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Julie Hallet, Laura Davis, Alyson Mahar, Michail Mavros, Kaitlyn Beyfuss, Ying Liu, Calvin H.L. Law, Craig Earle, and Natalie Coburn

Background: Although pancreatic adenocarcinoma (PA) surgery performed by high-volume (HV) providers yields better outcomes, volume–outcome relationships are unknown for medical oncologists. This study examined variation in practice and outcomes in noncurative management of PA based on medical oncology provider volume. Methods: This population-based cohort study linked administrative healthcare datasets and included nonresected PA from 2005 through 2016. The volume of PA consultations per medical oncology provider per year was divided into quintiles, with HV providers (≥16 patients/year) constituting the fifth quintile and low-volume (LV) providers the first to fourth quintiles. Outcomes were receipt of chemotherapy and overall survival (OS). The Brown-Forsythe-Levene (BFL) test for equality of variances was performed to assess outcome variability between provider-volume quintiles. Multivariate regression models were used to examine the association between management by HV provider and outcomes. Results: A total of 7,062 patients with noncurable PA consulted with medical oncology providers. Variability was seen in receipt of chemotherapy and median survival based on provider volume (BFL, P<.001 for both), with superior 1-year OS for HV providers (30.1%; 95% CI, 27.7%–32.4%) compared with LV providers (19.7%; 95% CI, 18.5%–20.6%) (P<.001). After adjustment for age at diagnosis, sex, comorbidity burden, rural residence, income, and diagnosis period, HV provider care was independently associated with higher odds of receiving chemotherapy (odds ratio, 1.19; 95% CI, 1.05–1.34) and with superior OS (hazard ratio, 0.79; 95% CI, 0.74–0.84). Conclusions: Significant variation was seen in noncurative management and outcomes of PA based on provider volume, with management by an HV provider being independently associated with superior OS and higher odds of receiving chemotherapy. This information is important to inform disease care pathways and care organization. Cancer care systems could consider increasing the number of HV providers to reduce variation and improve outcomes.

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Elliott K. Yee, Natalie G. Coburn, Laura E. Davis, Alyson L. Mahar, Victoria Zuk, Vaibhav Gupta, Ying Liu, Craig C. Earle, and Julie Hallet

Background: Little is known about how the geographic distribution of cancer services may influence disparities in outcomes for noncurable pancreatic adenocarcinoma. We therefore examined the geographic distribution of outcomes for this disease in relation to distance to cancer centers. Methods: We conducted a retrospective population-based analysis of adults in Ontario, Canada, diagnosed with noncurable pancreatic adenocarcinoma from 2004 through 2017 using linked administrative healthcare datasets. The exposure was distance from place of residence to the nearest cancer center providing medical oncology assessment and systemic therapy. Outcomes were medical oncology consultation, receipt of cancer-directed therapy, and overall survival. We examined the relationship between distance and outcomes using adjusted multivariable regression models. Results: Of 15,970 patients surviving a median of 3.3 months, 65.6% consulted medical oncology and 38.5% received systemic therapy. Regions with comparable outcomes were clustered throughout Ontario. Mapping revealed regional discordances between outcomes. Increasing distance (reference, ≤10 km) was independently associated with lower likelihood of medical oncology consultation (relative risks [95% CI] for 11–50, 51–100, and ≥101 km were 0.90 [0.83–0.98], 0.78 [0.62–0.99], and 0.77 [0.55–1.08], respectively) and worse survival (hazard ratios [95% CI] for 11–50, 51–100, and ≥101 km were 1.08 [1.04–1.12], 1.17 [1.10–1.25], and 1.10 [1.02–1.18], respectively), but not with likelihood of receiving therapy. Receipt of therapy seems less sensitive to distance, suggesting that distance limits entry into the cancer care system via oncology consultation. Regional outcome discordances suggest inefficiencies within and protective factors outside of the cancer care system. Conclusions: These findings provide a basis for clinicians to optimize their practices for patients with noncurable pancreatic adenocarcinoma, for future studies investigating geographic barriers to care, and for regional interventions to improve access.

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Julie Hallet, Bourke Tillman, Jesse Zuckerman, Matthew P. Guttman, Tyler Chesney, Alyson L. Mahar, Wing C. Chan, Natalie Coburn, Barbara Haas, and members of the Recovery after Surgical Therapy for Older adults Research–Cancer (RESTORE-Cancer) Group

Background: Although frailty is known to impact short-term postoperative outcomes, its long-term impact is unknown. This study examined the association between frailty and remaining alive and at home after cancer surgery among older adults. Methods: Adults aged ≥70 years undergoing cancer resection were included in this population-based retrospective cohort study using linked administrative datasets in Ontario, Canada. The probability of remaining alive and at home in the 5 years after cancer resection was evaluated using Kaplan-Meier methods. Extended Cox regression with time-varying effects examined the association between frailty and remaining alive and at home. Results: Of 82,037 patients, 6,443 (7.9%) had preoperative frailty. With median follow-up of 47 months (interquartile range, 23–81 months), patients with frailty had a significantly lower probability of remaining alive and at home 5 years after cancer surgery compared with those without frailty (39.1% [95% CI, 37.8%–40.4%] vs 62.5% [95% CI, 62.1%–63.9%]). After adjusting for age, sex, rural living, material deprivation, immigration status, cancer type, surgical procedure intensity, year of surgery, and receipt of perioperative therapy, frailty remained associated with increased hazards of not remaining alive and at home. This increase was highest 31 to 90 days after surgery (hazard ratio [HR], 2.00 [95% CI, 1.78–2.24]) and remained significantly elevated beyond 1 year after surgery (HR, 1.56 [95% CI, 1.48–1.64]). This pattern was observed across cancer sites, including those requiring low-intensity surgery (breast and melanoma). Conclusions: Preoperative frailty was independently associated with a decreased probability of remaining alive and at home after cancer surgery among older adults. This relationship persisted over time for all cancer types beyond short-term mortality and the initial postoperative period. Frailty assessment may be useful for all candidates for cancer surgery, and these data can be used when counseling, selecting, and preparing patients for surgery.