Ethnicity and breast cancer characteristics in Kenya.

PURPOSE: There are no published data from specific regions of sub-Saharan Africa describing the clinical and pathological characteristics and molecular subtypes of invasive breast cancer by ethnic group. The purpose of this study was to investigate these characteristics among the three major ethno-cultural groupings in Kenya. METHODS: The study included women with pathologically confirmed breast cancer diagnosed between March 2012 and May 2015 at 11 hospitals throughout Kenya. Sociodemographic, clinical, and reproductive data were collected by questionnaire, and pathology review and immunohistochemistry were performed centrally. RESULTS: The 846 cases included 661 Bantus (78.1%), 143 Nilotes (16.9%), 19 Cushites (2.3%), and 23 patients of mixed ethnicity (2.7%). In analyses comparing the two major ethnic groups, Bantus were more educated, more overweight, had an older age at first birth, and had a younger age at menopause than Nilotes (p < 0.05 for all comparisons). In analyses restricted to definitive surgery specimens, there were no statistically significant differences in tumor characteristics or molecular subtypes by ethnicity, although the Nilote tumors tended to be larger (OR for ≥ 5 cm vs. < 2 cm: 3.86, 95% CI 0.77, 19.30) and were somewhat more likely to be HER2 enriched (OR for HER2 enriched vs. Luminal A/B: 1.41, 95% CI 0.79, 2.49). CONCLUSION: This case series showed no significant differences in breast cancer tumor characteristics or molecular subtypes, but significant differences in sociodemographic characteristics and reproductive factors, among the three major ethnic groups in Kenya. We suggest further evaluation of ethnic differences in breast cancer throughout the genetically and culturally diverse populations of sub-Saharan Africa.

Frequency of KRAS and BRAF mutations in colorectal carcinoma and their association with clinical-pathological characteristics in a tertiary hospital in Kenya.

Introduction: Colorectal carcinoma is a leading cause of cancer morbidity and mortality globally. Its management includes the use of targeted therapy which require assessment for biomarkers to choose eligible patients. KRAS and BRAF mutations are biomarkers predictive of response to anti-EGFR therapy. This study aimed at determining the frequency of BRAF V600E and KRAS exon 2,3,4 mutations in colorectal carcinoma patients at the Aga Khan University Hospital Nairobi, Kenya. Methods: Study participants were patients who had colectomy for colorectal carcinoma. They were identified from the laboratory information system. The patients age, gender and tumor location were determined from the medical records. The histological diagnosis, pathological tumor and nodal stage were confirmed by examining hematoxylin and eosin-stained slides prepared from the colectomy specimen. DNA was extracted from the specimens using Qiagen QIAamp DNA FFPE Tissue Kit and PCR performed using EntroGen KRAS/BRAF mutation analysis kit following manufacturer's protocol. Results: One hundred fourteen patients were enrolled. Colorectal carcinoma was significantly more common in males than females. The mean age at diagnosis was 58 years. Majority of the tumors were in the right colon, were of pathological tumor stage T3 and had nodal involvement. Forty six percent (46%) of the cases had KRAS mutations while 5.3% had BRAF V600E mutation. KRAS mutation was associated with a high pathological tumor stage and nodal involvement. Conclusion: Colorectal carcinoma in our patients is more common in males and tend to occur at a younger age. The patients tend to have a high tumor pathological stage and nodal involvement at diagnosis. The high frequency of KRAS exon 2,3,4 mutation and low frequency of BRAF V600E mutations is similar to what has been reported in literature.

Frequency of IDH1 mutation in adult-type diffuse astrocytic gliomas in a tertiary hospital in Kenya.

The 2021 WHO classification of gliomas has separated gliomas based on their IDH mutation status, reflecting differences in their pathogenesis and clinical characteristics. There is a paucity of data on the prevalence of IDH mutations in gliomas in this region. This study aimed to determine the frequency of the IDH1 mutation in adult-type diffuse astrocytic gliomas in a tertiary hospital in Kenya. Approximately half of the gliomas were positive for the IDH1 mutation, with a slight male predominance. Our study provides crucial insights into the frequency of IDH1 mutations in gliomas in Kenya.

