Prostate cancer has long been recognised as one of the greatest threats to men's health. However, the increased risk faced by men from black and minority ethnic (BME) backgrounds is less well understood. There is evidence that BME men are both more likely than their white counterparts to develop prostate cancer and less likely to approach health professionals for assessment or treatment, which increases their risk of progression to more advanced disease. This article attempts to understand this added complexity in an already complicated disease.
Background
Prostate cancer poses a serious threat to men's health and is a major issue in health care. Cancer of the prostate is the most common malignancy in men, accounting for almost a quarter of all male cancer diagnoses, and is the cause of 1–2% of overall deaths in men (Attard et al, 2016; Pullar and Shah, 2016). Cancer Research UK (2019) tells us that one in eight men will develop prostate cancer in their lifetime. This puts it well ahead of lung cancer, which is the second most common cancer in men, with one in 14 men developing that condition.
Prostate cancer is a highly complex disease to identify and manage. It does not come with any specific signs and symptoms, which makes it difficult to detect (Thompson and Ankerst, 2012; Pullar and Shah, 2016). Most men approach health professionals with symptoms relating to urinary flow, which are caused primarily by benign prostatic hypertrophy, a non-cancerous swelling of the prostate gland which is normal in ageing men. Although this condition is not connected with prostate cancer, these presentations give a good opportunity to assess for cancer by performing digital rectal examination (DRE) and testing levels of prostate-specific antigen (PSA) in blood (National Institute for Health and Care Excellence, 2017; NHS website, 2019).
Ethnic origin is a major factor in the prevalence of prostate cancer, and African-American men have a higher incidence of prostate cancer than any other racial group in the world (McIntosh, 1997). Why this is the case is not fully understood, although there are several theories as to why men from BME backgrounds are likely to be at greater risk. These range from a lack of knowledge and understanding within some ethnic minority communities and a lack of trust in or access to health care, through to socioeconomic factors and genetic predisposition (Cybulski and Wokołorczyk, 2011; White et al, 2011; Cremin, 2015).
Chinegwundoh et al (2006) studied the incidence of prostate cancer in north-east London to compare the rates of diagnosis in black and white men. They found that, although PSA levels, clinical staging and Gleason scores were comparable regardless of ethnic background in men with the condition, African-Caribbean men were three times more likely to be diagnosed with prostate cancer than their white counterparts.
In 2008, a major cohort study was carried out to look at the incidence of prostate cancer in black men (Ben-Shlomo et al, 2008). The study, based in London and Bristol, examined all incidences of prostate cancer over 5 years. By establishing the ethnicity of 2140 men diagnosed with prostate cancer within that time period, the study was able to demonstrate that black men, specifically the first generation born to migrants in the UK, were at significantly higher risk of being diagnosed with this disease than white men in the same geographical and economic areas. These findings are in line with the results of other studies examining the prevalence of prostate cancer in black men (Powell et al 2010; Jones and Chinegwundoh, 2014). In light of these findings, it is vital that practitioners are aware of the increased risk of prostate cancer faced by BME patients, and are proactive in providing information regarding prostate cancer and screening patients appropriately (Brooks, 2013).
Appropriateness, risks and benefits of screening
Screening programmes aimed at detecting prostate cancer have proven controversial over the years. According to Hernandez (2013) and Adhyam and Gupta (2012), although the benefits of early detection of significant prostate cancer cannot be denied, prostate cancer remains a complex disease and general screening programmes can expose men to unnecessary testing or treatment. They acknowledged that PSA and DRE, although useful tools, and indeed the only tools available for first-line assessment, were variable and could be unreliable, pointing out that many factors could alter PSA readings, including prostate size, recent exercise, recent ejaculation and infection. DRE can also be misleading, because cancerous glands may feel normal, while benign prostatic hypertrophy or scarring from previous surgery can leave prostates feeling asymmetrical or malignant. Abnormal PSA or DRE results often lead to invasive tissue sampling, raising concerns surrounding the risk of overtesting, overdiagnosis and patients potentially undergoing unnecessary procedures and treatments which may not significantly improve their outcome (Dunn and Kazer, 2011; Marcus et al, 2016; Pullar and Shah, 2016; Roth et al, 2016).
