Lung Cancer Risk Factors Beyond Smoking in Ethiopia: A Multicenter Matched Case–Control Study
by
, and
Nathan Estifanos
1,2,*, 
Gudina Egata
1,
Adamu Addissie
1,
Rahel Argaw Kebede
3,
Aschalew Worku
3,
Amsalu Bekele
3,
Biruk Habtamu
4,
Selam Tesfaye
5,
Aman Yesuf Endries
1,6,
Zemzem Shigute
7,
Anagaw Derseh Mebratie
1,
Getnet Alemu
8,
Arjun S. Bedi
7 and
Negussie Deyessa
1 1
School of Public Health, College of Health Sciences, Addis Ababa University, Addis Ababa P.O. Box 9086, Ethiopia
2
College of Medicine and Health Science, Wollo University, Dessie P.O. Box 1145, Ethiopia
3
School of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa P.O. Box 9086, Ethiopia
4
Oncology Department, School of Medicine, College of Health Sciences, Haramaya University, Harar P.O. Box 235, Ethiopia
5
Department of Oncology, Faculty of Medical Sciences, Institute of Health, Jimma University, Jimma P.O. Box 378, Ethiopia
6
School of Public Health, St Paul’s Hospital Millennium Medical College, Addis Ababa P.O. Box 1271, Ethiopia
7
International Institute of Social Studies (ISS), Erasmus University Rotterdam, P.O. Box 29776 The Hague, The Netherlands
8
Institute of Development and Policy Research, Addis Ababa University, Addis Ababa P.O. Box 1176, Ethiopia
*
Author to whom correspondence should be addressed.
Cancers 2026, 18(6), 914; https://doi.org/10.3390/cancers18060914
Submission received: 27 January 2026
/
Revised: 27 February 2026
/
Accepted: 2 March 2026
/
Published: 12 March 2026
(This article belongs to the Section Cancer Epidemiology and Prevention)
Simple Summary
In Ethiopia, smoking explains only a fraction of lung cancer cases, highlighting the importance of other local risk factors. This study examined 351 lung cancer patients and 702 matched hospital controls to uncover these drivers. Beyond smoking, lung cancer was independently associated with low education and wealth, use of solid fuels, occupational exposures, limited physical activity, processed food- and meat-based dietary patterns, secondhand smoke, prior tuberculosis, and family history of cancer. While both men and women were affected by these risks, men were more exposed to smoking, occupational hazards, meat-based diets, and family history. In contrast, women faced greater exposure to secondhand smoke, solid fuels, and processed food diets. These findings underscore the need for gender-sensitive public health strategies that address multiple local risk factors to improve lung cancer prevention and early detection in resource-limited settings like Ethiopia.
Abstract
Background: While smoking is the dominant global driver of lung cancer, less than a quarter of Ethiopian patients have ever smoked, pointing to locally relevant risk factors. Evidence to guide prevention and early detection in resource-limited settings is scanty. Methods: To address this gap, we conducted a multicenter matched case–control study including 351 histopathologically confirmed primary lung cancer cases and 702 hospital-based controls matched by sex, age (±5 years), and residence. Directed acyclic graphs informed the selection of variables, and multivariable hierarchical conditional logistic regression was used to identify risk factors beyond smoking. Results: The analysis shows that lung cancer was independently associated with low education, wealth, solid-fuel use, occupational exposure, insufficient physical activity, meat-based and processed food dietary patterns, secondhand smoke (SHS), prior tuberculosis, and family history of cancer. Subgroup analysis by sex revealed consistent associations across males and females, but exposure distributions explained sex-specific patterns: smoking, occupational exposure, meat-based diets, and family history were more common among males, whereas SHS, the use of solid fuels, and processed food dietary patterns predominated in females. Conclusions: Lung cancer in Ethiopia appears to be associated with several factors in addition to smoking. Gender-sensitive public health interventions targeting these locally relevant risk factors are essential for effective prevention and early detection.
Keywords:
lung cancer; risk factors; case–control study; Ethiopia
