BACKGROUND: Treatment progression for men on active surveillance (AS) for prostate cancer (PCa) is driven primarily by grade and volume progression on isolated prostate biopsies (PBx). As PCa is a multifocal disease, regional disease progression over time should be accounted for.
OBJECTIVE: To validate the utility of the cumulative cancer location (CCLO) metric, which assesses regional core involvement, as described by Erickson et al (Cumulative cancer locations is a novel metric for predicting active surveillance outcomes: a multicenter study. Eur Urol Oncol 2018;1:268-75), in predicting AS outcomes in a North American cohort.
DESIGN, SETTING, AND PARTICIPANTS: A single-institutional retrospective chart review of all AS patients evaluated between 2015 and 2017.
OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: CCLO defined as the total number of cancer-positive sextant locations among all PBx to that point in time (range 1-6). Baseline demographics and clinical characteristics of the entire cohort were stratified by CCLOΔ, defined as the difference between the first and the last CCLO. CCLOΔ then correlated with progression to treatment and treatment outcomes.
RESULTS AND LIMITATIONS: A total of 261 men met the inclusion criteria. Though the mean number of biopsies was slightly higher in the CCLOΔ 3-5 cohort than in the CCLOΔ 0-2 cohort (p = 0.006), mean AS follow-up time (3.3 yr) was not significantly different (p = 0.327). As CCLOΔ increased, the proportion of men remaining on AS decreased, while the proportion of men receiving treatment increased (p < 0.001). In men undergoing radical prostatectomy, a higher CCLOΔ was not associated with higher rates of Gleason 7-10 (p = 0.38) or pT3 (p = 0.52) disease. However, as CCLOΔ increased, upgrading from final PBx to RP pathology increased, while downgrading decreased (p = 0.12). In Kaplan-Meier analyses, lower CCLOΔ and lower initial cancer location scores were associated with the highest 5-yr treatment-free survival rates (p < 0.001).
CONCLUSIONS: Higher regional cancer core involvement is associated with higher rates of progression to treatment in AS patients. The CCLO metric is a potentially useful modality in stratifying AS patients among the North American cohort for treatment, while not compromising disease outcomes.
PATIENT SUMMARY: In the North American population, cumulative cancer-positive locations among biopsies can be used to predict active surveillance outcomes in men with prostate cancer.
Leong, Joon Yau; Capella, Courtney; Teplitsky, Seth; Gomella, Leonard G.; Trabulsi, Edouard J.; Lallas, Costas D.; and Chandrasekar, Thenappan, "Impact of Tumor Regional Involvement on Active Surveillance Outcomes: Validation of the Cumulative Cancer Location Metric in a US Population." (2019). Department of Urology Faculty Papers. Paper 51.
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