|Year : 2022 | Volume
| Issue : 3 | Page : 233-237
Evaluation of prostate-specific antigen testing: An empirical survey of laboratories in Nigerian tertiary care centers
Ijeoma A Meka1, Chika J Okwor1, Ekene J Arum1, Michael I Ogamba2, Babatunde I Omotowo3, Okezie O Kanu4
1 Department of Chemical Pathology, College of Medicine, University of Nigeria/University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu State, Nigeria
2 Department of Chemical Pathology, PAMO University of Medical Sciences, Port Harcourt, Rivers State, Nigeria
3 Department of Community Medicine, College of Medicine, University of Nigeria, Ituku/Ozalla, Enugu State, Nigeria
4 Department of Surgery, College of Medicine, University of Lagos, Lagos, Nigeria
|Date of Submission||26-Aug-2021|
|Date of Decision||07-Jan-2022|
|Date of Acceptance||14-Feb-2022|
|Date of Web Publication||2-Jun-2022|
Ijeoma A Meka
Department of Chemical Pathology, College of Medicine, University of Nigeria/University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu State
Source of Support: None, Conflict of Interest: None
Background: Prostate-specific antigen (PSA) testing has been recommended for prostate cancer screening by the World Health Organization. The combined use of total and free PSA and digital rectal examination is said to improve the sensitivity and specificity of total PSA and also to reduce the need for 20% of unnecessary biopsies. Tertiary hospital laboratories ought to be appropriately equipped to offer these tests for improved patient outcomes. Objective: The objective was to determine the proportion of Nigerian tertiary care laboratories that offer quantitative total and free PSA testing. Materials and Methods: A cross-sectional survey was carried out in functional government-owned tertiary hospitals in all the geopolitical zones of Nigeria. Respondents were drawn from the Laboratory section of each hospital. Data were collected using semi-structured self-administered questionnaires and analyzed using SPSS version 22. Results: The study included a total of 34 tertiary care laboratories. The mean (SD) age of respondents was 43.71 (5.2) years. Of the surveyed hospitals, 27 (79.41%) had facilities for PSA testing, whereas 7 (20.59%) had no functional PSA testing facility. Of those with a functional testing facility, 27 (100%) had facilities for total PSA whereas 12 (44.44%) had facilities for free PSA. Three facilities [3 (42.85%)] out of the seven facilities with no functional testing facilities cited equipment breakdown as the reason. Conclusion: Availability of PSA testing facilities was not adequate in tertiary care laboratories in Nigeria, with free PSA facilities being less than total PSA facilities. More support is needed in making these important testing facilities more readily available in Nigerian tertiary healthcare laboratories.
Keywords: Cancer, free PSA, prostate, tertiary care laboratories, total PSA
|How to cite this article:|
Meka IA, Okwor CJ, Arum EJ, Ogamba MI, Omotowo BI, Kanu OO. Evaluation of prostate-specific antigen testing: An empirical survey of laboratories in Nigerian tertiary care centers. Int J Med Health Dev 2022;27:233-7
|How to cite this URL:|
Meka IA, Okwor CJ, Arum EJ, Ogamba MI, Omotowo BI, Kanu OO. Evaluation of prostate-specific antigen testing: An empirical survey of laboratories in Nigerian tertiary care centers. Int J Med Health Dev [serial online] 2022 [cited 2022 Jul 1];27:233-7. Available from: https://www.ijmhdev.com/text.asp?2022/27/3/233/346439
| Introduction|| |
Tumor biomarkers are measurable and reproducible biochemical indicators of the presence of tumors and cancers in biological body fluids and are usually naturally occurring molecules. Among the replete malignancies seen today, prostate cancer (CaP) has gained significant prominence as it has been documented as the second most commonly occurring cancer in men and fourth most commonly diagnosed cancer worldwide.,
Several documented evidences,,, note that the risk of diagnosis with CaP is higher in black men compared with their Caucasian counterparts. It is equally documented that black men are more likely to present with distant metastasis and die from the disease when compared with non-Hispanic white men.
CaP currently ranks as the commonest cancer in Nigerian males,, and constitutes 11% of all male cancers in Nigeria, according to Ogunbiyi and Shittu. A 7.7-fold increase in the incidence of CaP in Nigeria over a 10-year period has equally been recorded, with two different researchers reporting hospital incidences of 182.5 and 127 per 105 male admissions.
