Presentation Authors: Sho Uehara*, Yoh Matsuoka, Hiroshi Tanaka, Yosuke Yasuda, Shingo Moriyama, Toshiki Kijima, Soichiro Yoshida, Minato Yokoyama, Junichiro Ishioka, Kazutaka Saito, Yasuhisa Fujii, Tokyo, Japan
Introduction: Tumor contact length (TCL), defined as the length of a lesion in contact with the prostatic capsule on MRI, is an objective marker. TCL >10 mm was added to the extracapsular extension (ECE) criteria of PI-RADS version 2; however, we have reported these criteria could increase overstaging (AJR 2017). Additionally, the impact of TCL on biochemical recurrence (BCR) after radical prostatectomy (RP) has not been established. Several studies reported that the extent of pathological ECE (pECE) is associated with BCR after RP. The aim of this study is to investigate the impact of TCL on the extent of pECE and BCR after RP.
Methods: We enrolled 220 clinically localized prostate cancer patients who had undergone MRI and RP without prior treatment. MRI findings including PI-RADS score, tumor diameter (TD), morphologic features suggestive of ECE (MF-ECE), and TCL were assessed. BCR was defined as PSA >0.2 ng/ml. Preoperative variables including MRI findings were examined for association with pECE and BCR by logistic and Cox regression analyses, respectively. To evaluate the extent of pECE, the radial length was measured based on a previous report (Am J Surg Pathol 2007). We defined pECE with a radial length of >0.6 mm as extensive ECE.
Results: Median PSA was 6.8 ng/ml. PI-RADS scores â‰¤2/3/4/5 were found in 18/30/75/97 men (8/14/34/44%), and MF-ECE was identified in 73 men (33%). Median TD and TCL were 13 mm and 10 mm, respectively. Biopsy ISUP grade group (bGG) 1/2/3/â‰¥4 were found in 43/69/17/6 men. Fifty-six men (25%) had pECE, 24 men (11%) had extensive ECE, and 61 men (28%) experienced BCR at a median follow-up of 49 months. Multivariate analysis showed MF-ECE (odds ratio [OR] 4.7, p < 0.001) and TCL >10 mm (OR 7.6, p = 0.002) were independent predictors for pECE. However, multivariate analysis for extensive ECE showed MF-ECE (OR 9.9, p < 0.001) was a single independent predictor, while TCL >10 mm was not. Regarding BCR, PSA (hazard ratio [HR] 1.05, p = 0.01), bGG (HR 1.8, p < 0.001), and MF-ECE (HR 2.8, p < 0.001) were independent predictors, whereas TCL >10 mm was not. Extensive ECE was identified in 2 of 44 men with TCL >10 mm and without MF-ECE and in 17 of 60 men with TCL >10 mm and with MF-ECE, respectively (5% vs. 28%, p = 0.002).
Conclusions: TCL >10 mm is useful in the detection of pECE. However, TCL alone does not have a significant impact on the prediction of extensive ECE and BCR after RP.