Prevalence Of Prostate Cancer Among Nigerians With Intermediate Total Prostate Specific Antigen Levels (4-10ng/Ml): Experience At Lagos University Teaching Hospital, Nigeria

摘要

Prostate cancer is a common clinical condition among adult males world wide1 ; its prevalence in the intermediate total PSA values (4-10ng/ml) has not been assessed among Nigerians. This study was carried out to determine the prevalence of prostate cancer among patients with intermediate total PSA values seen in Lagos University Teaching Hospital (LUTH), a tertiary hospital located in Nigeria. A total number of 105 patients aged 50years and above with total PSA values within the intermediate PSA range (4-10ng/ml) and normal findings of the prostate on digital examination seen from January 2010 to December 2010 were recruited for the study. These patients had no features suggestive of metastasis on clinical examination. All the patients subsequently had free PSA assay and trans-rectal guided six core biopsy of the prostate. The mean age of the patients studied was 64.4years (SD=1.6) with mean total PSA value of 6.6ng/ml (SD=1.7). One hundred patients (95.1%) presented with lower urinary tract symptoms. The prostate cancer rate following analysis of biopsy specimen was 13.3 % ( 14 patients) with most patients (78.6%) within 61-70 year old bracket. The histology was adenocarcinoma in all the patients; Gleason scores 5-7 predominating. We therefore concluded that the prevalence of prostate cancer among Nigerian males with intermediate total PSA and palpably benign prostate gland from this study is 13.3%. Awareness of the prevalence of prostate cancer in this range should be created among Nigerians, as this will help improve the overall management of prostate cancer patients in this category. Introduction The prevalence of prostate cancer varies across various racial groups worldwide1, this is attributable to differences in patients characteristics. In the United States of America, it is the leading cancer diagnosis and the second most common cause of cancer death among adult males1. It is the fourth most common cancer in men worldwide1. Nigerian males have been shown to have a high incidence of Prostate cancer as documented in the study done by Osegbe2 in 1997 which revealed an incidence rate of 127/100,000 men. In a similar study by Eke and Sappira3 an incidence rate of 114/100, 000 men was documented. Prostate cancer is the commonest cancer among Nigerian males4. Measurement of serum level of prostate specific antigen (PSA) is widely used as a screening test for early detection of prostate cancer,5 its elevation in serum is suggestive of cancer of the prostate. The commonly used cut-off for prostate biopsy in most centre is total PSA>4ng/ml7, however this low cut-off for biopsy leads to significant number of unnecessary biopsies among patients with intermediate total PSA values (4-10ng/ml) where the prevalence of prostate cancer have been shown to be 22%8. Percentage Free PSA (%FPSA) have been shown to be very sensitive (95%) for prostate cancer in the intermediate PSA range at <25% cut-off point9, thus it is currently used in the evaluation of this group of patients for biopsy in other to reduce the number of unnecessary biopsy. There is however paucity of data on the prevalence of this disease in the intermediate range among Nigerian patients. Abbyesiku et al10 noted that among Nigerian patients who had cancer of the prostate gland, 20% of them had PSA values below 10ng/ml while 10% had their own below 4ng/ml. In another study of rural Nigerian men,11 out of the 140 men screened for prostate cancer using PSA, 10% had elevated PSA level greater than 4ng/ml.Though the controversy over survival benefit from early intervention for prostate cancer has not been resolved, there is no organized screening programme for prostate cancer in Nigeria. The management of this pathology in Nigeria is therefore very challenging as most cases present in advanced stage12. The modality of care usually adopted in this scenario is palliative, the prognosis being poor12. Most centres in Nigeria perform total PSA dependent biopsy when the level is abo