Low-Risk Prostate Cancer and Tumor Upgrading in the Surgical Specimen: Analysis of Clinical Factors Predicting Tumor Upgrading in a Contemporary Series of Patients Who were Evaluated According to the Modified Gleason Score Grading System.

OBJECTIVE

To identify significant clinical factors associated with prostate cancer (PCa) upgrading the low-risk PCa patients graded according to the modified Gleason score system.

MATERIALS AND METHODS

The logistic regression model was used to evaluate the records of 438 patients.

RESULTS

There were 170 cases (38.8%) of low-risk PCa and tumors were upgraded in 111 patients (65.3%). Only prostate specific antigen (PSA) and the proportion of positive cores (P+) were independent predictors of tumor upgrading. Further exploration was investigated by categorizing and regressing PSA (≤ 5.0 vs. > 5.0 ng/ml) and P+ (≤ 0.20 vs. > 0.20). The odds ratio of PSA > 5 ng/ml was 1.32 and of P+ > 0.20 was 2.71. The population was stratified into very low-risk with PSA ≤ 5 ng/ml and P+ ≤ 0.20 (class A), low-risk with PSA > 5 ng/ml and P+ ≤ 0.20 (class B), intermediate risk with PSA ≤ 5 ng/ml and P+ > 0.20 (class C), and high risk with PSA > 5 ng/ml and P+ 0.20 (class D). Upgrading rates were extremely low in class A (9%), extremely high in D (50.5%), and moderate (20%) in B and C.

CONCLUSION

Patients diagnosed with low-risk PCa at biopsy are a heterogeneous population because they include subsets with undetected high-grade disease. Significant clinical predictors of upgrading include the PSA value and P+. In low-risk PCa, we identified a high-risk upgrading subgroup that needed repeat biopsies in order to reclassify the tumor grade and to reassess the clinical risk category.