Long-term Outcomes Following Active Surveillance of Low-grade Prostate Cancer: A Population-based Study Using a Landmark Approach.

PURPOSE: Active surveillance is widely used to manage low-risk prostate cancer, but population-level long-term outcomes are limited. Our objective was to determine long-term population-level oncological outcomes in active surveillance patients. A secondary objective examined the active surveillance discontinuation rate. MATERIALS AND METHODS: In this retrospective, population-based study using linked administrative databases from Ontario, Canada, we identified low-grade prostate cancer patients managed with active surveillance or initial treatment between 2002-2014. The 10- and 15-year metastasis-free survival, overall survival, and cancer-specific survival were compared between active surveillance and initial treatment. A landmark of 24 months was selected for the primary analysis. Long-term outcomes were examined using multivariable proportional hazards models and a propensity-based approach. RESULTS: The cohort consisted of 21,282 low-grade prostate cancer patients with a median follow-up of 9.8 years. At 10-year follow-up the survival rate of remaining on active surveillance was 39%, metastasis-free survival was 94.2%, overall survival 88.7%, and cancer-specific survival 98.1%. In adjusted models active surveillance was associated with higher risk of metastasis (HR 1.34, 95%CI 1.15-1.57), overall mortality (HR 1.12, 95%CI 1.01-1.24), and prostate cancer-specific mortality (HR 1.66, 95%CI 1.15-2.39) compared to initial treatment. Survival analysis using 7,525 propensity-matched pairs was consistent with the primary analysis for metastasis-free survival, overall survival and cancer-specific survival. CONCLUSIONS: In this large population-based study of long-term outcomes in men with low-grade prostate cancer, active surveillance is associated with excellent long-term metastasis-free survival and overall survival. However, long-term cancer-specific survival was slightly inferior (1% worse at 10 years with active surveillance), and this must be balanced against known harms of overtreatment.

Opioid Use After Nephrectomy for Kidney Cancer in Ontario: A Population-Based Study.

OBJECTIVE: To compare the odds of early and prolonged post-operative opioid use in patients undergoing minimally invasive surgery (MIS) vs open surgery for nephrectomy. METHODS: For opioid-naïve patients in Ontario who underwent nephrectomy for kidney cancer (1994-2017, n = 7900), post-discharge opioid use was determined by prescriptions in the Ontario Drug Benefit database (age ≥65 years) and the Narcotics Monitoring System (all patients from 2012). Early opioid use was defined as ≥1 prescription 1-90 days after surgery. Two separate definitions of prolonged opioid use were examined: (1) prescription(s) for ≥60 days during post-operative days 90-365; (2) ≥1 prescriptions between both of: 1-90 days AND 91-180 days after surgery. Predictors of opioid use were assessed using multivariable generalized estimating equation logistic regression, accounting for surgeon clustering. RESULTS: Overall, 67.4% of patients received early opioid prescriptions; however, prolonged use was low, ranging from 1.6 to 4.4% of patients depending on the definition. In multivariable analysis, open nephrectomy was associated with higher odds of early opioid use compared to MIS nephrectomy (Odds Ratio [OR] 1.36, 95% Confidence Interval [CI] 1.19-1.55). Surgery type was not significantly associated with prolonged opioid use for either definition (OR 1.22, CI 0.79-1.89 and OR 1.06, CI 0.83-1.35). CONCLUSIONS: In this population-level study of patients undergoing nephrectomy for kidney cancer, patients who received open surgery were at increased odds of receiving early post-operative opioids compared to MIS. Prolonged opioid use was low overall and was not significantly with associated with type of surgery.

Factors Associated with Discontinuation of Active Surveillance among Men with Low-Risk Prostate Cancer: A Population-Based Study.

PURPOSE: The purpose of this study was to describe the uptake, discontinuation and variation of active surveillance (AS) by provider and patient level characteristics. MATERIALS AND METHODS: This observational, population-based study used linked administrative databases and pathology reports to identify all men diagnosed with Gleason score ≤6 prostate cancer (PC) between January 1, 2008 and December 31, 2014 in Ontario, Canada. The Cochran-Armitage test was used for AS trend over time. Treatment-free survival was estimated using cumulative incidence function. Factors associated with discontinuation of AS were evaluated using Cox proportional hazard models. RESULTS: Active surveillance was the initial management strategy for 8,541 cases (51%). Use of AS significantly increased from 38% in 2008 to 69% in 2014 (p=0.001). Men on AS were significantly older (64 years, SD 8.0) than those on initial treatment (62 years, SD 7.7; p=0.001). After a median followup of 48 months, 4,337 (51%) patients had discontinued AS. Treatment-free survival for AS patients at 1, 3, and 5 years were 85%, 58% and 52%, respectively. Median time to definitive treatment after initial AS was 16 months (IQR 11-25 months). Factors associated with AS discontinuation were younger age at diagnosis, year of diagnosis, higher comorbidities, treatment at academic center, treatment by physician and institution in the highest volume tertile, and adverse cancer-specific characteristics (higher prostate specific antigen [PSA], higher number of positive cores and higher percentage of core involvement at diagnosis). CONCLUSIONS: Although the uptake of AS significantly increased over time, there has been a relatively high rate of discontinuation over 5 years. Factors associated with transition to definitive treatment were younger age, care provided by higher volume physicians and institutions, higher PSA and greater PC volume at diagnosis. These results may help guide policy making, developing quality indicators, and developing targeted continued education for physician and patients embarking on AS to establish realistic expectations.

Real-World Practice Patterns and Predictors of Continuous versus Intermittent Androgen Deprivation Therapy Use for Prostate Cancer in Older Men.

PURPOSE: Phase-III randomized control trial evidence suggests intermittent androgen deprivation therapy (IADT) is not significantly inferior to continuous androgen deprivation therapy (ADT) for patients with prostate cancer (PC). However, clinical practice and guidelines differ in their recommendations. We evaluate real-world utilization and practice patterns of IADT. MATERIALS AND METHODS: Ontario men ≥65 years of age with PC who initiated ADT for ≥3 months were identified (1997-2017). Lapses in ADT ≥6 months (initial gap) and ≥3 months (subsequent gaps) were used to classify IADT. Neoadjuvant/adjuvant therapy was excluded. Disease stage adjustment was completed for patients with likely metastatic disease based on de novo presentation with ADT. Patient and physician predictors of IADT were analyzed using multivariable logistic regression. RESULTS: We identified 8,544 patients with 1,715 having previously received local therapy. Among all patients, 16.4% received IADT. This ranged from 11.4%-24.8% across health-planning regions and increased to 26.6% in those with previous local therapy. Mean followup was 8.3 years. Patients with prior local therapy (OR 1.85, 95% CI 1.59-2.17, p <0.001) and those in the highest income quintile (OR 1.32, 95% CI 1.08-1.60, p=0.005) had increased odds of receiving IADT. Radiation oncologists were more likely to use IADT than urologists (OR 1.99, 95% CI 1.59-2.50, p <0.001), as were physicians with more experience (≥10 years in practice: OR 1.44, 95% CI 1.11-1.88, p=0.007). In specialty-stratified analyses, case volume was significantly associated with IADT for radiation oncologists (highest quartile: OR 1.73, 95% CI 1.14-2.62, p=0.009). CONCLUSIONS: IADT remains underutilized for patients with PC who ≥65 years of age with only 1 in 4 to 1 in 6 eligible patients receiving this form of care. Clinical, sociodemographic and physician characteristics play an important role in treatment selection.