Abstract Introduction Lung cancer remains the leading cause of cancer-related death globally. Among individuals younger than 35 years, it is extremely rare, comprising only 1.3% of all cancers, with adenocarcinoma representing 48% of these cases. Although tobacco use contributes to 15-71% of lung cancers in those under 55 years, the latency period of 10-30 years makes tobacco an unlikely sole cause in very young adults. We report the case of a 22-year-old non-smoker male found to have a right lung mass with biopsy confirming pulmonary adenocarcinoma. Case Description A 22-year-old non-smoker male presented with a two-week history of non-productive cough and hemoptysis. Patient denied any associated symptoms including weight loss. He denied travel history, sick contacts or occupational exposure. He was hemodynamically stable. Physical examination and laboratory data was unrevealing. Chest imaging revealed a right upper lobe mass measuring 6.8 × 4.7 × 5.0 cm abutting the mediastinum, with an additional soft tissue component measuring 4.2 × 3.3 × 4.2 cm, causing obstruction of the right upper lobe bronchus and exerting mild compression on the superior vena cava (Figures 1a,1b). Bronchoscopy identified an endobronchial mass (Figure 1c) with biopsy confirming invasive, poorly differentiated non-small cell lung carcinoma (NSCLC) and immunohistochemical features of pulmonary adenocarcinoma. Discussion Only 3.2% of NSCLC cases occurred in individuals aged 20-46 years with adenocarcinoma being the predominant type. The etiology of NSCLC in patients under 35 years remains unclear, with genetic factors playing a key role. Adenocarcinoma in patients under 40 years exhibits a high prevalence of EGFR mutations (40%) and ALK rearrangements (34%). Tobacco use is an unlikely sole cause in such patients. Hence, other Group 1 carcinogens such as pollutants or occupational exposures should be considered. This case highlights the importance of considering lung cancer in the differential in non-smoker young adults presenting with non-specific pulmonary symptoms and the need for further work up. Early diagnosis and treatment in such cases has been linked to superior overall survival. Conclusions Although rare, adenocarcinoma is the predominant subtype of NSCLC in young adults, with a slightly higher incidence in females. Lack of suspicion and non-specific symptoms leads to delay in diagnosis and treatment in such patients, with most being diagnosed at advanced stages (IIIb/IV). The etiology remains uncertain, and exposure to non-tobacco Group 1 carcinogens should be explored. Recognition of genetic mutations as well as early diagnosis and treatment leads to improved survival in this rare population. This abstract is funded by: HCA Healthcare
Thomas et al. (Fri,) studied this question.