|Year : 2016 | Volume
| Issue : 8 | Page : 51-54
Incidence of hospital-based screen-detected prostate cancer in Abuja, Nigeria
Oseremen Inokhoife Aisuodionoe-Shadrach1, Olabode Peter Oluwole2, Echebiri F Magnus3, Amaka P Ehighibe3
1 Division of Urology, Department of Surgery, College of Health Sciences, University of Abuja; Department of Surgery, University of Abuja Teaching Hospital, Gwagwalada, Federal Capital Territory, Nigeria
2 Department of Surgery, University of Abuja Teaching Hospital, Gwagwalada, Federal Capital Territory; Department of Pathology and Forensic Medicine, College of Health Sciences, University of Abuja, Abuja, Nigeria
3 Department of Surgery, University of Abuja Teaching Hospital, Gwagwalada, Federal Capital Territory, Nigeria
|Date of Web Publication||3-Jan-2017|
Oseremen Inokhoife Aisuodionoe-Shadrach
Aisuodionoe-Shadrach, Division of Urology, Department of Surgery, College of Health Sciences, University of Abuja, Abuja & University of Abuja Teaching Hospital, Gwagwalada, Federal Capital Territory
Source of Support: None, Conflict of Interest: None
Objective: The objective of this study was to determine the incidence of screen-detected prostate cancer (CaP) in a University Hospital in Abuja. Methodology: This is a retrospective review of all patients seen with lower urinary tract symptoms (LUTS) and or enlargement of the prostate who were screened for CaP over a 4-year period from January 2010 to December 2013. Data retrieved from the medical records of these patients were collated using a pro forma and analyzed with SPSS software Version 20. Results: The records of 103 patients were utilized for this study. The average age was 65.9 ± 9.0 years. Of this number, 99 had LUTS at presentation, while 4 had no LUTS. Digital rectal examination findings revealed a clinical suspicion of malignancy in 84.5% (n = 87) and features of benign enlargement in the remainder. Serum prostate-specific antigen was <4 ng/ml in 3.8% (n = 4), 4-10 ng/ml in 9.7% (n = 10), and >10 ng/ml in 85.4% (n = 88). Histology revealed adenocarcinoma in 50% of the patients (n = 38) with 71% (n = 27) being moderately and 29% (n = 11) being poorly differentiated. The incidence of screen-detected CaP in this series was 38.7%. Conclusions: The incidence of screen-detected CaP may be higher than it is actually reported in this part of the world. The place of opportunistic screening for the well informed may not reflect the high cancer burden. Most patients presented late in the advanced stage of the disease with moderately to poorly differentiated adenocarcinoma being the most common histological type.
Keywords: Abuja, hospital-based, incidence, Nigeria, prostate cancer, screen-detected
|How to cite this article:|
Aisuodionoe-Shadrach OI, Oluwole OP, Magnus EF, Ehighibe AP. Incidence of hospital-based screen-detected prostate cancer in Abuja, Nigeria. N Niger J Clin Res 2016;5:51-4
|How to cite this URL:|
Aisuodionoe-Shadrach OI, Oluwole OP, Magnus EF, Ehighibe AP. Incidence of hospital-based screen-detected prostate cancer in Abuja, Nigeria. N Niger J Clin Res [serial online] 2016 [cited 2020 Aug 11];5:51-4. Available from: http://www.mdcan-uath.org/text.asp?2016/5/8/51/197437
| Introduction|| |
Prostate cancer (CaP) is currently the second most common cause of cancer death in men after lung cancer.  Global cancer incidence rates show that CaP has become the third most common cancer in men with half a million new cases occurring each year, representing about 10% of all cancers in men. ,
The prevalence of CaP as reported by different researchers across Nigeria is between 2% and 11% ,,, with the country ranking first among nine African countries with the highest prevalence of the disease. Nigeria is also ranked third among countries with significant death from CaP s after the United States and India according to the World Health Organization.  An estimated hospital prevalence of 127/100,000 in Lagos, Nigeria, was reported in 1997.  A recently published data from South-West Nigeria also reported a hospital prevalence rate of 182.5/100,000 male admissions in the hospital.  However, the true prevalence in the Nigerian community is not known.
