Socioeconomic disparities in the receipt of radiation for node-positive prostate cancer

53 Background: Radiation therapy in the setting of node-positive prostate cancer has been controversial, although some recent data suggests a survival benefit to radiation in this setting. We evaluated socioeconomic disparities in the receipt of radiation for node-positive prostate cancer to identify groups that may be less likely to receive this potentially life-saving treatment. Methods: We identified 3,283 patients with N1M0 prostate cancer diagnosed 1982-2011 using the Surveillance, Epidemiology, and End Results database who were treated with radiation or no local therapy. We conducted multivariable logistic regression to determine socioeconomic predictors of not receiving radiation treatment. Results: Several patient and demographic factors were associated with a reduced likelihood of receiving radiation: African American (AA) vs non-AA race (31.7% vs. 37.7%, adjusted odds ratio [AOR] 0.74, p = 0.012); unmarried vs married status (31.9% vs 38.6%, AOR 0.72, p < 0.001); bottom third vs top third in income level (33.7% vs. 39.8%, AOR 0.72, p < 0.001); age over 65 versus < = 65 years (34.6% vs 39.8%, AOR 0.81, p = 0.005); diagnosis before 2000 versus starting in 2000 (31.6% vs 43.5%, AOR 0.56, p < 0.001). In a separate analysis, patients under the age of 65 who had Medicaid or no insurance were less likely than patients with other insurance to receive radiation (43.5% vs 55.9%, OR 0.61, p = 0.041), although on multivariable analysis, no significant association persisted (p = 0.512). Conclusions: African American race, unmarried status, lower income level, older age, and insurance status were all associated with significantly reduced odds of receiving radiation therapy for node-positive prostate cancer compared with no local therapy. Given the accumulating data suggesting that radiation therapy can improve survival in node-positive patients, it is increasingly important to understand the reasons for these treatment disparities so that they can be reduced

Can pelvic lymph node dissection be omitted in intermediate-risk prostate cancer patients? A SEER-based comparative study using inverse-probability-of-treatment weighting

95 Background: To investigate whether pelvic lymph node dissection (PLND) reduces prostate cancer specific mortality (PCSM) in surgically-treated men with intermediate-risk prostate cancer (Pca). Methods: We identified 44,112 men diagnosed with intermediate-risk Pca from 2004-2009 in Surveillance, Epidemiology and End Results Program (SEER). We used inverse-probability-of-treatment weighting (IPTW) to adjust for baseline characteristics between PLND + radical prostatectomy (RP, N=26,571), versus RP alone (N=17,541) groups; Cox competing-risk model and propensity score-adjusted analyses were used for validation. Gleason scores were based on prostatectomy since biopsy scores were not available for RP-treated patients in SEER from 2004-2009. Results: After a median follow-up of 54 months, there was no survival benefit associated with PLND + RP compared to RP alone (Gray's test, P=0.30). After IPTW adjustment for baseline characteristics, PLND was still not associated with PCSM (AHR: 0.93, 95% CI: 0.65-1.33). This result was consistent with propensity score-adjusted model (AHR=1.05, 95% CI: 0.71-1.55) and the Cox competing-risk model (AHR=1.06, 95% CI: 0.71-1.57). Of men who received RP with PLND, 502 men (1.9%) had pathologically positive lymph nodes, which were associated with a higher risk for PCSM (AHR: 4.02, 95%CI: 1.83-8.84). Conclusions: PLND with RP was not associated with reduced PCSM compared with RP alone in men with intermediate-risk disease, suggesting that PLND is diagnostic but not therapeutic in this patient population. However, a caveat of this study is that risk group was defined by pathologic Gleason score; the 5% of clinically intermediate risk patients who are typically found to have Gleason 8-10 disease at prostatectomy could not be included in this analysis. [Table: see text

National predictors and trends for androgen deprivation therapy use in low-risk prostate cancer

50 Background: Androgen deprivation therapy (ADT) is not recommended for low-risk prostate cancer due to its known harms and lack of benefits. We evaluated the incidence and predictors of ADT use in men with low-risk prostate cancer. Methods: We identified 197,980 patients in the National Cancer Database (NCDB) with low-risk prostate cancer (Gleason 3+3 = 6, PSA < 10ng/mL, and cT1-T2a) diagnosed from 2004 to 2012 with complete demographic and treatment information. We determined the incidence of ADT use and utilized multiple logistic regression to evaluate predictors of ADT use. Results: ADT use in low-risk prostate cancer patients declined steadily from 2004 to 2012 (17.6% vs. 3.5%). 80.6% of these patients underwent radiation, and 10.0% received ADT as primary therapy. Among 82,354 low-risk disease patients treated with radiation, demographic and treatment factors associated with increased likelihood of ADT use include older age (adjusted odds ratio [AOR] 1.04 per year, p < 0.001); Hispanic vs. non-Hispanic white ethnicity (18.9% vs. 17.8%, AOR 1.26, p < 0.001); having Medicare at age < 65 (15.3%, AOR 1.14, p = 0.008) or Medicare at age ≥ 65 (21.5%, AOR 1.11, p < 0.001) vs. private insurance (13.9%); having bottom quartile vs. top quartile income (19.4% vs. 16.3%, AOR 1.26, p < 0.001); being treated in a community cancer program (22.0%, AOR 1.60, p < 0.001) or a comprehensive community cancer program (18.7%, AOR 1.38, p < 0.001) vs. an academic/research cancer program (13.9%); and receiving brachytherapy vs. external beam radiation therapy (19.3% vs. 15.5%, AOR 1.32, p < 0.001). Increasing distance from the treatment facility was associated with decreased likelihood of receiving ADT (AOR 0.97 for every 100 miles, p = 0.001). Conclusions: Among men with low-risk prostate cancer, increasing age, Hispanic ethnicity, Medicare insurance, lower income level, treatment in a non-academic/research cancer program, and brachytherapy use were all associated with increased odds of receiving ADT. Given the lack of evidence supporting ADT use in low-risk disease and increasing evidence of its many side-effects, it is critical to understand why low-risk prostate cancer patients are still receiving ADT so that this practice may be reduced