Clinicopathologic features of renal cell carcinomas seen at the Aga Khan University Hospital in Kenya.

Introduction: Kidney cancer accounted for 1. 8% of global cancer deaths according to Globocan 2020 estimates, with most of these being renal cell carcinomas. Lower rates of renal cell carcinoma are reported for Africa and these are expected to change for a combination of reasons. The clinical and morphologic characteristics of renal cell carcinoma seen within Kenya have not been described before. This study aims to partially fill this gap. Materials and methods: This was a cross-sectional descriptive study examining electronic histopathology reports from the Aga Khan University Hospital Nairobi Laboratory for the period January 2016 to May 2022. Results: Sixty cases of renal cell carcinoma were identified. The mean age at diagnosis was 55.3 years. The most common histologic subtype diagnosed was clear cell renal cell carcinoma (41.7%), followed by papillary renal cell carcinoma and renal cell carcinoma not further specified (both 21.7%), and chromophobe renal cell carcinoma (11.7%). The most frequent specimen type was resection, followed by cores of renal masses. The mean tumor size was 8.5 cm. Sixty-seven percent of patients presented with Stage III and above. Discussion: Renal masses were the commonest clinical indication for biopsy among the records reviewed. The male to female ratio, as well as the mean age at presentation were comparable to what is described in literature for other regions of the world. The proportions of the commonest histologic subtypes matched what is described in other parts of the world. Challenges in the identification of histologic subtypes included having a limited panel of antibodies for diagnosis and the lack of genetic molecular tests for histotyping. Conclusion: The spectrum of histologic subtypes of renal cell carcinoma seen at a tertiary referral hospital in Nairobi, Kenya was similar to that described in other parts of Africa and the globe. The age at presentation with renal cell carcinoma was consistent with what has been described in literature. Challenges were identified in the accurate histotyping of renal cell carcinoma due to constrained resources. Majority of cases diagnosed presented at advanced stage.

Geographic Variability of Nodular Lymphocyte-Predominant Hodgkin Lymphoma.

OBJECTIVES: Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) differs from classic Hodgkin lymphoma (CHL) in terms of clinicopathologic features, including Epstein-Barr virus (EBV) association. CHL geographic variability is well known, with higher frequencies of mixed-cellularity subtype and EBV positivity in low/middle-income countries (LMICs), but there are few well-characterized series of NLPHL from LMICs. METHODS: We detail clinicopathologic findings of 21 NLPHL cases received in consultation from Kenya and summarize reports of NLPHL with EBV testing published since 2000. RESULTS: Median age of consultation cases was 36 years, and male/female ratio was 3.2. All cases involved peripheral lymph nodes and showed at least some B-cell-rich nodular immunoarchitecture, with prominent extranodular lymphocyte-predominant (LP) cells and T-cell-rich variant patterns most commonly seen. LP cells expressed pan-B-cell markers, including strong OCT2; lacked CD30 and CD15 expression in most cases; and were in a background of expanded/disrupted follicular dendritic cell meshworks and increased T-follicular helper cells. LP cells were EBV negative in 18 cases. Historical cases showed a low rate of EBV positivity with no significant difference between LMICs and high-income countries. CONCLUSIONS: Unlike CHL, NLPHL shows few geographic differences in terms of clinicopathologic features and EBV association. These findings have implications for diagnosis, prognostication, and treatment of patients with NLPHL in LMICs.

Xpert® MTB/RIF assay on formalin-fixed paraffin-embedded tissues in the diagnosis of extrapulmonary tuberculosis.

