Chemotherapy outcome predictive effectiveness by the Oncogramme: pilot trial on stage-IV colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) remains a major public concern. While conventional chemotherapeutic regimens have proved useful against advanced/metastatic diseases, progresses are to be made to effectively cure the large portion of patients not benefiting from these treatments. One direction to improve response rates is to develop chemosensitivity and resistance assays (CSRAs) efficiently assisting clinicians in treatment selection process, an already long preoccupation of oncologists and researchers. Several methods have been described to this day, none achieving yet sufficient reliability for recommended use in the clinical routine. METHODS: We led a pilot study on 19 metastatic CRC patients evaluating capacity of the Oncogramme, a standardized process using tumor ex vivo models, to provide chemosensitivity profiles and predict clinical outcome of patients receiving standard CRC chemotherapeutics. Oncogramme responses were categorized according to the method of percentiles to assess sensitivity, specificity and concordance. RESULTS: We report from a primary analysis a success rate of 97.4 %, a very good sensitivity (84.6 %), a below-average specificity (33.3 %), along with a global agreement of 63.6 % and a concordance between Oncogramme results and patients' responses (Kappa coefficient) of 0.193. A supplementary analysis, focusing on CRC patients with no treatment switch over a longer time course, demonstrated improvement in specificity and concordance. CONCLUSIONS: Results establish feasibility and usefulness of the Oncogramme, prelude to a larger-scale trial. Advantages and drawbacks of the procedure are discussed, as well as the place of CSRAs within the future arsenal of methods available to clinicians to individualize treatments and improve patient prognosis. TRIAL REGISTRATION: ClinicalTrials.gov database, registration number: NCT02305368.

Psychoactive drugs influence brain-derived neurotrophic factor and neurotrophin 4/5 levels in the serum of colorectal cancer patients.

Previous studies have reported the association between brain-derived neurotrophic factor (BDNF) and tumor development in numerous cancers. However, the accurate implication of the two specific ligands of tropomyosin kinase B receptor, BDNF and neurotrophic factor 4 (NT4/5), has not been studied in colorectal cancer (CRC) patients. The present study investigated the significance of serum BDNF and the NT4/5 in association with the intake of psychoactive drugs in CRC patients. Soluble BDNF and NT4 in the serum were assessed by ELISA. Although no correlation of BDNF and NT4 with the CRC stage was identified, a positive correlation was found between NT4 and the intake of psychoactive drugs (P=0.0457). For BDNF, a correlation was found in particular with the intake of benzodiazepine (P=0.0221). As BDNF and NT4/5 are implicated in the response of psychoactive treatments applied to manage depression, which frequently occurs in cancer patients, they cannot be used as prognostic or diagnostic markers for CRC in these patients. However, high expression of BDNF and NT4 was significantly associated with better survival. Therefore, these NTs may be used as markers for monitoring depression or predicting survival in CRC patients.

Circulating DNA as a Strong Multimarker Prognostic Tool for Metastatic Colorectal Cancer Patient Management Care.

PURPOSE: Circulating cell-free DNA (ccfDNA) is a valuable source of tumor material obtained from a simple blood sampling that enables noninvasive analysis of the tumor genome. Our goal was to carry out a multiparametric analysis of ccfDNA and evaluate its prognostic value by investigating the overall survival (OS) of 97 metastatic colorectal cancer patients (mCRC). EXPERIMENTAL DESIGN: Qualitative parameters (determination of the main KRAS exon2 and BRAF V600E mutations) and quantitative parameters (total ccfDNA concentration, mutant ccfDNA concentration, the proportion of mutant ccfDNA, and ccfDNA integrity index) were determined simultaneously in a single run using a unique Q-PCR multimarker approach (100% success rate). RESULTS: The median follow-up time was 36 months and median OS was 22 months. Patients showing high ccfDNA levels had significantly shorter OS (18.07 months vs. 28.5 months, P = 0.0087). Moreover, multivariate analysis revealed that a high ccfDNA level is an independent prognostic factor (P = 0.034). All ccfDNA parameters were of prognostic interest: patients with higher levels of mutant ccfDNA and higher mutation loads for the detected mutations had shorter OS (P = 0.0089 and P = 0.05, respectively). In addition, the level of ccfDNA fragmentation correlated positively with decreased OS in the exclusive KRAS/BRAF-mutant cohort of patients (P = 0.0052) and appeared as a strong independent prognostic factor (P = 0.0072), whereas it was not significant in the exclusive KRAS/BRAF WT cohort of patients (P = 0.67). CONCLUSIONS: Our data provide for the first time qualitative and quantitative evidence in favor of multiparametric ccfDNA analysis in mCRC patients for prognostic assessment. Clin Cancer Res; 22(12); 3067-77. ©2016 AACR.

