Séroprévalence du virus de l’herpès humain-8 chez des patients VIH positif à l’hôpital général de Yaoundé – Cameroun

L'épidémiologie de l'infection par le virus herpès humain de type 8 (HHV8) associée à celle à VIH, reste encore méconnue au Cameroun, bien quele pays soit considéré comme une zone endémique pour ces deux virus. L’objectif de ce travail était de ressortir le profil de la séroprévalence duHHV8 au sein de notre population d'étude. 57 personnes ont été recrutées à l'Hôpital Général de Yaoundé et suivies sur une durée 12 mois. Desanticorps IgG anti-HHV8 ont été déterminés par ELISA. Des paramètres autres, tels que l'âge, le sexe, le stade des maladies (SK et VIH/SIDA), leprotocole ARV, ainsi que les taux de CD4 ont été utilisés pour déterminer les variables associées à la séropositivité au HHV8. Cette association aété évaluée par le test khi carré. La séroprévalence du HHV8 était de 90% dans notre population en début d'étude et de 74% douze mois plustard, une séroprévalence qui restait élevée quelque soit le profil clinique, la tranche d'âge, le sexe ou le taux de CD4+ de l'individu. Aucune variable de l'étude n'était significativement associée à la séropositivité du HHV8. Le virus HHV8 semblait circuler au sein de notre population d'étude. Cependant l'on constate, douze mois plus tard, l'absence de  manifestations cliniques du SK chez les patients VIH+ positifs, malgré destitres très élevés en IgG anti-HHV8

Gynecological cancer profile in the Yaounde population, Cameroon

This population-based retrospective study was carried out in the Yaounde Population Cancer Registry (YPCR) at the General Hospital Yaounde, Cameroon. The aim was to find out the socio-economic, epidemiologic, anatomic and pathologic profile of patients with gynecological cancers in the Yaounde population. The database of the registry was reviewed between January 1, 2004 and June 30 2005 (18 months). All cases of microscopically confirmed gynecological cancers registered within this period were recruited. Defined as gynecological cancers are cancers of the breast (in women), ovary, uterine corpus, vulva, vagina, and cervix. The results showed that gynecological cancers have a monthly incidence of 30 cases. Whereas cancers of the placenta, vagina, breast, and ovary affect younger adults, endometrial, vulval and cervical cancers predominate in the elderly. 58% of the women were aged between 34-54 years. Most patients are from the West (30.55%), Centre (28.90%) and Littoral (10.00%) provinces respectively. The commonest cancers are the breast (48.12%), cervix (40.18%), and ovary (5.82%) at respective average ages of 42.80 years (19-76 years range), 53.08 years (24-78 years range) and 44.22 years (9-75 years range). Cancers of the uterine corpus are rare. Most patients were illiterate, of low to average socio-economic status, presenting at advanced stage of disease. Cancer of the breast is common in the upper social class; while malignancies of the cervix, endometrium, and vagina predominate in the low and middle classes. Only 17.5% of our patients had been previously screened for any form of cancer prior to present disease. We had no data on family history of cancer. We recommend intensive public health education and sensitization of women on primary and secondary prevention especially for cervical and breast cancers. Gynaecological services should be vulgarized and existing ones improved with defined referral and counter referral systems. Further in-depth studies to document trends on cancer survival are recommended. Clinics in Mother and Child Health Vol. 3(1) 2006: 437-44

Chimiotherapie des angiosarcomes de Kaposi au service d'oncologie medicale de L'hopital General de Yaounde, Cameroun

Compte tenu de la séroprévalence de l'infection à VIH/SIDA au Cameroun (5,5%), le service d'oncologie médicale de l'Hôpital Général de Yaoundé, prend en charge par chimiothérapie les patients porteurs d'angiosarcome de Kaposi. Nous avons voulu évaluer la chimiothérapie de l'angiosarcome de Kaposi dans notre service. Une étude descriptive rétrospective a été menée sur une année. Les patients recrutés ont été ceux avec un diagnostic d'angiosarcome de Kaposi. Les données collectées étaient les suivantes : le sexe, l'âge, la localisation, les pathologies associées, la chimiothérapie administrée, les réponses et la tolérance. Les deux dernières données ont été évaluées selon les critères de l'OMS. Au cours de cette année, 57 patients ont été reçus pour un angiosarcome de Kaposi dont 31 (54,4%) hommes et 26 (47,6%) femmes. Les âges extrêmes ont été 14 et 76 ans avec une moyenne de 39,05 ans. La localisation principale était tégumentaire (65,6% des localisations), diffuse pour la plupart des cas. Des 43 patients testés, 38 (88,4%) avaient une sérologie VIH positive et 5 (11,6%) négatifs. Dans notre échantillon, 84,6% ont reçu une polychimiothérapie associant la doxorubucine, la bléomycine et la vincristine. Seuls 20 patients des 38 séropositifs soit 52,6% ont reçu des antiretroviraux. La réponse partielle a été objectivée chez 16 sur 19 (84,2%) de nos patients. La toxicité observée a été hématologique et 13 patients (22,8%) ont été transfusés pour anémie. Nous concluons que la chimiothérapie est bénéfique dans le traitement du sarcome de Kaposi. Des études comparatives ultérieures précisent si le traitement de ces patients améliore la qualité de vie et la survie. Clinics in Mother and Child Health Vol. 3(1) 2006: 469-47