Many CaP patients in Nigeria are noted to present late usually in advanced stages of the disease and often with complications generally culminating in poor outcomes. This has been attributed to several factors such as low socio-economic factors, low literacy level, poor awareness due to inadequate public health education on CaP, possible genetic predisposition, etc. These may culminate in limited access and utilization of healthcare facilities and CaP screening opportunities. Added to this and very importantly, inadequate screening tools pose another serious challenge to the diagnosis and management of CaP. Prostate-specific antigen (PSA) has been recommended for early detection of CaP at the pre-symptomatic stage for the purpose of reducing CaP mortality. PSA is a serine protease of the kallikrein family secreted by prostate epithelial cells and exists as a single chain glycoprotein of 237 amino acids with a molecular weight of 28,430 Da.
PSA exists in both free and complexed forms, together making up total PSA (tPSA). Although complexed forms are bound to protease inhibitors, free PSA is not bound. It has been stated that for some unknown reasons, percentage of free PSA tends to be lower in patients with CaP when compared with those with normal prostate or benign disease. Percentage free PSA is particularly useful when tPSA values fall within 4–10 ng/dL, a range referred to as the diagnostic gray zone. It is said that for individuals within this gray zone, CaP is present in only 25%. Hence, reliance upon only the tPSA causes many unnecessary biopsies to be done on patients. This is deemed a limitation of tPSA. A large prospective study from seven university medical centers documented that the use of percentage-free PSA, using a cut-off of 25% or less free PSA, would detect 95% of cancers and spare 20% of patients with benign prostatic disease from biopsy.
Clinically, the utility of PSA can be seen in its use as a screening, diagnostic, cancer staging, and treatment monitoring tool. With the burden of CaP, particularly in Nigeria, already established in literature, it becomes highly necessary that tertiary care hospitals which form the apex hospitals in Nigeria be equipped with facilities needed for testing in this area. PSA testing should therefore be minimum in the tumor marker test repertoire for every tertiary care hospital laboratory. Interestingly, there is a dearth of literature on the availability of PSA testing in tertiary care hospital laboratories in Nigeria, as the proportion of those offering total and free PSA testing services is unknown.
In an attempt to fill this literature gap and to contribute information in this very important area, the authors’ objective in the present study was to determine the proportion of Nigerian tertiary care laboratories offering total and free PSA testing services.
| Materials and Methods|| |
This study was carried out in government-owned tertiary care hospitals across Nigeria. Nigeria is a tropical country situated in the western coast of Sub-Saharan Africa. With a population of 214,279,253 as of February 6, 2022, based on Worldometer elaboration of the latest United Nations data, it stands as the most populous nation in Africa. It is geographically divided into six geopolitical zones: South-East, South-West, South-South, North-East, North-West, and North-Central.
This was a cross-sectional hospital-based descriptive survey.
This included teaching hospitals and Federal Medical Centers which were registered with the Federal Ministry of Health and operational in the six geopolitical zones of Nigeria: South-East, South-West, South-South, North-East, North-West, and North-Central.
Sampling and data collection method
The total population sampling method was adopted, and respondents were drawn from the Laboratory section of each hospital. Data were collected using self-administered, researcher-designed semi-structured questionnaires. These questionnaires were sent to the different consenting respondents by email.
Collected data were entered into an Excel Spread Sheet and double-checked for accuracy. Data analysis was done using Statistical Package for Social Sciences (SPSS) version 22 (IBM Inc.). Categorical variables were summarized using frequencies and proportion, whereas continuous variables were summarized using mean and standard deviation.
