Breast cancer trends differ by ethnicity: a report from the South African National Cancer Registry (1994-2009)

Population-based temporal trends and ethnic disparity in breast cancer mortality in South Africa (1999-2018): Joinpoint and age-period-cohort regression analyses

Globally, breast cancer is the leading cause of cancer deaths, accounting for 15.5% of female cancer deaths in 2020. Breast cancer is also the leading cause of female cancers in South Africa. The rapid epidemiological transition in South Africa may have an impact on the trends in breast cancer mortality in the country. We therefore evaluated the trends in the breast cancer mortality in SA over 20 years (1999-2020).

Methods

Joinpoint regression analyses of the trends in crude and age-standardized mortality rates (ASMR) of breast cancer among South African women were conducted from 1999 to 2018 using mortality data from Statistics South Africa. Age-period-cohort regression analysis was then conducted to evaluate the independent effect of age, period, and cohort on breast cancer mortality, and analysis was stratified by ethnicity.

Results

The mortality rate of breast cancer (from 9.82 to 13.27 per 100,000 women) increased at around 1.4% per annum (Average Annual Percent Change (AAPC): 1.4%, 95% CI:0.8-2.0, P-value< 0.001). Young women aged 30-49 years (1.1%-1.8%, P-value< 0.001) had increased breast cancer mortality. The risk of breast cancer mortality increased among successive birth cohorts from 1924 to 1928 but decreased among recent cohorts born from 1989 to 1993. In 2018, the breast cancer mortality rate among Blacks (9.49/100,000 women) was around half of the rates among the non-Blacks. (Coloreds: 18.11 per 100,000 women; Whites: 17.77/100,000 women; Indian/Asian: 13.24 per 100,000 women).

Conclusions

Contrary to the trends in high- and middle-income countries, breast cancer mortality increased in South Africa especially among young women. Breast cancer prevention programs should be intensified and should also target young women. The marked disparity in ethnic burden of breast cancer should be considered during planning and implementation of interventions.

Clinical profile, risk factors and functional outcomes in women and men presenting with hip fractures in KwaZulu-Natal, South Africa

Rationale Appropriate screening can prevent osteoporotic hip fractures (HF). There is little data on clinical risk factors (CRFs) from Africa.

MAIN RESULT

Subjects with HF had similar CRFs to high income countries and poor functional outcomes post HF.

SIGNIFICANCE

Screening and treatment algorithms to improve outcomes post HF need to be implemented.

PURPOSE

Limited data exist on clinical risk factors (CRFs) for and functional outcomes following hip fractures (HF) in South Africa (SA).

METHODS

In a prospective observational study conducted in two municipalities in KwaZulu-Natal, a structured questionnaire recorded demographic data, CRFs, self-reported chronic medical conditions and functional status. Parametric and non-parametric tests were used to test for differences and the McNemar test for change over time.

RESULTS

The median age of the 287 subjects was 72 years (IQR 64-80 years) with the majority women (67.2%), who were significantly older than men. Two or more comorbidities were present in 76.3%. Hypertension (71.4%) and diabetes (29.6%) were most common. Eleven (3.8%) reported a previous diagnosis of osteoporosis and four (1.4%) prior treatment for osteoporosis. A history of cancer (15.4% v. 1.2%, p < 0.001), previous diagnosis of osteoporosis (17.9% v. 1.6%, p < 0.001) and treatment for osteoporosis (7.7% v. 0.4%, p < 0.001) was significantly more common in private compared to public sector subjects. African subjects had a higher prevalence of HIV infection compared to Indian (12.5% v. 0%, p < 0.001) while Indian subjects were more likely to report two or more comorbidities (p = 0.003) and hypertension (p = 0.005) compared to African subjects. Common CRFs were a previous fracture (32.4%), prior fall (24.7%), weight below 57 kg (23.3%), smoking (19.2%) and alcohol use of more than 3 units per day (17.8%). Less than 5% reported a history of parental HF or glucocorticosteroid use. Functional status was available for 206 subjects. Of the 163 participants who had surgery, 81% were independent prior to the HF, compared to the significantly lower 6.7% and 56.4% at 30 days and 1 year post fracture, respectively. The proportion with some degree of dependency rose significantly from 19% pre-fracture to 43.6%, 1 year post-fracture. Walking up stairs and transfer from bed to chair were the most commonly affected activities.

CONCLUSION

Clinical risk factors for HF are similar to those published internationally and support the use of current risk assessment models in SA. Targeted management and rehabilitation programs are required to improve functional outcomes post-HF.

Estimating the Specialist Surgical Workforce Density in South Africa

Background

South Africa is an upper middle-income country with inequitable access to healthcare. There is a maldistribution of doctors between the private and public sectors, the latter which serves 86% of the population but has less than half of the human resources.

Objective

The objective of this study was to estimate the specialist surgical workforce density in South Africa.

Methods

This was a retrospective record-based review of the specialist surgical workforce in South Africa as defined by registration with the Health Professionals Council of South Africa for three cadres: 1) surgeons, and 2) anaesthesiologists, and 3) obstetrician/gynaecologists (OBGYN).

