Long-term clinical outcomes after the second metastasectomy in patients with resected metastatic colorectal cancer

Purpose: Primary tumor resection and metastasectomy are curative for metastatic colorectal cancer. However, there is still a paucity of data regarding the clinical outcomes and risk factors after disease recurrence and second metastasectomy. Materials and Methods: We retrospectively evaluated the clinical outcomes of patients who underwent the second metastasectomy. In addition, risk factors for the outcomes were analyzed. Results: A total of 94 patients (39 females and 55 males) received a second metastasectomy after the recurrence. Recurrent sites included the lung (47 patients), liver (36 patients), both lung and liver (four patients), and non-lung/non-liver (seven patients). Among them, 89 (94.7 %) patients achieved R0 resection, while three (3.2 %) and two (2.1 %) patients achieved R1 and R2 resections, respectively. The 5-year disease-free survival (DFS) and overall survival (OS) were 42.8 +5.3 % and 67.2+4.9 %, respectively. Multivariable analysis for DFS identified that primary rectal cancer (hazard ratio [HR] 0.45, P=0.033) and disease-free interval after the first metastasectomy of >= 12 months (HR 0.39, P=0.002) were good predictive factors; in contrast, nonlung/non-liver metastasis (HR 3.32, P=0.020) was a poor predictive factor. Multivariable analysis for OS showed that age >= 70 years (HR 3.27, P=0.011), non-lung/non-liver metastasis (HR 4.04, P=0.024), and lesion number >= 2 (HR 2.25, P=0.023) were poor prognostic factors. Conclusion: Patients who underwent a second metastasectomy had a long-term disease-free state and good OS. Our data suggest that a second metastasectomy should be considered if a patient has a limited number of metastases confined to the liver and/or lung and long DFS after the first metastasectomy.