Characteristics of case-control study population of aggressive prostate cancer.

aSome totals do not add to 100 percent due to missing data.bFrom T-test comparing means, or chi-square tests comparing counts.cSD, standard deviation.dPositive family history of prostate cancer was defined as prostate cancer in a first degree relative.a. 因存在缺失数据，部分合计值未达到100%。 b. 均值比较采用t检验，频数比较采用卡方检验。 c. SD即标准差（standard deviation）。 d. 前列腺癌阳性家族史定义为一级亲属罹患前列腺癌。