Impact of percent positive biopsy cores on cancer-specific mortality for patients with high-risk prostate cancer

78 Background: A high percent positive biopsy cores (PBC), typically dichotomized at ≥50%, is prognostic of worse cancer-specific outcomes for patients with low- and intermediate-risk prostate cancer. The prognostic value of ≥50% PBC for patients with high-risk disease is poorly understood. We examined the association between ≥50% PBC and prostate cancer-specific mortality (PCSM) for patients with high-risk prostate cancer. Methods: We identified 7,569 men from the Surveillance, Epidemiology, and End Results program who were diagnosed with high-risk prostate cancer (Gleason 8-10, prostate-specific antigen > 20 ng/mL, or cT3-T4 stage without evidence of nodal or metastatic disease) in 2010 or 2011 and had 6-24 cores sampled at biopsy. Multivariable Fine and Gray competing risks regression was utilized to examine the association between ≥50% PBC and PCSM, with adjustments for sociodemographic and clinicopathologic factors. Results: Median follow-up was 3.8 years (interquartile range 3.3-4.3 years). 56.2% of patients (4,253) had ≥50% PBC. The 4-year unadjusted cumulative incidences of PCSM were 2.0% (95% confidence interval [CI] 1.5-2.6%) and 5.6% (95% CI 4.9-6.4%) for patients with < 50% and ≥50% PBC, respectively. On multivariable analysis, the presence of ≥50% PBC was associated with a significantly higher risk of PCSM (adjusted hazard ratio [AHR] 1.95, 95% CI 1.43-2.66, P< 0.001). On subgroup analysis, ≥50% PBC was associated with a significantly higher risk of PCSM only for cT1-T2 disease (AHR 2.21, 95% CI 1.59-3.07, P< 0.001) but not cT3-T4 disease (AHR 0.77, 95% CI 0.33-1.81, P= 0.547), with a significant interaction ( Pinteraction= 0.012). Conclusions: In this large, contemporary cohort of patients with high-risk prostate cancer, ≥50% PBC was independently associated with a two-fold increased risk of PCSM for patients with cT1-T2, but not cT3-T4, tumors. Percent PBC should be used to routinely risk stratify men with high-risk disease and identify patients who may benefit from intensification of therapy, such as adding docetaxel or abiraterone to radiotherapy with androgen deprivation therapy, to optimize cancer-specific outcomes

Incidence and predictors of prostate cancer death in men with other prior malignancies: An analysis from SEER Database

34 Background: Men with cancer are screened 22% more for prostate cancer (PCa) than men without cancer, yet very little has been published on their prostate cancer outcomes. We aim to describe PCa death and clinical factors associated with dying from PCa in this population. Methods: We studied 22,769 men in the Surveillance, Epidemiology, and End Results database diagnosed with PCa as a second cancer from 1973 to 2006. Proportions of PCa death versus primary-cancer death were calculated, stratified by the nine primary cancers with highest incidence among US men and then further stratified by PCa grade and interval between primary and PCa diagnoses. Results: Urinary-bladder (30.4%), colorectal (27.9%) and lung cancer (10.5%) were the most common primary cancers. Overall, 12.4% of men died from PCa. A greater proportion of patients died from PCa than their first cancer with primary melanoma (11.7 vs 6.97%) and oral cavity/pharynx cancer (15.3 vs 6.98%), a similar proportion for colorectal (14.8% vs 13.7%) and kidney/renal pelvis cancer (11.1 vs 12.7%), but a lower proportion for lung (11.3 vs 42.1%) and bladder cancer (10.8 vs 17.4%). When the interval between cancer diagnoses was more than 5 years, PCa was the leading cause of death for five of the nine cancers. Patients who died from PCa compared to those who died from their primary had higher baseline PSA (39.5 vs 16.9 ng/mL, p<0.001), more Gleason 8-10 (36.7 vs 18.2%, p<0.001), more N1/M1 PCa (2.35 vs 0.30%, p<0.001), were older at PCa diagnosis (74.7 vs 71.9 years, p=0.015), and had a longer interval between diagnoses (63.9 vs 28.8 months, p<0.001). Conclusions: PCa remains a significant cause of mortality when diagnosed as a second cancer, especially if the interval from prior cancer is greater than 5 years, suggesting that treatment of aggressive prostate cancer may be reasonable for many patients with prior cancers