The cost effectiveness of screening programmes for prostate cancer is also hotly debated. Keller et al (2017) found that, without universally agreed screening tools and evidence regarding appropriate sampling, most screening programmes simply do not offer value for money either in economic or health terms and can only become cost effective if used in conjunction with robust surveillance plans for low-grade disease. This conclusion supports previous studies by Heijnsdijk et al (2016) and Roth et al (2016).
In response to published evidence, NHS England (2018) issued recommendations for the modification of the prostate cancer assessment pathway in all UK urology departments. The guidance advocates the routine use of magnetic resonance imaging (MRI) before biopsy for all men with an indication for prostate cancer assessment and recommends targeted biopsy for men with an abnormal MRI. This recent guidance has dramatically cut the numbers of people undergoing unnecessary transrectal ultrasound (TRUS) biopsies, and enabled urology centres to give clearer surveillance guidelines to GPs.
Ethnicity as reflected in the literature
When reviewing the available literature surrounding prostate cancer and its association with ethnicity, it became immediately clear that the volume of literature on prostate cancer specific to ethnic minority groups is severely limited. Searches for prostate cancer tended to return large quantities of papers; however, when keywords such as ‘ethnic minority’, ‘BME’ or ‘African-Caribbean’ were added, the numbers returned were dramatically reduced. In one instance, a search for prostate cancer returned over 180 000 results, and one for cancer screening returned more than 110 000 papers. However, when these searches were refined to focus on ethnic minorities, only 140 and 45 papers respectively were returned, leading to the conclusion that this is a vastly under-researched area.
Although individual databases each have their own target audience and methods of working, it is clear there is a universal lack of investigation into the association between ethnicity and prostate cancer. Given that BME men are twice as likely as white men to develop prostate cancer (Toms et al, 2016), there is a major gap in the published literature. More knowledge and understanding is required, by both the general population and medical practitioners, to address this health inequality. Further research and investigation in this area would improve the understanding of the complex factors behind ethnic variation in prostate cancer.
Racial and ethnic differences in prostate cancer
While there is a paucity of literature that directly explores ethnicity and prostate cancer, the studies that have been done appear to reach a consensus that ethnic origin has a definite bearing on all aspects of the disease from prevalence, to the likelihood of men from specific backgrounds seeking diagnosis or treatment, and the beliefs and behaviours of communities surrounding prostate cancer.
Latino men have a lower incidence of prostate cancer than non-Latino men (Carozza and Howe, 2006; Martinez-Tyson, et al, 2009). Men of Maori background have a lower incidence of prostate cancer than non-Maori New Zealanders, but they also have a higher mortality rate from the disease (Lamb et al, 2016). Black and African-Caribbean men, however, have both a higher incidence of prostate cancer and a higher mortality rate than Caucasian men (Chinegwundoh et al, 2006; Ben-Shlomo et al, 2008; Anderson and Marshall-Lucette, 2016). While the lowest rates of both diagnosis and mortality associated with prostate cancer are found in East Asian countries (Xu et al, 2015). Kimura (2012) found that Asian migrants living in North America and Europe have a higher diagnostic rate than their counterparts in their country of origin. This rise appears to be linked to the dual effects of a change in lifestyle and diet, and greater access to information and screening programmes following a move to Western countries.
Lamb et al (2016) found that a major cause of the mortality rate among men from ethnic minority backgrounds is thought to be an ingrained reluctance to engage with health professionals, which prevents men from seeking help before their symptoms become debilitating. This finding has been supported by Goggins and Wong (2007), who investigated communities in the Pacific Islands, and Martins et al (2015), who compared the behaviour of black and white British men with regard to testing for prostate cancer. Xiao et al (2013) highlighted the need for health professionals to understand the race-related risks of prostate cancer to ensure that patients received optimum care.
Throughout all the literature available on ethnicity and prostate cancer, there is little evidence regarding a cause for the disparities between different ethnic groups. Many studies indicate that diet and lifestyle play a large part, while health behaviours are also a major factor (Kimura, 2012; Rolison et al, 2012; Farris et al, 2017). It is also likely that there is a genetic component (Cybulski and Wokołorczyk, 2011; Jing et al, 2014), a theory that is strengthened by strong evidence of heredity in prostate cancer (Rebbeck, 2017). Jones and Chingewundoh (2014) urged caution in interpreting these results because of the potential for error in ethnicity data, and the limited amount of research that has been undertaken in this field. The ongoing 100 000 Genome Project (https://tinyurl.com/genomes-project), which aims to sequence the genetic codes of people with cancer and those who have rare diseases, hopes to further the understanding of this complex area.
