Primary Treatment Modification and Treatment Tolerability Among Older Chemotherapy Recipients With Advanced Cancer.

Importance: Older adults with advanced cancer are less likely to tolerate treatment with cytotoxic chemotherapy compared with younger patients due to their aging-related conditions. Hence, oncologists sometimes opt to employ primary treatment modifications (deviation from standard of care) during the first cycle of chemotherapy. Objective: To examine the association between primary treatment modification and treatment tolerability in older adults with advanced cancer who were starting new palliative chemotherapy regimens. Design, Setting, and Participants: This cohort study was a secondary analysis of the GAP70+ (Geriatric Assessment Intervention for Reducing Toxicity in Older Patients with Advanced Cancer) trial, which was conducted between July 2014 and March 2019. The GAP70+ trial included patients aged 70 years or older who had advanced (ie, incurable) cancer, had 1 or more geriatric assessment domain impairments, and planned to start a new palliative chemotherapy regimen. Data analysis was conducted in November 2022. Exposures: Receipt of standard-of-care chemotherapy regimens vs primary treatment modification defined as any change from National Comprehensive Cancer Network guidelines or published clinical trials (eg, primary dose reduction, schedule change). Main Outcomes and Measures: Tolerability outcomes were assessed within 3 months of treatment. These outcomes included the following: (1) any grade 3 to 5 toxic effect, according to the National Cancer Institute Common Terminology Criteria for Adverse Events; (2) patient-reported functional decline, defined as the development of worse dependency in activities of daily living using scale scores; and (3) a composite adverse outcome (an end point that combined toxic effects, functional decline, and 6-month overall survival). Multivariable cluster-weighted generalized estimating equation models examined the association between primary treatment modification and outcomes adjusting for covariates. Results: This study included 609 patients with a mean (SD) age of 77.2 (5.2) years; more than half (333 [54.7%]) were men. Race and ethnicity was available for 607 patients: 39 (6.4%) were Black, 539 (88.5%) were non-Hispanic White, and 29 (4.8%) were of other race or ethnicity. Nearly half (281 [46.1%]) received a primary modified treatment regimen. The most common cancer types were gastrointestinal cancer (228 [37.4%]) and lung cancer (174 [28.6%]). In multivariable analysis, primary treatment modification was associated with a reduced risk of grade 3 to 5 toxic effects (relative risk [RR], 0.85 [95% CI, 0.77-0.94]) and functional decline (RR, 0.80 [95% CI, 0.67-0.95]). Patients who received primary treatment modification had 32.0% lower odds of having a worse composite adverse outcome (odds ratio, 0.68 [95% CI, 0.48-0.97]). Conclusions and Relevance: In this cohort study, primary treatment modification was associated with improved tolerability of chemotherapeutic regimens among older adults with advanced cancer and aging-related conditions. These findings may help optimize cancer treatment dosing in older adults with advanced cancer and aging-related conditions.

Visualizing External Validity: Graphical Displays to Inform the Extension of Treatment Effects from Trials to Clinical Practice.

BACKGROUND: In the presence of effect measure modification, estimates of treatment effects from randomized controlled trials may not be valid in clinical practice settings. The development and application of quantitative approaches for extending treatment effects from trials to clinical practice settings is an active area of research. METHODS: In this article, we provide researchers with a practical roadmap and four visualizations to assist in variable selection for models to extend treatment effects observed in trials to clinical practice settings and to assess model specification and performance. We apply this roadmap and visualizations to an example extending the effects of adjuvant chemotherapy (5-fluorouracil vs. plus oxaliplatin) for colon cancer from a trial population to a population of individuals treated in community oncology practices in the United States. RESULTS: The first visualization screens for potential effect measure modifiers to include in models extending trial treatment effects to clinical practice populations. The second visualization displays a measure of covariate overlap between the clinical practice populations and the trial population. The third and fourth visualizations highlight considerations for model specification and influential observations. The conceptual roadmap describes how the output from the visualizations helps interrogate the assumptions required to extend treatment effects from trials to target populations. CONCLUSIONS: The roadmap and visualizations can inform practical decisions required for quantitatively extending treatment effects from trials to clinical practice settings.

