Minimally invasive liver surgery for metastases from colorectal cancer: oncologic outcome and prognostic factors.

BACKGROUND: Few reports exist on long-term survival after minimally invasive liver surgery (MILS) for colorectal liver metastases (CRLM). No data are available assessing prognostic factors in the era of current modern treatment strategies.
METHODS: Between October 2002 and December 2008, 274 consecutive patients were analyzed on an intention-to-treat basis. Open liver surgery (OLS) was performed in 193 patients for a total of 437 metastases, and MILS was performed in 81 patients for 176 metastases. Systemic chemotherapy was administered preoperatively in 173 and postoperatively in 174 patients. The impact of 23 potential prognostic factors on disease-free (DFS) and overall survival (OS) was evaluated using univariable and multivariable Cox regression models.
RESULTS: Postoperative complications were observed in 54 patients after OLS and in 11 after MILS (p = 0.016). The median postoperative length of hospital stay was 9 days after OLS and 5 days after MILS (p < 0.0001). For the entire patient population, the 5 year DFS and OS rates were 29.9 and 59.5%, respectively. No differences in survival between patients treated with MILS and OLS were observed (p = 0.63). In univariable analyses, the number of liver metastases and the overall Fong's clinical risk score (CRS) were the only two variables that predicted DFS (p ≤ 0.0035) and OS (p ≤ 0.0005). In multivariable analyses, the total CRS was the only independent predictor of both DFS (p = 0.0002) and OS (p = 0.002).
CONCLUSION: The long-term oncologic outcome of surgically treated patients with CRLM is determined by the Fong's CRS. Although MILS does not influence long-term survival, it has a beneficial impact on the immediate postoperative clinical outcome.