Background: This study sought to ascertain whether there is an association between prostate cancer (PC)–specific mortality (PCSM) and timing of salvage androgen deprivation therapy (ADT) among men with short versus long prostate-specific antigen doubling times (PSA-DTs). Methods: The study cohort was selected from 206 men with localized unfavorable-risk PC randomized to radiation therapy (RT) or RT plus 6 months of ADT between 1995 and 2001. A total of 54 men who received salvage ADT for PSA failure after a median follow-up of 18.72 years following randomization defined the study cohort. The Fine-Gray competing risks regression model was used to analyze whether the timing of salvage ADT was associated with an increased risk of PCSM after adjusting for age, comorbidity, known PC prognostic factors, and previously identified interactions. Results: After a median follow-up of 5.68 years (interquartile range, 3.05–9.56) following salvage ADT, 49 of the 54 men (91%) died, of which 27 from PC (54% of deaths). Increasing PSA-DT as a continuous covariate (per month increase) was associated with a decreasing risk of PCSM (adjusted hazard ratio [HR], 0.33; 95% CI, 0.13–0.82; P=.02). Among men with a long PSA-DT (≥6 months), initiating salvage ADT later (PSA level >12 ng/mL, upper quartile) versus earlier was associated with an increased risk of PCSM (adjusted HR, 8.84; 95% CI, 1.99–39.27; P=.004), whereas for those with a short PSA-DT (<6 months; adjusted HR, 1.16; 95% CI, 0.38–3.54; P=.79) this was not true. Conclusions: Early initiation of salvage ADT for post-RT PSA failure in men with a PSA-DT of ≥6 months may reduce the risk of PCSM.
Brandon A. Mahal, Ming-Hui Chen, Andrew A. Renshaw, Marian J. Loffredo, Philip W. Kantoff and Anthony V. D'Amico
Nina N. Sanford, Todd A. Aguilera, Michael R. Folkert, Chul Ahn, Brandon A. Mahal, Herbert Zeh, Muhammad S. Beg, John Mansour and David J. Sher
Background: Adjuvant therapy for resected pancreatic adenocarcinoma was given a category 1 NCCN recommendation in 2000, yet many patients do not receive chemotherapy after definitive surgery. Whether sociodemographic disparities exist for receipt of adjuvant chemotherapy is poorly understood. Methods: The National Cancer Database was used to identify patients diagnosed with nonmetastatic pancreatic adenocarcinoma who underwent definitive surgery from 2004 through 2015. Multivariable logistic regression defined the adjusted odds ratio (aOR) and associated 95% CI of receipt of adjuvant chemotherapy. Among patients receiving chemotherapy, multivariable logistic regression assessed the odds of treatment with multiagent chemotherapy. Results: Among 18,463 patients, 11,288 (61.1%) received any adjuvant chemotherapy. Sociodemographic factors inversely associated with receipt of any adjuvant chemotherapy included uninsured status (aOR, 0.61; 95% CI, 0.50–0.74), Medicaid insurance (aOR, 0.66; 95% CI, 0.57–0.77), and lower income (P<.001 for all income levels compared with ≥$46,000). Black race (aOR, 0.72; 95% CI, 0.57–0.90) and female sex (aOR, 0.75; 95% CI, 0.65–0.86) were associated with lower odds of receiving multiagent chemotherapy. There was a statistically significant interaction term between black race and age/comorbidity status (P=.03), such that 26.4% of black versus 35.8% of nonblack young (aged ≤65 years) and healthy (Charlson-Deyo comorbidity score 0) patients received multiagent adjuvant chemotherapy (P=.006), whereas multiagent adjuvant chemotherapy rates were similar among patients who were not young and healthy (P=.15). Conclusions: In this nationally representative study, receipt of adjuvant chemotherapy appeared to be associated with sociodemographic characteristics, independent of clinical factors. Sociodemographic differences in receipt of adjuvant chemotherapy may represent a missed opportunity for improving outcomes and a driver of oncologic disparities.
Vinayak Muralidhar, Paul L. Nguyen, Brandon A. Mahal, David D. Yang, Kent W. Mouw, Brent S. Rose, Clair J. Beard, Jason A. Efstathiou, Neil E. Martin, Martin T. King and Peter F. Orio III
Background: Management of patients with a very high prostate-specific antigen (PSA) level (≥98.0 ng/mL) but clinically localized (N0M0) prostate cancer is challenging. This study sought to determine practice patterns and outcomes among these patients. Patients and Methods: A total of 748,825 patients with prostate cancer from 2004 through 2012 were identified using the National Cancer Database. These patients were subdivided by PSA level (0–9.9, 10.0–19.9, 20.0–39.9, 40.0–59.9, 60.0–79.9, 80.0–97.9, and ≥98.0 ng/mL), nodal status (N0 vs N1), and distant metastases (M0 vs M1). Rates of locoregional treatment and 5-year overall survival (OS) in each group were determined. Survival was compared using Cox regression after adjusting for multiple patient-specific factors. Results: The rate of locoregional treatment for patients with N0M0 disease and PSA level ≥98.0 ng/mL was significantly lower than for those with N1M0 disease (52.6% vs 60.4%; P<.001) or N0M0 disease and PSA level <98.0 ng/mL (52.6% vs 86.6%; P<.001). The 5-year OS rate was similar for patients with N1M0 disease and those with N0M0 disease and a very high PSA level (63.2% vs 59.1%; adjusted hazard ratio [aHR], 0.91; P=.063). The survival benefit associated with locoregional treatment was higher among those with N0M0 disease and a very high PSA level than among those with N1M0 disease (aHR, 0.28 vs 0.44; P<.001). Conclusions: Patients with clinical N0M0 disease and a very high PSA level (≥98.0 ng/mL) have outcomes similar to those with N1 disease but receive locoregional treatment at a lower rate. Future work is needed to investigate the utility of locoregional treatment in this population.
