134P Real-world clinical, molecular, treatment patterns and outcomes of rare mutations in lung cancer from community oncology centres in Western India

Background: 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 < 0.001).Ki-67 was higher in advanced-stage, conservatively treated tumors (46.3%) than in surgically resected tumors (15%; p = 0.064) and moderately correlated with SUVmax (R = 0.44; p = 0.02).Weak but significant correlations were observed between SUVmax and CRP (R = 0.23; p = 0.03) and leukocyte count (R = 0.21; p = 0.04).Poorly differentiated (G3) tumors treated with cisplatin plus pemetrexed showed rapid metabolic response on follow-up PET.Conclusions: SUVmax reflects key biological features of lung adenocarcinoma.High uptake indicates aggressive histology and proliferation, while lepidic tumors show lower metabolic activity.SUVmax may aid in risk stratification and monitoring treatment response.