#20 Undiagnosed prostate cancer in southern nigeria. Disease risk and prevalence.

摘要

PURPOSE: In contrast to previous reports of low prostate cancer (Pca) incidence in Sub-Saharan Africa, a Nigerian cancer register reported Pca to be the most prevalent cancer diagnosed in hospitals with a relative incidence of 16.14%. This study investigates the risk of undiagnosed prostate cancer in three communities in southern Nigeria.METHODS: Men 40 years and older in 300 consecutive households in three southern Nigerian communities were screened by serum prostate specific antigen (PSA) and digital rectal examination (DRE) and those with PSA >/=4ng./ml. and/or abnormal DRE were referred for biopsy.RESULTS: Of 309 men contacted, 235 (76.0%) consented and presented for the study but 40(17.0%) did not allow blood draw and/or DRE. 158 (70.9%) were farmers and low-income workers, 41 (18.4%) were middle income workers and 24 (10.8%) were professionals and managers. Their ages ranged from 40-110, mean 56.4 years and 210 (89.4%) were married. PSA ranged from 0.1-723.5 ng./ml., 169 (79.3%) had PSA <2.5ng/ml; 21 (9.9%) from 2.5-3.9ng/ml; 9 (4.2%) from 4.00-9.9ng/ml, 11 (5.2%) from10-50ng./ml and 3 (1.4%) had PSA >50ng./ml. 83 (35.3%) had BPH, 23 (9.8%) with symptoms and two already had transurethral prostatectomy. 89 (37.9%) had either abnormal PSA and/or DRE. The abnormal PSA rate for men 50yrs. and older was 21 (17.5%). Among men 60 years and older abnormal PSA rate for those with normal or abnormal DRE was 6.5% and 33.3% respectively, p < 0.005. Only 4 (4.5%) presented for biopsy as advised and two of them had positive histology for prostate cancer. Fear and lack of understanding are the major reasons for refusing prostate biopsy.CONCLUSION: The proportion of men with PSA >/=4ng/ml is comparable with that for regions with high incidence of Pca, such as America. There is an urgent need for education about cancer, cancer screening, diagnosis and treatment. Future work to evaluate percent free to total PSA may be useful to target men at higher risk for Pca for biopsy.