Findings

The specialist surgical workforce in South Africa doubled from 2004 (N = 2956) to 2019 (N = 6144). As of December 2019, there were 3096 surgeons (50.4%), 1268 (20.6%) OBGYN, and 1780 (29.0%) anaesthesiologists. The specialist surgical workforce density in 2019 was 10.5 per 100,000 population which ranged from 1.8 in Limpopo and 22.8 per 100,000 in Western Cape province. The proportion of females and those classified other than white increased between 2004-2019.

Conclusion

South Africa falls short of the minimum specialist workforce density of 20 per 100,000 to provide adequate essential and emergency surgical care. In order to address the current and future burden of disease treatable by surgical care, South Africa needs a robust surgical healthcare system with adequate human resources, to translate healthcare services into improved health outcomes.

Clustering time trends of breast cancer incidence in Africa: a 27-year longitudinal study in 53 countries

Background

Breast cancer is the most common, frequently diagnosed cancer with the highest incidence among female worldwide. Although the incidence is decreasing in developed countries, it is on increase in most of the African countries.

Objective

This study aimed to identify different time trends of breast cancer incidence among African countries using latent mixture approach.

Methods

The information includes newly diagnosed breast cancer patients per 100,000 women for 53 African countries in a period of 1990–2016. Latent mixture modeling was performed in Mplus 7.4 software.

Results

The overall trend of breast cancer in Africa was increasing. Latent mixture model with 5 clusters was estimated as the best using fit indices and linear growth trajectories were specified for each cluster. Nigeria was the only country which belongs to a cluster with negative slope indicating a slow decrease in the breast cancer incidence; also, Seychelles was the only country that showed a sharp increase over time. 31 countries belonged to a cluster with a slope of 0.08, indicating that the incidence of breast cancer is almost constant over time. Cluster 3 including Algeria, Angola, Botswana, Central African Republic, Cote d'lvoire, Equatorial Guinea, Lesotho, Libya, Namibia, Somalia, Sudan, Swaziland, Uganda and Zimbabwe and cluster 2 including Gabon, Mauritius, Morocco, South Africa, Tunisia and Congo showed a slow and moderate increase in the incidence of breast cancer, respectively.

Conclusion

Providing health education programs is essential in African countries with rising trend of breast cancer during the last decades.

Epidemiological, clinical and diagnostic profile of breast cancer patients treated at Potchefstroom regional hospital, South Africa, 2012-2018: an open-cohort study

Introduction

Breast cancer is the second most diagnosed cancer worldwide. We aimed to depict the diagnostic approach as well as the epidemiological and clinical profile of patients with breast cancer at Potchefstroom regional hospital, South Africa.

Methods

This descriptive open-cohort study included patients with primary invasive breast cancer, confirmed by histology results and treated at the hospital from 01 January 2012 to 31 December 2018. Data such as demographics, patient history, histology, breast clinical findings, physical mass description and diagnostic investigations were captured from hospital registries and patient files.

Result

One-hundred thirty-eight patients (mean age 56.2 (SD: 14.4) (95% CI 54.6-59.7) years) met inclusion criteria. Most patients were female (98.6%), from African (67.4%) or Caucasian (23.9%) descent. Findings included mostly left-sided breast involvement (51.8%), lesions in the upper-outer quadrant (43.1%), extensions to the skin (25.6%, N = 39), and tumour size of 2 ≤ 5 cm (49.3%), or > 5 cm (39.1%). Most patients (57.9%, N = 135) were categorised as BIRADS-5, with a ductal pattern (89.6%) (p < 0.01). Patients mostly presented in stages II to IV of disease (89.1%; p < 0.05). Late-stage (stages III-IV) at time of diagnosis (n = 84) was significantly associated with mass location (p = 0.006; Cramér's V = 0.280), tumour size (p < 0.001, Cramér's V = 0.239), and skin changes (p = 0.027, Cramér's V = 0.492).

Conclusion

Most patients consulted at a late-stage of the disease, indicating a need for the promotion of breast awareness campaigns, early detection, and timeous referral.

Association between ATM rs1801516 polymorphism and cancer susceptibility: a meta-analysis involving 12,879 cases and 18,054 controls

Background

Ataxia telangiectasia mutated (ATM) gene plays a key role in response to DNA lesions and is related to the invasion and metastasis of malignancy. Epidemiological studies have indicated associations between ATM rs1801516 polymorphism and different types of cancer, but their results are inconsistent. To further evaluate the effect of ATM rs1801516 polymorphism on cancer risk, we conducted this meta-analysis.

Methods

Studies were identified according to specific inclusion criteria by searching PubMed, Web of Science, and Embase databases. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) under recessive, dominant, codominant, and overdominant models of inheritance were calculated to estimate the association between rs1801516 polymorphism and cancer risk.

