[Circulating prostate cells and bone marrow micro-metastasis and not treatment modality determine the risk and time to biochemical failure in low risk prostate cancer.]

INTRODUCTION

Minimal residual disease (MRD) is that which persists after curative treatment for prostate cancer. It has the potential to grow and cause metastasis. The detection of circulating prostate cells (CPCs) and bone marrow micro-metastasis could represent different sub-types of MRD.

OBJECTIVE

To determine biochemical failure free survival and time to failure, the presence of circulating prostate cells and bone marrow micro-metastasis in men treated for low risk prostate cancer.

HYPOTHESIS

The presence of MRD and not the treatment modality determines the results of therapy.

METHODS

Blood and bone marrow samples were taken one month after completing treatment to detect CPCs and micro-metastasis. Patients were classified into three groups; A: CPC negative, micro-metastasis negative, B: CPC negative, micro-metastasis positive and C: CPC positive. Biochemical failure was defined as a PSA >0.2ng/ml after radical prostatectomy and >2.0ng/ml post nadir after radiotherapy. After 10 years of follow up the Kaplan-Meier survival curve was determined and using a flexible adjusted parametric model the mean restricted survival time (MRST) was calculated for all groups.

RESULTS

343 men participated, 183 post surgery and 160 post radiotherapy, 181 (53%) had clinical stage T1 and 162 (47%) clinical stage T2a. There were no differences in treatment results between prostatectomy and radiotherapy. T1 patients had a significantly lower frequency of MRD than T2 patients (20% versus 67% p<0.001). Patients negative for MRD (Group A) had a 97% 10-year survival rate and a MRST to failure of 9.9 years. Men with only micro-metastasis (Group B) had a survival rate similar to Group A during the first five years, afterwards there was increasing treatment failure (late failure). Men positive for CPCs had a high risk of early failure.

CONCLUSIONS

The treatment results of surgery and radiotherapy are similar and depend on the sub-type of MRD. Men negative for MRD could be considered cured with a biochemical failure free survival of >95% at 10 years. The sub-type of MRD determines early or late failure and could be useful in the risk classification of patients after curative treatment.

[Evaluation of our series of first biopsies and rebiopsies by applying a prostate cancer risk calculator.]

OBJECTIVES

1.- To know the risk of detectable Prostate Cancer (PC) and significant PC by applying a Risk Calculator to patients who underwent a prostate biopsy (PB) and to analyze if there are significant differences between the risk of patients who had positive versus negative biopsies. 2.- To compare the risk of those patients with positive results who were detected in the first biopsies vs re-biopsies. 3.- To compare our results with those obtained if we had applied the cut points established in the CP risk calculator.

METHODS

Through a retrospective descriptive analytical study, we studied 496 prostate biopsies (PB) performed during 3 years (2014-2016), applying the SWOP risk calculator, analyzing if there are significant differences between those patients who had a positive vs negative result and those submitted to re-biopsies.

RESULTS

The mean risk of detectable PC by the calculator for positive PB was 34.98% versus 24.71% of negative PB; in relation to the risk of significant PC, for positive PB it was 19.13% versus 8.8% of the negative PB, with significant differences (p<0.01) in both comparisons. When patients were grouped by first biopsies vs re-biopsies, we observed that patients with the first positive biopsy had an estimated risk by the calculator of 44% compared to 31% of the first negative prostate biopsies, this difference being statistically significant.

CONCLUSIONS

The application of a prostate cancer risk calculator in candidates for first biopsy allows optimization of the test, although it loses effectiveness in patients with previous negative PB.

Screening: Actual trends on PSA marker. When, who, how?

Prostate cancer (PCa) is the most common non-skin malignancy among men world-wide. PCa incidence is higher among African American (AA) menin comparison to the white population. Men with a previous history of PCa in first-line relatives carry also an increased risk for this disease. The incidence of PCa diminished in United States (US) since the publication in 2012 of US Preventive Service Task Force (USPSTF), in which PCa screening was bestowed with a grade D of recommendation. Nonetheless, locally advanced andmetastatic disease rates increased notably. In 2018, the USPSTF drop back in their statement against PCa screening and recommended this to be a shared-decision between men 55-69 years old and their physicians.A side-by-side evaluation methodology of the three trials included in USPSTF review was performed. The high intensity screening modality and the lower contamination rate in the control arm found in the ERSPC trial justify theearlier splitting in the cumulative mortality curves between the screening and control arm when contrasted with the CAP and PCLO trials presented. We aim to perform an objective and critical review of the current practice on prostate cancer screening, regarding its limitations and when the physician should offer a shared-decision process screening based on PSA.The controversy over PSA screening has not ended despite unequivocal evidence that it saves lives. Although the USPSTF's 2017 new draft is a step in the right direction, there is more progress to be made concerning the identification of patients harboring high-risk tumors and, consequently, die of PCa. PSA baseline may lead us to differentiate properly patients at high-risk from those under risk of overdiagnosis and overtreatment. It is well established that mpMRI has come to help us in the diagnosis of PCa and in the identification of clinically significanttumors. Finally, studies ongoing on biomarkers may assist us to improve our understanding about this frequent malignancy.