Abstract 328P
Background
Small cell lung cancer (SCLC) is a deadly tumour accounting for approximately 15% of lung cancers. SCLC is classified into central and peripheral types based on the anatomic location. Previous studies revealed different genetic alteration and survival in central and peripheral NSCLC. Our study aimed to investigate the differences of biological behavior and prognosis between central and peripheral SCLC.
Methods
Clinical data of patients diagnosed with SCLC by pathology admitted to the First Affiliated Hospital of Xi’an Jiaotong University from January 2017 to March 2022 was collected, and regular follow-up was conducted. The clinical pathological factors and survival data of central and peripheral SCLC was compared.
Results
For all 489 patients, peripheral SCLC tended to have interstitial lung abnormalities, locate in the lower lobe of right lung, be diagnosed at early stage, have higher proportion of no symptom, while lower proportion of cough sputum. The mPFS (10.1 months vs. 7.4 months, P < 0.001) and mOS (22.6 months vs. 17.3 months, P < 0.001) were longer in peripheral SCLC. 2. For 138 limited stage patients, peripheral SCLC tended to be diagnosed at early T stage (T1-2: 77.6% vs. 59.6%, P=0.033), have a longer mPFS (13.6 months vs. 10.2 months, P=0.041) and mOS (35.8 months vs. 25.8 months, P=0.039). For 351 extensive stage patients, the ORR (83.7% vs. 65.7%, P=0.021), DCR (94.2% vs. 84.5%, P=0.001), mPFS (8.35 months vs. 6.9 months, P=0.002) and mOS (19.8 months vs. 15.8 months, P < 0.001) were better in peripheral SCLC. Further PSM and subgroup analysis confirmed the better prognosis in peripheral SCLC.
Conclusions
Central SCLC in extensive stage tended to locate in upper lobe of left lung while peripheral type tended to locate in lower lobe of right lung with ILA. Central SCLC was diagnosed at late stage and had poorer response rate to the first-line treatment and prognosis, requiring more aggressive treatment. Gender, location, DLNM, hepatic metastasis, baseline hyponatremia and the first-line treatment were independent prognostic factors for PFS. Gender, location, DLNM, hepatic metastasis and the first-line treatment were independent prognostic factors for OS.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.