Prostate specific antigen density values among patients with symptomatic prostatic enlargement in Nigeria

Background This study aims to estimate the prostate specific antigen density(PSAD) cut off level for detecting prostate cancer( CAP) in Nigerian men with “grey zone PSA’’(4-10ng/ml) and normal digital rectal examination findings . We addressed this research question: Is the international PSAD cut off of 0.15 ideal for detecting CAP in our symptomatic patients with “grey zone PSA’’? Methods Aim: To estimate the prostate specific antigen density(PSAD) cut off level for detecting prostate cancer( CAP) in Nigerian men with “grey zone PSA’’(4-10ng/ml) and normal digital rectal examination findings . Design: prospective Setting: A tertiary medical center in Enugu Nigeria Participants: Two hundred and fifty four men with either benign prostatic hyperplasia (BPH) or prostate cancer (CAP) were recruited. Intervention: Patients with PSA above 4ng/ml or abnormal digital rectal examination or hypoecoic lesion in the prostate were biopsied. Outcome measures: PSAD and histology report of BPH or CAP Results Ninety seven patients had cancer of the prostate (CAP) while 157 has benign prostatic hyperplasia (BPH). Seventy two patients had their serum PSA value within the range of 4.0 and 10ng/ml . PSAD cut off level to detect CAP was 0.04(sensitivity 95.88 %; specificity 28.7 %). CONCLUSION The PSAD cut off level generated for Nigerian men in this study is 0.04 which is relatively different from international consensus. This PSAD cut off level has a positive correlation with histology and could detect patients with CAP who have “grey zone PSA’’.

## 研究背景
本研究旨在针对直肠指检结果正常、且血清PSA处于灰区（4~10ng/ml）的尼日利亚男性，估算用于检测前列腺癌（prostate cancer, CAP）的前列腺特异性抗原密度（prostate specific antigen density, PSAD）截断值。本研究拟解答的科学问题为：国际通用的0.15 PSAD截断值，是否适用于本研究中灰区PSA的有症状前列腺癌患者？

## 研究方法
### 研究目的
本研究旨在为直肠指检结果正常、PSA处于灰区（4~10ng/ml）的尼日利亚男性，估算用于检测前列腺癌的PSAD截断值。
### 研究设计
前瞻性研究
### 研究机构
尼日利亚埃努古市的一所三级医疗中心
### 研究对象
共招募254名男性受试者，均被诊断为良性前列腺增生（benign prostatic hyperplasia, BPH）或前列腺癌（CAP）。
### 干预方案
对于血清PSA＞4ng/ml、直肠指检异常或前列腺存在低回声病灶的患者，实施前列腺穿刺活检。
### 结局指标
PSAD值以及良性前列腺增生或前列腺癌的组织病理学诊断报告。

## 研究结果
本研究中，97名患者被确诊为前列腺癌（CAP），157名患者被确诊为良性前列腺增生（BPH）。其中72名患者的血清PSA值处于4.0~10ng/ml的灰区范围内。本研究得到的用于检测前列腺癌的PSAD截断值为0.04（灵敏度95.88%；特异度28.7%）。

## 研究结论
本研究针对尼日利亚男性得出的PSAD截断值为0.04，与国际通用的共识阈值存在显著差异。该PSAD截断值与组织病理学结果呈正相关，可有效识别灰区PSA范围内的前列腺癌患者。