Metastatic colorectal cancer: Therapeutic options

Pulmonary resection for metastases from colorectal carcinoma

A pulmonary resection of metastatic colorectal carcinoma is an accepted method of treatment. The purpose of this study was to confirm the role of resections for pulmonary metastases from colorectal carcinoma, and to determine the clinical course, outcome, and prognostic factors after surgery. A retrospective analysis was conducted of the records of all patients with pulmonary metastases from colorectal carcinoma who underwent a surgical resection between 1995 and 2008, at a single surgical center. The overall 5-year survival rate was 74%. Multivariate Cox analysis demonstrated that the number of pulmonary metastases (HR: 9.40, 95% confidence interval (CI): 1.08-82.2, P=0.0428) and prethoracotomy carcinoembryonic antigen (CEA) level (HR: 9.79, 95% CI: 1.11-86.8, P=0.0404) were statistically significant predictors of survival after the first pulmonary metastasectomy. In addition, a second resection for recurrent metastases was performed in eight patients, and a third resection was done in one patient. There were no major postoperative complications among the patients who underwent second or third resections. Pulmonary resections are considered to be a safe and effective treatment in selective patients.

Identification of new accessible tumor antigens in human colon cancer by ex vivo protein biotinylation and comparative mass spectrometry analysis

One of the most promising new strategies for the development of efficacious cancer therapies relies on the targeted delivery of biopharmaceutical to the tumor environment by the use of selective and specific antibodies. The identification of accessible perivascular proteins selectively overexpressed in cancer tissue may facilitate the development of antibody-based biopharmaceutical administration. This approach is potentially highly selective and specific, combining the presence of tumor biomarkers readily accessible from the blood vessels and the high rate of angiogenesis characteristic of cancer tissues. We performed ex vivo perfusions of surgically resected human colon cancer using a reactive ester derivative of biotin, thus achieving a selective covalent modification of accessible proteins in vascular structures and stroma. After extraction and purification, biotinylated proteins were digested and the resulting peptides submitted to a comparative mass spectrometry-based proteomic analysis, revealing quantitative differences between normal and cancer colon. Sixty-seven of the total 367 proteins identified were found to be preferentially expressed at the tumor site. We generated human monoclonal antibodies against 2 potential tumor targets, NGAL and GW112, and we proved their selective expression in cancer colon and not or barely in healthy tissues. This article presents the first proteomic analysis of human colorectal cancer structures readily accessible from the tumor vasculature, revealing the overexpression of novel tumor antigens which may serve as selective targets for antibody-based imaging and therapeutic biomolecular strategies.