LAUSR

BACKGROUND The association of treatment-induced tumor shrinkage with symptom palliation for patients with lung cancer remains unknown. We investigated this correlation using the Edmonton Symptom Assessment System-Revised. METHODS Using the in-hospital cancer registry, we identified patients receiving chemotherapy and/or immunotherapy for newly diagnosed advanced or metastatic lung cancer. Tumor response and post-treatment Edmonton Symptom Assessment System-Revised were obtained after 2-3 treatment cycles. Patients were divided into groups with or without >30% unidirectional tumor shrinkage (objective response [OR] or non-OR [N-OR] groups, respectively). They were further classified as good-objective response (>50% unidirectional tumor shrinkage), moderate-objective response (30-50% shrinkage), progressive disease (>20% tumor growth or new lesion) or stable disease (SD; N-objective response and non-progressive disease). The primary endpoint was change in the total Edmonton Symptom Assessment System-Revised score from baseline. The Mann-Whitney U test was used for analysis. RESULTS In total, 113 patients were enrolled. The total Edmonton Symptom Assessment System-Revised score was significantly more improved in the OR group versus the N-OR group (median: 5 vs. 2, respectively; P = 0.013). This association was more prominent in patients with small-cell lung cancer and large-cell neuroendocrine tumor than those with other histology. Sensitivity analyses showed that the total Edmonton Symptom Assessment System-Revised score was more improved in the OR group versus the SD group (median: 5 vs. 3, respectively; P = 0.029) and in the 'good-OR' group versus the 'moderate-OR and SD' group (median: 7.5 vs. 2, respectively; P = 0.003), suggesting that greater tumor shrinkage led to more symptom amelioration. CONCLUSIONS Tumor shrinkage was associated with Edmonton Symptom Assessment System-Revised score improvement in patients with lung cancer receiving systemic therapy.