Traditional and commercial alcohols and esophageal cancer risk in Kenya.

Squamous cell esophageal cancer is common throughout East Africa, but its etiology is poorly understood. We investigated the contribution of alcohol consumption to esophageal cancer in Kenya, based on a hospital-based case-control study conducted from 08/2013 to 03/2018 in Eldoret, western Kenya. Cases had an endoscopy-confirmed esophageal tumor whose histology did not rule out squamous cell carcinoma. Age and gender frequency-matched controls were recruited from hospital visitors/patients without digestive diseases. Logistic regression was used to calculate odds ratios (ORs) and their 95% confidence intervals (CI) adjusting for tobacco (type, intensity) and 6 other potential confounders. A total of 422 cases (65% male, mean at diagnosis 60 (SD 14) years) and 414 controls were included. ORs for ever-drinking were stronger in ever-tobacco users (9.0, 95% CI: 3.4, 23.8, with few tobacco users who were never drinkers) than in never-tobacco users (2.6, 95% CI: 1.6, 4.1). Risk increased linearly with number of drinks: OR for >6 compared to >0 to ≤2 drinks/day were 5.2 (2.4, 11.4) in ever-tobacco users and 2.1 (0.7, 4.4) in never-tobacco users. Although most ethanol came from low ethanol alcohols (busaa or beer), for the same ethanol intake, if a greater proportion came from the moonshine chang'aa, it was associated with a specific additional risk. The population attributable fraction for >2 drinks per day was 48% overall and highest in male tobacco users. Alcohol consumption, particularly of busaa and chang'aa, contributes to half of the esophageal cancer burden in western Kenya.

Hot beverages and oesophageal cancer risk in western Kenya: Findings from the ESCCAPE case-control study.

Oesophageal squamous cell carcinoma (ESCC) has markedly high incidence rates in Kenya and much of East Africa, with a dire prognosis and poorly understood aetiology. Consumption of hot beverages-a probable carcinogen to humans-is associated with increased ESCC risk in other settings and is habitually practiced in Kenya. We conducted a case-control study in Eldoret, western Kenya between August 2013 and March 2018. Cases were patients with endoscopically confirmed oesophageal cancer whose histology did not rule out ESCC. Age and sex-matched controls were hospital visitors and hospital out and in-patients excluding those with digestive diseases. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for self-reported drinking temperatures; consumption frequency; mouth burning frequency and hot porridge consumption using logistic regression models adjusted for potential confounders. Drinking temperature association with tumour sub-location was also investigated. The study included 430 cases and 440 controls. Drinkers of 'very hot' and 'hot' beverages (>95% tea) had a 3.7 (95% CI: 2.1-6.5) and 1.4-fold (1.0-2.0) ESCC risk, respectively compared to 'warm' drinkers. This trend was consistent in males, females, never and ever alcohol/tobacco and was stronger over than under age 50 years. The tumour sub-location distribution (upper/middle/lower oesophagus) did not differ by reported drinking temperature. Our study is the first comprehensive investigation in this setting to-date to observe a link between hot beverage consumption and ESCC in East Africa. These findings provide further evidence for the role of this potentially modifiable risk factor in ESCC aetiology.

Dental fluorosis and oral health in the African Esophageal Cancer Corridor: Findings from the Kenya ESCCAPE case-control study and a pan-African perspective.

