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Breast cancer survival and survival gap apportionment in sub-Saharan Africa (ABC-DO): a prospective cohort study.

ABSTRACT: BACKGROUND:Breast cancer is the second leading cause of death from cancer in women in sub-Saharan Africa, yet there are few well characterised large-scale survival studies with complete follow-up data. We aimed to provide robust survival estimates in women in this setting and apportion the survival gaps. METHODS:The African Breast Cancer-Disparities in Outcomes (ABC-DO) prospective cohort study was done at eight hospitals across five sub-Saharan African countries (Namibia, Nigeria, South Africa, Uganda, and Zambia). We prospectively recruited women (aged ?18 years) who attended these hospitals with suspected breast cancer. Women were actively followed up by use of a telephone call once every 3 months, and a mobile health application was used to keep a dynamic record of follow-up calls due. We collected detailed sociodemographic, clinical, and treatment data. The primary outcome was 3-year overall survival, analysed by use of flexible proportional mortality models, and we predicted survival under scenarios of modified distributions of risk factors. FINDINGS:Between Sept 8, 2014, and Dec 31, 2017, 2313 women were recruited from these eight hospitals, of whom 85 did not have breast cancer. Of the remaining 2228 women with breast cancer, 58 women with previous treatment or recurrence, and 14 women from small racial groups (white and Asian women in South Africa), were excluded. Of the 2156 women analysed, 1840 (85%) were histologically confirmed, 129 (6%) were cytologically confirmed, and 187 (9%) were clinically confirmed to have breast cancer. 2156 (97%) women were followed up for up to 3 years or up to Jan 1, 2019, whichever was earlier. Up to this date, 879 (41%) of these women had died, 1118 (52%) were alive, and 159 (7%) were censored early. 3-year overall survival was 50% (95% CI 48-53), but we observed variations in 3-year survival between different races in Namibia (from 90% in white women to 56% in Black women) and in South Africa (from 76% in mixed-race women to 59% in Black women), and between different countries (44-47% in Uganda and Zambia vs 36% in Nigeria). 215 (10%) of all women had died within 6 months of diagnosis, but 3-year overall survival remained low in women who survived to this timepoint (58%). Among survival determinants, improvements in early diagnosis and treatment were predicted to contribute to the largest increases in survival, with a combined absolute increase in survival of up to 22% in Nigeria, Zambia, and Uganda, when compared with the contributions of other factors (such as HIV or aggressive subtypes). INTERPRETATION:Large variations in breast cancer survival in sub-Saharan African countries indicate that improvements are possible. At least a third of the projected 416?000 breast cancer deaths that will occur in this region in the next decade could be prevented through achievable downstaging and improvements in treatment. Improving survival in socially disadvantaged women warrants special attention. FUNDING:Susan G Komen and the International Agency for Research on Cancer.

SUBMITTER: McCormack V

PROVIDER: S-EPMC7450275 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

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Breast cancer survival and survival gap apportionment in sub-Saharan Africa (ABC-DO): a prospective cohort study.

McCormack Valerie V McKenzie Fiona F Foerster Milena M Zietsman Annelle A Galukande Moses M Adisa Charles C Anele Angelica A Parham Groesbeck G Pinder Leeya F LF Cubasch Herbert H Joffe Maureen M Beaney Thomas T Quaresma Manuela M Togawa Kayo K Abedi-Ardekani Behnoush B Anderson Benjamin O BO Schüz Joachim J Dos-Santos-Silva Isabel I

The Lancet. Global health 20200901 9

<h4>Background</h4>Breast cancer is the second leading cause of death from cancer in women in sub-Saharan Africa, yet there are few well characterised large-scale survival studies with complete follow-up data. We aimed to provide robust survival estimates in women in this setting and apportion the survival gaps.<h4>Methods</h4>The African Breast Cancer-Disparities in Outcomes (ABC-DO) prospective cohort study was done at eight hospitals across five sub-Saharan African countries (Namibia, Nigeria ...[more]