Introducing longitudinal cumulative dose to describe chemotherapy patterns over time: Case study of a colon cancer trial.

Adjuvant chemotherapy regimens take months to complete. Despite this, studies evaluate chemotherapy adherence via measures assessed at the end of treatment (eg, number of patients missing any dose, relative dose intensity [RDI]). This approach ignores information like the timing of treatment delays. We propose longitudinal cumulative dose (LCD) to integrate impacts of dose reductions, missed doses and dose delays over time. We obtained data from the 2246 participants in the MOSAIC trial randomized to FOLFOX (all three agents) or 5-FU/LV (only 5-fluorouracil and leucovorin). We evaluated proportions of patients stopping treatment early and reducing, missing or delaying a dose in each arm for each chemotherapy agent at each cycle. We calculated LCD, the fraction of the final standard dose a participant reached by a given day, for each participant and each agent and compared it over time and at 24 weeks between treatment arms. Participants randomized to FOLFOX were more likely to stop treatment, reduce doses, miss doses or delay cycles; these differences increased over time. Median LCD for oxaliplatin in the FOLFOX arm at 24 weeks was 77%. The LCD for 5-fluorouracil differed between arms (FOLFOX arm median: 81%; 5-FU/LV arm median: 96%). Visualizing LCD highlighted the timing of deviations from standard administration in a way RDI could not, with major differences in 5-fluorouracil LCD across treatment arms beginning after the sixth dose. Further evaluation of LCD and its impacts on clinical outcomes may clarify mechanisms for heterogeneous patient outcomes.

Effectiveness of adjuvant FOLFOX vs 5FU/LV in adults over age 65 with stage II and III colon cancer using a novel hybrid approach.

PURPOSE: Estimates of cancer therapy effects can differ in clinical trials and clinical practice, partly due to underrepresentation of certain patient subgroups in trials. We utilize a hybrid approach, combining clinical trial and real-world data, to estimate the comparative effectiveness of two adjuvant chemotherapy regimens for colon cancer. METHODS: We identified patients aged 66 and older enrolled in the Multicenter International Study of Oxaliplatin/5FU-LV in the Adjuvant Treatment of Colon Cancer. Similar patients were identified in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, initiating adjuvant chemotherapy with either 5-fluorouracil (5FU) alone or in combination with oxaliplatin (FOLFOX). We used logistic regression to estimate the likelihood of trial enrollment as a function of age, sex, and substage. Using inverse odds of sampling weights (IOSW), we compared 5-year mortality in patients randomized to FOLFOX vs 5FU using weighted Cox proportional hazards regression, the Nelson-Aalen estimator for cumulative hazards, and bootstrapping for 95% confidence intervals (CIs). RESULTS: There were 690 trial participants and 3834 SEER-Medicare patients. The SEER-Medicare population was older and had a higher proportion of stage IIIB and IIIC patients than the trial. After controlling for differences between populations, the IOSW 5-year HR was 1.21 (0.89, 1.65), slightly farther from the null than the trial estimate (HR = 1.14, 95%CI: 0.87, 1.49). CONCLUSIONS: This study supports mounting evidence of little to no incremental reduction in 5-year mortality for FOLFOX vs 5FU in older adults with stage II-III colon cancer, emphasizing the importance of combining clinical trial and real-world data to support such conclusions.

Use of High-Cost Cancer Treatments in Academic and Nonacademic Practice.

