Emergent trends in the reported incidence of prostate cancer in Nigeria

Prevalence of prostate cancer at autopsy in Nigeria-A preliminary report

BACKGROUND AND OBJECTIVES

Prostate cancer is the most commonly diagnosed cancer in Nigerian men despite the lack of PSA based screening. Current prevalence estimates in Nigeria are based on cancer registry data obtained primarily from hospital admissions and therefore not truly reflective of prostate cancer incidence. Prior autopsy series did not adhere to modern pathologic quality practices. The aim of this study was to explore the prevalence of asymptomatic prostate cancer among Nigerian men at the time of autopsy.

METHODS

Prostates were collected at autopsy at the Universities of Lagos and Calabar Teaching Hospitals from men aged more than 40 who died from causes other than prostate cancer. Thirty-nine prostates from Nigerian men autopsied in 2017 to 2018 were formalin-fixed, weighed, and sliced at 4 mm intervals. Haematoxylin and eosin-stained paraffin sections were prepared from these slices. Presence and Gleason grade of prostatic adenocarcinomas and presence of high-grade prostatic intraepithelial neoplasia (HGPIN) were recorded.

RESULTS

Mean age of cases was 55 ± 11 years and mean prostatic weight was 23.0 ± 10.9 g. The crude prevalence of HGPIN was 20.6%. Overall crude prevalence of prostate cancer was 8.8% (n = 34), increasing from 8.3% for men aged 40-59 (n = 23) to 10.0% for men ≥60 years old (n = 10). Two tumors were small and had Gleason Grade 3 + 3 or 3 + 4, and one large stage T3 tumor with Gleason Grade 4 + 3 disease and neuroendocrine appearance was found in a 54-year-old man.

CONCLUSIONS

The 8.8% prevalence of subclinical prostate cancer at autopsy was similar to previously reported Nigerian studies with more limited tissue sampling (6.7%-10%), but considerably lower than estimates in other populations, including African Americans. Our findings suggest that latent, clinically asymptomatic prostate cancer is less frequent in Nigerians than in African Americans, despite shared genetic ancestry. Future studies with increased sample size are warranted to provide insight in the natural history and true prevalence of prostate cancer in West Africa.

High mortality risk of prostate cancer patients in Asia and West Africa: A systematic review

Globally, prostate cancer (PCa) is the second most preponderant cancer in men. It contributes to the high mortality-to-incidence ratio reported in West Africa and Asia largely due to low screening. The mortality risk is determined or predicted based on the prevalence of high-risk or aggressive PCa using a scoring or grading system such as Gleason score (GS), Gleason grade (GG), and prostate-specific antigen (PSA) level. In this review, peer-reviewed articles found on databases such as Google Scholar, Scopus, Web of Science, PubMed Central and, EMBASE were selected based on adherence to clinical guidelines for the classification of PCa. In West Africa and Asia, the result revealed that the frequency of high-risk PCa was 42% and 51.2% based on GS, 48.8% and 25.3% based on GG pattern, and 87.5% and 44.3% based on PSA level >10 ng/mL, respectively. Data revealed a high prevalence of high-risk PCa both in West Africa and Asia when compared with developed countries. However, the prevalence of high-risk PCa is higher in West Africa than in Asia. Studies have shown that high-risk PCas are associated with germline mutations and such mutations are prevalent in blacks and Asians than in whites. Thus, testing for germline mutations in patients with GS of ≥ 7, GG ≥ 3, high prostate density, low prostate volume, and PSA levels of >4.0 ng/mL may identify those at risk of developing lethal PCa and could reduce the mortality rates in Asia and West Africa.

The impact of plasma zinc status on the severity of prostate cancer disease

Purpose

The severity of prostate cancer (PCa), which determines the disease progression, is theorized to be a function of zinc status. Hence, this study was structured to determine the impact of zinc status on the severity and progression of PCa disease.

