Uniqueness of lung cancer in Southeast Asia

Abstract

Lung cancer varies between Caucasians and Asians. There have been differences recorded in the epidemiology, genomics, standard therapies and outcomes, with variations according to the geography and ethnicity which affect the decision for optimal treatment of the patients. To better understand the profile of lung cancer in Southeast Asia, with a focus on India, we have comprehensively reviewed the available data, and discuss the challenges and the way forward. A substantial proportion of patients with lung cancer in Southeast Asia are neversmokers, and adenocarcinoma is the common histopathologic subtype, found in approximately a third of the patients. EGFR mutations are noted in 23-30% of patients, and ALK rearrangements are noted in 5-7%. Therapies are similar to global standards, although access to newer modalities and molecules is a challenge. Collaborative research, political will with various policy changes and patient advocacy are urgently needed.

Keywords: Access; Chemotherapy; Equity; Lung cancer; Mutations; Southeast Asia.

Fig. 1

Genomic landscape of lung cancer in the Indian subcontinent. (a) Pie charts showing histological distribution of lung cancer in India. Non-small cell lung cancer (NSCLC) constitutes 85% of cases, comprising predominantly lung adenocarcinoma and squamous cell carcinoma. Small cell lung cancer (SCLC) represents 15% of cases. The frequency of key genomic alterations in lung adenocarcinoma and squamous cell carcinoma is represented. EGFR mutations occur in 23–30% of lung adenocarcinoma, while KRAS and ALK alterations are present in 10–12% and 5–7%, respectively (Noronha et al., 2020 Noronha et al., 2024⁵⁹). FGFR3 mutations occur in 5.5% of cases (Chandrani et al., 2017⁶⁰). The common mutations associated with EGFR and KRAS are shown. In squamous cell carcinoma, common mutations occur in EGFR, PIK3CA, TP53, KRAS, PTEN, FGFR2, AKT1, ERBB3 and NRAS (Joshi et al., 2021⁶¹). (b) Pie charts showing the relative prevalence of EGFR-mutant versus EGFR wildtype lung adenocarcinoma among males, females, smokers, and non-smokers (Chougule et al., 2013⁶²). (c) Pie chart showing mutation spectrum of KRAS mutations identified in NSCLC cases from the Indian subcontinent (Batra et al., 2023⁶³). NOTE: The frequency of gene alterations shown in the figure is not proportionate to their actual occurrence, as the figure is intended to represent the common genomic alterations rather than their precise frequencies.