There are no studies of oral health in relation to esophageal cancer in Africa, or of Eastern Africa's endemic dental fluorosis, an irreversible enamel hypo-mineralization due to early-life excessive fluoride intake. During 2014-18, we conducted a case-control study of squamous cell esophageal cancer in Eldoret, western Kenya. Odds ratios (AORs (95% confidence intervals)) were adjusted for design factors, tobacco, alcohol, ethnicity, education, oral hygiene and missing/decayed teeth. Esophageal cancer cases (N = 430) had poorer oral health and hygiene than controls (N = 440). Compared to no dental fluorosis, moderate/severe fluorosis, which affected 44% of cases, had a crude OR of 20.8 (11.6, 37.4) and on full adjustment was associated with 9.4-fold (4.6, 19.1) increased risk, whilst mild fluorosis (43% of cases) had an AOR of 2.3 (1.3, 4.0). The prevalence of oral leukoplakia and tooth loss/decay increased with fluorosis severity, and increased cancer risks associated with moderate/severe fluorosis were particularly strong in individuals with more tooth loss/decay. Using a mswaki stick (AOR = 1.7 (1.0, 2.9)) rather than a commercial tooth brush and infrequent tooth brushing also independently increased risk. Geographic variations showed that areas of high esophageal cancer incidence and those of high groundwater fluoride levels have remarkably similar locations across Eastern Africa. In conclusion, poor oral health in combination with, or as a result of, high-altitude susceptibility to hydro-geologically influenced dental fluorosis may underlie the striking co-location of Africa's esophageal cancer corridor with the Rift Valley. The findings call for heightened research into primary prevention opportunities of this highly fatal but common cancer.

Cancer epidemiology fieldwork in a resource-limited setting: Experience from the western Kenya ESCCAPE esophageal cancer case-control pilot study.

BACKGROUND: Case-control studies remain an important study design for aetiologic research on cancer, particularly when cohorts are not available. In addition to the potential biases inherent in this design, conducting fieldwork in settings with weak health care and information systems for cancer, such as in sub Saharan Africa, confer additional challenges which we present here with the aim to share experience to guide future studies. METHODS: We undertook a hospital-based case-control study of squamous cell esophageal cancer at the Moi Teaching and Referral Hospital in Eldoret, West Kenya. Cases were recruited at endoscopy and controls from hospital wards, age and gender frequency-matched to cases. Urine, toenails, blood and tumour biopsy were collected and a questionnaire administered. RESULTS: During this pilot phase, 143 cases and 155 controls were successfully recruited. Complete questionnaire data was obtained through e-data collection. Biospecimen collection was possible with support of an already existing equipped laboratory. We introduce changes made in the main study phase, including on expansion of the control groups to allow to consideration of selection bias. CONCLUSIONS: Extra attention and funding to train and monitor data quality and biospecimen collection and collaboration of a large group held together by strong leadership are essential. We recommend studies based on regional treatment centres with their more defined catchment areas rather than in the capital cities as referral routes in multi-level health care systems are severely attrition prone.

Cytokines associated with Burkitt's lymphoma in western Kenya.

OBJECTIVE: Burkitt's lymphoma (BL) is a common aggressive non-Hodgkin's lymphoma in East and Central Africa among children. Persistent infections with Epstein Barr virus or Plasmodium falciparum are associated with immune hyperstimulation. It is hypothesised that inadvertent cytokine responses to infections indirectly or directly influence B cell neoplastic transformation through c-myelocytomatosis (c-myc) gene translocation. We sought to describe cytokines in children and adolescents with BL. Participants were recruited from western Kenya with parental consent, diagnosis confirmed using histology and consensus panel of immunohistochemistry antibodies. T helper1/2/17A and transforming growth factor-ß1 (TGF-ß1) cytokines were estimated using cytometric bead array in plasma. Complete blood counts (CBC) were determined by Beckman Coulter®. RESULTS: Out of 104 enrolled participants, 32% were confirmed BL and 68% grouped as non-BL. Mean (pg/ml) levels of cytokines in BL and non-BL were: interleukin (IL)-6 100.3 and 39.4 p = 0.152; IL-10 11.5 and 12.5 p = 0.363; IL-17A 17.8 and 64.9 p = 0.094 respectively. Expressions of interferon-γ, IL-2 and tumour necrosis factor-α were low and TGF-ß1 undetectable in both groups. Mean CBC differed between the two groups before and after chemotherapy, WBC being significantly so. Interleukin-6, IL-17A and IL-10 responses to infections in the study area may be associated with pathogenesis and be potential therapeutic targets.

