History of malignancy is a predictor of prostate cancer detection: incorporation into a pre-biopsy nomogram.

Objectives: To examine whether history of malignancy adds any significant information to the prediction of positive prostate biopsy in referred men with moderately elevated prostate-specific antigen (PSA) and to develop a predicting nomogram that does not require extra examinations other than PSA.

Methods: A total of 1767 consecutive Japanese men with PSA less than 10 ng/mL who underwent prostate biopsy were included in the study cohort. Age, digital rectal examination (DRE), PSA, body mass index, family history of prostate cancer and number of previous malignancies other than the prostate were evaluated in regard to their association with prostate cancer. A logistic regression-based nomogram for predicting prostate cancer was developed and externally validated.

Results: Of the 1767 men, 269 had a history of malignancy with a total of 312 primary sites. Univariate and multivariate analyses revealed that DRE, PSA, age, family history and number of previous malignancies are independent and significant predictors of positive biopsy result. External validation revealed that the predicting accuracy of a nomogram incorporating these five variables is significantly higher than those of PSA or PSA and DRE. Using the nomogram, 8% of unnecessary biopsies would be saved at 95% sensitivity.

Conclusions: We demonstrated for the first time that history of malignancy is a potent predictor of prostate cancer in men with moderately elevated PSA even if the established risk factors are adjusted. The nomogram can be a useful tool in decision-making of prostate biopsy. In daily practice, history of malignancy should be rigorously taken from these men before a decision is made regarding prostate biopsy.