Pulmonary metastasis in rectal cancer: a retrospective study of clinicopathological characteristics of 404 patients in Chinese cohort

Abstract

ObjectivesThis study aim to investigate the incidence, timing and risk factors of metachronous pulmonary recurrence after curative resection in patients with rectal cancer.DesignA retrospective cohort study.SettingThis study was conducted at a tertiary referral cancer hospital.ParticipantsA total of 404 patients with rectal cancer who underwent curative resection from 2007 to 2012 at Beijing Hospital were enrolled in this study.InterventionsThe pattern of recurrence was observed and evaluated.Primary and secondary outcome measuresThe incidence and timing of recurrences by site were calculated, and the risk factors of pulmonary recurrence were analysed.ResultsThe 5-year disease-free survival for the entire cohort was 77.0%. The most common site of recurrence was the lungs, with an incidence of 11.4%, followed by liver. Median interval from rectal surgery to diagnosis of pulmonary recurrence was much longer than that of hepatic recurrence (20 months vs 10 months, P=0.022). Tumour location, pathological tumor-node-metastasis (TNM) stage and positive circumferential resection margin were identified as independent risk factors for pulmonary recurrence. A predictive model based on the number of risk factors identified on multivariate analysis was developed, 5-year pulmonary recurrence-free survival for patients with 0, 1, 2 and 3 risk factors was 100%, 90.4%, 77.3% and 70.0%, respectively (P<0.001).ConclusionsThis study emphasised that the lung was the most common site of metachronous metastasis in patients with rectal cancer who underwent curative surgery. For patients with unfavourable risk profiles, a more intensive surveillance programme that could lead to the early detection of recurrence is strongly needed.