanoma cells differing in BRAF or KRAS mutations; 3) OxPt in mutant p53 CRC cells devoid of KRAS and BRAF mutations or harbouring either KRAS or BRAF mutations. TTM was not toxic against V600E-mut-BRAF A375 and G12D-mut-KRAS/high c-myc C8161 melanoma cells. Moreover, TTM protected both melanoma types from toxicity induced by DSF, NC and co-treatment with sub-lethal levels of DSF and the MEK inhibitor, UO126. Toxicity by co-treatment with DSF+OPT was poorly reversed by TTM in C8161 melanoma cells. In contrast to the greater toxicity of 0.1 μM DSF against mutant p53 CRC cells irrespective of their KRAS mutation, TTM did not protect G12V-mut-KRAS/high c-myc SW620 CRC from DSF+OxPt compared to KRAS-WT/BRAF-WT Caco-2 CRC. Our results show that DSF co-treatment with: a) MEK inhibitors may enhance tumour suppression; b) OxPt in CRC may counteract impaired response to cetuximab by KRAS/BRAF mutations and c) as a single treatment, TTM may be less effective than DSF and decreases the efficacy of the latter.HighlightsPotentiation of melanoma antitumour toxicity of DSF by MEK inhibitor is reversed by TTM.KRAS/c-MYC dysregulation attenuates TTM reversion of melanoma toxicity by DSF + OPT.KRAS/c-MYC dysregulation increases melanoma NC toxicity reversed by TTM.BRAF mutation and lower c-MYC may attenuate toxicity by DSF ± OxPt in colorectal cancer cells

Circulating Myeloid-Derived Suppressor Cell Subsets in Patients with Colorectal Cancer – Exploratory Analysis of Their Biomarker Potential

Myeloid-derived suppressor cells (MDSCs) contribute to tumor escape from host immune surveillance and to tumor progression by producing tumor-promoting factors. We focused on clinical and analytical MDSCs-related issues as potential biomarkers and immune regulators involved in tumor progression. We analyzed 10 patients with advanced colorectal carcinoma (CRC) with (M1 subgroup) or without (M0 subgroup) distant metastases at diagnosis. Peripheral blood was collected at diagnosis prior to treatment and subsequently 12 months after therapy initiation. Using multicolor flow cytometry MDSC subsets were evaluated. Monocytic MDSCs (M-MDSCs) were detected as CD45+ CD11b+ CD33+ HLA-DRlow/ CD14+ CD15-, granulocytic MDSCs (CD33hi PMN-MDSC) were detected as CD45+ CD11b+ CD33hi HLA-DRlow/ CD14 CD15+. For analytical and preanalytical studies, random fresh blood specimens predominantly from cancer patients were analyzed. Levels of circulating M-MDSCs were not associated with metastatic disease within advanced CRC patients. Levels of circulating CD33hi PMN-MDSCs were elevated in patients with distant metastases compared to T3 M0 subgroup. Circulating M-MDSCs increased upon treatment initiation in 9 out of 10 patients. CD33hi PMN-MDSCs substantially dropped upon treatment initiation in 5 out of 10 patients and substantially increased in 2 out of 10 patients. Analytical part showed that absolute and relative counts within each MDSC subset are correlated. Coefficient of variation (CV) for repeatability was 6-11% for M-MDSCs and 25-44% for CD33hi PMN-MDSCs. CV for reproducibility was higher with 8-22% for M-MDSCs and 35-79% for CD33hi PMN-MDSCs demonstrating that delay in measurement of MDSCs in whole blood specimen may distort quantification of circulating MDSC subsets. The quantification of MDSC subsets is substantially dependent on the type of specimen examined and its preanalytical processing. Exploratory analysis of M-MDSCs and CD33hi PMN-MDSCs in CRC patients revealed different dynamics of M-MDSC and CD33hi PMN-MDSC subsets in the context anti-cancer treatment. Key words: myeloid-derived suppressor cells - preanalytics - colorectal cancer - flow cytometry - immune monitoring.