BACKGROUND: Academic physicians, such as those affiliated with National Cancer Institute (NCI)-designated Comprehensive Cancer Centers, may have different practice patterns regarding the use of high-cost cancer drugs than nonacademic physicians. MATERIALS AND METHODS: For this cohort study, we linked cancer registry, administrative, and demographic data for patients with newly diagnosed cancer in North Carolina from 2004 to 2011. We selected cancer types with multiple U.S. Food and Drug Administration-approved, National Comprehensive Cancer Network-recommended treatment options and large differences in reimbursement between higher-priced and lower-priced options (stage IV colorectal, stage IV lung, and stage II-IV head-and-neck cancers). We assessed whether provider's practice setting-NCI-designated Comprehensive Cancer Center ("NCI") versus other location ("non-NCI")-was associated with use of higher-cost treatment options. We used inverse probability of exposure weighting to control for patient characteristics. RESULTS: Of 800 eligible patients, 79.6% were treated in non-NCI settings. Patients treated in non-NCI settings were more likely to receive high-cost treatment than patients treated in NCI settings (36.0% vs. 23.2%), with an unadjusted prevalence difference of 12.7% (95% confidence interval [CI], 5.1%-20.0%). After controlling for potential confounding factors, non-NCI patients remained more likely to receive high-cost treatment, although the strength of association was attenuated (adjusted prevalence difference, 9.6%; 95% CI -0.1%-18.7%). Exploratory analyses suggested potential heterogeneity across cancer type and insurance status. CONCLUSION: Use of higher-cost cancer treatments may be more common in non-NCI than NCI settings. This may reflect differential implementation of clinical evidence, local practice variation, or possibly a response to the reimbursement incentives presented by chemotherapy billing. IMPLICATIONS FOR PRACTICE: Oncology care delivery and practice patterns may vary between care settings. By comparing otherwise similar patients treated in National Cancer Institute (NCI)-designated Comprehensive Cancer Centers with those treated elsewhere, this study suggests that patients may be more likely to receive treatment with certain expensive cancer drugs if treated in the non-NCI setting. These practice differences may result in differences in patient costs and outcomes as a result of where they receive treatment.

Oncology pharmacist-led medication reconciliation among cancer patients initiating chemotherapy.

BACKGROUND: Pharmacist-led medication reconciliation (PMR) ensures adequate recording and use of medications by patients. PMR may be important for cancer patients initiating new therapies, as they have a high burden of medication use and are more susceptible to inadvertent medication discrepancies. To describe medication changes (additions, discontinuations, and modifications) made to the electronic health record during a PMR among cancer patients initiating chemotherapy. METHODS: From October 2011 to March 2012, 397 cancer patients initiating chemotherapy underwent a PMR at the University of North Carolina Cancer Hospital. Self-reported medications and those in the patients' electronic health record were reviewed. Log-binomial regression models were used to estimate adjusted prevalence ratios and 95% confidence intervals for the associations between patient characteristics and medication changes made to the electronic health record. RESULTS: Mean age at time of the PMR was 58. Median number of medications taken prior to the PMR was 10 and median time to PMR completion was 11 min. Vitamins and herbal supplements accounted for the largest proportion of medication additions (38%) and modifications (20%). Antimicrobials accounted for the largest share of discontinuations (15%). After adjustment for all other covariates, patients aged 60-69 years were more likely to have additions than those aged 50 and under (aPR = 1.47, 95%CI: 1.10-1.97). Patients 70 years and over were more likely to have modifications (aPR = 1.74, 95%CI: 1.07-2.82). CONCLUSION: Our results show that most cancer patients had a medication change in the electronic health record. A brief oncology PMR can accurately capture and improve medication safety by preventing prescribing and administration errors.

Renin-Angiotensin-Aldosterone System-based Antihypertensive Agents and the Risk of Colorectal Cancer Among Medicare Beneficiaries.

