(UroToday.com) The 2023 American Urological Association (AUA) annual meeting held in Chicago, IL between April 28 and May 1st, 2023, was host to a late-breaking abstract oncology session. Dr. Shijie Jin presented the results of a systematic review and meta-analysis evaluating biochemical recurrence rates for patients with localized prostate cancer originating from the transition versus the peripheral zone.
The association between localized prostate cancer zonal origin and biochemical recurrence (BCR) outcomes remains controversial with numerous published studies in this disease space demonstrating conflicting results. The objective of this study was to conduct a meta-analysis of published articles comparing BCR of localized prostate cancer originating from the transition zone (TZ) versus peripheral zone (PZ).
The authors conducted systematic research of Medline, Embase, Scopus, Web of Science, and the Cochrane Library to identify all trials reporting on BCR of localized prostate cancer originating from the TZ and PZ. Study eligibility criteria included studies in which prostate cancer was pathologically confirmed, zonal origin was determined through MRI or pathological examination, and correlation of zonal origin with BCR was reported. Exclusion criteria included:
- Abstracts, letters, case reports, reviews, or nonclinical studies
- Non-English language reports
- Studies with insufficient data for estimating risk ratios (RR), odds ratio, hazard ratio, or 95% CI
- Duplicate data or repeat analysis
Study-specific summary measures were extracted for each study. BCR outcomes were pooled using fixed or random effects models and reported as RR and 95% CIs. Study heterogeneity was quantified using the I2 value. Substantial heterogeneity was defined as an I2 value >50%. Subgroup analysis was performed according to follow-up time, PSA levels, Newcastle–Ottawa Scale (NOS) score, and whether a multivariate or univariate Cox regression model was used. NOS score of 8 or higher was defined as being of high quality (i.e., low risk of bias).
The pooled analysis included 14 studies (16 cohorts) of 19,365 patients. The study flow chart is demonstrated below:
Included studies are summarized in the table below:
Of the 16 included cohorts in the analysis, 15/16 evaluated BCR post-RP and 1 was post-radiotherapy. The mean NOS score was 7.6. Pooled analysis of these 16 cohorts demonstrated a RR of 0.79 in favor of TZ lesions (95% CI: 0.69 – 0.92), with an I2 of 76.8%
On subgroup analyses, this association held true for:
- For studies with median follow-up time ≤60 months (RR: 0.65; 95%CI: 0.48 to 0.88) 56.8%)
- Median PSA <10ng/ml (RR: 0.68: 95% CI: 0.49 to 0.94)
- Median PSA >10ng/ml (RR: 0.91; 95% CI: 0.88 to 0.94)
- NOS score ≥ 8 (RR: 0.70: 95% CI: 0.62 to 0.80)
- Studies using a multivariate regression model (RR: 0.57; 95% CI: 0.48 to 0.69)
Assessment of publication bias did not demonstrate any evidence of clear publication bias in this disease space.
Dr. Shijie Jin acknowledged that this study is limited by the high observed between-study heterogeneity (high I2 value), use of summary measures as opposed to individual patient data, use of a non-standardized definition of TZ/PZ tumor, and poor external validity to clinical practice given that only one cohort evaluated BCR post-radiation therapy.
Dr. Shijie Jin concluded that:
- TZ tumors are associated with a lower risk of BCR when compared to PZ tumors (RR: 0.79, 95% CI: 0.69 – 0.92, I2=77%)
- This association held true in studies using multivariable regression analyses (RR: 0.57, 95% CI: 0.48 – 0.69, I2=23%).
- As such, TZ tumors may have different clinical profile,s and zonal origin is expected to be incorporated into existing classification systems
Presented by: Shijie Jin, MD, Department of General Surgery, Pecking Union Medical College Hospital, Beijing, China
Written by: Rashid K. Sayyid, MD, MSc – Society of Urologic Oncology (SUO) Clinical Fellow at The University of Toronto, @rksayyid on Twitter during the 2023 American Urological Association (AUA) Annual Meeting, Chicago, IL, April 27 – May 1, 2023