Advanced colorectal carcinoma with testicular metastasis in an adolescent: a case report

BackgroundColorectal carcinoma in the pediatric age group is rare and tends to be very aggressive and present late, due to which it has a very poor prognosis. It may present with distant metastasis; however, metastasis to the testes is very rare and signifies an advanced stage of the disease. Surgery is the only effective modality to cure patients with localized colorectal carcinomas. However, statistics show a higher incidence of unresectable disease and a higher metastasis rate in childhood colorectal carcinomas. We present a case of advanced colorectal carcinoma with testicular metastasis in an adolescent.Case presentationA 15-year-old Indian Hindu boy presented to surgical emergency with signs and symptoms of intestinal obstruction. He also had a history of passing blood and mucus per rectum. On examination he had abdominal distension. On digital rectal examination, a circumferential proliferative growth was felt 1 cm above the anal verge. On scrotal examination, a small nodule was felt in his right testis. In view of intestinal obstruction, he was taken into our emergency operation theater and a diverting loop sigmoid colostomy was performed to relieve the obstruction. A punch biopsy from anorectal growth was taken which suggested signet ring cell adenocarcinoma. Contrast-enhanced computed tomography of his chest, abdomen, and pelvis showed advanced colorectal carcinoma with distant metastasis. Ultrasonography of his testes showed a hypoechoic nodule in the right testis from which a needle aspiration biopsy was done which revealed metastatic adenocarcinoma.ConclusionsChildhood colorectal carcinomas have a very poor prognosis due to their aggressive nature and late presentation. In spite of all the advances in diagnosis and treatments, the overall long-term survival is still dismal in these patients. Due to the rarity of this disease, screening is not recommended for individuals under the age of 50. Thus, to improve outcome, early diagnosis and treatment is paramount. For that to happen, awareness needs to be created regarding pediatric colorectal carcinoma and its signs and symptoms.

Advanced Colorectal Carcinoma with Testicular Metastasis in an Adolescent: A Case Report

Advanced Colorectal Carcinoma with Testicular Metastasis in an Adolescent: A Case Report

Early Incidence of Malignant and Pre-Malignant Colorectal Lesions: Evaluation of 310 Cases

Introduction: The colorectal carcinoma (CRC) presents a high rate of morbidity and mortality in the world. Recent studies suggest an increase in the incidence of sporadic lesions at early ages, questioning the anticipation of CRC screening. Very recently, the American Cancer Society has released a new recommendations saying that the screening of CRC should begginning at age of 45 years. The main of this study was to determine the incidence of colic lesions (polyps / CCR) in individuals aged 40-49 years, evaluating their clinical and pathological characteristics. Methods: Retrospective and monocentric study in patients with age between 40 and 49 years-old, whose performed a colonoscopy/flexible rectosigmoidoscopy between January/2010 and June/2017, with a diagnostic of polyps or coloretal carcinoma. Patients with diagnosis of inflammatory bowel disease were excluded. Results: A total of 2106 patients were included, obtaining the diagnosis of polyps/CCR in 310 (15%). The majority (58%) were men, with a median age of 43 years (IQR 41 - 46). There was a relevant familiar history, mainly of CRC, in 24% of cases, and the presence of symptoms motivated the colonoscopy in 38% of individuals. Among the population with diagnosis of polyps, 77% has less than three lesions and in 39% of cases the lesion was a size between 5 and 9 mm. The majority (66%) of lesions were located to the rectum and sigmoid colon. The polyps were adenomatous in 55% of cases; of these, 79% had a tubular structure and 92% had low grade dysplasia. The presence of adenomas was associated with lesions greater than 5 mm (p<0.001) and the presence of symptoms (p=0.017). In 41% of cases, the adenomas were classified as advanced, which was associated with male Gender (p=0.073) and the presence ofsynchronous lesions (p=0.002). The diagnosis of CRC occurred in 31 patients (10%) and 52% of cases were in stage 4. The majority were in the rectum and sigmoid colon and their presence was associated with the existence of symptoms prior to colonoscopy (p=0.001) and the positivity for synchronous lesions (p=0.001). Conclusion: The incidence of colorectal lesions, namely advanced adenomas and CRC was higher than expected and described in the literature, reinforcing the eventual need to revise current recommendations.