Cetuximab plus chemotherapy as second line treatment of patient with metastatic colorectal cancer after failure of cetuximab containing regiment in first line: Single cancer center experience.

Background: Combination of targeted and standard cytotoxic therapy (CT) has been shown to significantly increase both overall (OS) and progression free (PFS) in patients with metastatic colorectal cancer (mCRC). There are no data about treatment results with cetuximab (cet) and chemotherapy after failure of first line treatment containing cet. Methods: A retrospective analysis of pts with mCRC treated with cet-containing regimen beyond first line progression was conducted for all pts treated from January 2012 to December 2014. The primary objective was to evaluate the efficacy of cet beyond first line progression. Results: A total of 16 pts were identified. The median age was 61,3 (range 42,7-73,2) and at baseline all pts had an ECOG performance status (PS( of 0 or 1 (46% and 54% resp). Metastases were localized in the liver in 75% of pts and in lungs in 19%. All pts were KRAS exon2 wild type. In the first line 15 pts were treated with FOLFOX4 and one with FOLFIRI. In the second line 12 pts were treated with FOLFIRI, 3 with irinotecan monotherapy and 1 with FOLFOX 4. The median PFS for first line was 12,5 month and median PFS for second line was 7,3 months. The median overall survival was 40,15 months. Tissue samples of 13 pts were available for reanalysis of RAS and BRAF. Two mutation of NRAS were found. No BRAF mutation was found. The median PFS1 for RAS wt pts (N = 10) was 14,5 month and PFS2 was 13,4 months (8 pts are still on treatment). The median overall survival was not reached. Conclusions: The small retrospective analysis shows results of cet plus CT beyond progression after failure of cet-containing regimens in first line. RAS and BRAF wild type status together with good PS play key role in selection of pts who may profit from continuing treatment with cet plus CT

Citation: 

J Clin Oncol 33, 2015 (suppl; abstr e14678)

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