Small Cell Lung Cancer (Sclc) Extensive Stage (Es) In Spain: Efficacy Of Treatments, Data From The Thoracic Tumours Registry (Ttr Study)

Lung cancer is the leading cause of cancer incidence and mortality worldwide. SCLC represents about 15% of all lung cancer, more than two-thirds of SCLC patients are diagnosed with ES. The TTR is an observational, non-post-authorization, prospective cohort multicenter study promoted by the Spanish Lung Cancer Group. We conducted an observational cohort multicenter study in Spain, including all patients diagnosed with SCLC ES between August 2016 and January 2020. A Kaplan Meier survival analysis was carried out to study the overall survival (OS). 12,897 patients were registered in the TTR. A total of 1,658 patients diagnosed with SCLC were recruited at 67 Spanish hospitals. A total of 956 had extensive stage. 78.6% male, median age 65 years (37-88). 60.6% active smokers and 37.3% former smokers. 91.9% of the patients (879/956) received chemotherapy. Of the 879 patients who received a first line of chemotherapy, 262 received radiation therapy after the chemotherapy, 29.8% thoracic radiotherapy and 58.8% holocranial radiotherapy. Platinum and etoposide (PE) combination was the first-line chemotherapy regimen in 826 of the 879 patients. After the initial treatment, up to 67.9% of the patients progressed. Only 36% received a second line of chemotherapy, and 13.8% a third line. The median follow-up of all patients was 6.9 months, of the 956 patients included in the study, 640 (66.9%) died during follow-up. Median progression free survival (PFS) was 6.3 months (95% CI, 6.0-6.7 months). Median OS was 9.5 months (95% CI, 8.8-10.2), with an estimated OS of 70.3% (95% CI, 67.2-73.4) at 6, 38.9% (95% CI, 35.4-42.4%) at 12, 26.2% (95% CI, 22.8-29.6%) at 18, and 14.8% (95% CI, 11.8-17.8%) at 24 months after diagnosis. For SCLC ES, female sex, age (younger patients), smoking habit (never or former smokers) and ECOG (ECOG 0) were significantly associated with better prognostic. Our findings suggest that the TTR study accurately describes the clinical reality of SCLC ES in Spain. The OS for SCLC patients in a real-world setting was found to be similar to those reported in clinical trials. Despite the fact that patients respond to initial treatment with PE, most of them relapse.