title: Outcome of microscopic incomplete resection (R1) of colorectal liver metastases in the era of neoadjuvant chemotherapy.
abstract: BACKGROUND
  Data from patients with colorectal liver metastases (CRLM) who received neoadjuvant chemotherapy before resection were reviewed and evaluated to see whether neoadjuvant chemotherapy influences the predictive outcome of R1 resections (margin is 0 mm) in patients with CRLM.
  
  
  METHODS
  Between January 2000 and December 2008, all consecutive patients undergoing liver resection for CRLM were analyzed. Patients were divided into those who did and did not receive neoadjuvant chemotherapy. The outcome after R0 (tumor-free margin >0 mm) and R1 (tumor-free margin 0 mm) resection was compared.
  
  
  RESULTS
  A total of 264 were eligible for analysis. Median follow-up was 34 months. Patients without chemotherapy showed a significant difference in median disease-free survival (DFS) after R0 or R1 resection: 17 [95% confidence interval (CI) 10-24] months versus 8 (95% CI 4-12) months (P < 0.001), whereas in patients with neoadjuvant chemotherapy the difference in DFS between R0 and R1 resection was not significant: 18 (95% CI 10-26) months versus 9 (95% CI 0-20) months (P = 0.303). Patients without chemotherapy showed a significant difference in median overall survival (OS) after R0 or R1 resection: 53 (95% CI 40-66) months versus 30 (95% CI 13-47) months (P < 0.001). In patients with neoadjuvant chemotherapy, the median OS showed no significant difference: 65 (95% CI 39-92) months for the R0 group versus the R1 group, in whom the median OS was not reached (P = 0.645).
  
  
  CONCLUSIONS
  In patients treated with neoadjuvant chemotherapy, R1 resection was of no predictive value for DFS and OS.
authors: Division of Surgical Oncology, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam, The Netherlands.
authors: Ninos
authors: N
authors: Ayez
authors: Zarina S
authors: ZS
authors: Lalmahomed
authors: Alexander M M
authors: AM
authors: Eggermont
authors: Jan N M
authors: JN
authors: Ijzermans
authors: Jeroen
authors: J
authors: de Jonge
authors: Kees
authors: K
authors: van Montfort
authors: Cornelis
authors: C
authors: Verhoef
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology*; D005260:Female; D006498:Hepatectomy / Q000379:methods*; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000556:secondary* / Q000601:surgery*; D008207:Lymphatic Metastasis; D008297:Male; D059146:Metastasectomy / Q000379:methods*; D008875:Middle Aged; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D015996:Survival Rate; D016896:Treatment Outcome