Rescue surgery for unresectable colorectal liver metastases downstaged by chemotherapy: a model to predict long-term survival.

OBJECTIVE: To evaluate the long-term survival of patients resected for primarily unresectable colorectal liver metastases (CRLM) downstaged by systemic chemotherapy and to use prognostic factors of outcome for a model predictive of survival on a preoperative setting. SUMMARY BACKGROUND DATA: Surgery of primarily unresectable CRLM after downstaging chemotherapy is still questioned, and prognostic factors of outcome are lacking.
METHODS: From a consecutive series of 1439 patients with CRLM managed in a single institution during an 11-year period (1988-1999), 1104 (77%) initially unresectable (NR) patients were treated by chemotherapy and 335 (23%) resectable were treated by primary liver resection. Chemotherapy mainly consisted of 5-fluorouracil and leucovorin combined to oxaliplatin (70%), irinotecan (7%), or both (4%) given as chronomodulated infusion (87%). NR patients were routinely reassessed every 4 courses. Surgery was reconsidered every time a documented response to chemotherapy was observed. Among 1104 NR patients, 138 "good responders" (12.5%) underwent secondary hepatic resection after an average of 10 courses of chemotherapy. At time of diagnosis, mean number of metastases was 4.4 (1-14) and mean maximum size was 5.2 cm (1-25). Extrahepatic tumor was present in 52 patients (38%). Multinodularity or extrahepatic tumor was the main cause of initial unresectability. All factors likely to be predictive of survival after liver resection were evaluated by uni- and multivariate analysis. Estimation of survival was adjusted on risk factors available preoperatively.
RESULTS: Seventy-five percent of procedures were major hepatectomies (> or =3 segments) and 93% were potentially curative. Liver surgery was combined to portal embolization, to ablative treatment, or to a second-stage hepatectomy in 42 patients (30%) and to resection of extrahepatic tumor in 41 patients (30%). Operative mortality within 2 months was 0.7%, and postoperative morbidity was 28%. After a mean follow-up of 48.7 months, 111 of the 138 patients (80%) developed tumor recurrence, 40 of which were hepatic (29%), 12 extrahepatic (9%), and 59 both hepatic and extrahepatic (43%). Recurrence was treated in 52 patients by repeat hepatectomy (71 procedures) and in 42 patients by extrahepatic resection (77 procedures). Survival was 33% and 23% at 5 and 10 years with a disease-free survival of 22% and 17%, respectively. It was decreased as compared with that of patients primarily resected within the same period (48% and 30% respectively, P = 0.01). At the last follow-up, 99 patients had died (72%) and 39 (28%) were alive; 25 were disease free (18%) and 14 had recurrence (10%). At multivariate analysis, 4 preoperative factors were independently associated to decreased survival: rectal primary, > or =3 metastases, maximum tumor size >10 cm, and CA 19-9 >100 UI/L. Mean adjusted 5-year survival according to the presence of 0, 1, 2, 3, or 4 factors was 59%, 30%, 7%, 0%, and 0%.
CONCLUSIONS: Modern chemotherapy allows 12.5% of patients with unresectable CRLM to be rescued by liver surgery. Despite a high rate of recurrence, 5-year survival is 33% overall, with a wide use of repeat hepatectomies and extrahepatic resections. Four preoperative risk factors could select the patients most likely to benefit from this strategy.