Molecular profile of non-small cell lung cancer in a predominantly Black African population in Kenya: A single institution review

Abstract

Introduction

Targeted therapies for patients with non-small cell lung cancer (NSCLC) have significantly improved the outcomes for patients with oncogenic driver mutations. Testing for epidermal growth factor receptor (EGFR) mutations, anaplastic lymphoma kinase (ALK) rearrangement, c-ros oncogene 1 (ROS1) rearrangement and programmed death ligand 1 (PDL 1) testing are now highly recommended for all patients with NSCLC. There are clear geographical differences in the rate of driver mutations with higher EGFR mutation rates in the Asian population in comparison to the Caucasian population. Little is known about the rate of oncogenic driver mutations in predominantly Black African populations like those living in the East African region. This study describes the oncogenic driver mutations found in lung cancer patients diagnosed in a single institution in Kenya.

Patients and methods

We retrospectively reviewed the charts of patients who had a pathological diagnosis of NSCLC at Aga Khan University Hospital, Nairobi (AKUHN) between January 2012 and December 2022. Data was analyzed for socio-demographic characteristics, smoking status, clinical stage, histological sub-type and presence or absence of driver mutations.

Results

123 cases of non-small cell lung cancer (NSCLC) were included in the analysis. The median age at diagnosis was 62 years (IQR: 53.0 – 71.0) and 41.5 % (n = 51) of patients were under 60 years at time of diagnosis, 47.2 % (n = 58) were female and 78.9 % (n = 97) were of Black African descent. Only 29.4 % (n = 30) were known smokers whereas 73.2 % (n = 90) had stage IV disease. Adenocarcinoma was the most common sub-type in 85.4 % (n = 105) patients and 60 % of cases had EGFR testing done and a mutation was detected in 35 % (n = 26/74) patients tested. ALK and ROS rearrangement was positive in 19.5 % (n = 8/41) and 6.0 % (n = 2/33) patients tested respectively. Only 23.5 % (n = 8/34) of patients tested for PDL1 had an expression of >1 %. There was no significant association between gender, ethnicity and smoking with EGFR mutation.

Conclusion

In our setting, EGFR testing was the most common molecular test done for lung cancer with a positive rate like that reported in Asian communities. Further studies are needed in a larger population to define further the molecular profile of lung cancer in Sub Saharan Africa. Access to testing will enhance targeted therapies for patients leading to improved outcomes.