Materials and Methods

This was a descriptive cross-sectional study of 220 histologically-confirmed PCa patients and 220 age-matched controls, conducted prospectively in a Nigerian tertiary hospital. Plasma zinc, prostate-specific antigen, creatinine, fasting glucose, and estimated glomerular filtration rate were determined for both study groups. The International Society of Urological Pathology (ISUP) grades and the American Joint Committee on Cancer clinical staging were employed as indices for PCa severity (grade) and progression (stage) respectively.

Results

The PCa patients had markedly reduced plasma zinc status compared to controls (cases: 9.42±3.02 µmol/L versus controls: 15.23±4.47 µmol/L; p<0.001). Low zinc status was more pronounced within the severe grade and advanced PCa disease subgroups (p<0.001). Inverse relationships existed between zinc status and ISUP grades among the entire PCa patient (p<0.001) and the categorized PCa grade and stage subgroups (p<0.001). Low zinc status had significant impact of predicting severe (crude=odds ratio [OR], 8.714; p<0.001; age-adjusted=OR, 11.152; p<0.001) and advanced (crude=OR, 17.160; p<0.001; age-adjusted=OR, 18.927; p<0.001) PCa disease.

Conclusions

This study suggests that low plasma zinc status is associated with severe grade and advanced PCa disease. However, further well-designed studies with large sample sizes are warranted to confirm these associations.

Prostate Cancer Detected by Screening in a Semi Urban Community in Southeast Nigeria: Correlations and Associations between Anthropometric Measurements and Prostate-specific Antigen

Context:

Prostate cancer (PCa) is frequently diagnosed at advanced stages in Nigeria.

Aims:

To determine the screen detected PCa prevalence in a suburban community and explore any relationships between prostate-specific antigen (PSA) and anthropometric measurements.

Settings and Design:

Nsukka is a town and local government area (LGA) in Southeast Nigeria in Enugu State. Towns that share a common border with Nsukka are Edem Ani, Alor-uno, Opi, Orba, and Ede-Oballa. Nsukka LGA has an area of 1810 km² and a population of 309,633 at the 2006 census. All consecutive responders who met the inclusion criteria were recruited.

Subjects and Methods:

A screening outreach was conducted in one location in Nsukka. PSA testing and digital rectal examinations were performed. Height and weight were measured and body mass index (BMI) was calculated.

Statistical Analysis Used:

Results were subjected to statistical analysis using SPSS 20 (IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY, USA). Categorical data were analyzed using the Chi-square test, with significance level set at P < 0.05. Pearson's correlation was conducted for interval data (P < 0.05).

Results:

One-hundred and sixty men met the inclusion criteria and were screened. Age range was 40–81 years; PSA range was 1.20–33.9 ng/ml. Digital rectal examinations (DREs) was abnormal in 17 men. Median BMI was 27.49. A Pearson's correlation coefficient showed a significant correlation between age and PSA, r = 0.127; P ≤ 0.05, and DRE findings and PSA, r = 0.178; P ≤ 0.05. There was no significant correlation between height and PSA, r = −0.99; P = 0.211; weight and PSA, r = −0. 81 P = 0.308; and BMI and PSA, r = −0.066; P = 0.407. 8/21 men consented to prostate biopsy with three positive, giving a screen detected PCa prevalence of 1.875%.

Conclusions:

Screen detected PCa prevalence in high this population and efforts to improve early detection may be of value in improving treatment outcomes.

An Estimate of the Incidence of Prostate Cancer in Africa: A Systematic Review and Meta-Analysis

BACKGROUND

Prostate cancer (PCa) is rated the second most common cancer and sixth leading cause of cancer deaths among men globally. Reports show that African men suffer disproportionately from PCa compared to men from other parts of the world. It is still quite difficult to accurately describe the burden of PCa in Africa due to poor cancer registration systems. We systematically reviewed the literature on prostate cancer in Africa and provided a continent-wide incidence rate of PCa based on available data in the region.

METHODS

A systematic literature search of Medline, EMBASE and Global Health from January 1980 to June 2015 was conducted, with additional search of Google Scholar, International Association of Cancer Registries (IACR), International Agency for Research on Cancer (IARC), and WHO African region websites, for studies that estimated incidence rate of PCa in any African location. Having assessed quality and consistency across selected studies, we extracted incidence rates of PCa and conducted a random effects meta-analysis.

