Cancer risks in Nairobi (2000-2014) by ethnic group

Gastric cancer in Sub-Saharan Africa - a systematic review of primary data

Introduction

Gastric cancer (GC) is the third leading cause of global cancer-related mortality. Despite the shifting burden of GC to low-and middle-income countries, the data regarding incidence, treatment, and outcomes in these settings are sparse. The primary aim of this systematic review was to aggregate all available data on GC in sub-Saharan Africa (SSA) to describe the variability in incidence across the region.

Methods

Studies reporting population-based primary data on GC in SSA were considered. The inclusion was limited to primary studies published between January 1995 and March 2022 which comprised of adult patients in SSA with GC. Studies without accessible full text in either French or English language were excluded. Unadjusted GC incidence rates with their standard errors for each study were recalculated from the crude numerators and denominators provided in individual studies.

Results

A total of 5,626 articles were identified in the initial search, of which, 69 studies were retained. Reported incidence rates ranged from a high of 5.56 GC cases per 100,000 in Greater Meru Kenya to a low of 0.04 GC cases per 100,000 people in Benin City Nigeria. The overall crude pooled incidence was 1.20 GC cases per 100, 000 (95%CI 1.15-1.26) with a variability of 99.83% (I2 p < 0.001). From the 29 high-quality population-based registry studies the crude pooled incidence was 1.71 GC cases per 100,000 people (95%CI 1.56-21.88) with a variability of 99.60%.

Conclusion

This systemic review demonstrates that GC incidence is highly variable across SSA. The limited data on GC treatment, mortality, and survival presents a significant challenge to providing a complete epidemiologic description of the burden of GC in SSA. There is a need for further robust data collection, exploration, and research studies on cancer care in SSA, with continued assessment of primary data availability.

Linking African ancestral substructure to prostate cancer health disparities

Prostate cancer (PCa) is a significant health burden in Sub-Saharan Africa, with mortality rates loosely linked to African ancestry. Yet studies aimed at identifying contributing risk factors are lacking within the continent and as such exclude for significant ancestral diversity. Here, we investigate a series of epidemiological demographic and lifestyle risk factors for 1387 men recruited as part of the multi-ethnic Southern African Prostate Cancer Study (SAPCS). We found poverty to be a decisive factor for disease grade and age at diagnosis, with other notably significant PCa associated risk factors including sexually transmitted diseases, erectile dysfunction, gynaecomastia, and vertex or complete pattern balding. Aligned with African American data, Black ethnicity showed significant risk for PCa diagnosis (OR = 1.44, 95% CI 1.05-2.00), and aggressive disease presentation (ISUP ≥ 4: OR = 2.25, 95% CI   1.49-3.40). New to this study, we demonstrate African ancestral population substructure associated PCa disparity, observing increased risk for advanced disease for the southern African Tsonga people (ISUP ≥ 4: OR = 3.43, 95% CI   1.62-7.27). Conversely, South African Coloured were less likely to be diagnosed with aggressive disease overall (ISUP ≥ 3: OR = 0.38, 95% 0.17-0.85). Understanding the basis for PCa health disparities calls for African inclusion, however, lack of available data has limited the power to begin discussions. Here, focusing on arguably the largest study of its kind for the African continent, we draw attention to the contribution of within African ancestral diversity as a contributing factor to PCa health disparities within the genetically diverse region of southern Africa.

Review of prostate cancer genomic studies in Africa

Prostate cancer (PCa) is the second most commonly diagnosed in men worldwide and one of the most frequent cancers in men in Africa. The heterogeneity of this cancer fosters the need to identify potential genetic risk factors/biomarkers. Omics variations may significantly contribute to early diagnosis and personalized treatment. However, there are few genomic studies of this disease in African populations. This review sheds light on the status of genomics research on PCa in Africa and outlines the common variants identified thus far. The allele frequencies of the most significant SNPs in Afro-native, Afro-descendants, and European populations were compared. We advocate how these few but promising data will aid in understanding, better diagnosing, and precisely treating this cancer and the need for further collaborative research on the genomics of PCa in the African continent.

Birth month and risk of skin tumors-Follow up of six million Caucasians born from 1950 to 2014 in Sweden

BACKGROUND

Some studies hypothesize that birth month-as a proxy of exposure to ultraviolet radiation in early infancy-is associated with increased risk of skin tumors.

