Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Transcription profiling of rectal adenocarcinomas biopsied before and after pre-operative short-course radiotherapy or 5-flurouracil-based chemoradiotherapy

ABSTRACT: The molecular mechanisms of clinical response or resistance to therapy were evaluated in colorectal cancer patients in a prospective biomarker discovery project. Rectal adenocarcinomas, biopsied before (diagnostic biopsy) and after (surgical resection) pre-operative short-course radiotherapy [RT] or 5-flurouracil (5-FU)-based chemoradiotherapy [CRT], were profiled using Affymetrix HGU133 Plus 2.0 microarrays. Tumour tissues from untreated controls at diagnosis and surgical resection were used to identify treatment-independent gene expression changes. Candidate resistance biomarkers were identified in this pilot study for validation in a larger cohort.

ORGANISM(S): Homo sapiens

SUBMITTER: Elaina Collie-Duguid

PROVIDER: E-MEXP-1901 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Publications

APRIL is a novel clinical chemo-resistance biomarker in colorectal adenocarcinoma identified by gene expression profiling.

Petty Russell D RD Samuel Leslie M LM Murray Graeme I GI MacDonald Graham G O'Kelly Terrence T Loudon Malcolm M Binnie Norman N Aly Emad E McKinlay Aileen A Wang Weiguang W Gilbert Fiona F Semple Scot S Collie-Duguid Elaina S R ES

BMC cancer 20091211

<h4>Background</h4>5-Fluorouracil(5FU) and oral analogues, such as capecitabine, remain one of the most useful agents for the treatment of colorectal adenocarcinoma. Low toxicity and convenience of administration facilitate use, however clinical resistance is a major limitation. Investigation has failed to fully explain the molecular mechanisms of resistance and no clinically useful predictive biomarkers for 5FU resistance have been identified. We investigated the molecular mechanisms of clinica ...[more]

PMID: 20003335

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Project description:Using Human WG CodeLink microarrays, we established the expression profiling of 26 LARC without metastasis to gain insight into the molecular signatures associated with response to treatment after CRT. The study initially included a total of 35 consecutive patients with locally advanced rectal cancer (LARC) treated at Virgen de las Nieves Hospital from 2008 until 2010. Written informed consent was obtained from all the patients, and the study protocol was approved by the local Clinical Research (Ethics) Committee. They were distributed in two subgroups following a histological classification of response to treatment. Pretherapeutic staging was performed, including complete medical history and physical evaluation, digital rectal examination, endorectal ultrasound, rigid rectoscopy, colonoscopy, PET/TC and chest x-ray. Tumor samples were prospectively obtained during the rectoscopy. All patients subsequently received a total dose of 50.4Gy of radiatio (28 fractions of 1.8Gy) associated with capecitabine or capecitabine and oxaliplatine. Standardized surgery was performed, including total mesorectal excision, after an interval of 8 weeks after chemoradiotherapy. Tumor response was assessed in surgical specimen by semi-quantitative pathological examination (regression grade) including UICC stage. Histopathological tumor regression was graded based on the semiquantitative 5 point tumor regression grading (TRG) system: TRG1 or a TRG2 scores were considered Responders, whereas TRG3, TRG4, and TRG5 scores were classified as Non-Responders. In addition, the tumor regression or radiotherapy effects were assessed by positron emission tomography (18F-FDG PET). Tumor samples of LARC were collected from 35 patients. Nine patients were finally excluded due to the poor quality of the RNA or contradictory results of MandardM-BM-4s criteria and histopathological downstaging, resulting a total of 26 patients. Complete clinical data regarding, age, sex, stage of disease, response to therapy, and overall survival from 26 patients (10 responders and 16 non-responders) was provided in the sample characteristics field. CRT: Chemoradiation; Cap: Capecitabine; Capox: Capecitabine and Oxaliplatine; cTN: clinical stage; Surg: surgical technique; LAR: Low anterior resection; APR: Abdmino-perineal resection; HART: Hartmann, TRG: Tumor Regression Grade; Downst: Downstaging; Downs: downsizing, Resp: response, CPR: complete pathologic response

Dataset Information

Transcription profiling of rectal adenocarcinomas biopsied before and after pre-operative short-course radiotherapy or 5-flurouracil-based chemoradiotherapy

Publications

APRIL is a novel clinical chemo-resistance biomarker in colorectal adenocarcinoma identified by gene expression profiling.

Similar Datasets

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