The Impact of Transrectal Needle Biopsy Core Length on Prostate Cancer Diagnosis

INTRODUCTION: Prostate cancer is diagnosed by histological evaluation of the prostatic glandular structure, and ultrasound-guided needle biopsy is the most commonly used method in diagnosis. Various strategies have been developed to overcome diagnostic limitations of prostate biopsy and to increase the rate of cancer detection. In this study, it was aimed to reveal the relationship between biopsy core lengths and cancer detection rates and to establish standardization criteria that can increase the diagnostic value of biopsy core length.
METHODS: Between January 2016 and September 2017, 394 patients who underwent transrectal ultrasound-guided prostate biopsy for abnormal digital rectal examination and/or prostate-specific antigen (PSA) >2.5 ng/mL were retrospectively evaluated. Under transrectal ultrasound, a total of 12 core biopsies were performed from each patient from the apical, medial, and basal regions of the both sides of the prostate. Each core length and tumor length were noted. Core lengths were compared in cancer and non-cancer patients and divided into Groups A and B, respectively. Statistical analysis was performed to determine an acceptable limit for biopsy length.
RESULTS: The mean age of the patients was 63.84±7.26, mean PSA was 15.88±7.40 ng/dl, and the mean prostate volume was 54.30±28.48 ml. Prostate cancer was seen in 24% of patients. Average core length was 12.7 mm in cancer group and 12.3 mm in non-cancer group. Although the core lengths are high in cancer patients, the relationship between average core length and cancer detection rates and also cancer grade was compared with the Kruskal–Wallis test and no statistically significant difference was found (p=0.232).
DISCUSSION AND CONCLUSION: In pathological evaluation, the relationship between the biopsy core length of prostate tissue and the diagnosis of prostate cancer could not be shown, and therefore, a cutoff value for the sufficient glandular tissue could not be determined. The presence of studies with similar and opposite results, relevant to this subject, showed that the need for further clinical studies.