Neoadjuvant therapy for resectable colorectal cancer pulmonary oligometastases: a retrospective cohort study

Lung metastasectomy has been considered the cornerstone of treatment of resectable colorectal cancer pulmonary oligometastases (CRCPOM). However, the role of chemotherapy in the neoadjuvant setting remains unclear. This study aimed to determine whether neoadjuvant therapy (NAT) could further improve survival outcomes of patients with resectable CRCPOM.

We included all 253 consecutive patients at our center between 2010 and 2022. Propensity score matching (PSM) was performed to balance the baseline characteristics. The efficacy of NAT was evaluated using the Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1). Disease-free survival (DFS) was the primary endpoint, which was estimated by the Kaplan-Meier method. Multivariate analyses were conducted using Cox proportional hazards regression to identify independent predictors.

The cumulative 5- and 10-year DFS rates following lung metastasectomy were 48.3% and 39.4%, respectively. After PSM, NAT was significantly associated with improved DFS (HR, 0.52; P = 0.009). A clinical risk score was constructed using four independent predictors of worse DFS (serum carcinoembryonic antigen > 5.0 ng/mL, disease-free interval after colorectal resection < 2 years, primary tumor with nodal involvement, extrapulmonary metastases) and enabled risk stratification. The administration of NAT could improve DFS in patients with ≥ 1 risk factor (HR, 0.60; P = 0.020), while such benefit was not observed in those with no risk factor. RECIST-defined response was noted in 34/74 (46.0%) patients who received NAT, which was correlated with improvement in DFS (HR, 0.31; P = 0.008).

NAT may confer a survival benefit in patients with resectable CRCPOM. Using an easy-to-use clinical risk score, patients with ≥ 1 risk factor are good candidates for initial NAT. The RECIST criteria are deemed suitable for the assessment of efficacy of NAT before lung metastasectomy.