The oncologic risk of magnetic resonance imaging‐targeted and systematic cores in patients treated with radical prostatectomy

Abstract

BackgroundMagnetic resonance imaging (MRI)‐targeted prostate biopsy (MRI‐biopsy) detects high‐Grade Group (GG) prostate cancers not identified by systematic biopsy (S‐biopsy). However, questions have been raised whether cancers detected by MRI‐biopsy and S‐biopsy, grade‐for‐grade, are of equivalent oncologic risk. The authors evaluated the relative oncologic risk of GG diagnosed by S‐biopsy and MRI‐biopsy.MethodsThis was a retrospective analysis of all patients who had both MRI‐biopsy and S‐biopsy and underwent with prostatectomy (2014–2022) at Memorial Sloan Kettering Cancer Center. Three logistic regression models were used with adverse pathology as the primary outcome (primary pattern 4, any pattern 5, seminal vesicle invasion, or lymph node involvement). The first model included the presurgery prostate‐specific antigen level, the number of positive and negative S‐biopsy cores, S‐biopsy GG, and MRI‐biopsy GG. The second model excluded MRI‐biopsy GG to obtain the average risk based on S‐biopsy GG. The third model excluded S‐biopsy GG to obtain the risk based on MRI‐biopsy GG. A secondary analysis using Cox regression evaluated the 12‐month risk of biochemical recurrence.ResultsIn total, 991 patients were identified, including 359 (36%) who had adverse pathology. MRI‐biopsy GG influenced oncologic risk compared with S‐biopsy GG alone (p < .001). However, if grade was discordant between biopsies, then the risk was intermediate between grades. For example, the average risk of advanced pathology for patients who had GG2 and GG3 on S‐biopsy was 19% and 66%, respectively, but the average risk was 47% for patients who had GG2 on S‐biopsy and patients who had GG3 on MRI‐biopsy. The equivalent estimates for 12‐month biochemical recurrence were 5.8%, 15%, and 10%, respectively.ConclusionsThe current findings cast doubt on the practice of defining risk group based on the highest GG. Because treatment algorithms depend fundamentally on GG, further research is urgently required to assess the oncologic risk of prostate tumors depending on detection technique.Plain Language Summary Using magnetic resonance imaging (MRI) to help diagnose prostate cancer can help identify more high‐grade cancers than using a systematic template biopsy alone. However, we do not know if high‐grade cancers diagnosed with the help of an MRI are as dangerous to the patient as high‐grade cancers diagnosed with a systematic biopsy. We examined all of our patients who had an MRI biopsy and a systematic biopsy and then had their prostates removed to find out if these patients had risk factors and signs of aggressive cancer (cancer that spread outside the prostate or was very high grade). We found that, if there was a difference in grade between the systematic biopsy and the MRI‐targeted biopsy, the risk of aggressive cancer was between the two grades.

MRI-Targeted Prostate Biopsy Introduces Grade Inflation and Overtreatment

“…The existing literature on targeted biopsy-induced grade inflation is mostly based on data available at diagnosis (pathology at biopsy and radical prostatectomy) and extrapolation into cohorts with virtually no prostate cancer mortality after benign or low-grade prostate cancer on systematic biopsy, even after an extended follow up [8,17]. While our results and empirical evidence support grade inflation, they are also in line with both the expert opinion raised in the literature [18,19] and with the available literature findings [14,[20][21][22]. Vickers 2021 [8] addressed the possibility of overtreatment related to the use of targeted biopsies.…”

“…Furthermore, there is accumulating data on the extent of Gleason pattern 4, total cancer length, PSA density, and perineural invasion determining adverse findings in RP and worse prognosis during follow-up. However, these studies were conducted mainly on systematic biopsy cohorts, and systematic biopsies and targeted biopsies are different and may predict oncologic risk differently[14]. Our results add to the notion that a more precise risk stratification among targeted biopsy-detected cancers is warranted.…”

Magnetic Resonance Imaging in Prostate Cancer Screening

“…However, several questions remain to be addressed in future investigations, including whether to use targeted-only biopsy, the optimal method for fusion biopsy, a comprehensive analysis of screening costs, and an examination of long-term survival outcomes. Furthermore, differences in oncologic risk profiles have been observed between PCa cases diagnosed via MRI-based targeted biopsy and those identified through standard biopsy methods . These findings underscore the need for further research to elucidate the behavior of PCas identified with MRI and targeted biopsy and their implications for treatment strategies.…”

External Validation of the IMPROD-MRI Volumetric Model to Predict the Utility of Systematic Biopsies at the Time of Targeted Biopsy

“…Despite the previously mentioned articles stating that TBx helps in detecting high-GG tumors that SBx fails to identify [1][2][3], a very recent study highlighted a very interesting issue about the oncological risk equivalence of positive target and systematic biopsy, supporting somehow the need of concomitant standard biopsy [23]. Gaffney et al retrospectively analyzed data from 991 patients who had both systematic and MRI-targeted biopsy before undergoing radical prostatectomy and showed that patients with higher GGG on TBx compared to SBx did not have the same level of oncologic risk as those with identical GGG on both biopsy methods.…”