Background/Aim: The impact of interstitial lung disease (ILD) on the clinical outcome of patients with smallcell lung cancer (SCLC) is not fully understood. The aim of this study was to investigate the impact of ILD on treatment and survival outcomes of SCLC patients. Patients and Methods: A retrospective analysis was performed on the clinical outcomes of SCLC patients, treated with chemotherapy, with or without ILD ([ILD group (n=16) and non-ILD group (n=51)]. Results: Median PFS and OS were significantly shorter in the ILD group than in the non-ILD group (median PFS, 184 vs. 290 days, p=0.008; median OS, 236 vs. 691 days, p<0.001). Multivariate analysis revealed that coexisting ILD was an independent predictive factor of PFS (hazard ratio [HR]=2.06; 95% confidence interval [CI]=1.01-4.18; p=0.046) and OS (HR=3.29; 95%CI=1.53-7.08; p=0.002). Conclusion: Coexisting ILD might be a negative predictive factor of PFS and OS of SCLC patients treated with chemotherapy.

Sebaceous carcinoma is a rare cutaneous malignant tumor, usually occurring on the eyelids, head, neck, and trunk. There have been few reports about sebaceous carcinoma with primary lung cancer, for which optimal therapy has not yet been established. A 70‐year‐old man presented with a mass in the left iliac bone and tumor of the lower left lung. The morphological characteristics of the iliac bone biopsy pathology and immunostaining results showed sebaceous gland differentiation. After systemic examination, we diagnosed a primary lung sebaceous carcinoma with intrapulmonary and bone metastases. PD‐L1 was positive in 1%–24% of tumor cells, and microsatellites were stable. We detected protein kinase B (AKT1) mutations using the Oncomine Dx target test. Palliative radiotherapy (RT) of a total of 45 Gy was provided in 15 fractions to the left iliac region, which resulted in a 25% reduction in the tumor size. Subsequently, four courses of first‐line pembrolizumab led to a 30% reduction in the total tumor count. RT and pembrolizumab may be treatment options for certain rare primary sebaceous carcinomas of the lungs. A synergistic effect from RT and subsequent administration of immune checkpoint inhibitors may have contributed to tumor reduction.