Clinical validation of the detection of KRAS and BRAF mutations from circulating tumor DNA.

Assessment of KRAS status is mandatory in patients with metastatic colorectal cancer (mCRC) before applying targeted therapy. We describe here a blinded prospective study to compare KRAS and BRAF mutation status data obtained from the analysis of tumor tissue by routine gold-standard methods and of plasma DNA using a quantitative PCR-based method specifically designed to analyze circulating cell-free DNA (cfDNA). The mutation status was determined by both methods from 106 patient samples. cfDNA analysis showed 100% specificity and sensitivity for the BRAF V600E mutation. For the seven tested KRAS point mutations, the method exhibited 98% specificity and 92% sensitivity with a concordance value of 96%. Mutation load, expressed as the proportion of mutant alleles in cfDNA, was highly variable (0.5-64.1%, median 10.5%) among mutated samples. CfDNA was detected in 100% of patients with mCRC. This study shows that liquid biopsy through cfDNA analysis could advantageously replace tumor-section analysis and expand the scope of personalized medicine for patients with cancer.

Implications of cleaved caspase 3 and AIF expression in colorectal cancer based on patient age.

A high incidence of colorectal cancer (CRC) has been established in the elderly population. Apoptosis is a key event in maintaining colon homeostasis, both in aging as well as in cancer prevention. Here, we report that colon morphology is affected during the aging process: crypt loss (P=0.045) and increasing distances between crypts (P=0.0001678) were observed, associated with a tendency for mucosa reduction (P=0.083). In addition, our results show that apoptosis plays a determining role on the effect of aging during CRC. Increased expression of cleaved caspase 3 (the key factor implicated in the caspase-dependent pathway; P=0.026 for non-tumor tissues, P=0.0013 for tumor tissues) and AIF (implicated in the caspase-independent pathway; P=0.037) in tissue from elderly patients has been observed. Furthermore, elderly patients respond better to chemotherapy than younger ones (P=9.27 x 10(-5)). These results suggest that patient age should be taken into account to adapt treatment of CRC.

Expression of p53 and DR5 in normal and malignant tissues of colorectal cancer: correlation with advanced stages.

Apoptosis has to be drastically controlled in organs with important cell turnover such as the colon. Deregulation of this process is often present in tumor progression. Tissues of 82 patients treated for colorectal cancer (CRC) were analyzed using antibodies against AIF, p53, DR4, DR5, cleaved caspase-3 and the TUNEL method to detect apoptosis; whereas staining of Ki-67 was used as a proliferation marker. In situ immunohistochemical analyses were compared in non-tumor (NT) cells from normal adjacent mucous membranes with tumor (T) cells from patients with Stage I (n=6), Stage II (n=35), Stage III (n=27) and Stage IV (n=14) CRC. Results were correlated with the tumor stages and the treatment response of patients to improve the understanding of CRC development. p53 and DR5 expression decreased progressively with CRC stage, suggesting that these proteins are important markers of advanced tumor stages. Moreover, p53 appears as a prognostic factor to predict recurrence-free survival. Including the detection of p53 and DR5 for establishing the diagnosis of CRC and adapting the treatment to each patient is strongly suggested by our work.

Retinoid acid receptors in human colorectal cancer: An unexpected link with patient outcome.

The status of the three retinoic acid receptors (RARs) α, ß and γ in human colorectal cancer (CRC) has not as yet been examined. RARs are in part responsible for the actions of the retinoids (vitamin A and its derivatives), which are essential for human health and survival due to their extensive involvement in numerous cellular processes, in particular in epithelial morphology. The present study examined the expression of the three RARs in CRC using immunohistochemical analysis of paraffin-embedded tissue sections. RAR expression in tumor (T) and adjacent non-tumor (NT) specimens from stage I (n=6), stage II (n=34), stage III (n=26) and stage IV (n=14) CRC patients was compared with that in normal mucous membranes (n=10) from control individuals. The findings were correlated with tumor grade, treatment response (progression during treatment, remission, chemoresistance) and survival as clinicopathological parameters. RARα and γ expression was decreased with CRC stage in the T tissues (P=0.016 and P=0.052, respectively), suggesting that they may be used as predictive markers. RARß expression in the NT tissues was associated with a more favorable prognosis (P=0.04). These results provide important information on the tumor microenvironment (the area adjacent to tumor cells).