BACKGROUND: Biologic evidence suggests that angiotensin II may play a role in tumor progression or growth. We compared the short-term colorectal cancer (CRC) risk among initiators of angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) versus guideline-recommended clinical alternatives (beta blockers, calcium channel blockers [CCB], and thiazides). METHODS: We conducted a new-user cohort study on U.S. Medicare beneficiaries aged over 65 years, who initiated antihypertensive monotherapy during 2007-2013 and were free of cancer diagnosis before drug initiation. Follow-up began 6 months postinitiation to allow time for the diagnostic delay. We estimated hazard ratios (HR) with 95% confidence intervals (CI) using propensity score weighted Cox regression, overall and stratified by time since drug initiation, and 5-year cumulative risk differences (RD) using Kaplan-Meier estimator. We assessed the potential for unmeasured confounding using supplemental data from Medicare Current Beneficiary Survey. RESULTS: For analyses without censoring for treatment changes, we observed 532 CRC events among 111,533 ACEI/ARB initiators. After a median follow-up of 2.2 years (interquartile range: 1.0-3.7), CRC risk was similar between ACEI/ARB and active comparators, with adjusted HRs of 1.0 (95% CI = 0.85, 1.1) for ACEI/ARB versus beta blockers, 1.2 (95% CI = 0.97, 1.4) for ACEI/ARB versus CCB and 1.0 (95% CI = 0.80, 1.3) for ACEI/ARB versus thiazide. Five-year RDs and as-treated analyses, which censored follow-up at medication changes, produced similar findings. CONCLUSIONS: Based on real-world antihypertensive utilization patterns in Medicare beneficiaries, our study suggests no association between ACEI/ARB initiation and the short-term CRC risk.

Comparison of Medicare Claims-based Proxy Measures of Poor Function and Associations With Treatment Receipt and Mortality in Older Colon Cancer Patients.

BACKGROUND: Multiple claims-based proxy measures of poor function have been developed to address confounding in observational studies of drug effects in older adults. We evaluated agreement between these measures and their associations with treatment receipt and mortality in a cohort of older colon cancer patients. METHODS: Medicare beneficiaries age 66+ diagnosed with stage II-III colon cancer were identified in the Surveillance, Epidemiology, and End Results-Medicare database (2004-2011). Poor function was operationalized by: (1) summing the total poor function indicators for each model; and (2) estimating predicted probabilities of poor function at diagnosis. Agreement was evaluated using Fleiss' κ and Spearman's correlation. Associations between proxy measures and: (1) laparoscopic versus open surgery; (2) chemotherapy versus none; (3) 5-fluorouracil (5FU)+oxaliplatin (FOLFOX) versus 5FU monotherapy; and (4) 1-year mortality were estimated using log-binomial regression, controlling for age, sex, stage, and comorbidity. Survival estimates were stratified by functional group, age, and comorbidity. RESULTS: Among 29,687 eligible colon cancer patients, 67% were 75+ years and 45% had stage III disease. Concordance across the poor function indicator counts was moderate (κ: 0.64) and correlation of predicted probability measures varied (ρ: 0.21-0.74). Worse function was associated with lower chemotherapy and FOLFOX receipt, and higher 1-year mortality. Within age and comorbidity strata, poor function remained associated with mortality. CONCLUSIONS: While agreement varied across the claims-based proxy measures, each demonstrated anticipated associations with treatment receipt and mortality independent of comorbidity. Claims-based comparative effectiveness studies in older populations should consider applying one of these models to improve confounding control.

Evaluating the Strength of the Association Between Industry Payments and Prescribing Practices in Oncology.