METHODS

We studied a national cohort of all 5 874 607 individuals born in Sweden to parents of Swedish or Nordic origin as a proxy for Caucasian origin, 1950 to 2014. The cohort was followed for incident skin tumors, including squamous cell carcinomas and melanomas but not basal cell carcinomas, through 2015 from birth up to age 65 for the oldest cohort. Cox regression estimated the association between month of birth and risk of skin tumors in models adjusted for sex, calendar period, and education. Crude observed to expected ratios were also calculated.

RESULTS

There were 33 914 cases of skin tumors, of these, 3025 were squamous cell cancer, 16 968 malignant melanoma and 8493 melanoma in situ/other and 5 428 squamous cell in situ/other in 192 840 593 person-years of follow-up. Observed to expected ratios by month of birth showed no association between month of birth and risk of skin tumors, and the same result was seen when Cox regression analysis was used. Subgroup analyses by sex, educational level, calendar period, or age at follow-up similarly showed no association.

CONCLUSION

This large register-based cohort study showed no evidence of a higher risk of skin tumors in those born during the spring. Thus, this study lends no support to the hypothesis that birth during spring is a major risk factor for later skin tumors.

Human papillomavirus genotype profiles and cytological grades interlinkages in coinfection with HIV

Introduction

The study aimed to examine and characterize human papilloma virus (HPV) cytological grade trends and genotypes among HPV/HIV co-infected/cases and HPV monoinfected/control women attending Kisii Teaching and Referral Hospital, Kenya.

Methods

HIV positive co-infected with HPV (HPV/HIV) and HIV negative women monoinfected with HPV profiled as co-infected/cases and monoinfected/control arms respectively were enrolled. HPV subtypes were assayed by Xpert^® HPV system (GXHPV-CE-10) alongside pathological cytology analysis of cervical tissue samples.

Results

Low grade intraepithelial lesion (LSIL) was the most predominant cytological grade across cases and controls with a prevalence of 32 (38.1%) while high grade squamous intraepithelial lesion (HSIL) was highest among HPV/HIV co-infected with a prevalence of 23 (27.38%). Among the monoinfected (controls) the predominant lesion was low grade intraepithelial lesions (LSIL) with a prevalence of 23 (27.38%). HPV type 16 had the highest prevalence 26 (30.8%) among the VIA positive women in the overall study participants followed by combinations of HPV types (16, 18/45) at 19 (22.6%).

Conclusion

High risk HPV types 16 and 18/45 were the most predominant in the established cytological grades and among the co-infected women. Routine screening using both cytological and HPV testing should be embraced and/or reinforced as early screening and preventive strategies in the covered geographical region population. Provision of the currently available vaccines to these women at an early age would provide effective protection since the HPV type profiles in this population are covered by such vaccines.

Estimation of associations between 10 common gene polymorphisms and gastric cancer: evidence from a meta-analysis

AIMS

Associations between polymorphisms in cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4)/mannose-binding lectin (MBL)/interleukin-4 (IL-4)/interleukin-6 (IL-6)/phospholipase C ε-1 (PLCE1) and gastric cancer (GC) were already reported by many studies, yet the conclusions of these studies were somehow controversial. The aim of this meta-analysis was to better clarify associations between polymorphisms in CTLA-4/MBL/IL-4/IL-6/PLCE1 and GC by combing the results of all relevant studies.

METHODS

Eligible studies were searched from PubMed, Embase, WOS and CNKI. We used Review Manager to combine the results of individual studies.

RESULTS

Forty-three studies were included in this meta-analysis. Combined results revealed that CTLA-4 rs5742909 (dominant comparison: OR: 1.58, 95 % CI: 1.01 to 2.48; allele comparison: OR: 1.69, 95 % CI: 1.12 to 2.56) and PLCE1 rs2274223 (dominant comparison: OR: 0.84, 95 % CI: 0.72 to 0.98; recessive comparison: OR: 1.23, 95 % CI: 1.08 to 1.40; over-dominant comparison: OR: 1.16, 95 % CI: 1.00 to 1.34; allele comparison: OR 0.88, 95 % CI 0.78 to 0.99) polymorphisms were significantly associated with GC in the general population. We also obtained similar significant associations with GC for rs5742909 and rs2274223 polymorphisms in East Asians. Nevertheless, no positive results were observed for the other eight investigated polymorphisms.