Tumor infiltrating leukocyte density is independent of tumor grade and molecular subtype in aggressive breast cancer of Western Kenya.

BACKGROUND: Tumors commonly are infiltrated by leukocytes, or tumor infiltrating leukocytes (TILs). It remains unclear, however, if the density and type of individual TILs has a direct or simply correlative role in promoting poor prognosis in breast cancer patients. Breast cancer in Kenyan women is aggressive with presentation at a young age, with advanced grade (grade III), large tumor size (>2.0 cm), and poor prognosis. We previously observed that the tumors were predominantly estrogen receptor positive (ER+) but also included both a high percentage of triple negative tumors and also increased immune cell infiltration within the tumors. We used breast tumor tissues from each patient to make tissue microarrays that were then stained for leukocyte and myeloid markers including CD4, CD8, CD20, CD25, CD68, and CD163 using immunohistochemical techniques. The immune cell infiltration into the cancer tissue included increased numbers of macrophages (CD68+), helper T cells (CD4+), and CD25+ lymphocytes compared to benign tissue. RESULTS: This study characterized the grade, molecular subtypes, and proliferation index of these tumors and determined if TIL density was enriched across any of these factors. We analyzed 49 malignant patient tissue samples for this study. The patient population had a mean age of 51.9 years. The tumors analyzed were heterogeneous by grade: grade I (6%), grade II (47%), and grade III (39%). Most patients presented with large tumors (>2.0 cm) (69%). We classified the tumors into molecular subtypes based on clinical marker expression. Based on this analysis, the molecular subtype distribution was heterogeneous with luminal B (41%), basal/triple negative (TN) (37%), luminal A (14%) and HER2 (8%) breast cancer subtypes. While the basal/TN subtype had a much higher proliferative index (Ki-67+) than did the other molecular subtypes, we did not see a significant correlation between TIL density and either subtype or tumor grade. Therefore, TIL density is independent of molecular subtype and grade. CONCLUSION: This study identified a Kenyan patient cohort that develops large, high-grade tumors primarily of the luminal B and basal molecular subtypes. After analyzing the TILs within these tumors, we found that immune cell infiltration of these tumors correlated with increased proliferation but not grade or molecular subtype. Future research is required to determine if the aberrant recruitment of TILs to tumors contributes to cancer progression and response to cancer treatments.

Use of visual inspection with acetic acid, Pap smear, or high-risk human papillomavirus testing in women living with HIV/AIDS for posttreatment cervical cancer screening: same tests, different priorities.

OBJECTIVES: Few studies have addressed optimal follow-up for HIV-infected women after cervical treatment. This study aimed to compare performance of three available tests to detect posttreatment cervical disease in HIV-infected women in Kenya. DESIGN: This is a prospective cohort study. METHODS: At least 6 months following cryotherapy, 517 HIV-infected women were evaluated concurrently with visual inspection with acetic acid (VIA), papanicolaou (Pap) smear, and high-risk human papillomavirus (HR-HPV) testing. Women positive by any test (≥low-grade squamous intraepithelial lesion for Pap) were scheduled for colposcopy and biopsy. Among 248 with histological confirmation [and 174 assumed to be truly negative for cervical intraepithelial neoplasia (CIN)2+ after testing negative by all three tests], the ability of each test alone, or in combination, to detect CIN2+ was calculated to determine their utility in posttreatment follow-up. RESULTS: The median age of women was 35 years, 68% were WHO stage 1-2, with a median CD4 cell count of 410 cells/µl, and 87% were on combination antiretroviral therapy. At a median of 6.3 months posttreatment, 64% had an abnormal screen by VIA, Pap, and/or HR-HPV. Among women with histological confirmation, 72 (30%) had persistent/recurrent CIN2+. As single tests, Pap correctly classified the most cases (83%) and had the highest specificity [91% (88 and 95%); sensitivity 44% (35 and 53%)], whereas HR-HPV had the highest sensitivity [85% (75 and 96%); specificity 54% (49 and 58%)]. VIA was not sensitive [27% (18 and 36%)] for the detection of posttreatment CIN2+ [specificity 82% (79 and 86%)]. CONCLUSION: With the goal to minimize the number of false negatives (e.g. not miss CIN2+ posttreatment) in this population that is high-risk due to both prior cervical disease and HIV infection, HR-HPV-based algorithms are recommended.

