[870] Length of Prostate Biopsy Core: Does It Impact the Detection of Cancer?

Pierre O Fiset, Armen Aprikian, Fadi Brimo. McGill University, Montreal, QC, Canada

Background: The detection of prostate carcinoma relies on adequate sampling. This has led to changes in practice from sextant biopsies to more extended biopsy techniques. The role of core length however, has not been fully investigated. We aimed to evaluate whether core length is a significant biopsy parameter in the detection of cancer, especially in the low-risk cancer category group.
Design: We retrospectively analyzed consecutive pathology reports of 197 patients (2196 biopsy cores) undergoing initial transrectal ultrasound guided biopsy trigerred by elevated PSA, and recorded the association of different clinical and pathological parameters (including number and length of cores) with the detection of: 1) overall cancer, 2) cancer with Gleason score (GS)≥7, and 3) very-low risk biopsy cancer category (one core of GS=6).
Results: Mean age, PSA, prostate volume, and total number of cores were 66.9 years, 12.5 ng/ml, 148.3ml and 11.1 cores, respectively. The overall cancer detection rate was 43.1% and the highest GS per case was 6 in 54.1%, 7 in 30.6%, and 8-10 in 15.3% of positive cases, respectively. The average number of positive cores per patient was 1.6. Whereas detection of cancer was sginificantly associated with advanced age (p<0.01) and smaller prostate volumes (p<0.01), PSA levels (p=0.40) and number of cores (p=0.20) were not significant predictive factors. Assessment of biopsy core lengths showed that cores harbouring cancer (n=307, average length 14.1mm) were significantly longer than benign cores (n=1889, average length = 13.2mm) (p<0.001). In the very low-risk biopsy cancer category, cancer tended to be present in cores with a length of >13mm (13.4 versus 11.9 mm p<0.05). Finally, the detection of GS ≥ 7 was not significantly affected by core's length compared to lower grades.
Conclusions: This study suggests that core length is a biopsy parameter that affects detection of cancer within individual patients with a length > 13 mm as a significant cut-off in our cohort. It may also affect the detection of very limited cancer and should therefore be taken into account by clinicians in their interpretation of prostatic biopsy reports.
Category: Genitourinary (including renal tumors)

Tuesday, March 5, 2013 9:30 AM

Poster Session III # 73, Tuesday Morning


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