Characteristics and outcomes of thymomas in Latin America: Results from over 10 years of experience (CLICaP-LATimus).

BACKGROUND: Thymomas are a group of rare neoplasms of the anterior mediastinum. The objective of this study was to describe the demographics, clinical characteristics and treatment approaches in Latin America. METHODS: This was a retrospective multicenter cohort study including patients with histologically proven thymomas diagnosed between 1997 and 2018. Demographics, clinicopathological characteristics and therapeutic outcomes were collected locally and analyzed in a centralized manner. RESULTS: A total of 135 patients were included. Median age at diagnosis was 53 years old (19-84), 53.3% (n = 72) of patients were female and 87.4% had an ECOG performance score ranging from 0-1. A total of 47 patients (34.8%) had metastatic disease at diagnosis. Concurrent myasthenia gravis occurred in 21.5% of patients. Surgery was performed in 74 patients (54.8%), comprising 27 (20%) tumorectomies and 47 (34.8%) thymectomies. According to the Masaoka-Koga system, overall survival (OS) at five-years was 73.4%, 63.8% and 51%, at stages I-II, III-IVA and IVB, respectively (p = 0.005). Furthermore, patients with low lactate dehydrogenase (LDH) (≤373 IU/L) at baseline and myasthenia gravis concurrence showed significantly better OS (p = 0.001 and p = 0.008, respectively). In multivariate analysis, high LDH levels (HR 2.8 [95% confidence interval [CI]: 1.1-7.8]; p = 0.036) at baseline and not performing a surgical resection (HR 4.1 [95% CI: 1.3-12.7]; p = 0.016) were significantly associated with increased risk of death. CONCLUSIONS: Our data provides the largest insight into the clinical characteristics and outcomes of patients with thymomas in Latin America. Survival in patients with thymomas continues to be very favorable, especially when subjected to adequate local control.

Epidemiology of thymic epithelial tumors: 22-years experience from a single-institution.

BACKGROUND: To assess the correlation of WHO histological classification and Masaoka-Koga staging system of thymic epithelial tumors (TETs) with prognosis. METHODS: We retrospectively analyzed 83 patients with TETs in the Instituto Nacional de Enfermedades Neoplasicas between 1996 to 2018. We analyzed the clinical stages, histological types and treatment modalities and attempted to determine the impact on overall survival. The data was retrieved from clinical files and reviewed by a pathologist who reclassificated according to the 2004 WHO classification system. The staging was performed with the Masaoka-Koga staging system. Survival curves were constructed with Kaplan-Meir method. RESULTS: There was a total of 83 patients with a median age of 55 years old included in the study. The histological type corresponded to thymoma (T) in 63.8% (n = 53) and to thymic carcinoma (TC) in 36.1%. T were type A, AB, B1, B2 and B3 in 14.4%, 18%, 12%, 3.6%, 7.4% of cases, respectively. The proportion of advanced disease (Masaoka stage III-IV) was high (65%). With a median follow-up of 88.4 months, median overall survival (OS) was 81.6 months for T and 12.3 months for TC (P = 0.01). Univariate analysis showed that sex, histological type, clinical stage and surgery (P = 0.01) were significant independent prognostic factors. On multivariate analysis, histology type and Masaoka-Koga staging had an effect on survival. CONCLUSIONS: The results indicates a clear association between the WHO histological classification and Masaoka-Koga staging system with survival. We found a higher proportion of TETs with advanced disease at diagnosis. Further research are required and collaboration is important to foster knowledge focused on classification and treatment. KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: The WHO histological classification, the Masaoka-Koga system and surgery treatment were associated with overall survival. WHAT THIS STUDY ADDS: To determine prognosis factors in TETs.