Aggressive breast cancer in western Kenya has early onset, high proliferation, and immune cell infiltration.

BACKGROUND: Breast cancer incidence and mortality vary significantly among different nations and racial groups. African nations have the highest breast cancer mortality rates in the world, even though the incidence rates are below those of many nations. Differences in disease progression suggest that aggressive breast tumors may harbor a unique molecular signature to promote disease progression. However, few studies have investigated the pathology and clinical markers expressed in breast tissue from regional African patient populations. METHODS: We collected 68 malignant and 89 non-cancerous samples from Kenyan breast tissue. To characterize the tumors from these patients, we constructed tissue microarrays (TMAs) from these tissues. Sections from these TMAs were stained and analyzed using immunohistochemistry to detect clinical breast cancer markers, including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor 2 receptor (HER2) status, Ki67, and immune cell markers. RESULTS: Thirty-three percent of the tumors were triple negative (ER-, PR-, HER2-), 59% were ER+, and almost all tumors analyzed were HER2-. Seven percent of the breast cancer patients were male, and 30% were <40 years old at diagnosis. Cancer tissue had increased immune cell infiltration with recruitment of CD163+ (M2 macrophage), CD25+ (regulatory T lymphocyte), and CD4+ (T helper) cells compared to non-cancer tissue. CONCLUSIONS: We identified clinical biomarkers that may assist in identifying therapy strategies for breast cancer patients in western Kenya. Estrogen receptor status in particular should lead initial treatment strategies in these breast cancer patients. Increased CD25 expression suggests a need for additional treatment strategies designed to overcome immune suppression by CD25+ cells in order to promote the antitumor activity of CD8+ cytotoxic T cells.

Screening by Clinical Breast Examination in Western Kenya: Who Comes?

PURPOSE: More than 80% of women with breast cancer in Kenya present to medical care with established late-stage disease. We sought to understand why women might not participate in breast cancer screening when it is offered by comparing the views of a cohort of those who attended a screening special event with those of community controls who did not attend. METHODS: All residents living close to three health centers in western Kenya were invited to participate in screening. Participants (attendees) underwent clinical breast examination by trained physician oncologists. In addition, women who consented were interviewed by using a modified Breast Cancer Awareness Module questionnaire. Nonattendees were interviewed in their homes the following day. RESULTS: A total of 1,511 attendees (1,238 women and 273 men) and 467 nonattendee women participated in the study. Compared with nonattendees, the women attendees were older, more often employed, knew that breast cancer presented as a lump, and were more likely to have previously felt a lump in a breast. In addition, they were more likely to report previously participating in screening activities, were more likely to have performed breast self-examination, and were less concerned about wasting a doctor's time. Almost all those surveyed (attendees and nonattendees) expressed interest in future breast cancer screening opportunities. CONCLUSION: The women who volunteer for breast cancer screening in western Kenya are more aware of breast cancer than those who do not volunteer. Screening recruitment should seek to close these knowledge gaps to increase participation.

Development of immunohistochemistry services for cancer care in western Kenya: Implications for low- and middle-income countries.