Results

A total of 37 studies with 12,879 cases and 18,054 controls were included in our study. No significant association was found between rs1801516 polymorphism and cancer risk in overall comparisons (AA vs GG + GA: OR = 0.91, 95% CI, 0.78–1.07; AA+GA vs GG: OR = 1.00, 95% CI, 0.90–1.11; AA vs GG: OR = 0.89, 95% CI, 0.75–1.06; GA vs GG: OR = 1.01, 95% CI, 0.91–1.13; GG + AA vs GA: OR = 1.00, 95% CI, 0.88–1.10). However, after subgroup analyses by region-specified population, significant associations were found in European (AA vs GG + GA: OR = 0.79, 95% CI, 0.65–0.96, P = 0.017; AA vs GG: OR = 0.79, 95% CI, 0.65–0.96, P = 0.017), South American (AA+GA vs GG: OR = 2.15, 95% CI, 1.37–3.38, P = 0.001; GA vs GG: OR = 2.19, 95% CI, 1.38–3.47, P = 0.001; GG + AA vs GA: OR = 0.46, 95% CI, 0.29–0.72, P = 0.001), and Asian (AA vs GG + GA: OR = 7.45, 95% CI, 1.31–42.46, P = 0.024; AA vs GG: OR = 7.40, 95% CI, 1.30–42.19, P = 0.024). Subgroup analyses also revealed that compared with subjects carrying a GG genotype, those carrying a homozygote AA had a decreased risk for breast cancer (AA vs GG: OR = 0.76, 95% CI, 0.59–0.98, P = 0.035), and the homozygote AA was associated with decreased cancer risk in subjects with family history (AA vs GG: OR = 0.68, 95% CI, 0.47–0.98, P = 0.039).

Conclusions

ATM rs1801516 polymorphism is not associated with overall cancer risk in total population. However, for subgroup analyses, this polymorphism is especially associated with breast cancer risk; in addition, it is associated with overall cancer risk in Europeans, South Americans, Asians, and those with family history.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4941-1) contains supplementary material, which is available to authorized users.

Temporal trends in the epidemiology of cervical cancer in South Africa (1994-2012)

Cervical cancer (CC) is the leading cause of cancer death among female South Africans (SA). Improved access to reproductive health services following multi-ethnic democracy in 1994, HIV epidemic, and the initiation of CC population-based screening in early 2000s have influenced the epidemiology of CC in SA. We therefore evaluated the trends in CC age-standardised incidence (ASIR) (1994-2009) and mortality rates (ASMR) (2004-2012) using data from the South African National Cancer Registry and the Statistics South Africa, respectively. Five-year relative survival rates and average per cent change (AAPC) stratified by ethnicity and age-groups was determined. The average annual CC cases and mortalities were 4,694 (75,099 cases/16 years) and 2,789 (25,101 deaths/9 years), respectively. The ASIR was 22.1/100,000 in 1994 and 23.3/100,000 in 2009, with an average annual decline in incidence of 0.9% per annum (AAPC = -0.9%, p-value < 0.001). The ASMR decreased slightly by 0.6% per annum from 13.9/100,000 in 2004 to 13.1/100,000 in 2012 (AAPC = -0.6%, p-value < 0.001). In 2012, ASMR was 5.8-fold higher in Blacks than in Whites. The 5-year survival rates were higher in Whites and Indians/Asians (60-80%) than in Blacks and Coloureds (40-50%). The incidence rate increased (AAPC range: 1.1-3.1%, p-value < 0.001) among young women (25-34 years) from 2000 to 2009. Despite interventions, there were minimal changes in overall epidemiology of CC in SA but there were increased CC rates among young women and ethnic disparities in CC burden. A review of the CC national policy and directed CC prevention and treatment are required to positively impact the burden of CC in SA.

Knockdown of Chloride Channel-3 Inhibits Breast Cancer Growth In Vitro and In Vivo

Purpose

Chloride channel-3 (ClC-3) is a member of the chloride channel family and plays a critical role in a variety of cellular activities. The aim of the present study is to explore the molecular mechanisms underlying the antitumor effect of silencing ClC-3 in breast cancer.

Methods

Human breast cancer cell lines MDA-MB-231 and MCF-7 were used in the experiments. Messenger RNA and protein expression were examined by quantitative real-time polymerase chain reaction and western blot analysis. Cell proliferation was measured by the bromodeoxyuridine method, and the cell cycle was evaluated using fluorescence-activated cell sorting. Protein interaction in cells was analyzed by co-immunoprecipitation. Tumor tissues were stained with hematoxylin-eosin and tumor burden was measured using the Metamorph software.

Results

Breast cancer tissues collected from patients showed an increase in ClC-3 expression. Knockdown of ClC-3 inhibited the secretion of insulin-like growth factor (IGF)-1, cell proliferation, and G1/S transition in breast cancer cells. In the mouse xenograft model of human breast carcinoma, tumor growth was significantly slower in animals injected with ClC-3-deficient cells compared with the growth of normal human breast cancer cells. In addition, silencing of ClC-3 attenuated the expression of proliferating cell nuclear antigen, Ki-67, cyclin D1, and cyclin E, as well as the activation of extracellular signalregulated protein kinases (ERK) 1/2, both in vitro and in vivo.

Conclusion

Together, our data suggest that upregulation of ClC-3 by IGF-1 contributes to cell proliferation and tumor growth in breast cancer, and ClC-3 deficiency suppresses cell proliferation and tumor growth via the IGF/IGF receptor/ERK pathway.