Ethical approval was obtained from the University of Nigeria Teaching Hospital Health Research Ethics Committee before commencement of the study, and study-specific informed consent was obtained from participants after the purpose of the study was explained to them.
| Results|| |
A total of 34 tertiary care laboratories participated in the study with a response rate of 87.18%. The mean (SD) age of respondents was 43.71 (5.2) years. The study included only facilities for quantitative PSA testing. Of the surveyed laboratories, 27 (79.41%) had facilities for PSA testing, while 7 (20.59%) had no functional PSA testing facility [Figure 1]. Of those with a functional testing facility, 27 (100%) had facilities for tPSA, while only 12 (44.44%) had facilities for free PSA [Figure 2]. Majority [3 (42.85%)] of those with no functional testing facilities cited equipment breakdown as the reason [Table 1]. All respondents indicated that tPSA was the most commonly requested tumor marker in their laboratory. The cost of tPSA was between N3000 and N4999 by majority [14 (51.85%)] of the respondents [Table 2]. For most [13 (48.15%)] of the respondents, this cost could not be afforded by many patients who need this test [Table 3].
|Figure 1: Distribution of laboratories with functional PSA testing facilities|
Click here to view
|Figure 2: Free PSA testing availability among laboratories with functional testing facilities|
Click here to view
| Discussion|| |
The availability of total and free PSA testing facilities was explored in this study. The finding that one-fifth of the surveyed laboratories lacked PSA testing falls short of expectation. In addition, more than half of those testing for tPSA lacked facilities to estimate free PSA. This finding is in agreement with a report by Badmus et al., in which they documented that the PSA assay was not readily available in most of the urban health institutions in South West, Nigeria. Though the Badmus report was made in 2010, as at the time of the present study, it could be said that only little had changed in this respect, and this is certainly not good enough as it continues to impact negatively on the care of the patients who require these services.
PSA has been recommended for CaP screening in men. It has been estimated that early detection of the disease achievable through screening has the potential to cure one-third of cases and prevent another one-third of CaP. This is particularly important in the background of increasing prevalence of CaP in Nigeria, coupled with documented evidence of black men having a higher CaP-specific mortality and a higher likelihood of disease recurrence after treatment. Again in the Nigerian environment in which people usually present late to hospital, the availability of PSA testing facilities will greatly enhance early disease detection and early treatment for a better outcome.
The surveyed laboratories having only tPSA without free PSA facilities are equally limited in rendering adequate and needed services to the clinicians and the public. This is because free PSA enables the calculation of percent free PSA which is a very good predictor of CaP risk in men, particularly in those whose tPSA falls within the diagnostic gray zone and with a non-suspicious digital rectal examination. Additionally, as earlier stated, it reduces the number of unnecessary biopsies done on patients when relying solely on tPSA. To buttress this fact, Tijani et al. reported that “percentage free PSA is an effective discriminating tool in determining the need for prostate biopsy in indigenous West African men with PSA 4–10 ng/mL.”
The present study included only laboratories with facilities for quantitative PSA testing. This is because qualitative assays do not give precise values needed to properly guide the clinician in the patient’s management decision.
Majority of the respondents in the present study felt that the cost of tPSA, which was put at between N3000 and N4999 ($6.229 and $10.380), could not be afforded by those who need the test. This is not surprising as poverty is a major challenge to the Nigerian populace. Using the current exchange rate of N481.60 to 1USD, the 2020 report of the National Bureau of Statistics which documented that 40% of Nigerians lived below its poverty line of 137,430 naira ($381.75) per year would translate to living below $285.36 per year and $0.78 per day. This level of poverty in a populace also burdened with poor literacy, high rates of communicable and chronic diseases, high maternal and infant mortality rate, and poor living conditions make life quite challenging for many Nigerians. Hence, in order to promote equitable access to health and to alleviate the sufferings of the poor masses, the cost of this very important test ought to be subsidized in some way. This can be done through health insurance system, sustainable free screening services targeted at men of appropriate age, and other appropriate cost reduction measures.
| Conclusion|| |
Availability of both total and free PSA testing facilities was still suboptimal in Nigerian tertiary care laboratories. Also the cost of the test where available is mostly out of reach of the poor masses. In order to maximally harness the potential benefits, there is need to ensure availability and affordability of the tests. To achieve this, strengthening the national health insurance system, sustainable free screening services, and test subsidization may be steps in the right direction.
The authors deeply appreciate all respondents who took time to answer our questionnaires.
Financial support and sponsorship
No external funding was received for this study. It was funded by the authors.
Conflicts of interest
There are no conflicts of interest.
