In this study, we aimed to assess the prevalence of interstitial lung abnormalities (ILAs) and investigate the rates and risk factors associated with radiologic ILA progression among patients with lung cancer following surgical resection. Patients who underwent surgical resection for lung cancer at our institution from January 2015 to December 2020 were retrospectively evaluated and grouped according to their ILA status as having no ILAs, equivocal ILAs, or ILAs. Progression was determined by simultaneously reviewing the baseline and corresponding follow-up computed tomography (CT) scans. Among 346 patients (median age: 67 (interquartile range: 60–74) years, 204 (59.0%) men), 22 (6.4%) had equivocal ILAs, and 33 (9.5%) had ILAs detected upon baseline CT. Notably, six patients (6/291; 2.1%) without ILAs upon baseline CT later developed ILAs, and 50% (11/22) of those with equivocal ILAs exhibited progression. Furthermore, 75.8% (25/33) of patients with ILAs upon baseline CT exhibited ILA progression (76.9% and 71.4% with fibrotic and non-fibrotic ILAs, respectively). Multivariate analysis revealed that ILA status was a significant risk factor for ILA progression. ILAs and equivocal ILAs were associated with radiologic ILA progression after surgical resection in patients with lung cancer. Hence, early ILA detection can significantly affect clinical outcomes.

Background/Objectives: To evaluate changes in background parenchymal enhancement (BPE) in the contralateral breast on MRI before and after neoadjuvant chemotherapy (NAC), stratified by molecular subtype in patients with unilateral breast cancer. Methods: This study retrospectively analyzed 116 individuals diagnosed with unilateral breast cancer by biopsy, all of whom underwent breast MRI examinations before and after neoadjuvant chemotherapy. Contralateral breast BPE was graded into four levels (BPEC: 1 = minimal, 2 = mild, 3 = moderate, 4 = marked) by two readers in consensus. Histopathological features and BPE reduction were compared according to molecular subtype. Results: BPE showed a reduction across all molecular subtypes after NAC. In ER-positive cancers, BPEC shifted from 26/16/28/30% to 68/28/4/0%; in HER2-positive cancers, from 37.8/26.7/22.2/13.3% to 73.3/20.0/6.7/0%; and in triple-negative breast cancers, from 47.6/14.3/23.8/14.3% to 76.2/14.3/9.5/0%. Compared to the ER-positive cancer, the reduction in BPE over time was significantly greater in the HER2-positive cancer group (Estimate = 0.48, p = 0.0168) and TNBC (Estimate = 0.55, p = 0.0321), suggesting that the extent of BPE decrease varied by subtype. Conclusions: The extent of BPE reduction on breast MRI following NAC varies significantly across different molecular subtypes of breast cancer.