RESULTS

Our search returned 9766 records, with 40 studies spreading across 16 African countries meeting our selection criteria. We estimated a pooled PCa incidence rate of 22.0 (95% CI: 19.93-23.97) per 100,000 population, and also reported a median incidence rate of 19.5 per 100,000 population. We observed an increasing trend in PCa incidence with advancing age, and over the main years covered.

CONCLUSION

Effective cancer registration and extensive research are vital to appropriately quantifying PCa burden in Africa. We hope our findings may further assist at identifying relevant gaps, and contribute to improving knowledge, research, and interventions targeted at prostate cancer in Africa.

Apolipoprotein E gene polymorphism influences aggressive behavior in prostate cancer cells by deregulating cholesterol homeostasis

High circulating cholesterol and its deregulated homeostasis may facilitate prostate cancer progression. Genetic polymorphism in Apolipoprotein (Apo) E, a key cholesterol regulatory protein may effect changes in systemic cholesterol levels. In this investigation, we determined whether variants of the Apo E gene can trigger defective intracellular cholesterol efflux, which could promote aggressive prostate cancer. ApoE genotypes of weakly (non-aggressive), moderate and highly tumorigenic (aggressive) prostate cancer cell lines were characterized, and we explored whether the ApoE variants were associated with tumor aggressiveness generated by intra cellular cholesterol imbalance, using the expression of caveolin-1 (cav-1), a pro-malignancy surrogate of cholesterol overload. Restriction isotyping of ApoE isoforms revealed that the non-aggressive cell lines carried ApoE ε3/ε3 or ε3/ε4 alleles, while the aggressive cell lines carried the Apoε2/ε4 alleles. Our data suggest a contrast between the non-aggressive and the aggressive prostate cancer cell lines in the pattern of cholesterol efflux and cav-1 expression. Our exploratory results suggest a relationship between prostate aggressiveness, ApoE isoforms and cholesterol imbalance. Further investigation of this relationship may elucidate the molecular basis for considering cholesterol as a risk factor of aggressive prostate tumors, and underscore the potential of the dysfunctional ApoE2/E4 isoform as a biomarker of aggressive disease.

Management of prostate cancer in port harcourt, Nigeria: changing patterns

BACKGROUND

This is a follow up to a study done at the University of Port Harcourt Teaching Hospital (UPTH) 11 years ago on the management of prostate cancer.

AIMS

To assess the current pattern in the management of prostate cancer in Port Harcourt, Nigeria and the impact of changes in diagnosis and treatment.

METHODS

All the case notes of prostate cancer presenting in the University of Port Harcourt Teaching Hospital between January 2003 and December 2012 were reviewed. Data on demography, clinical presentations, co-morbidities, investigations, treatment, complications and outcome of treatment were extracted and analyzed using SPSS 20.0 0 RESULTS: A total of 294 histologically confirmed patients with cancer of the prostate were treated within the study period. Out of these, 216 (73.5%) case notes were analysed. The mean age was 69.9 years (51 -90 years). All the patients had lower urinary tract symptoms, 30 (14.0%) had haematuria while 19(8.8%) presented with paraplegia. The prostate specific antigen (PSA) ranged from 0.5 - 760ng/ml. Two hundred and five (95%) received androgen deprivation therapy. Of these, 123 (60%) had bilateral subcapsular orchidectomy and anti androgen, 3 (1.4%) had abiraterone. Five (2.3%) had radical prostatectomy, 22 (10.2%) had chemotherapy while 16(7.4%) had radiotherapy. Seventy-two (33.5%) died within 2 years of diagnosis while 49(30.2%) survived more than 5 years.

CONCLUSION

There is rising prevalence of carcinoma of the prostate in this centre. Many patients presented late. There has been expansion in diagnostic and therapeutic capabilities with attendant improvement in patients' survival. Co-morbidities adversely affected the outcome of treatment.