PMID: 32827482

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Project description:BackgroundStudies have shown increased mortality among women living with HIV diagnosed with breast cancer compared with HIV-negative women with breast cancer. We aimed to examine how this HIV differential varies by patient or breast tumour characteristics.MethodsThe African Breast Cancer-Disparities in Outcomes (ABC-DO) study is a prospective cohort of women (aged ≥18 years) with incident breast cancer recruited consecutively at diagnosis (2014-17) from hospitals in Namibia, Nigeria, South Africa, Uganda, and Zambia. Detailed clinical and epidemiological data, including self-reported or tested HIV status, were collected at baseline. Participants were actively followed up via telephone calls every 3 months. The primary outcome was all-cause mortality, assessed in all women who had at least one updated vital status after baseline interview. Using Cox regression, we examined differences in overall survival by HIV status in the cohort, and across country and patient subgroups, adjusted for age, tumour grade, and tumour stage at cancer diagnosis.FindingsBetween Sept 8, 2014, and Dec 31, 2017, we recruited 2154 women with primary breast cancer, 519 of whom were excluded due to their countries having small numbers of women with HIV for comparison. Among the remaining 1635 women, 313 (19%) were living with HIV, 1184 (72%) were HIV negative, and 138 (9%) had unknown HIV status. At breast cancer diagnosis, women with HIV were younger and had lower body-mass index (BMI) than their HIV-negative counterparts, but had similar tumour stage, grade, and receptor subtypes. At the end of the follow-up (Jan 1, 2019), a higher proportion of women with HIV (137 [44%] of 313) had died than had HIV-negative women (432 [37%] of 1184). Crude 3-year survival was 9% lower for women with HIV (46% [95% CI 40-53]) than for HIV-negative women (55% [52-59]; hazard ratio (HR) 1·41 [1·15-1·74]). The HIV survival differential did not differ by age, BMI, tumour subtype, or tumour grade, but was stronger in women with non-metastatic disease (3-year survival 52% HIV-positive vs 63% HIV-negative women, adjusted HR 1·65 [1·30-2·10]), whereas women with metastatic cancer had low survival, regardless of HIV status.InterpretationThe larger survival deficit among women with HIV with non-metastatic breast cancer calls for a better understanding of the reasons underlying this differential (eg, biological mechanisms, health behaviours, detrimental HIV-breast cancer treatment interactions, or higher HIV background mortality) to inform strategies for reducing mortality among this patient group.FundingSusan G Komen, International Agency for Research on Cancer, National Cancer Institute, and UK-Commonwealth Scholarships.

Project description:Sub-Saharan Africa represents 69% of the total number of individuals living with HIV infection worldwide and 72% of AIDS deaths globally. Pulmonary infection is a common and frequently fatal complication, though little is known regarding the lower airway microbiome composition of this population. Our objectives were to characterize the lower airway microbiome of Ugandan HIV-infected patients with pneumonia, to determine relationships with demographic, clinical, immunological, and microbiological variables and to compare the composition and predicted metagenome of these communities to a comparable cohort of patients in the US (San Francisco). Bronchoalveolar lavage samples from a cohort of 60 Ugandan HIV-infected patients with acute pneumonia were collected. Amplified 16S ribosomal RNA was profiled and aforementioned relationships examined. Ugandan airway microbiome composition and predicted metagenomic function were compared to US HIV-infected pneumonia patients. Among the most common bacterial pulmonary pathogens, Pseudomonas aeruginosa was most prevalent in the Ugandan cohort. Patients with a richer and more diverse airway microbiome exhibited lower bacterial burden, enrichment of members of the Lachnospiraceae and sulfur-reducing bacteria and reduced expression of TNF-alpha and matrix metalloproteinase-9. Compared to San Franciscan patients, Ugandan airway microbiome were significantly richer, and compositionally distinct with predicted metagenomes that encoded a multitude of distinct pathogenic pathways e.g secretion systems. Ugandan pneumonia-associated airway microbiome is compositionally and functionally distinct from those detected in comparable patients in developed countries, a feature which may contribute to adverse outcomes in this population. Please note that the data from the comparable cohort of patients in the USUS data was published as supplemental material of PMID: 22760045 but not submitted to GEO The 'patient_info.txt' contains 12 clinical, 7 immunological and 3 microbiological variables for each patient.