The main diagnostic tools to obtain evidence of CaP include digital rectal examination (DRE), serum concentration of prostate-specific antigen (PSA), with the normal PSA as <4 ng/ml, and transrectal ultrasonography while definitive diagnosis is by histopathological examination of prostate biopsy cores or operative specimens.
Screening in CaP is an important aspect of diagnosis and management of the disease as it can be diagnosed at early stages during which time they are amenable to curative therapies. In the Western world, screening is recommended as part of a routine clinical checkup for middle-aged and the elderly.  In Nigeria, however, as in many other sub-Saharan African countries, it is not routine, hence the incidence of screen-detected CaP is not well documented and studies are difficult to come by.  This study was, therefore, conducted to determine the hospital-based incidence of screen-detected CaP in Abuja.
| Methodology|| |
The review was carried out in the Urology Division of the Department of Surgery, University of Abuja Teaching Hospital Gwagwalada, Federal Capital Territory (FCT), a tertiary health center, which serves as a referral center to the FCT and its neighboring states of Kogi, Nasarawa, Niger, and Benue.
A retrospective review of all patients seen with lower urinary tract symptoms (LUTS) and/or enlargement of the prostate benign prostatic hyperplasia (BPH) who were screened for CaP over a 4-year period from January 2010 to December 2013 was done and the information collected included bio data, presenting complaints, DRE findings, PSA values and prostate biopsy histology results. Patients included in the review were those with LUTS who had features of benign enlargement or clinical suspicion of malignancy on rectal examination and a serum PSA value >4.0 ng/ml. Excluded from this study were patients who had low back pain, lower limb weakness, paraparesis, or paraplegia which could suggest metastatic disease.
Data retrieved from the medical records of these patients were collated using a pro forma and analyzed with SPSS software Version 20 (Armonk, NY: IBM Corp).
| Results|| |
The mean age of the 103 patients whose medical records recruited into this study was 65.9 ± 9.0 years with a range of 45-92 years. Of the 103 patients, 86.4% (n = 89) had mixed irritative and obstructive LUTS, 3.9% (n = 4) had only obstructive LUTS, 5.8% (n = 6) had only irritative LUTS while 3.9% (n = 4) had no LUTS at presentation.
The duration of patients LUTS before presentation was greater than a year in 40.7% (n = 42) of patients while it was between 6 months to 1 year in 29.1% (n = 30) and for <6 months in the remaining 30% (n = 31).
DRE findings revealed that although 15.5% (n = 16) of the cases had features of benign BPH, a clinical suspicion of malignancy was entertained in 84.5% (n = 87) of them [Chart 1].
Of the cases reviewed, 3.8% (n = 4) had a serum PSA <4 ng/ml while it was between 4 and 10 ng/ml in 9.7% (n = 10) and >10 ng/ml in 85.4% (n = 88) of patients, respectively [Table 1]. The PSA result record for 1 (1%) patient was not found.
Of the 98 patients with serum PSA >4 ng/ml who had transrectal biopsy of the prostate, histology reports of the biopsies were retrievable in only 76 patients (77.5%). Histological diagnosis in 50% of the patients (n = 38) was adenocarcinoma, out of which 71% (n = 27) were moderately and 29% (n = 11) were poorly differentiated adenocarcinomas. The remaining half had benign conditions on histology [Table 2]. The incidence of screen-detected CaP in this series was found to be 38.7%.
|Table 2: Findings on histopathology of transrectal ultrasonography-guided prostate biopsy specimen of patients|
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| Discussion|| |
Population or mass screening is defined as the examination of asymptomatic men.  It usually takes place as part of a trial or study and is initiated by the screener. In contrast, early detection or opportunistic screening comprises individual case findings, which are initiated by the person being screened (patient) and or his/her physician. The primary end point of both types of screening has two aspects. First, reduction in mortality from CaP. The goal is neither to detect more carcinomas nor is survival the end point because survival is strongly influenced by lead time from diagnosis. Second, the quality of life is important as expressed by quality of life-adjusted gain in life years (QUALYs). 
