Qureshi Ayman M, Makhdomi Khalid, Stones William
Department of Radiology, Aga Khan University Hospital Nairobi, Nairobi, Kenya.
Department of Obstetrics and Gynaecology, Aga Khan University Hospital, Nairobi, Kenya.
World J Nucl Med. 2017 Jan-Mar;16(1):26-32. doi: 10.4103/1450-1147.181150.
Prostate cancer is the most common noncutaneous cancer in males. Men of African origin are at a significantly higher risk as reflected in the higher incidence and mortality rates in this racial group. Metastases incidence increases parallel to serum levels of prostate-specific antigen (PSA), contributing significantly to morbidity and mortality. Staging of the disease involves bone scans, which are sensitive in detecting skeletal metastases. Suggestions that these scans may be omitted in some situations in patients with low prostate specific antigen levels have drawn attention to the matter. In this case-control study, using radiology and pathology records, a registry of prostate cancer patients recorded as being of dark-skinned ethnicity was obtained. Images were presented to image reviewers blinded to the PSA level, to determine the presence of skeletal metastases. The risk factor for the outcome of interest (skeletal metastases) was PSA level above 20 ng/mL. The reliability of image reporting was also assessed. Of the 122 patients, skeletal metastases were present in 50 (41%) while these were absent in 72 (59%). The prevalence of metastases among the high PSA group was 55.9% [95% confidence interval (CI) 44.1-67.7%] and among the normal/low PSA group was 22.2% (95% CI 11.1-33.3%). The odds ratio (OR) for skeletal metastases in the exposed (high PSA) group was 4.4 (95% CI, 2.01-9.78.) Intraobserver agreement on image interpretation was 88.5% with a Kappa statistic of 0.76. A relatively higher prevalence of skeletal metastasis is seen in regional dark-skinned African males with prostate cancer at both low and high prostate specific antigen levels. Bone scanning in this population should therefore, be considered even at PSA levels below 20 ng/mL.
前列腺癌是男性最常见的非皮肤癌。非洲裔男性的患病风险显著更高，这体现在该种族群体较高的发病率和死亡率上。转移发生率与前列腺特异性抗原（PSA）的血清水平平行上升，对发病率和死亡率有显著影响。疾病分期涉及骨扫描，其对检测骨转移很敏感。关于在某些前列腺特异性抗原水平较低的患者中可省略这些扫描的建议引起了人们对该问题的关注。在这项病例对照研究中，利用放射学和病理学记录，获得了一份记录为深色皮肤种族的前列腺癌患者登记册。将图像呈现给对PSA水平不知情的图像评审人员，以确定是否存在骨转移。感兴趣的结果（骨转移）的危险因素是PSA水平高于20 ng/mL。还评估了图像报告的可靠性。在122名患者中，50名（41%）存在骨转移，72名（59%）不存在骨转移。高PSA组中转移的患病率为55.9%[95%置信区间（CI）44.1 - 67.7%]，正常/低PSA组中为22.2%（95% CI 11.1 - 33.3%）。暴露（高PSA）组中骨转移的优势比（OR）为4.4（95% CI，2.01 - 9.78）。观察者内部对图像解读的一致性为88.5%，kappa统计量为0.76。在前列腺特异性抗原水平低和高的情况下，局部深色皮肤的非洲裔前列腺癌男性中骨转移的患病率相对较高。因此，即使在PSA水平低于20 ng/mL时，也应考虑对该人群进行骨扫描。