BACKGROUND: Cancer is becoming a major cause of mortality in low- and middle-income countries. Unlike infectious disease, malignancy and other chronic conditions require significant supportive infrastructure for diagnostics, staging and treatment. In addition to morphologic diagnosis, diagnostic pathways in oncology frequently require immunohistochemistry (IHC) for confirmation. We present the experience of a tertiary-care hospital serving rural western Kenya, which developed and validated an IHC laboratory in support of a growing cancer care service. OBJECTIVES METHODS AND OUTCOMES: Over the past decade, in an academic North-South collaboration, cancer services were developed for the catchment area of Moi Teaching and Referral Hospital in western Kenya. A major hurdle to treatment of cancer in a resource-limited setting has been the lack of adequate diagnostic services. Building upon the foundations of a histology laboratory, strategic investment and training were used to develop IHC services. Key elements of success in this endeavour included: translation of resource-rich practices to a resource-limited setting, such as using manual, small-batch IHC instead of disposable- and maintenance-intensive automated machinery, engagement of outside expertise to develop reagent-efficient protocols and supporting all levels of staff to meet the requirements of an external quality assurance programme. CONCLUSION: Development of low- and middle-income country models of services, such as the IHC laboratory presented in this paper, is critical for the infrastructure in resource-limited settings to address the growing cancer burden. We provide a low-cost model that effectively develops these necessary services in a challenging laboratory environment.

Development of imunohistochemistry services for cancer care in western Kenya: implications for low-and middle-income countries

Background: Cancer is becoming a major cause of mortality in low- and middle-income countries. Unlike infectious disease; malignancy and other chronic conditions require significant supportive infrastructure for diagnostics; staging and treatment. In addition to morphologic diagnosis; diagnostic pathways in oncology frequently require immunohistochemistry (IHC) for confirmation. We present the experience of a tertiary-care hospital serving rural western Kenya; which developed and validated an IHC laboratory in support of a growing cancer care service. Objectives; methods and outcomes: Over the past decade; in an academic North-South collaboration; cancer services were developed for the catchment area of Moi Teaching and Referral Hospital in western Kenya. A major hurdle to treatment of cancer in a resource-limited setting has been the lack of adequate diagnostic services. Building upon the foundations of a histology laboratory; strategic investment and training were used to develop IHC services. Key elements of success in this endeavour included: translation of resource-rich practices to are source-limited setting; such as using manual; small-batch IHC instead of disposable- and maintenance-intensive automated machinery; engagement of outside expertise to develop reagent-efficient protocols and supporting all levels of staff to meet the requirements of an external quality assurance programme. Conclusion: Development of low- and middle-income country models of services; such as the IHC laboratory presented in this paper; is critical for the infrastructure in resource-limited settings to address the growing cancer burden. We provide a low-cost model that effectively develops these necessary services in a challenging laboratory environment

Distinct Viral and Mutational Spectrum of Endemic Burkitt Lymphoma.

Endemic Burkitt lymphoma (eBL) is primarily found in children in equatorial regions and represents the first historical example of a virus-associated human malignancy. Although Epstein-Barr virus (EBV) infection and MYC translocations are hallmarks of the disease, it is unclear whether other factors may contribute to its development. We performed RNA-Seq on 20 eBL cases from Uganda and showed that the mutational and viral landscape of eBL is more complex than previously reported. First, we found the presence of other herpesviridae family members in 8 cases (40%), in particular human herpesvirus 5 and human herpesvirus 8 and confirmed their presence by immunohistochemistry in the adjacent non-neoplastic tissue. Second, we identified a distinct latency program in EBV involving lytic genes in association with TCF3 activity. Third, by comparing the eBL mutational landscape with published data on sporadic Burkitt lymphoma (sBL), we detected lower frequencies of mutations in MYC, ID3, TCF3 and TP53, and a higher frequency of mutation in ARID1A in eBL samples. Recurrent mutations in two genes not previously associated with eBL were identified in 20% of tumors: RHOA and cyclin F (CCNF). We also observed that polyviral samples showed lower numbers of somatic mutations in common altered genes in comparison to sBL specimens, suggesting dual mechanisms of transformation, mutation versus virus driven in sBL and eBL respectively.

Improvement of pathology in sub-Saharan Africa.