An early detection program and free treatment have been used to explain the 33% decrease in the CaP mortality rate seen in the state of Tyrol compared to the rest of Austria.  In addition, a Canadian study has claimed lower mortality rates in men randomized to active CaP screening. 
Although the 2015 American Urological Association guideline does not recommend routine screening in men between ages 40 and 54 years at average risk, it suggests that in men younger than age 55 years who are at higher risk (e.g., positive family history or of African-American race), decisions regarding CaP screening should be individualized. The guidelines recognizes that the greatest benefit of screening appears to be in men aged 55-69 years and does not recommend routine PSA screening in men aged 70+ years or in any man with less than a 10-15-year life expectancy. 
In the European Randomized Study of Screening for Prostate Cancer (ERSPC), the cumulative incidence of CaP was 8.2% in the screened group and 4.8% in the control group.  This is lower when compared to 38.7% obtained in our study. This disparity may be due to the overall higher burden of CaP among the black race.  The ERSPC investigators concluded that PSA-based screening reduced the rate of death from CaP by 20%, but was associated with a high risk of over-diagnosis.
In an update of the Gothenburg section of the ERSPC trial, which includes 20,000 men, the authors reported a reduction in CaP mortality of 50% after a median follow-up of 14 years. However, this finding was accompanied by a substantial risk of over-diagnosis. 
Based on the results of these two large, randomized trials, most if not all of the major urological societies conclude that at present widespread mass screening for CaP is not appropriate. Rather, early detection (opportunistic screening) should be offered to the well-informed man. 
On the contrary, in developing countries such as Nigeria, there may be a need for health policies which advocate targeted screening as the awareness and information level in the general populace is low leading to late presentation and higher incidence of advanced CaP.  In a survey of urologists on clients' demand for screening for CaP in Nigeria, Ajape et al.  showed that the majority of practitioners in Nigeria affirmed that patients with CaP present late and the mean number of patients requesting for screening for CaP per month, per respondent, for CaP is still low. This late presentation is similar to our findings as about half of our patients (40.7%) presented with LUTS of >1-year duration. Hence, opportunistic screening may not detect the large CaP burden in Nigeria.
Screen-detected CaP incidence rose rapidly when PSA-based population screening was introduced in the late 1980s but with it was a steady decline in the incidence of advanced CaP at a rate of 1%/year.  By 2008, mortality rates had fallen nearly 40% relative to their highs in the early 1990s.  In Nigeria, the awareness of PSA as a screening tool is still very low as Ajape et al.  in their study showed that only 5.8% of the respondents have heard of PSA screening for CaP.
Hsing et al.  have shown that there is a high prevalence of screen-detected CaP among Africans, about 7%. Total CaP rates in Africa are similar to distant-stage disease rates in the US, though underreported and incidence appears to be rising in several African countries. This lower reported total CaP incidence is accounted for by the lack of population-based screening in these African countries. 
Data from our current study show the incidence of screen-detected CaP to be 38.7%, with adenocarcinoma being the most common histological type. This incidence appears high coming out of a hospital-based population who had prostate biopsy following screening for CaP. When compared to a similar hospital-based study on screen-detected CaP in Lagos, it is still high.  However in a community-based population study in Lagos by Ikuerowo et al.,  they also recorded a high prevalence of screen-detected CaP with rates of at least 1.046% (1046/100,000) of healthy men >40 years and all had adenocarcinoma with majority of them having a Gleason grade of >7. Local studies for comparison are difficult to come by due to lack of routine screening in hospitals as well as the general population.
| Conclusions And Recommendation|| |
Our study though severely limited by its retrospective nature, inadequate documentation, and preservation of patients records, the small sample size of the study shows that the incidence of screen-detected CaP may be higher than it is actually reported in this part of the world where population-based screening is nonexistent.
With patients still presenting late in advanced stages of disease, the place of opportunistic screening for the well informed may not reflect the high cancer burden and hence achieve the needed reduction in morbidity and mortality.
We recommend that prospective studies should be carried out to better define the place of screening (opportunistic or mass) in the management of CaP in developing countries such as Nigeria.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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