Journal Article

KRAS Mutation Status Dictates Optimal Surgical Margin Width in Patients Undergoing Resection of Colorectal Liver Metastases

Sasaki, Kazunari, Wagner, Doris, Pawlik, Timothy M., Buettner, Stefan, Amini, Neda, Kim, Yuhree, Andreatos, Nikolaos, Merath, Katiuscha, Wilson, Ana, Margonis, Georgios A., Antoniou, Efstathios

2017

Overview

Background The optimal tumor-free margin width remains controversial and may be inappropriate to investigate without considering differences in the underlying tumor biology. Methods R1 resection was defined as margin clearance less than 1 mm. R0 resection was further divided into 3 groups: 1–4, 5–9, and ≥10 mm. The impact of margin width on overall survival (OS) relative to KRAS status [wild type (wt KRAS ) vs. mutated (mut KRAS )] was assessed. Results A total of 411 patients met inclusion criteria. Median patient age was 58 years (interquartile range, 49.7–66.7); most patients were male ( n  = 250; 60.8 %). With a median follow-up of 28.3 months, median and 5-year OS were 69.8 months and 55.1 %. Among patients with wt KRAS tumors, although margin clearance of 1–4 mm or more was associated with improved OS compared to R1 (all P  < 0.05), no difference in OS was observed when comparing margin clearance of 1–4 mm to the 5–9 mm and the ≥10 mm groups (all P  > 0.05). In contrast, among patients with mut KRAS tumors, all three groups of margin clearance (1–4, 5–9, and ≥10 mm) fared no better in terms of 5-year survival compared to R1 resection (all P  > 0.05). Conclusions While a 1–4 mm margin clearance in patients with wt KRAS tumors was associated with improved survival, wider resection width did not confer an additional survival benefit. In contrast, margin status—including a 1 cm margin—did not improve survival among patients with mut KRAS tumors.

• Publisher: Springer International Publishing,Springer Nature B.V
• Subject: Aged / Colorectal Neoplasms - pathology / Female / Hepatectomy / Hepatobiliary Tumors / Humans / Liver Neoplasms - genetics / Liver Neoplasms - secondary / Liver Neoplasms - surgery / Male / Margins of Excision / Medicine / Medicine & Public Health / Middle Aged / Mutation / Oncology / Prognosis / Proto-Oncogene Proteins p21(ras) - genetics / Surgery / Surgical Oncology / Survival Rate