Is Adjuvant Chemotherapy Worthwhile After Radical Resection for Single Lung Metastasis From Colorectal Cancer? A Multicentric Analysis Evaluating the Risk of Recurrence

Background: Adjuvant chemotherapy after resection of colorectal cancer (CRC) lung metastasesmay reduce recurrences and improve survival. The choice of best candidates for adjuvant chemotherapy in this setting is controversial, especially when a single lung metastases (SLM) is resected. The aim of this study is to evaluate the risk of recurrence after radical resection for single lung metastasis from CRC. Patients and methods: Demographic, clinical, and pathological data were retrospectively collected for patients radically operated on for single pulmonary metastasis from CRC in 4 centers. Survival was computed by Kaplan-Meyer methods. Chi-square, log-rank test, and formultivariate analysis, Cox-regression and binary logistic regression were used when indicated. Results: The sample consisted of 344 patients, mean age 65 yrs. Overall 5 yrs survival was 61.9%. Recurrence occurred in 113 pts (32.8%). At univariate analysis, age > 70 (p = 0.046) and tumor size > 2 cm (p = 0.038) were predictive of the worst survival chance, while synchronous lung metastasis (p = 0.039), previous resection of extrathoracic metastasis (p = 0.017), uptake at FDG-PET scan (p = 0.006) and short (< 12 months) disease-free interval (DFI) prior to lung metastasectomy (p = 0.048) were risk factors for recurrence. At multivariate analysis, only high CEA (> 4 ng/mL) was associated with worst survival (HR: 4.3, p = 0.014), while prior abdominal surgery (HR: 3, p = 0.033), PET positivity (HR: 2.7, p = 0.041), and DFI > 12 months (HR: 0.14, p < 0.001) confirmed to predict recurrence of disease. Conclusions: Surgical resection of solitary lung metastases from CRC is associated with prolonged survival. High value of CEA, PET positivity, previous extrathoracic resected metastasis, and short (<12 months) DFI were found to be predictive of death or disease recurrence and might identify in this scenario patients at higher risk which could potential benefit of chemotherapy.