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

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

Research output: Contribution to journalArticle


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 (wtKRAS) vs. mutated (mutKRAS)] 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 wtKRAS 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 mutKRAS 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 wtKRAS 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 mutKRAS tumors.

Original languageEnglish (US)
Pages (from-to)1-8
Number of pages8
JournalAnnals of Surgical Oncology
Publication statusAccepted/In press - Sep 30 2016


ASJC Scopus subject areas

  • Surgery
  • Oncology

Cite this