Enrolment of ethnic minorities in screening programmes
Evidence suggests that, although screening is provided for many cancers including prostate cancer, there can be major issues in engaging ethnic minorities in these programmes (Toms et al 2016; Trinh et al, 2016). The reasons behind this lack of engagement can range from issues such as language barriers or access to health care, to more complex issues such as cultural beliefs surrounding cancer and the potential of embedded racism within healthcare provision.
Trinh et al (2016) examined the uptake of screening for several cancers, comparing the attendance of Asian Americans with that of white Americans. They found that, while Asian Americans were more likely to be well educated, affluent and live in suburban areas, they were less likely to engage in cancer screening programmes than their white counterparts, with contributing reasons being limited access to health care, perceived bias within health care and cultural perceptions towards the diagnosis and treatment of cancer. Ilunga Tshiswaka et al (2017) also studied the uptake of screening by race, and revealed similar findings. In their study, white men were more likely to have regular access to health care, and therefore greater access to screening than non-whites, despite similarities in age, income and education. This study simply compared attendance rates and did not posit any theories as to the causes of disparities in screening uptake. It must be noted that both of these studies were undertaken in the USA, where access to health care depends on income and may not be available to all.
In the UK, where all residents have access to health care on an equal footing through the NHS, von Wagner et al (2011) analysed the response pattern for a national bowel screening programme where more than 2.6 million invitations were sent out over a 28-month period. This screening project was designed to be as accessible as possible, with preaddressed, prepaid return envelopes to minimise barriers to uptake. The researchers analysed responses by age, sex and postcode, excluding postcodes for which they were unable to obtain data on ethnic diversity. They found that postcodes with greater ethnic diversity were less likely to return test kits, although women in BME groups were more likely to participate than men from the same groups. Although they acknowledge that their data, which is based on census information, is not completely reliable, their study strongly indicates that BME men are less likely than other demographics to access screening programmes.
Toms et al (2016) recruited two focus groups comprising BME men undergoing treatment for prostate cancer in a London hospital to help understand their views on recruitment to research studies. They found that a combination of factors, including mistrust of medical professionals and a lack of understanding of cancer, along with a reliance on traditional healing practices, were among the barriers to screening for BME men. In the context of prostate cancer, these factors can be compounded by objections to rectal examinations driven by connotations of homosexuality (Seymour-Smith et al, 2016). However, Taskila et al (2009) found significant differences between Asians and African-Caribbeans in their responses to screening invitations, which underlines the importance of maintaining awareness of individual cultures rather than grouping all non-whites together.
Emerging technology has been used to improve education and engagement in prostate cancer screening, with games, quizzes and apps being created for ethnic minority groups, in collaboration with the relevant populations, using culturally appropriate imagery and language. These have proven highly successful in increasing the uptake of screening programmes (Sultan et al, 2014; Cosma et al, 2016). Bacigalupe and Askari (2013) analysed online health care, including social media, e-health sites and online healthcare providers, and found that the accessibility of emerging technological health care is a potent tool for breaking down barriers and health inequalities, although they caution that it is difficult to guarantee that advice offered online is reliable, credible and of an appropriate quality.
Conclusion
While there is an abundance of literature surrounding prostate cancer in general, and significant evidence pertaining to testing and screening for this disease, there is a clear gap in published knowledge concerning the specific challenges faced by men with BME backgrounds. What evidence there is paints a discouraging and complex picture of barriers to accessing health care, from a lack of understanding of the increased risks on the part of both patients and health professionals, a lack of trust between BME men and their healthcare providers, through to cultural issues and engagement. However, there is evidence of positive engagement with minority groups, with specific efforts to engage communities through targeted information and the use of new technologies to disseminate information.
More knowledge and understanding is required, by both the general population and medical practitioners, to address this health inequality. It is clear that significant progress is required to narrow the gap in information, diagnosis and treatment between white and non-white communities, providing an opportunity for further investigation and study.