Low rates of androgen deprivation therapy use with salvage radiation therapy in patients with prostate cancer after radical prostatectomy

The RTOG 9601 and GETUG-AFU 16 randomized controlled trials demonstrated that the addition of androgen deprivation therapy (ADT) to salvage radiation therapy (SRT) improves progression-free and, for RTOG 9601, overall survival. We examined national trends in the use of ADT with SRT. Of the 484,009 patients in the National Cancer Database from 2004 to 2012 with localized or locally advanced prostate cancer treated with radical prostatectomy (RP), 4,200 men received SRT (≥6mo after surgery). We used Pearson’s chi-squared test to evaluate changes in ADT use, and multiple logistic regression to examine predictors of ADT use. Overall, 32.1% of SRT patients received ADT, which increased after initial results of RTOG 9601 showed an improvement in metastasis-free survival in 2010 (28.5% in 2008/2009 vs. 34.5% in 2011/2012, P = 0.006). Predictors of ADT use include presurgery prostate-specific antigen>20ng/ml vs.<10ng/ml (adjusted odds ratio [AOR] = 1.34, P = 0.002; 36.7% vs. 29.6%); positive vs. negative margins (AOR = 1.29, P = 0.001; 34.9% vs. 27.8%); Gleason 3+4 (AOR = 1.53; 21.3%), Gleason 4+3 (AOR = 2.40; 32.0%), or Gleason 8 to 10 (AOR = 4.49; 49.2%) vs. Gleason 2 to 6 (P≤0.005 for all; 13.2%); and pathologic T3a (AOR = 1.46; 30.9%), T3b (AOR = 2.50; 47.6%), or T4 (AOR = 4.14; 60.9%) vs. T2 (P<0.001 for all; 19.1%). Starting SRT 12 to 23.9 months (AOR = 0.69; 23.2%) or≥24 months (AOR = 0.25; 8.0%) after RP was associated with decreased odds of ADT use vs. starting SRT 6 to 8.9 months after RP (P≤0.002 for both; 35.0%). Although less than one-third of SRT patients from the study era received ADT, there is evidence that physicians and patients have begun slowly adopting this practice with the 2010 reporting of a decrease in the cumulative incidence of metastases with the addition of ADT to SRT. Given the newly reported survival benefit of RTOG 9601, additional work will be necessary to identify which patients benefit the most from the use of ADT with SRT to individualize treatment. •We studied trends in androgen deprivation therapy (ADT) use with salvage radiation.•From 2004 through 2012, 32.1% of salvage radiation patients received ADT.•ADT use rose to 6% with the 2010 reporting of a metastasis benefit by RTOG 9601.•Higher Gleason score, pT3–4 stage, and positive margins were predictors of ADT use

National Trends and Predictors of Androgen Deprivation Therapy Use in Low-Risk Prostate Cancer

Androgen deprivation therapy (ADT) is not recommended for low-risk prostate cancer because of its lack of benefit and potential for harm. We evaluated the incidence and predictors of ADT use in low-risk disease. Using the National Cancer Database, we identified 197,957 patients with low-risk prostate cancer (Gleason score of 3 + 3 = 6, prostate-specific antigen level <10 ng/mL, and cT1-T2a) diagnosed from 2004 to 2012 with complete demographic and treatment information. We used multiple logistic regression to evaluate predictors of ADT use and Cox regression to examine its association with all-cause mortality. Overall ADT use decreased from 17.6% in 2004 to 3.5% in 2012. In 2012, 11.5% of low-risk brachytherapy patients and 7.6% of external beam radiation therapy patients received ADT. Among 82,352 irradiation-managed patients, predictors of ADT use included treatment in a community versus academic cancer program (adjusted odds ratio [AOR], 1.60; 95% confidence interval [CI], 1.50-1.71; P<.001; incidence, 14.0% vs 6.0% in 2012); treatment in the South (AOR, 1.51), Midwest (AOR, 1.81), or Northeast (AOR, 1.90) versus West (P<.001); and brachytherapy use versus external beam radiation therapy (AOR, 1.32; 95% CI, 1.27-1.37; P<.001). Among 25,196 patients who did not receive local therapy, predictors of primary ADT use included a Charlson-Deyo comorbidity score of ≥2 versus 0 (AOR, 1.42; 95% CI, 1.06-1.91; P=.018); treatment in a community versus academic cancer program (AOR, 1.61; 95% CI, 1.37-1.90; P<.001); and treatment in the South (AOR, 1.26), Midwest (AOR, 1.52), or Northeast (AOR, 1.28) versus West (P≤.008). Primary ADT use was associated with increased all-cause mortality in patients who did not receive local therapy (adjusted hazard ratio, 1.28; 95% CI, 1.14-1.43; P<.001) after adjustment for age and comorbidity. ADT use in low-risk prostate cancer has declined nationally but may remain an issue of concern in certain populations and regions