Prostate cancer is one of the most commonly diagnosed cancers among men, with a rising global incidence, but a landscape differing vastly between developed countries and Africa, where cases are rising, and which has a higher mortality rate.
In South Africa, it’s the most commonly diagnosed cancer among men of all races, but black African men generally present later with a more advanced stage and higher histological grade than their non-black counterparts.
Of concern, say experts, is that cases in southern Africa have increased by around 60% in 15 years and could lead to an increase in mortality rates in this population if not adequately and timeously managed.
There is also a disparity in resources for diagnosing and treating the cancer at any stage in developing countries, especially African countries, when compared with the developed world.
For various reasons, black African men often present with more advanced disease and suffer greater mortality from the disease, write B Marais, G Klopper, J John in the SA Medical Journal, who suggest that specialists and non-specialists in sub-Saharan Africa should aim not only to understand the extent of this burden in their regions, but also explore the best alternative solutions when resources fall short and gold standards cannot be met.
While Northern and Western Europe have some of the highest incidence rates globally, they also have very low mortality rates, they observed.
Epidemiology
The WHO reports that prostate cancer was the second most common cancer diagnosed among men of all ages globally in 2020, accounting for 14.1% of all cancers diagnosed in men that year.
That year alone, there were 1 414 259 new cases worldwide.
That same year, prostate cancer was responsible for 375 304 deaths globally – or 6.8% of all deaths among men worldwide.
It’s the most commonly diagnosed cancer among men of all ages in 112 out of 185 countries, making it the most commonly diagnosed cancer among men in more than half of the world, and the leading cause of cancer-related deaths among men in a quarter of the world (48 out of 185 countries).
It was also the most commonly cancer diagnosed among African men in 2020, and the leading cause of cancer-related death among African men, the rise thought to be linked to better awareness, improvements in healthcare systems, and wider use of prostate-specific antigen (PSA) testing.
But it’s concerning that Africa carries one of the highest prostate cancer mortality rates, and rising, yet these rates have declined in most high-income countries since the mid-1990s, write the authors.
According to the 2020 GLOBOCAN report, the incidence and mortality rate in Africa were 36.8 and 18.3 per 100 000, respectively, compared with 23.2 and 17.0 per 100 000 in 2012.
The highest incidence was found in southern Africa (65.1 per 100 000), while the lowest was in North Africa (16.6 per 100 000).
Middle/Central Africa has the highest mortality rate (24.8 per 100 000), which is the second highest globally. North Africa has the lowest mortality rate (8.2 per 100 000).
Prostate cancer was also the most diagnosed cancer among SA men of all ages in 2020, with the incidence increasing by ~41% between 2007 and 2017.
The SA prostate cancer mortality rate in 2020 was reported as 22.1 per 100 000.
Financial burden of disease
Prostate cancer places a significant financial burden on healthcare systems worldwide. In Africa, patients often present with more advanced disease than in developed nations.
Unfortunately, there are few recent robust data in peer-reviewed journals regarding the financial burden of prostate cancer in SA, and the published figures are obtained from medical aid/insurance reports.
In 2018, the average cost for a member within 12 months after diagnosis was R123 334, according to the Discovery Health Medical Scheme oncology claims tracker.
Gabela et al evaluated the cost of managing and treating patients with metastatic castrate-resistant prostate cancer over almost three years in SA, and found a total cost of R10 338 558. This worked out to R161 540 per patient.
Screening
Evidence of the impact of screening on overall survival and cancer-specific survival is conflicting. Currently, the European Association of Urology (EAU) guidelines suggest that PSA testing cannot be performed without counselling.
An individualised risk-adapted approach for PSA-based screening has been suggested. Men with an increased risk of prostate cancer include those >50-years-old, men of black African descent aged >45, men aged >45 with a family history of the disease, and men aged >40 carrying BRCA2 mutations.
