Chinese Medical Journal study reveals that surgical removal of prostate cancer is possible without biopsy

Prostate cancer (PCa) is one of the most common cancers among men. Currently, PCa is diagnosed using biopsy, a technique in which a small amount of sample is retrieved from the affected region guided by imaging techniques, such as ultrasonography. However, the sensitivity of ultrasound-guided prostate biopsy is poor, often resulting in the detection of clinically insignificant PCa. Additionally, transrectal ultrasound-guided prostate is associated with high costs and side effects, such as urinary tract infections. Biopsy is often a prerequisite before the recommendation of radical prostatectomy (RP), a common surgical treatment for PCa in which the prostate gland is removed.

To overcome these limitations, efforts are underway to develop strategies for avoiding biopsy before RP. Multiparametric magnetic resonance imaging (mpMRI; an imaging technique based on radio waves and magnetic field) and prostate-specific membrane antigen positron emission tomography (PSMA PET; an imaging technique that uses radioactive tracers to measure the activity of prostate cells)/computed tomography (CT; an X-ray-based imaging technique) have diagnostic values in PCa. In PET/CT, the presence of cancer is determined based on the maximum standardized uptake value (SUVmax), which represents the amount of radioactive tracer taken up by the cancer cells. Previous clinical trials have demonstrated that PSMA PET/CT combined with magnetic resonance errors (MRI) can decrease the incidence of overlooking clinically significant PCa (false negative cases).

In continuation with the ongoing efforts, a research team led by Dr. Nianzeng Xing from the National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin Medical University General Hospital, Dr. Yong Xu from The Second Hospital of Tianjin Medical University, and Dr. RanIu Liu from Tianjin Medical University General Hospital examined if PSMA PET/CT + MRI can aid patients with suspected PCa to avoid biopsy before undergoing RP. Their findings were published in the Chinese Medical Journal on August 23, 2024.

The researchers enrolled 56 patients with PCa who underwent RP without preoperative biopsy from two tertiary hospitals between December 2017 and April 2022. The consistency between clinical and pathological diagnosis was evaluated. Patients with high levels of prostate-specific antigen and/or aberrant results in digital rectal examination were advised to undergo mpMRI. The findings of mpMRI were considered positive when the Prostate Imaging Reporting and Data System (PI-RADS; a scoring system for PCa) score was greater than equal to four. Similarly, the findings of PSMA PET/CT were considered positive when the SUVmax value was greater than equal to four. The corresponding author Prof. Nianzeng Xing adds, “Only patients with high levels of prostate-specific antigen, positive mpMRI findings, and positive PSMA PET/CT findings who were unwilling to undergo biopsy were recommended for biopsy-free approach.”

Among the 56 recruited patients who underwent RP, postoperative pathological analysis confirmed PCa in 55 cases with 49 of these patients diagnosed with clinically significant PCa. Meanwhile, one PCa case was falsely diagnosed as high-grade prostatic intraepithelial neoplasia (HGPIN). The prostate-specific antigen levels and SUVmax values in patients with clinically significant PCa were higher than those in patients with clinically insignificant PCa and patients with HGPIN. In contrast, the median prostate volume was low in patients with clinically significant PCa. Extracapsular extension was correctly identified in 21 of 26 patients but was falsely classified as a localized disease in the other five patients. When the cut-off value of SUVmax was increased to greater than equal to 7.5, the diagnostic accuracy of PSMA PET/CT for clinically significant PCa was 100%.

These findings indicate that the implementation of PSMA PET/CT + MRI strategy can aid in achieving biopsy-free RP in patients with PCa. According to Prof. Nianzeng Xing, “This diagnostic technique is a boon for patients to decrease the medical costs and hospitalization duration and avoid complications associated with biopsy.” However, the limitation of this study was the small number of patients. Hence, future studies must increase the sample size and establish predictive models based on next-generation imaging and other biomarkers to recommend biopsy-free RP.

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Reference

Titles of original papers: Preliminary clinical practice of radical prostatectomy without preoperative biopsy

Journal: Chinese Medical Journal

DOI: 10.1097/CM9.0000000000003204