RFA was used as an adjunct to resection in patients with greater disease burden. Despite this, RFA was not significantly associated with a higher risk of local failure and was not associated with worse survival, when compared with liver resection alone.

ConclusionsCompared with patients who did not receive chemotherapy, those who received chemotherapy, regardless of timing, experienced improved overall survival and disease-free survival. Use of rfa where required as an adjunct to hepatic resection appears to be effective and is not associated with worse overall survival. KEY WORDSColorectal cancer, hepatic resection, timing of chemotherapy, radiofrequency ablation INTRODUCTIONOf the estimated 23,800 Canadians diagnosed with colorectal cancer (crc) annually, approximately 9200 (40%) will die from their disease, most with distant metastatic spread 1 . When feasible, hepatic resection offers the greatest probability of cure for patients with isolated liver metastases 2 . However, even for those with disease that is largely liver-limited, there are barriers to curative resection such as the extent and distribution of lesions within the liver, extrahepatic disease, comorbidities, and age 3 .The maldistribution of lesions within the liver, making complete excision of all disease impossible without the risk of subsequent liver insufficiency, is one barrier that has received considerable attention. Strategies include serial resection, portal vein embolization, and the adjuvant use of radiofrequency ablation (rfa). The rfa procedure uses heat derived from radiofrequency waves at the end of a probe inserted into a metastasis to induce tumour necrosis. The use of rfa as an adjunct to hepatic resection is gaining acceptance. However, its efficacy in comparison with resection is controversial because of high rates of recurrence at the ablation site in some studies 4 .Despite the increasing opportunity for potentially curative hepatic resection, recurrence in resected patients is the most frequent outcome. Chemotherapy, ABSTRACT BackgroundAlmost 40% of people diagnosed with colorectal cancer will die from their disease, most with metastatic spread. When feasible, hepatic resection offers the greatest probability of cure for isolated liver metastases, but there are barriers to curative resection. Those barriers include the extent and distribution of lesions within the liver, extrahepatic disease, comorbidities, and age. Chemotherapy is often administered before or after resection with the intention of improving disease-free and overall survival. The timing of chemotherapy (adjuvant vs. neoadjuvant vs. perioperative) for patients undergoing potentially curative hepatic resection of metastasis of colorectal cancer origin is controversial. MethodsColorectal cancer patients with liver metastases resected at The Ottawa Hospital between January 1, 2003, and December 31, 2009, were identified, and their clinical records were retrospectively reviewed. Patients receiving intraoperative radiofrequency ablation (rfa) as part of their management were included. Factors associated with overall and diseasefree survival were evaluated. ResultsThe 168 identified patients (57% men, 43% women) had a median age of 63 years (range: 31-84 years). After hepatectomy, 10% had positive resection margi...

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436 Background: Mutations affecting the KRAS gene are established predictive markers of outcome with anti–epithelial growth factor receptor antibodies in metastatic colorectal cancer (mCRC). The relevance of these markers for chemotherapy has not been established. This analysis was performed to assess the predictive impact of KRAS mutation status in patients receiving chemotherapy. Methods: KRAS mutational status was available for 223 patients treated for mCRC. Predictive analysis of mutational status by type of fluoropyrmidine the 1st-line regimen contained (either capecitabine [C] based chemotherapy or infusional 5Fluorouracil [I-5Fu]) for clinical outcomes: progression-free survival (PFS), time to chemotherapy resistance (TTCR) and overall survival (OS). Results: KRAS mutations were observed in 43.5% of the patients. 165 patients received I-5Fu, 44 patients received C. KRAS mutation status (wild type [WT] v mutated [MT]) had no prognostic impact for OS (hazard ratio [HR], 0.81; CI, 0.69 to 1.1 p=0.17) for PFS (hazard ratio [HR], 0.87; CI, 0.66 to 1.14 p=0.3) and TTCR (hazard ratio [HR], 0.85; CI, 0.65to 1.12 p=0.26). C based 1st-line chemotherapy vs. I- 5FU based was predictive of PFS (hazard ratio [HR], 0.52; CI, 0.37 to 0.74 p=0.0003) and TTCR (hazard ratio [HR], 0.54; CI, 0.38 to 0.75p=0.0005) and not of OS (hazard ratio [HR], 0.74; CI, 0.52 to 1.1 p=0.1). KRAS mutational status had predictive impact in patients receiving C based 1st-line chemotherapy on OS (hazard ratio [HR], 0.47; CI, 0.23 to 0.948 p<0.0001) TTCR (hazard ratio [HR], 0.49; CI, 0.25 to 0.97 p=0.0398) and was not predictive of PFS (hazard ratio [HR], 0.78; CI, 0.4 to 1.53 p=0.47) Conclusions: KRAS gene mutation status was predicitve for OS and for TTCR in patients who received C based 1st-line chemotherapy.