Cohort Of Metastatic Colorectal Cancer Patients Research Articles

A consensus molecular subtypes classification strategy for clinical colorectal cancer tissues.

Consensus Molecular Subtype (CMS) classification of colorectal cancer (CRC) tissues is complicated by RNA degradation upon formalin-fixed paraffin-embedded (FFPE) preservation. Here, we present an FFPE-curated CMS classifier. The CMSFFPE classifier was developed using genes with a high transcript integrity in FFPE-derived RNA. We evaluated the classification accuracy in two FFPE-RNA datasets with matched fresh-frozen (FF) RNA data, and an FF-derived RNA set. An FFPE-RNA application cohort of metastatic CRC patients was established, partly treated with anti-EGFR therapy. Key characteristics per CMS were assessed. Cross-referenced with matched benchmark FF CMS calls, the CMSFFPE classifier strongly improved classification accuracy in two FFPE datasets compared with the original CMSClassifier (63.6% versus 40.9% and 83.3% versus 66.7%, respectively). We recovered CMS-specific recurrence-free survival patterns (CMS4 versus CMS2: hazard ratio 1.75, 95% CI 1.24-2.46). Key molecular and clinical associations of the CMSs were confirmed. In particular, we demonstrated the predictive value of CMS2 and CMS3 for anti-EGFR therapy response (CMS2&3: odds ratio 5.48, 95% CI 1.10-27.27). The CMSFFPE classifier is an optimized FFPE-curated research tool for CMS classification of clinical CRC samples.

Malignant ascites as a marker of peritoneal carcinomatosis burden in patients with colorectal and gastroesophageal cancer.

455 Background: Malignant ascites occurs frequently in patients with gastric cancer (GC) and colorectal cancer (CRC) with peritoneal metastasis (PM). The presence of PM and malignant ascites have been independently reported to confer resistance to systemic therapy and poorer prognosis. However, the occurrence of malignant ascites as a function of increasing peritoneal carcinomatosis burden has been less studied and reported. Methods: We reviewed prospective cohorts of gastric cancer and colorectal cancer patients with PM. The first cohort was a prospective group of GCPM patients receiving bi-directional systemic and peritoneal-directed therapies (catheter-based intraperitoneal chemotherapy and/or pressurized intraperitoneal aerosol chemotherapy respectively) at a tertiary oncology center in Singapore. Clinico-pathological data, including Peritoneal Cancer Index (PCI) and the presence or absence of ascites based on diagnostic laparoscopy, was collected. To orthogonally validate the hypothesis of malignant ascites as a function of peritoneal carcinomatosis burden in gastrointestinal malignancies, we studied the relationship between ascites, PM and survival in an independent cohort of metastatic CRC patients eligible for first-line systemic treatment enrolled in two randomized clinical trials in different Italian cancer centers. Results: In the first cohort of 82 patients with GCPM, the median PCI was 19 (inter-quartile range (IQR) 8 – 26) in the group with ascites and 3 (IQR 1 – 12) in the group without ascites (p=0.005), suggesting ascites occurs with higher PM burden. The median overall survival (OS) was poorer in patients with ascites (13.4 vs 16.4 months, HR 1.6, 95% CI 0.9 – 2.8, p=0.082). The median OS in patients with PCI of <7 was 17.3 months (95% 12.0 – 22.7) and 13.8 months (95% CI 11.0 – 16.6) in those with PCI score >7. In the validation cohort of 900 CRC patients, presence of malignant ascites and PM resulted in poorer survival compared to patients with PM and no malignant ascites (HR for OS PM with ascites vs PM without ascites 2.01 (95% CI 1.37 - 2.96), p<0.001). Interestingly, those with PM and ascites had a poorer survival to those with stage IV disease without peritoneal involvement, while those with PM without ascites did not have a statistically significant difference (PM with malignant ascites vs. no peritoneal disease, HR for OS 2.14, 95% CI 1.57 – 3.01, p=0.007; PM without ascites vs no peritoneal disease, HR for OS 1.10, 95% CI 0.91 – 1.34). Conclusions: Our study of patients with colorectal or gastric cancer and peritoneal metastases suggest the presence of malignant ascites as a function of increased peritoneal carcinomatosis burden among patients with metastatic gastrointestinal malignancies, with correspondingly poorer survival outcomes.

Treatment monitoring in metastatic colorectal cancer patients by quantification and KRAS genotyping of circulating cell-free DNA.