It is also recommended that men at increased risk be followed up every two years, whereas follow-up can be delayed by eight years in those not in the high-risk group.
Men with a life expectancy of <15 years are unlikely to benefit from screening and early diagnosis.
Screening practices and guidelines and their availability vary across Africa. It is not unreasonable to associate the higher incidence of late or more advanced stage disease in sub-Saharan Africa with a lack of screening, or at least the unavailability of accessible and/or affordable screening programmes.
It has been widely reported that PSA-based screening is more prevalent in higher socioeconomic populations with better access to healthcare, but the cost of screening varies among regions and countries and can be a major barrier to screening.
Even though screening costs in some areas are relatively low, the higher cost of diagnostic tests and treatment might lead to unwillingness of men to undergo screening.
A lack of knowledge about prostate cancer and screening for the disease may be a significant factor in the high rate of advanced or metastatic disease, even at presentation.
In a questionnaire-based study from Bloemfontein, which included 346 men aged ≥35, only 45.7% had heard of prostate cancer and only 24.7% knew from what age screening was important.
A survey-based study conducted among urologists from East and West Africa and SA showed interesting differences in screening practices. Although more common in SA, screening had not been reported as part of routine medical care in East and West Africa. Men with a family history of prostate cancer were less commonly screened in East Africa than in West Africa or SA.
The prostate cancer landscape in Africa, and specifically in SA, appears markedly different from that in the developed world. Studies across SA have provided insights into how and at what stage patients present at the time of diagnosis. Data from Cape Town found no difference in the mean age at presentation (65.7– 66.4 years) between black and non-black men.
The mean PSA level in men diagnosed with prostate cancer was 66.6 ng/dL. However, in a subgroup analysis, this level among black men was 166.8 ng/dL v. 47.5 ng/dL in non-black men.
Racial disparities
Dietary and lifestyle factors that may affect prostate cancer disparities include a high-fat diet, obesity and hypertension, which are said to be more prevalent among black American men than among other races.
Obesity and hypertension have been linked to an increased release of inflammatory cytokines and reactive oxygen species, leading to oxidative stress and DNA damage. In addition, activation of nuclear factor kappa-light-chain enhancer of activated B cells (NF-kB) leads to prostate cancer cell proliferation.
Southern African data suggest that the same dietary and lifestyle risks are prevalent among black South Africans.
The long-term and ongoing use of dichloro-diphenyl-trichloroethane (DDT) in Limpopo Province, a pesticide banned in most countries, has been linked to increased prostate cancer risk, specifically the Venda population.
Finally, the role of traditional medicines in Africa should be noted. A large proportion of SA men report utilising traditional health practitioners for their primary care needs and are influenced by personal and cultural beliefs, accessibility and affordability.
While traditional medicine often plays a significant role in palliative care, especially among rural South Africans, it can be argued that relying solely on traditional medicine risks delaying early detection and prevention of the cancer.
While the varied factors that affect the different landscapes of the disease in Africa and the rest of the world, these discrepancies, which have serious physical, psychosocial and financial implications for patients, are all targets to be addressed to eliminate the observed disparities.
B Marais – Division of Urology, Department of Surgery, Frere Hospital and Faculty of Medicine and Health Sciences, Walter Sisulu University, East London.
G Klopper – Division of Otolaryngology, Department of Surgery, Frere Hospital and Faculty of Medicine and Health Sciences, Walter Sisulu University, East London.
J John – Division of Urology, Department of Surgery, Frere Hospital and Faculty of Medicine and Health Sciences, Walter Sisulu University, East London; Division of Urology, Department of Surgery, Faculty of Health Sciences, University of Cape Town.
See more from MedicalBrief archives:
Prostate cancer risk higher for black men – US study
SA cancer cases climb as unequal treatment causes ‘needless deaths’
Experts call for comprehensive, large-scale response to slash Africa’s cancer burden
Prostate cancer cases could double by 2040 – global analysis