SUVmax in PET/CT and Tumor Biology in Lung Adenocarcinoma: Clinical, Histological, and Molecular Associations

Introduction: Lung adenocarcinoma is a heterogeneous disease with diverse clinical, histopathological, and molecular features influencing prognosis and treatment. ^18F-FDG PET-CT provides metabolic information, but its correlation with histology, proliferation, and molecular alterations is not fully defined. The aim of our study was to evaluate the clinical, pathological, and molecular characteristics of lung adenocarcinoma and explore the relationship between tumor metabolism, growth patterns, and proliferation. Methods: We retrospectively analyzed 110 patients diagnosed between 2012 and 2015. Data on demographics, smoking history, histopathology, molecular alterations, and PET-CT SUVmax were collected. Ki-67 proliferation index and inflammatory markers (CRP, leukocyte count) were assessed. Correlation and comparative analyses between subgroups were performed. Results: The cohort included 64 men (58.2%) and 46 women (41.8%), mean age 65.5±10.9 years. Most patients (87.9%) were smokers (mean 48.9 pack-years); 56.4% had stage IV disease. Mean SUVmax was 11.6±7.6, higher in conservatively treated patients (13.5±6.9) than surgically treated patients (8.6±7.7; p=0.001). Among 40 surgically treated patients, lobectomy was most common (61%). Solid growth pattern predominated (56.7%), followed by acinar (20.6%), papillary (10.3%), lepidic (8.2%), and micropapillary (3.1%). Lepidic tumors had lower SUVmax (5.1±4.7; p=0.015), while solid tumors had higher SUVmax (10.2±4.9; p