Impact of radiological follow-up frequency on resected lung cancer: a propensity score matching analysis

Despite advances in lung cancer treatment and the subsequent improvement in oncological outcomes, the optimal frequency of radiological follow-up remains unclear. Current recommendations lack consensus and do not consider individual patient characteristics and tumor factors. This study aimed to examine the impact of radiological follow-up frequency on oncological outcomes following lung cancer resection.

A prospective multicenter study, involving patients who underwent anatomical lung resection in the GEVATS database between December 2016 and March 2018. The relationship between surveillance frequency and oncological outcomes was evaluated. Two groups were established based on follow-up frequency: low frequency (LF) and high frequency (HF). Subgroup analyses were performed based on tumor stage, histology, lymphadenectomy, and adjuvant therapy. Propensity score matching (PSM) was applied to balance the groups.

A total of 1,916 patients were included in the study, LF 444 (23.17%), HF 1,472 (76.83%). Factors associated with HF surveillance included higher stage, adjuvant chemotherapy and adjuvant radiotherapy. Subanalyses were performed after PSM for various factors, revealing significant differences between LF and HF groups in cancer-specific survival among who received adjuvant therapy {LF 53.021 months [95% confidence interval (CI): 48.622-57.421] vs. HF 58.836 months (95% CI: 55.343-62.330); HR 0.453, 95% CI: 0.242-0.849; P=0.013}, as well as overall survival for patients with squamous cell carcinoma [LF 54.394 months (95% CI: 51.424-57.364) vs. HF 61.578 months (95% CI: 59.091-64.065); HR 0.491, 95% CI: 0.299-0.806; P=0.005] and those who received adjuvant therapy LF 50.176 months [95% CI: 45.609-54.742) vs. HF 57.189 months (95% CI: 53.599-60.778); HR 0.503, 95% CI: 0.293-0.865; P=0.013].

Findings suggest that high-frequency surveillance only improves survival outcomes in lung cancer patients who received adjuvant treatment or had squamous cell carcinoma. Therefore, future guidelines for lung cancer follow-up should consider individualizing the frequency of radiological surveillance based on patients' risk profiles.