Alexander P. Cole, Chang Lu, Marieke J. Krimphove, Julie Szymaniak, Maxine Sun, Sean A. Fletcher, Stuart R. Lipsitz, Brandon A. Mahal, Paul L. Nguyen, Toni K. Choueiri, Adam S. Kibel, Adil H. Haider and Quoc-Dien Trinh
Background: Insurance coverage is associated with better cancer outcomes; however, the relative importance of insurance coverage may differ between cancers. This study compared the association between insurance coverage at diagnosis and cancer-specific mortality (CSM; insurance sensitivity) in 6 cancers. Patients and Methods: Using the SEER cancer registry, data were abstracted for individuals diagnosed with ovarian, pancreatic, lung, colorectal, prostate, or breast cancer in 2007 through 2010. The association between insurance coverage at diagnosis and CSM was modeled using a Fine and Gray competing-risks regression adjusted for demographics. An interaction term combining insurance status and cancer type was used to test whether insurance sensitivity differed between cancers. Separate models were fit for each cancer. To control for lead-time bias and to assess whether insurance sensitivity may be mediated by earlier diagnosis and treatment, additional models were fit adjusting for disease stage and treatment. Results: Lack of insurance was associated with an increased hazard of CSM in all cancers (P<.01). The magnitude of the effect differed significantly between cancers (P interaction=.04), ranging from an adjusted hazard ratio of 1.13 (95% CI, 1.01–1.28) in ovarian and 1.19 (95% CI, 1.11–1.29) in pancreatic cancer to 2.19 (95% CI, 2.02–2.37) in breast and 2.98 (95% CI, 2.54–3.49) in prostate cancer. The benefit of insurance was attenuated after adjusting for stage and treatment (eg, screening/early treatment effect), with the largest reductions in prostate, breast, and colorectal cancers. Conclusions: Greater insurance sensitivity was seen in screening-detected malignancies with effective treatments for early-stage disease (eg, prostate, breast, and colorectal cancers). Given that this differential is significantly reduced after adjusting for stage and treatment, our results suggest that a significant portion (but not all) of the benefit of insurance coverage is due to detection and treatment of certain curable early-stage cancers.
Vinayak Muralidhar, Paul J. Catalano, Gally Reznor, Brandon A. Mahal, Toni K. Choueiri, Christopher J. Sweeney, Neil E. Martin, Clair J. Beard, Yu-Wei Chen, Michelle D. Nezolosky, Karen E. Hoffman, Felix Y. Feng, Quoc-Dien Trinh and Paul L. Nguyen
Background: The current NCCN Clinical Practice Guidelines in Oncology for Prostate Cancer recommend long-term androgen deprivation therapy (ADT) for all men with high-risk prostate cancer treated with external-beam radiation therapy (EBRT). We determined whether the use of long-term ADT varied by the recently defined subcategories of high-risk disease (favorable, other, and very high) versus unfavorable intermediate-risk disease. Methods: We identified 5,524 patients with unfavorable-risk prostate cancer diagnosed from 2004 to 2007 and managed with EBRT using the SEER-Medicare linked database. Patients were stratified by risk group: unfavorable intermediate-risk, favorable high-risk (previously defined and validated as clinical stage T1c, Gleason score of 4 + 4 = 8, and prostate-specific antigen [PSA] level <10 ng/mL, or clinical stage T1c, Gleason score of 6, and PSA level >20 ng/mL), very-high-risk (clinical stage T3b–T4 or primary Gleason pattern 5), or other high risk (ie, neither favorable nor very high). We used multivariable competing risks regression to estimate the rates of long-term (≥2 years) ADT by group. Results: Men with favorable high-risk prostate cancer were significantly less likely to receive long-term ADT than those with other high-risk disease (15.4% vs 24.6%, adjusted hazard ratio [AHR], 0.68; 95% CI, 0.60–0.76; P<.001), and similarly likely as those with unfavorable intermediate-risk disease (AHR, 1.10; 95% CI, 0.99–1.23; P=.087). Other high-risk disease was less likely to receive long-term ADT than very high-risk cancer (24.6% vs 30.8%; AHR, 0.83; 95% CI, 0.74–0.93; P=.002). Conclusions: Despite current guidelines, patients with EBRT-managed high-risk prostate cancer received significantly different rates of long-course ADT based on subclassification. Our results suggest that oncologists view these patients as a heterogeneous group with favorable high-risk cancer warranting less aggressive therapy than other high-risk or very high-risk disease.