Results of frequent CT surveillance on recurrence detection and survival after radical resection for non-small cell lung cancer

Non-small lung cancer (NSCLC) carries a substantial risk for recurrence even after complete resection. Evidence regarding the survival impact of post-resection surveillance strategies remains limited. Danish guidelines for lung cancer recommend contrast-enhanced computed tomography (CE-CT) every 3 months for the first 2 years and every 6 months for the subsequent 3 years, a frequency twice that of major international guidelines. This study retrospectively assessed the outcomes of this high-frequency CT surveillance in Denmark, specifically focusing on recurrence detection within two years post-surgery, the potential for renewed curative-intent treatment, and post-recurrence prognosis during this initial period. A cohort of 1079 patients who underwent resection for NSCLC in the period 2019-2020 was identified from the Danish Lung Cancer Registry (DLCR). Detailed information regarding new diagnoses of lung cancer, offered treatments, and mortality was extracted from patients' medical records. Within two years following resection, 20% of patients developed a new diagnosis of lung cancer. Of these, 28.5% presented with localized disease (stage I-II), 26% with locally advanced disease (stage III), and 45% with metastatic disease. Recurrence frequencies ranged from 13% for pathological stage I (pStage I) to 44.5% for pStage III. Forty-eight percent of patients were offered renewed curative-intent treatment, demonstrating a 2-year post-recurrence survival of 78%. In contrast, patients offered palliative care or no treatment had a 2-year post-recurrence survival of 40%. The proportion of recurrences presenting with metastatic disease was lower than reported in cohort studies with less frequent surveillance. A further notable finding was the high proportion of patients offered curative-intent treatment for recurrent disease, exceeding previously reported rates. These patients demonstrated a 2 year post-recurrence survival comparable to that observed following a primary NSCLC diagnosis. The presence of symptoms at the time of recurrence was a negative prognostic indicator, even among patients receiving palliative treatment.