Heterogeneous radiological response to chemotherapy is associated with poor prognosis in advanced non-small-cell lung cancer

Background A heterogeneous radiological response is frequently observed in cancer patients and could reflect tumor heterogeneity. We investigated the prognostic impact of heterogeneous radiological responses in patients with advanced non-small-cell lung cancer (NSCLC) who received platinum-based chemotherapy. Methods The treatment response according to Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria was evaluated in 212 patients with advanced NSCLC who received platinum-based chemotherapy. Patients with partial response (PR) or stable disease (SD) were classified into "PR homo," "PR hetero," "SD homo," and "SD hetero" by the presence of a heterogeneous radiological response, and survival was compared between groups. We also compared survival based on the presence of metabolic responses in lesions with heterogeneous radiological responses. Results Fifty-two patients (24.5%) were classified as PR, 112 patients (52.8%) as SD, and 48 patients (22.7%) as progressive disease (PD). There was no significant difference in progression-free survival (PFS) and overall survival (OS) between the PR homo and PR hetero groups. The SD homo group had a longer PFS and OS than the SD hetero group. In the SD hetero group, patients with increased maximum standardized uptake value (SUVmax) in lesions with heterogeneous radiological responses had a shorter PFS than those with a stable SUVmax. Conclusions The presence of lesions with radiological heterogeneity was associated with disease progression and poor prognosis in the SD group. Patients with heterogeneous radiological responses require careful monitoring.