Various recurrence dynamics for non-small cell lung cancer depending on pathological stage and histology after surgical resection

BACKGROUND: Although there are numerous postoperative surveillance guidelines for non-small cell lung cancer (NSCLC), most guidelines recommend the same protocol for patients with different recurrence dynamics. In this study, we investigated the recurrence dynamics of NSCLC patients according to their clinical factors. METHODS: We retrospectively reviewed the data from NSCLC patients who underwent complete resection between 2007 and 2017. Recurrence dynamics were estimated using the hazard rate and displayed with kernel smoothing method according to tumor stage, sex, and histology. RESULTS: During the period, a total of 6,012 patients were enrolled: 3,687 (61.3%) in stage I, 1,194 (19.9%) in stage II, and 1,131 (18.8%) in stage III. The highest recurrence hazard rate was shown at about 12 months, regardless of tumor stage, but the maximum of hazard rate for stage III was 7 times higher than that in stage I. Depending on tumor histology, the highest peak of hazard curve was observed at different periods, 9 months in squamous cell carcinoma and 15 months in adenocarcinoma. These trends were similar when analyzed based on sex, 9 months in male patients and 15 months in female patients. In stage I adenocarcinoma, recurrence hazard rates were significantly different depending on histologic subtypes and tumor differentiation grade. CONCLUSIONS: Adopting the same follow-up strategy may be undesirable in NSCLC patients who have different clinical and pathological characteristics. Adequate consideration of these factors will help clinicians develop detailed follow-up strategy in lung cancer patients with different recurrence dynamics.