BACKGROUND: Financial relationships between physicians and the pharmaceutical industry are common, but factors that may determine whether such relationships result in physician practice changes are unknown. MATERIALS AND METHODS: We evaluated physician use of orally administered cancer drugs for four cancers: prostate (abiraterone, enzalutamide), renal cell (axitinib, everolimus, pazopanib, sorafenib, sunitinib), lung (afatinib, erlotinib), and chronic myeloid leukemia (CML; dasatinib, imatinib, nilotinib). Separate physician cohorts were defined for each cancer type by prescribing history. The primary exposure was the number of calendar years during 2013-2015 in which a physician received payments from the manufacturer of one of the studied drugs; the outcome was relative prescribing of that drug in 2015, compared with the other drugs for that cancer. We evaluated whether practice setting at a National Cancer Institute (NCI)-designated Comprehensive Cancer Center, receipt of payments for purposes other than education or research (compensation payments), maximum annual dollar value received, and institutional conflict-of-interest policies were associated with the strength of the payment-prescribing association. We used modified Poisson regression to control confounding by other physician characteristics. RESULTS: Physicians who received payments for a drug in all 3 years had increased prescribing of that drug (compared with 0 years), for renal cell (relative risk [RR] 1.81, 95% confidence interval [CI] 1.58-2.07), CML (RR 1.22, 95% CI 1.08-1.39), and lung (RR 1.69, 95% CI 1.58-1.82), but not prostate (RR 0.97, 95% CI 0.93-1.02). Physicians who received compensation payments or >$100 annually had increased prescribing compared with those who did not, but NCI setting and institutional conflict-of-interest policies were not consistently associated with the direction of prescribing change. CONCLUSION: The association between industry payments and cancer drug prescribing was greatest among physicians who received payments consistently (within each calendar year). Receipt of payments for compensation purposes, such as for consulting or travel, and higher dollar value of payments were also associated with increased prescribing. IMPLICATIONS FOR PRACTICE: Financial payments from pharmaceutical companies are common among oncologists. It is known from prior work that oncologists tend to prescribe more of the drugs made by companies that have given them money. By combining records of industry gifts with prescribing records, this study identifies the consistency of payments over time, the dollar value of payments, and payments for compensation as factors that may strengthen the association between receiving payments and increased prescribing of that company's drug.

Body mass index, calcium supplementation and risk of colorectal adenomas.

Calcium supplementation (1,200 mg/day) did not significantly reduce colorectal adenomas in our recent randomized, controlled trial (Vitamin D/Calcium Polyp Prevention Study, VCPPS, 2004-2013) in contrast to our previous trial (Calcium Polyp Prevention Study, CPPS, 1988-1996). To reconcile these findings, we identified participant characteristics that differed between the study populations and modified the effect of calcium supplementation on adenomas or high-risk findings (advanced or multiple adenomas). Compared to the CPPS, more participants in the VCPPS were obese (body mass index (BMI) ≥30 kg/m2 ; 37.5% vs. 24.4%) and fewer had normal BMI (BMI <25 kg/m2 ; 18.5% vs. 31%). BMI appeared to modify the effect of calcium supplementation on adenomas and especially on high risk-findings: in the VCPPS, there was a 44% reduction in high-risk findings among individuals whose BMI was normal (RR = 0.56, 95% CI = 0.26-1.23), but not among overweight (RR = 1.09, 95% CI = 0.62-1.91) or obese (RR = 1.54, 95% CI = 0.92-2.57) individuals (pinteraction = 0.03). Similarly, in the CPPS, there was a 56% reduction in high-risk findings among individuals whose BMI was normal (RR = 0.44, 95% CI = 0.26-0.74), but not among overweight (RR = 0.87, 95% CI = 0.55-1.39) or obese (RR = 1.02, 95% CI = 0.57-1.82) individuals (pinteraction = 0.02). Standardization of each trial's findings to the BMI distribution in the other attenuated calcium's protective effect on adenomas in the CPPS but enhanced it in the VCPPS. In conclusion, 1,200 mg/day calcium supplementation may reduce risk of colorectal adenomas among those with normal BMI but not in overweight or obese individuals; and differences in BMI distribution partially account for the apparent difference in calcium efficacy between the two trials.

Neoadjuvant Systemic Therapy Use for Younger Patients with Breast Cancer Treated in Different Types of Cancer Centers Across the United States.