Relationship between human leukocyte antigen alleles and risk of Kaposi’s sarcoma in Cameroon

Several studies published to date report associations between human leukocyte antigen (HLA) alleles and different types of Kaposi’s Sarcoma (KS). However, there is little concordance between the HLA alleles identified and the populations studied. To test whether HLA alleles associate with KS in a Cameroonian case–control study, we performed high-resolution HLA typing in KSHV seropositive individuals. Among HIV-positive individuals, carriers of HLA-B*14:01 were at a significantly higher risk of AIDS-KS (p = 0.033). For HIV-negative patients, a gene-wise comparison of allele frequencies identified the HLA-B (p = 0.008) and -DQA1 (p = 0.002) loci as possible risk factors for endemic KS. Our study provides additional understanding of genetic determinants of KS and their implications in disease pathogenesis. Further validation of these findings is needed to define the functional relevance of these associations

Using genome and transcriptome data from African-ancestry female participants to identify putative breast cancer susceptibility genes

African-ancestry (AA) participants are underrepresented in genetics research. Here, we conducted a transcriptome-wide association study (TWAS) in AA female participants to identify putative breast cancer susceptibility genes. We built genetic models to predict levels of gene expression, exon junction, and 3′ UTR alternative polyadenylation using genomic and transcriptomic data generated in normal breast tissues from 150 AA participants and then used these models to perform association analyses using genomic data from 18,034 cases and 22,104 controls. At Bonferroni-corrected P < 0.05, we identified six genes associated with breast cancer risk, including four genes not previously reported (CTD-3080P12.3, EN1, LINC01956 and NUP210L). Most of these genes showed a stronger association with risk of estrogen-receptor (ER) negative or triple-negative than ER-positive breast cancer. We also replicated the associations with 29 genes reported in previous TWAS at P < 0.05 (one-sided), providing further support for an association of these genes with breast cancer risk. Our study sheds new light on the genetic basis of breast cancer and highlights the value of conducting research in AA populations

Using Genome and Transcriptome Data From African-Ancestry Female Participants To Identify Putative Breast Cancer Susceptibility Genes

African-ancestry (AA) participants are underrepresented in genetics research. Here, we conducted a transcriptome-wide association study (TWAS) in AA female participants to identify putative breast cancer susceptibility genes. We built genetic models to predict levels of gene expression, exon junction, and 3\u27 UTR alternative polyadenylation using genomic and transcriptomic data generated in normal breast tissues from 150 AA participants and then used these models to perform association analyses using genomic data from 18,034 cases and 22,104 controls. At Bonferroni-corrected P \u3c 0.05, we identified six genes associated with breast cancer risk, including four genes not previously reported (CTD-3080P12.3, EN1, LINC01956 and NUP210L). Most of these genes showed a stronger association with risk of estrogen-receptor (ER) negative or triple-negative than ER-positive breast cancer. We also replicated the associations with 29 genes reported in previous TWAS at P \u3c 0.05 (one-sided), providing further support for an association of these genes with breast cancer risk. Our study sheds new light on the genetic basis of breast cancer and highlights the value of conducting research in AA populations

Genome-wide association analyses of breast cancer in women of African ancestry identify new susceptibility loci and improve risk prediction

We performed genome-wide association studies of breast cancer including 18,034 cases and 22,104 controls of African ancestry. Genetic variants at 12 loci were associated with breast cancer risk (P < 5 × 10−8), including associations of a low-frequency missense variant rs61751053 in ARHGEF38 with overall breast cancer (odds ratio (OR) = 1.48) and a common variant rs76664032 at chromosome 2q14.2 with triple-negative breast cancer (TNBC) (OR = 1.30). Approximately 15.4% of cases with TNBC carried six risk alleles in three genome-wide association study-identified TNBC risk variants, with an OR of 4.21 (95% confidence interval = 2.66–7.03) compared with those carrying fewer than two risk alleles. A polygenic risk score (PRS) showed an area under the receiver operating characteristic curve of 0.60 for the prediction of breast cancer risk, which outperformed PRS derived using data from females of European ancestry. Our study markedly increases the population diversity in genetic studies for breast cancer and demonstrates the utility of PRS for risk prediction in females of African ancestry

Refining breast cancer genetic risk and biology through multi-ancestry fine-mapping analyses of 192 risk regions

Genome-wide association studies have identified approximately 200 genetic risk loci for breast cancer, but the causal variants and target genes are mostly unknown. We sought to fine-map all known breast cancer risk loci using genome-wide association study data from 172,737 female breast cancer cases and 242,009 controls of African, Asian and European ancestry. We identified 332 independent association signals for breast cancer risk, including 131 signals not reported previously, and for 50 of them, we narrowed the credible causal variants down to a single variant. Analyses integrating functional genomics data identified 195 putative susceptibility genes, enriched in PI3K/AKT, TNF/NF-κB, p53 and Wnt/β-catenin pathways. Single-cell RNA sequencing or in vitro experiment data provided additional functional evidence for 105 genes. Our study uncovered large numbers of association signals and candidate susceptibility genes for breast cancer, uncovered breast cancer genetics and biology, and supported the value of including multi-ancestry data in fine-mapping analyses

Advanced cancer cases in the Yaounde general hospital, Cameroon

No Abstract. Clinics in Mother and Child Health Vol. 2(2) 2005: 391-39