CONCLUSION

Collectively, this meta-analysis demonstrated that CTLA-4 rs5742909 and PLCE1 rs2274223 polymorphisms may confer susceptibility to GC, especially for East Asians.

Cancer incidence in Northern Uganda (2013-2016)

Gulu Cancer Registry was established in 2014 to assess the incidence and survival of cancer in 4 districts of the Acholi Sub-region of northern Uganda. Here we report the results of the first 4 years of registration (2013-2016) in this largely rural population of 771,514. In total there were 1627 cases of cancers registered; 644 among men (corresponding to an ASR of 106.7 per 100,000 population) and 983 cancer cases among women (ASR 118.5 per 100,000). The most common cancers were cancers of the cervix and non-Hodgkin Lymphoma in females, and non-Hodgkin Lymphoma, Kaposi Sarcoma, prostate and liver cancers in men. Incidence rates of Burkitt lymphoma in children were high in comparison to elsewhere in Africa, whilst the incidence of breast cancer in women was rather low. The figures suggest a rather different pattern from that observed in the metropolitan population of Kampala, where there has been a cancer registry since 1951. This helps to provide a more complete picture of the national cancer profile, permitting more targeted interventions in prevention, early detection and treatment services.

Pilot study assessing the direct medical cost of treating patients with cancer in Kenya; findings and implications for the future

BACKGROUND

Currently the majority of cancer deaths occur in low- and middle-income countries, where there are appreciable funding concerns. In Kenya, most patients currently pay out of pocket for treatment, and those who are insured are generally not covered for the full costs of treatment. This places a considerable burden on households if family members develop cancer. However, the actual cost of cancer treatment in Kenya is unknown. Such an analysis is essential to better allocate resources as Kenya strives towards universal healthcare.

OBJECTIVES

To evaluate the economic burden of treating cancer patients.

METHOD

Descriptive cross-sectional cost of illness study in the leading teaching and referral hospital in Kenya, with data collected from the hospital files of sampled adult patients for treatment during 2016.

RESULTS

In total, 412 patient files were reviewed, of which 63.4% (n = 261) were female and 36.6% (n = 151) male. The cost of cancer care is highly dependent on the modality. Most reviewed patients had surgery, chemotherapy and palliative care. The cost of cancer therapy varied with the type of cancer. Patients on chemotherapy alone cost an average of KES 138,207 (USD 1364.3); while those treated with surgery cost an average of KES 128,207 (1265.6), and those on radiotherapy KES 119,036 (1175.1). Some patients had a combination of all three, costing, on average, KES 333,462 (3291.8) per patient during the year.

CONCLUSION

The cost of cancer treatment in Kenya depends on the type of cancer, the modality, cost of medicines and the type of inpatient admission. The greatest contributors are currently the cost of medicines and inpatient admissions. This pilot study can inform future initiatives among the government as well as private and public insurance companies to increase available resources, and better allocate available resources, to more effectively treat patients with cancer in Kenya. The authors will be monitoring developments and conducting further research.

Factors associated with the high prevalence of oesophageal cancer in Western Kenya: a review

Oesophageal carcinoma (OC) is highly prevalent in Western Kenya especially among the members of the Kalenjin community who reside in the Northern and Southern areas of the Rift Valley. Previous authors have suggested potential association of environmental and genetic risk factors with this high prevalence. The environmental factors that have been suggested include contamination of food by mycotoxins and/or pesticides, consumption of traditional alcohol (locally referred to “Busaa” and “Chan’gaa”), use of fermented milk (“Mursik”), poor diet, tobacco use and genetic predisposition. The aim of this paper is to critically examine the potential contribution of each of the factors that have been postulated to be associated with the high prevalence of the disease in order to establish the most likely cause. We have done this by analyzing the trends, characteristics and behaviours that are specifically unique in the region, and corroborated this with the available literature.

From our findings, the most plausible cause of the high incidence of OC among the Kalenjin community is mycotoxins, particularly fumonisins from the food chain resulting from poor handling of cereals; particularly maize combined with traditional alcohol laced with the toxins interacting synergistically with other high-risk factors such as dietary deficiencies associated alcoholism and viral infections, especially HPV. Urgent mitigating strategies should be developed in order to minimize the levels of mycotoxins in the food chain.