IAM and OOK conceived the study. IAM, CJO, and EJA participated in data collection. EJA and MIO handled data entry and cross-checking. CJO and BIO handled data analysis. IAM and MIO drafted the manuscript. OOK and BIO critically revised the manuscript for intellectual content. All authors read and approved the manuscript for publication.
| References|| |
Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomatarm I, Jemal A, et al
. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 cancers in 185 countries. CA Cancer J Clin 2021;71:209-49.
World Cancer Research Funds. Prostate Cancer Statistics. Available from: https://www.wcrf.org/dietandcancer/prostate-cancer-statistics/
. Last accessed on September 13, 2021.
Ward E, Jemal A, Cokkinides V, Singh GK, Cardinez C, Ghafoor A, et al
. Cancer disparities by race/ethnicity and socioeconomic status. CA Cancer J Clin 2004;54:78-93.
Hoffman RM, Gilliland FD, Eley JW, Harlan LC, Stephenson RA, Stanford JL, et al
. Racial and ethnic differences in advanced-stage prostate cancer: The Prostate Cancer Outcomes Study. J Natl Cancer Inst 2001;93: 388-95.
Barocas DA, Penson DF Racial variation in the pattern and quality of care for prostate cancer in the USA: Mind the gap. BJU Int 2010;106:322-8.
Hankey BF, Feuer EJ, Clegg LX, Hayes RB, Legler JM, Prorok PC, et al
. Cancer surveillance series: Interpreting trends in prostate cancer—Part I: Evidence of the effects of screening in recent prostate cancer incidence, mortality, and survival rates. J Natl Cancer Inst 1999;91:1017-24.
DeSantis CE, Siegel RL, Sauer AG, Miller KD, Fedewa SA, Alcaraz KI, et al
. Cancer Statistics for African Americans, 2016: Progress and opportunities in reducing racial disparities. CA Cancer J Clin 2016;66:290-308.
Mohammed AZ, Edino ST, Ochicha O, Gwarzo AK, Samaila AA Cancer in Nigeria: A 10-year analysis of the Kano Cancer Registry. Niger J Med 2008;17:280-4.
Badmus TA, Adesunkanmi AR, Yusuf BM, Oseni GO, Eziyi AK, Bakare TI, et al
. Burden of prostate cancer in Southwestern Nigeria. Urology 2010;76:412-6.
Ogunbiyi JO, Shittu OB Increased incidence of prostate cancer in Nigerians. J Natl Med Assoc 1999;91:159-64.
Ajape AA, Ibrahim KO, Fakeye JA, Abiola OO An overview of cancer of the prostate diagnosis and management in Nigeria: The experience in a Nigerian tertiary hospital. Ann Afr Med 2010;9:113-7.
Osegbe DN Prostate cancer in Nigerians: Facts and nonfacts. J Urol 1997;157:1340-3.
Burtis CA, Ashwood ER, Bruns DE, Tietz NW, editors. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. St Louis, MO: Elsevier/Saunders; 2017. Print.
Catalona WJ, Partin AW, Slawin KM, Brawer MK, Flanigan RC, Patel A, et al
. Use of the percentage of free prostate-specific antigen to enhance differentiation of prostate cancer from benign prostatic disease: A prospective multicenter clinical trial. JAMA 1998;279:1542-7.
Statistics. National Population Commission. Available from: https://nationalpopulation.gov.ng/statistics/
. Last accessed on February 6, 2022.
Theisen C Predicting the future: Projections help researchers allocate resources. J Natl Cancer Inst 2003;95:846-8.
Tijani KH, Anunobi CC, Adeyomoye AO, Alabi TO, Lawal AO, Akanmu NO et al
. The role of percentage free PSA in the diagnosis of prostate cancer in Blacks: Findings in indigenous West African men using TRUS guided biopsy. Afr J Urol 2017;23:14-9.
Central Bank of Nigeria. Monthly Average Exchange Rates of the Naira (Naira Per Unit of Foreign Currency)—2021. Available from: https://www.cbn.gov.ng/rates/exrate.asp?year=2021&month=6
. Last accessed on September 18, 2021.
National Bureau of Statistics. 2019 Poverty and Inequality in Nigeria: Executive summary. 2020. Available from: https://nigerianstat.gov.ng
›download pdf. Last accessed on September 18, 2021.
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3]