BACKGROUND: Diagnosis of extrapulmonary tuberculosis continues to be a challenge due to the complexity of the causative organism and the wide array of pathologic features seen in this infection. Xpert MTB/RIF can be used on fresh or frozen tissue specimens for diagnosis of tuberculosis with good results. However, there is little data on its use with formalin-fixed paraffin-embedded (FFPE) tissues. OBJECTIVES: The aim of this study was to demonstrate the potential utility of Xpert MTB/RIF and to compare its performance to Ziehl-Neelsen staining for the detection of Mycobacterium tuberculosis from FFPE tissues using histological features from haematoxylin and eosin staining as the gold standard. METHODS: Eighty randomly selected archival FFPE tissues exhibiting histological features of tuberculosis were included in the study. After deparaffinisation and lysis, all the tissue specimens were subjected to the Xpert® MTB/RIF assay. The outcome measures were proportions of positively identified cases by each test. RESULTS: Using histology as the gold standard, the sensitivity of Ziehl-Neelsen staining was 20.3% (95% confidence interval: 12% - 30.8%), and the sensitivity of the Xpert® MTB/RIF assay was 53.2% (95% confidence interval: 41.6% - 64.9%); the difference was statistically significant (p = 0.002). None of the cases tested positive for rifampicin resistance. CONCLUSION: With prior deparaffinisation and lysis, FFPE tissues are amenable to testing by Xpert® MTB/RIF assay. A validation study to determine the clinical utility, analytical optimisation and cost implications of this assay for FFPE tissues is recommended.

Sentinel Lymph Node Biopsy Pathology and 2-Year Postsurgical Recurrence of Breast Cancer in Kenyan Women.

PURPOSE: The goal of this study was to describe the pathologic findings and early follow-up experience of patients who underwent a sentinel lymph node biopsy (SLNB) at Aga Khan University Hospital (AKUH) between 2008 and 2017. PATIENTS AND METHODS: We performed a retrospective analysis of women with breast cancer who underwent an SLNB at AKUH between 2008 and 2017. The SLNB was performed on patients with stage I and stage II breast cancer, and identification of the sentinel lymph node was made by radioactive tracer, blue dye, or both, per availability and surgeon preference. Demographic, surgical, and pathologic data, including immunohistochemistry of the surgical sample for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2, were abstracted from the patient records. Follow-up data were available for a subset of patients. RESULTS: Between 2008 and 2017, six surgeons performed SLNBs on 138 women, 129 of whom had complete records and were included in the study. Thirty-one of 129 (24%) had a positive SLNB, including 10 of 73 (14%) with stage I and 21 of 56 (38%) with stage II disease. Seventy-eight patients (60%) received systemic adjuvant chemotherapy and 79 (62%) received radiation therapy, and of the 102 patients who were estrogen receptor positive, 86 (85%) received endocrine therapy. Seventy-nine patients were observed for > 2 years, and, of these, four (5.1%) had a regional recurrence. CONCLUSION: The SLNB positivity rates were similar to those of high-income country (HIC) cohorts. However, preliminary data suggest that recurrence rates are elevated at AKUH as compared with those of HIC cohorts, perhaps because of a lower use of radiotherapy and chemotherapy at AKUH compared with HIC cohorts or because of differences in the characteristics of the primary tumor in patients at AKUH as compared with those in HICs.

Telecytology in East Africa: a feasibility study of forty cases using a static imaging system.

We conducted a pilot study to assess the feasibility of telecytology as a diagnostic tool in difficult cases originating from a hospital in East Africa. Forty cytology cases considered difficult by a referring pathologist were posted on a telepathology website. Six pathologists independently assessed the static images. Telecytology diagnoses were compared with the consensus diagnoses made on glass slides and also with the histogical diagnoses when available. The diagnostic agreement of the six pathologists was 71-93% and tended to be higher for pathologists with more experience. Reasons for discordance included poor image quality, presence of diagnostic cells in thick areas of smears, sampling bias and screening errors. The consensus diagnoses agreed with histological diagnoses in all 17 cases in which a biopsy was performed. Diagnostic accuracy rates (i.e. telecytology diagnosis vs. histological diagnosis) for individual pathologists were 65-88%. To ensure diagnostic accuracy both referring and consulting pathologists must have adequate training in cytology, image acquisition and image-based diagnosis and the diagnostic questions of importance must be clearly communicated by the referring pathologist when posting a case.