Project description:Background:Non-communicable diseases (NCDs) cause a large and growing burden of morbidity and mortality in sub-Saharan Africa. Prospective cohort studies are key to study multiple risk factors and chronic diseases and are crucial to our understanding of the burden, aetiology and prognosis of NCDs in SSA. We aimed to identify the level of research output on NCDs and their risk factors collected by cohorts in SSA. Methods:We conducted a scoping review to map the extent of current NCDs research in SSA by identifying studies published after the year 2000 using prospectively collected cohort data on any of the six NCDs (cardiovascular diseases, diabetes, obesity, chronic kidney disease, chronic respiratory diseases, and cancers), ≥1 major risk factor (other than age and sex), set only within SSA, enrolled ≥500 participants, and ≥12 months of follow-up with ≥2 data collection points (or with plans to). We performed a systematic search of databases, a manual search of references lists from included articles and the INDEPTH network website, and study investigators from SSA were contacted for further articles. Results:We identified 30 cohort studies from the 101 included articles. Eighteen countries distributed in West, Central, East and Southern Africa, were represented. The majority (27%) set in South Africa. There were three studies including children, twenty with adults, and seven with both. 53% of cohorts were sampled in general populations, 47% in clinical populations, and 1 occupational cohort study. Hypertension (n = 23) was most commonly reported, followed by obesity (n = 16), diabetes (n = 15), CKD (n = 6), COPD (n = 2), cervical cancer (n = 3), and breast cancer (n = 1). The majority (n = 22) reported data on at least one demographic/environmental, lifestyle, or physiological risk factor but these data varied greatly. Conclusions:Most studies collected data on a combination of hypertension, diabetes, and obesity and few studies collected data on respiratory diseases and cancer. Although most collected data on different risk factors the methodologies varied greatly. Several methodological limitations were found including low recruitment rate, low retention rate, and lack of validated and standardized data collection. Our results could guide potential collaborations and maximize impact to improve our global understanding of NCDs (and their risk factors) in SSA and also to inform future research, as well as policies.

Project description:BackgroundImproving breast cancer survival in sub-Saharan Africa (SSA) is urgently needed, requiring early diagnosis and improved access to treatment. However, data on the types of and barriers to receiving breast cancer therapy in this region are limited and have not been compared between different SSA countries and treatment settings.MethodsIn different health care settings across Uganda, Nigeria and Namibian sites of the prospective African Breast Cancer - Disparities in Outcomes cohort study, we assessed the percentage of newly diagnosed breast cancer patients who received treatment (systemic, surgery and/or radiotherapy) for cancer and their socio-demographic and clinical determinants. Treatment data were systematically extracted from medical records, as well as self-reported by women during 6-month follow-up interviews, and were used to generate a binary indicator of treatment received within 12 months of diagnosis (yes/no), which was analysed via logistic regression.ResultsOf 1325 women, cancer treatment had not been initiated treatment within 1 year of diagnosis for 227 (17%) women and 185 (14%) of women with stage I-III disease. Untreated percentages were highest in two Nigerian regional hospitals where 38% of 314 women were not treated (32% among stage I-III). At a national referral hospital in Uganda, 18% of 430 women were not treated (15% among stage I-III). In contrast, at a cancer care centre in Windhoek, Namibia, where treatment is provided free to the patient, all non-black (100%) and almost all (98.7%) black women had initiated treatment. Percentages of untreated women were higher in women from lower socio-economic groups, women who believed in traditional medicine and, in Uganda, in HIV+ women. Self-reported treatment barriers confirmed treatment costs and treatment refusal as contributors to not receiving treatment.ConclusionsFinancial support to ensure treatment access and education of treatment benefits are needed to improve treatment access for breast cancer patients across sub-Saharan Africa, especially at regional treatment centres, for lower socio-economic groups, and for the HIV-positive woman with breast cancer.

Dataset Information

Breast cancer survival and survival gap apportionment in sub-Saharan Africa (ABC-DO): a prospective cohort study.

Publications

Breast cancer survival and survival gap apportionment in sub-Saharan Africa (ABC-DO): a prospective cohort study.

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