Nepal retrospective study characterizes 51 ALK- or ROS1-positive tumors

A single-centre retrospective observational study in Nepal found that patients with ALK- or ROS1-positive non-small cell lung cancer commonly had a history of non-smoking and were diagnosed with advanced-stage disease. The abstract reports that the analysis included 51 immunohistochemistry-positive cases with complete clinical data: 42 ALK-positive cases and nine ROS1-positive cases. Two of the ALK-positive cases were inflammatory myofibroblastic tumors rather than non-small cell lung cancers, leaving 49 lung cancers in the selected cohort.

The tertiary-care study initially covered 6,078 cancer cases, including 670 lung cancers and 560 cases of non-small cell lung cancer. All 560 non-small cell lung cancer cases underwent immunohistochemistry-based screening for ALK and ROS1. Among the 51 selected positive cases, the median age was 53 years, with a range of 26–82 years, and 53% were male. Eighty percent were non-smokers, 71% had stage IV disease, and adenocarcinoma was the predominant histological subtype, accounting for 65% of cases. Exploratory comparisons between the ALK and ROS1 subgroups showed no statistically significant differences in the evaluated clinicopathological characteristics.

All 51 patients had documented initiation of first-line crizotinib. The median time from diagnosis to tyrosine kinase inhibitor initiation was 0.82 months, with an interquartile range of 1.25 months, and the median observed duration of first-line treatment was 17.9 months, with an interquartile range of 22.6 months. Twelve patients, representing 23.5% of the cohort, subsequently received lorlatinib. Based on available clinical follow-up, the estimated median time to first-line treatment discontinuation was 36.4 months, with a 95% confidence interval of 27.0 months to not reached. Median progression-free survival was 41.7 months, with the same confidence interval, while median overall survival was not reached.

These treatment timelines and survival estimates are descriptive findings for the observed cohort, rather than evidence of comparative treatment efficacy. Interpretation is constrained by the retrospective design, single-centre scope, selected population of 51 immunohistochemistry-positive patients with complete data, and outcomes calculated from available follow-up. The exploratory ALK–ROS1 comparison was also limited by small subgroup sizes, particularly the nine ROS1-positive cases. The mixed cohort included two inflammatory myofibroblastic tumors, so the results were not drawn exclusively from patients with non-small cell lung cancer. The abstract states that the findings support improved access to confirmatory molecular testing and broader genomic profiling in Nepal’s resource-limited setting.

Subject of Research: Clinicopathological and treatment profile of ALK- and ROS1-positive tumors in a Nepalese retrospective cohort

Article Title: Clinicopathological profile of ALK and ROS1-positive lung tumors: a single-centre retrospective study from Nepal

Article References: Shahi, A., Poudel, B., Adhikari, S., Lama, M., & Mukherjee, A. K. (2026). Clinicopathological profile of ALK and ROS1-positive lung tumors: a single-centre retrospective study from Nepal. BMC Cancer. https://doi.org/10.1186/s12885-026-17002-1

Image Credits: AI Generated

DOI: 10.1186/s12885-026-17002-1

Keywords: ALK-positive tumors, ROS1-positive tumors, non-small cell lung cancer, Nepal, immunohistochemistry, crizotinib, lorlatinib, progression-free survival, retrospective cohort, Clinicopathological, profile, ROS1-positive