In the coming decades, cancer will be a major clinical and public health issue in sub-Saharan Africa. However, clinical and public health infrastructure and services in many countries are not positioned to deal with the growing cancer burden. Pathology is a core service required to serve many needs related to cancer in sub-Saharan Africa. Cancer diagnosis, treatment, and research all depend on adequate pathology. Pathology is also necessary for cancer registration, which is needed to accurately estimate cancer incidence and mortality. Cancer registry data directly guide policy-makers' decisions for cancer control and the allocation of clinical and public health services. Despite the centrality of pathology in many components of cancer care and control, countries in sub-Saharan Africa have at best a tenth of the pathology coverage of that in high-income countries. Equipment, processes, and services are lacking, and there is a need for quality assurance for the definition and implementation of high-quality, accurate diagnosis. Training and advocacy for pathology are also needed. We propose approaches to improve the status of pathology in sub-Saharan Africa to address the needs of patients with cancer and other diseases.

Breast cancer diagnosis in a resource poor environment through a collaborative multidisciplinary approach: the Kenyan experience.

INTRODUCTION: The majority of women with breast cancer in Kenya present with node-positive (stage II) or locally advanced Q7 disease (stage IIIB). Diagnosis is made on fine needle aspirate cytology and treatment is with surgery if resectable. Diagnostic core biopsy is available only at subspecialty hospitals. Processing and reporting of biopsy tissue are not standardised. Hormone receptor and HER2 analyses are rarely done preoperatively. METHODS: As part of a larger study investigating the prevalence of triple negative breast cancer in Kenya, a multidisciplinary workshop of collaborators from 10 healthcare facilities was held. Process gaps were identified, preanalytic variables impacting on ER/PR/HER2 discussed and training in core biopsy provided. Local remedial strategies were deliberated. CONCLUSION: We describe our experience and outcome from the workshop, which can be modelled for other resource poor settings.

Comparison of conventional cervical cytology versus visual inspection with acetic acid among human immunodeficiency virus-infected women in Western Kenya.

OBJECTIVE: This study aimed to determine the accuracy of visual inspection with acetic acid (VIA) versus conventional Pap smear as a screening tool for cervical intraepithelial neoplasia/cancer among human immunodeficiency virus (HIV)-infected women. MATERIALS AND METHODS: A total of 150 HIV-infected women attending the Moi Teaching and Referral Hospital HIV clinic in Eldoret underwent conventional Pap smear, VIA, colposcopy, and biopsy. Both VIA and Pap smears were done by nurses, whereas colposcopy and biopsy were done by a physician. Receiver operating characteristic analysis was conducted to compare the accuracies between VIA and Pap smear in sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). RESULTS: Among the study participants: VIA was abnormal in 55.3% (83/150, 95% confidence interval [CI] = 47.0%-63.5%); Pap smear showed atypical squamous cells of undetermined significance or worse in 43.7% (59/135, 95% CI = 35.2%-52.5%) and 10% (15/150) of the Pap smears were unsatisfactory. Of the abnormal Pap smears, 3% (2/59) had atypical squamous cells of undetermined significance, 7% (4/59) had high-grade atypical squamous cells, 60% (35/59) had low-grade squamous intraepithelial lesions, 29% (17/59) had high-grade squamous intraepithelial lesions, and 2% (1/59) was suspicious for cervical cancer. Using cervical intraepithelial neoplasia 2 or higher disease on biopsy as an end point, VIA has a sensitivity of 69.6% (95% CI = 55.1%-81.0%), specificity of 51.0% (95% CI = 41.5%-60.4%), PPV of 38.6% (95% CI = 28.8%-49.3%), and NPV of 79.1% (95% CI = 67.8%-87.2%). For conventional Pap smear, sensitivity was 52.5% (95% CI = 42.1%-71.5%), specificity was 66.3% (95% CI = 52.0%-71.2%), PPV was 39.7% (95% CI = 27.6%-51.8%), and NPV was 76.8% (95% CI = 67.0%-85.6%). CONCLUSIONS: Visual inspection with acetic acid is comparable to Pap smear and acceptable for screening HIV-infected women in resource-limited settings such as Western Kenya.