Treatment of metastatic colorectal cancer (CRC) has continuously improved over the last decade. However, disease monitoring remains underdeveloped and mostly dependent on imaging e.g. RECIST 1.1 criteria. The genetic landscape of individual cancers and subsequently occurring treatment-induced evolution remain neglected in current surveillance strategies. Novel biomarkers demand minimally invasive and repetitive tracking of the cancer mutagenome for therapy stratification and to make prognostic predictions. Carcinoembryonic antigen (CEA), a routinely used tumor marker for CRC, does not meet these goals and thus prevents its use as a reliable monitoring tool. A tumor-derived fraction of circulating cell-free DNA (cfDNA), isolated from blood samples, may bypass the limitations of currently available biomarkers and could be a tool for noninvasive disease monitoring. Here, total cfDNA levels differentiated a cohort of metastatic CRC patients from healthy controls. Furthermore, we correlated cfDNA during chemotherapy of 27 stage IV patients with clinical parameters to establish its prognostic and predictive value. Indeed, cfDNA levels in chemotherapy naive patients correlate with the tumor burden and CEA values at diagnosis and increase upon disease progression during 1st and 2nd line treatment. Moreover, we confirm the possibility of cfDNA-based genotyping of KRAS to early detect the emergence of resistance during chemotherapy. These data indicate that repetitive quantitative and mutational analysis of cfDNA might complement current treatment standards but may have also limited value in some patients.

ABC-Transporter Expression Does Not Correlate with Response to Irinotecan in Patients with Metastatic Colorectal Cancer.

Background: Active efflux of irinotecan by ATP-binding cassette (ABC)-transporters, in particular ABCB1 and ABCG2, is a well-established drug resistance mechanism in vitro and in pre-clinical mouse models, but its relevance in colorectal cancer (CRC) patients is unknown. Therefore, we assessed the association between ABC-transporter expression and tumour response to irinotecan in patients with metastatic CRC.Methods: Tissue microarrays of a large cohort of metastatic CRC patients treated with irinotecan in a prospective study (CAIRO study; n=566) were analysed for expression of ABCB1 and ABCG2 by immunohistochemistry. Kaplan-Meier and Cox proportional hazard regression analyses were performed to assess the association of ABC transporter expression with irinotecan response. Gene expression profiles of 17 paired tumours were used to assess the concordance of ABCB1/ABCG2 expression in primary CRC and corresponding metastases.Results: The response to irinotecan was not significantly different between primary tumours with positive versus negative expression of ABCB1 (5.8 vs 5.7 months, p=0.696) or ABCG2 (5.7 vs 6.1 months, p=0.811). Multivariate analysis showed neither ABCB1 nor ABCG2 were independent predictors for progression free survival. There was a mediocre to poor concordance between ABC-transporter expression in paired tumours.Conclusion: In metastatic CRC, ABC-transporter expression in the primary tumour does not predict irinotecan response.

AVASTERB OUEST: A prospective cohort study of unresectable metastatic colon cancer treated successively by FOLFIRI bevacizumab and cetuximab irinotecan

e15103 Background: Bevacizumab and cetuximab regimen are approuved since 2005 in Europe for Metastatic Colorectal Cancer Patients (MCCP). Very few studies have reported data concerning the sequence (FOLFIRI BEVA and after failure CETUXIMAB- CAMPTO) in MCCP from the real world. Methods: Since 2003, in west of France, (Bretagne-Pays de Loire),a network called OMIT(Observatoire des Médicaments et Innovations Thérapeutiques) directed by Regional Health Agencies has been created. This structure gathered prospectively data from MCCP treated with targeted therapies. Since 2006, a cohort of MCCP treated successively by FOLFIRI BEVACIZUMAB (same protocol : same dose) as first line to progression or unacceptable toxicity and CETUXIMAB- CAMPTO after the first line failure was constitued (AVASTERB cohort). Criteria for initial unresectability of metastic lesions was based on investigator's evaluations during local comitee (surgeons and oncologists). In order to have a large follow up, the 35 first patients of the cohort were studied in this abstract.Age, sex, response rate to the different regimens,secondary metastatic lesion resection, time to progression to the different regimens, follow up and overall survival are the criterias studied. Results: Median age 60 years (49–83), Males : 60%, colon 71%,rectum: 17%, colorectal jonction :12%.Response rate(OR+SD)with Folfiri Bevacizumab : 45.7%. 17% of the patients underwent hepatic surgery with curative intent (all during Folfiri bevacizumab) Time to progression with Bevacizumab : 6 months. Fifty eight percent of the patients are still alive with a median follow up of 25 months (11–29)Median overall survival was not reached.The 12 months and 24 months overall survival rates are respectively 71.4% and 45.7% (date of point: 01/01/2009). Actualisation of the data will be provided during the meeting Conclusions: The results from this prospective unselected cohort of MCCP treated with the sequence FOLFIRI BEVA and after failure CETUX-CAMPTO from the real world show promising TTP, and overall survival. The study of the Kras mutation and others biomarkers could improve these results by personalization of the treatment. This part of our study is actually ongoing. No significant financial relationships to disclose.