BACKGROUND: Multiple clinical trials have shown that neoadjuvant systemic therapy has a benefit in women who are borderline lumpectomy candidates and in those with locally advanced breast cancers by reducing the mastectomy rate and making inoperable tumors operable. The study aim was to examine the patterns of neoadjuvant chemotherapy and endocrine therapy use among younger women in the United States treated at different types of cancer centers. STUDY DESIGN: Data from the National Cancer Data Base for 118,086 women younger than 65 years with clinical stage IIA (T2N0 only) to IIIC breast cancer. Following the National Comprehensive Cancer Network guideline categorization, patients were grouped into those who were borderline lumpectomy candidates (clinical stage IIA [T2N0 only], IIB, or IIIA [T3N1 only]) or those with locally advanced disease (clinical stage IIIA [T0-3N2 only], IIIB, or IIIC). The main outcome was the proportion of women who received neoadjuvant systemic therapy. RESULTS: Use of neoadjuvant chemotherapy ranged from 17% (stage IIA) to 79% (stage IIIB). Across almost all stage and receptor subtypes, the use was lower in community vs academic centers. On multivariable analysis, use of neoadjuvant chemotherapy was decreased in community vs academic centers (borderline lumpectomy candidates: adjusted risk ratio = 0.73; 95% CI, 0.69-0.77; locally advanced disease: adjusted risk ratio = 0.78; 95% CI, 0.74-0.83). CONCLUSIONS: Use of guideline-concordant neoadjuvant chemotherapy is significantly higher among women treated at academic vs community centers in young and healthy women who do not commonly have contraindications to this treatment. Our study identified a potential disparity in cancer care by type of center where patients receive treatment.

Comparative effectiveness of postoperative chemotherapy among older patients with non-metastatic rectal cancer treated with preoperative chemoradiotherapy.

OBJECTIVE: Postoperative chemotherapy is standard following preoperative chemoradiation therapy (CRT) and curative resection for clinically staged II/III rectal cancer. Recent trials have questioned whether postoperative chemotherapy improves overall survival. The objective of the study was to evaluate the comparative effectiveness of postoperative chemotherapy following CRT or radiation therapy (RT) with specific attention to the impact of age on postoperative chemotherapy effectiveness. MATERIALS AND METHODS: Patients treated with CRT or RT then resection of pathologically staged 0-III rectal cancer diagnosed from 2004 to 2009 were identified from the Surveillance, Epidemiology and End Results program-Medicare database. Propensity score weighted Cox proportional hazards models and Kaplan Meier methods were used to compare the effectiveness of 1) postoperative 5-fluorouracil (5-FU) or capecitabine to no treatment and 2) postoperative oxaliplatin+5-FU/capecitabine to 5-FU/capecitabine alone on mortality. Results were stratified by age. RESULTS: We identified 1316 patients; 49% received postoperative chemotherapy, 341 (52%) included oxaliplatin. After weighting, postoperative 5-FU/capecitabine alone was associated with decreased mortality in patients aged 66-74 (adjusted hazard ratio (aHR)=0.46, 95% CI: 0.30, 0.72), corresponding to a 5-year risk difference of -0.23, (95% CI: -0.33, -0.12). No further mortality reduction from adding oxaliplatin to 5-FU/capecitabine was seen in patients aged 66-74 (aHR=1.57, 95% CI: 0.93, 2.65). No mortality reduction for 5-FU/capecitabine alone was observed among patients aged 75+ (aHR=1.11, 95% CI: 0.76, 1.63). CONCLUSIONS: Among patients <75years, postoperative 5-FU/capecitabine was associated with reduced mortality after preoperative CRT/RT and surgical resection; however, the addition of oxaliplatin was not associated with further mortality reduction. Decisions regarding postoperative chemotherapy after age 75 warrant consideration of individual patient risks and preferences, as benefits may be limited.