#GU15 - Best of journals: Prostate cancer - Session Highlights

ORLANDO, FL, USA (UroToday.com) - Dr. Edward Schaeffer from Johns Hopkins presented the results and discussed implications of four important articles.

The first article by Siddiqui MM, et al., JAMA 2015 assessed targeted (MRI/US fusion) vs standard TRUS prostate biopsy vs combination. The study included 1 215 men with elevated PSA or abnormal DRE. Four-hundred-sixty patients had prior negative biopsy, 347 patients had prior positive biopsy, and 196 patients were biopsy naïve. The biopsies were categorized into low (GS 6, GS 3+4 in < 50% one core, < 33% of standard cores), intermediate (GS 3+4 in > 50% of core or > 33% of standard biopsy), or high risk (GS > 3+4). The risk stratification is different from what is defined by NCCN. Targeted biopsies identified more high-grade lesions compared to standard TRUS biopsy. Among men with negative prior biopsy, targeted biopsy identified cancers in 59 men (17%) and high-grade lesions (Gleason > 6) in 57 (10%). Among men with prior low-risk standard biopsy, targeted biopsy identified no cancer/low-grade cancers in 158 men (77%) and higher-grade lesions in 48 (23%). In comparison to radical prostatectomy pathology, the sensitivity and specificity of targeted lesion was 77% and 68% respectively, in comparison to 55 % and 66% in standard biopsy group. On final pathology, 59 high-risk patients were identified -- of whom, 46 were detected by fusion biopsy while only 37 were detected by standard biopsy. In conclusion, this study illustrates that MRI-US fusion biopsy improves detection of clinically significant prostate cancer.

gucancerssympaltThe second article by Bill-Axelson A et al., NEJM 2014 is an update of Scandinavian Prostate Cancer Group Study Number 4 (SPCG-4). Between 1989 and 1999, 695 men with early prostate cancer (T1b-T2, 12% were cT1c) were randomized to watchful waiting (WW) or radical prostatectomy (RP) and followed through the end of 2012. There were 200 deaths in RP group and 247 in WW group with 0.71 relative risk of death in RP group. The NNT to prevent death was 8. There were 63 and 99 prostate cancer-related deaths in the RP and WW group respectively, with 0.56 relative risk of prostate cancer death in the RP group. Additionally, there was a 0.57 relative risk of metastasis in the RP group and a 0.49 relative risk of ADT in RP group. Most importantly, men < 65 years benefited from mortality reduction as compared to men > 65. In men < 65 years, there was a 25% reduction in overall mortality, a 15% reduction in prostate cancer death, and a 15% reduction in metastasis. The NNT to prevent death in men < 65 was 4. While there was no mortality reduction in men > 65, there was an 8.9% reduction in metastasis in this group. In conclusion, this study showed that local therapy improved prostate cancer control when compared to WW in a group of men presenting with intermediate risk of disease. The greatest benefit was in men < 65 years of age.

The third article presented was Nam RK et al., Lancet 2014 which looked at the incidence of complications other than urinary incontinence or erectile dysfunction after radical prostatectomy or radiotherapy in a population-based Ontario Health Insurance Plan (OHIP) cohort. 32 465 patients with prostate cancer were identified, of whom 15 870 underwent radical prostatectomy and 16 595 underwent radiotherapy. Outcomes measured were hospitalization to manage treatment-related problem, minimally-invasive urological procedures, minimally-invasive rectal or anal procedures, open surgical procedure for management of urologic/rectal/anal problem, or secondary malignancy. The study showed a 22.2% 5-year incidence of hospitalization, most commonly from urinary obstruction. 5-year cumulative incidence of urinary obstruction was 13%, rectal/anal procedure 13.7%, open procedure 0.9%, and secondary malignancy 3%. Surgery was associated with an increased number of minor urologic procedures. Radiation was associated with an increased number of admissions to hospital, rectal/anal procedures, open surgical procedures, or secondary malignancies.

The fourth article discussed was Den RB et al. JCO 2015 and it explored whether genomic classifier (GC) could provide prognostic and predictive information regarding timing of post-operative radiation in and at-risk cohort. The multi-institutional cohort of 188 men with T3 or M+ cancer s/p radical prostatectomy was treated with adjuvant or salvage RT. Genomic Classsifier-Decipher was performed in all men. The primary endpoint was metastasis as evidenced by positive CT and/or bone scans. Adjuvant and salvage radiation treatment was defined by PSA < 0.2 and > 0.2 prior to initiation of radiation, respectively. The study showed improved metastasis-free survival with adjuvant radiation therapy (ART) vs salvage radiation treatment (SRT). Patients with low GC (< 0.4) showed no difference in metastatic-free survival. However, patients with high GC score (> 0.4) had 80% reduction in hazards for developing metastasis. In conclusion, this study illustrates that GC can be used to identify men into risk groups where there may be potential benefit of ART vs SRT. This may guide physicians and patients in deciding on ART vs SRT. Given that this study included patients who received radiation therapy and did not have a control group that did not receive radiation, this study could not identify a patient population in whom post prostatectomy radiation therapy could be withheld completely.

Presented by Edward Schaeffer, MD, PhD at the 2015 Genitourinary Cancers Symposium - "Integrating Biology Into Patient-Centric Care" - February 26 - 28, 2015 - Rosen Shingle Creek - Orlando, Florida USA

Johns Hopkins Medicine, Baltimore, MD USA

Reported by Mohammed Haseebuddin, MD, medical writer for UroToday.com