晚期肺炎型肺癌：一项中国单中心临床-放射-病理特征回顾性研究及预后分析

BACKGROUND AND OBJECTIVE: Pneumonic-type lung carcinoma is a special type of lung cancer both clinically and radiologically. Here we present our experience on pneumonic-type lung carcinoma in an attempt to investigate the clinical, radiological and pathological features, diagnostic procedures, treatment, and prognosis of this type of tumor. METHODS: Pathologically confirmed lung cancer with a chest CT characterized by ground glass opacity or consolidation was defined as pneumonic-type lung carcinoma. Cases with advanced pneumonic-type lung carcinoma admitted to Peking Union Medical College Hospital (PUMCH) from January 1, 2013 to August 30, 2018 were enrolled. Retrospective analysis of clinical data and survival follow-up of these patients was conducted. RESULTS: A total of 46 cases were enrolled, all of which were adenocarcinoma. Cough (41/46, 89.1%) and expectoration (35/46, 76.1%) were the most prominent symptoms. The most frequent chest CT findings were ground glass attenuation (87.0%), patchy consolidation (84.8%), and multiple ground-glass nodules (84.8%). Multiple cystic changes (40%) and cavitation (13%) were also quite frequent. Ipsilateral and contralateral intrapulmonary metastasis were noted in 95.3% and 84.8% of cases respectively. The median duration from symptom onset to diagnosis was 214 days (95%CI: 129-298). Both surgical lung biopsy and CT-guided percutaneous lung biopsy had a diagnostic yield of 100%. Transbronchial lung biopsy (TBLB) combined with bronchoalveolar lavage (BAL) had a diagnostic yield of 80.9% (17/21). Sputum cytology had a diagnostic yield of 45% (9/20). Twenty-six cases were invasive mucinous adenocarcinoma (26/46, 56.5%) and the remainder were unable to identify pathological subtypes due to lack of adequate biopsy sample size. EGFR mutation was detected in 15.8% (6/38) of patients and ALK rearrangement was detected in 3.0% (1/33) of patients. The median overall survival for these patients was 522 d (95%CI: 424-619). In patients without EGFR mutation or ALK rearrangement, chemotherapy significantly improved survival (HR=0.155, P=0.002, 2). The median overall survival was 547 d (95%CI: 492-602 d) with chemotherapy and 331 d (95%CI: 22-919) without chemotherapy. CONCLUSION: Diagnosis of pneumonic-type carcinoma is usually delayed due to clinical and radiological features mimicking pulmonary infection. TBLB combined with BAL has a quite high diagnostic yield. The most frequent histological type is invasive mucinous adenocarcinoma. The incidence of EGFR mutation or ALK rearrangement is low in pneumonic-type carcinoma. For patients without cancer driver genes, chemotherapy is recommended to improve overall survival.