Prostate cancer screening among elderly men in Brazil: should we diagnose or not?

ABSTRACT Purpose: Prostate cancer screening in the elderly is controversial. The Brazilian government and the National Cancer Institute (INCA) do not recommend systematic screening. Our purpose was to assess prevalence and aggressiveness of prostate cancer in men aged 70 years and above, on the first Latin American database to date. Materials and Methods: Cross-sectional study (n=17,571) from 231 municipalities, visited by Mobile Cancer Prevention Units of a prostate-specific antigen (PSA) based opportunistic screening program, between 2004 and 2007. The criteria for biopsy were: PSA>4.0ng/ml, or PSA 2.5-4.0ng/ml with free/total PSA ratio ≤15%, or suspicious digital rectal examination findings. The screened men were stratified in two age groups (45-69 years, and ≥70 years). These groups were compared regarding prostate cancer prevalence and aggressiveness criteria (PSA, Gleason score from biopsy and TNM staging). Results: The prevalence of prostate cancer found was 3.7%. When compared to men aged 45-69 years, individuals aged 70 years and above presented cancer prevalence about three times higher (prevalence ratio 2.9, p<0.01), and greater likelihood to present PSA level above 10.0ng/ml at diagnosis (odds ratio 2.63, p<0.01). The group of elderly men also presented prevalence of histologically aggressive disease (Gleason 8-10) 3.6 times higher (p<0.01), and 5-fold greater prevalence of metastases (PR 4.95, p<0.05). Conclusions: Prostate cancer screening in men aged over 70 may be relevant in Brazil, considering the absence of systematic screening, higher prevalence and higher probability of high-risk disease found in this age range of the population studied.

摘要：老年前列腺癌筛查尚存争议。巴西政府与国家癌症研究所（National Cancer Institute, INCA）暂不推荐系统性前列腺癌筛查。本研究依托迄今为止首个拉丁美洲地区数据库，旨在评估70岁及以上男性前列腺癌的患病率与侵袭性特征。

材料与方法：本研究为横断面研究，共纳入17571名研究对象，数据来源于2004年至2007年间，由参与基于前列腺特异性抗原（prostate-specific antigen, PSA）机会性筛查项目的移动癌症预防单元所覆盖的231个市镇。活检指征设定为：PSA＞4.0ng/ml，或PSA处于2.5~4.0ng/ml且游离/总PSA比值≤15%，或直肠指检结果可疑阳性。将受筛男性按年龄分为两组：45~69岁组与≥70岁组，对比两组前列腺癌患病率及侵袭性相关指标，包括PSA水平、活检Gleason评分（Gleason score）与TNM分期（TNM staging）。

结果：本研究检出前列腺癌患病率为3.7%。与45~69岁男性相比，70岁及以上人群的前列腺癌患病率约为前者的3倍（患病率比2.9，p＜0.01），确诊时PSA水平＞10.0ng/ml的风险显著升高（比值比2.63，p＜0.01）。老年男性群体中，组织学侵袭性疾病（Gleason评分8~10分）的患病率高出3.6倍（p＜0.01），远处转移患病率则为对照组的5倍（患病率比4.95，p＜0.05）。

结论：鉴于巴西目前尚未开展系统性前列腺癌筛查，且本研究人群中70岁以上群体的前列腺癌患病率更高、高危疾病的发生概率更大，因此针对该年龄段男性开展前列腺癌筛查或具有临床意义。