The Role of Facility Variation on Racial Disparities in Use of Hypofractionated Whole Breast Radiation Therapy

Variation in Androgen Deprivation Therapy Use Among Men With Intermediate-Risk Prostate Cancer: Results From a Statewide Radiation Oncology Quality Consortium

PURPOSE

For men with intermediate-risk prostate cancer treated with definitive therapy, the addition of androgen deprivation therapy (ADT) reduces the risk of distant metastasis and cancer-related mortality. However, the absolute benefit of ADT varies by baseline cancer risk. Estimates of prognosis have improved over time, and little is known about ADT decision making in the modern era. We sought to characterize variability and identify factors associated with intended ADT use within the Michigan Radiation Oncology Quality Consoritum (MROQC).

MATERIALS AND METHODS

Patients with localized prostate cancer undergoing definitive radiation therapy were enrolled from June 9, 2020, to June 26, 2023 (n = 815). Prospective data were collected using standardized patient, physician, and physicist forms. Intended ADT use was prospectively defined and was the primary outcome. Associations with patient, tumor, and practice-related factors were tested with multivariable analyses. Random intercept modeling was used to estimate facility-level variability.

RESULTS

Five hundred seventy patients across 26 facilities were enrolled with intermediate-risk disease. ADT was intended for 46% of men (n = 262/570), which differed by National Comprehensive Cancer Network favorable intermediate-risk (23.5%, n = 38/172) versus unfavorable intermediate-risk disease (56.3%, n = 224/398; P < .001). After adjusting for the statewide case mix, the predicted probability of intended ADT use varied significantly across facilities, ranging from 15.4% (95% CI, 5.4%-37.0%) to 71.7% (95% CI, 57.0%-82.9%), with P < .01. Multivariable analyses showed that grade group 3 (OR, 4.60 [3.20-6.67]), ≥50% positive cores (OR, 2.15 [1.43-3.25]), and prostate-specific antigen 10 to 20 (OR, 1.87 [1.24-2.84]) were associated with ADT use. Area under the curve was improved when incorporating MRI adverse features (0.76) or radiation treatment variables (0.76), but there remained significant facility-level heterogeneity in all models evaluated (P < .05).

CONCLUSIONS

Within a state-wide consortium, there is substantial facility-level heterogeneity in intended ADT use for men with intermediate-risk prostate cancer. Future efforts are necessary to identify patients who will benefit most from ADT and to develop strategies to standardize appropriate use.

Geographic and Physician-Level Variation in the Use of Hypofractionated Radiation Therapy for Breast Cancer in the U.S.: A Cross-Classified Multilevel Analysis

Purpose

We aimed to assess geographic and physician-level variation for hypofractionated whole-breast irradiation (HF-WBI) use for early-stage breast cancer patients in the United States. We further evaluated the association between HF-WBI use and demographic factors after accounting for these variations.

Methods and Materials

We performed a retrospective study of early-stage breast cancer patients using private employer-sponsored insurance claims from 2008 to 2017. Patients were clustered according to geographic level and by radiation oncologist. Bayesian cross-classified multilevel logistic models were used to examine the geographic heterogeneity and variation of radiation oncologists simultaneously. Intracluster correlation coefficient (ICC) and median odds ratios (MOR) were calculated to quantify the variation at different levels. We also used the cross-classified model to identify patient demographic factors associated with receiving HF-WBI.

Results

The study included 79,747 women (74.0%) who received conventionally fractionated whole-breast irradiation (CF-WBI) and 27,999 women (26.0%) who underwent HF-WBI. HF-WBI adoption increased significantly across time (2008-2017). The variation in HF-WBI utilization was attributed mostly to physician-level variability (MOR = 2.59). The variability of HF-WBI utilization across core-based statistical areas (CBSAs) (MOR = 1.55) was found to be the strongest among all geographic classifications. After accounting for variability in both CBSAs and radiation oncologists, age, receiving chemotherapy, and several community-level factors, including distance from home to facility, community education level, and racial composition, were found to be associated with HF-WBI utilization.

Conclusion

This study demonstrated geographic and physician-level heterogeneity in the use of HF-WBI among early-stage breast cancer patients. HF-WBI utilization was also found to be associated with patient and community-level characteristics. Given observed physician-level variability, intervention through continuing medical education could help doctors to better understand the advantages of HF-WBI and promote the adoption of HF-WBI in the U.S. Influence of physician-level characteristics on HF-WBI utilization merits further study.

Radiation Therapy Practice Patterns for Treatment of Curative Breast Cancer in a Large Tertiary Health Care System

Purpose

Disparities have been reported in women treated for breast cancer (BrCa). This study examines potential disparities in BrCa treatment offered based on race and age from a multicenter radiation department.

Methods and Materials

We identified 901 patients with early stage BrCa who received curative intent radiation therapy (RT) between 2004 and 2018. Data extracted included age, race, disease stage, treatment technique, treatment dates, and fractionation. Patient race was recorded as Asian, Black, Hispanic, and White. RT technique delivered was classified as a type of external beam radiation therapy or brachytherapy/intraoperative radiation therapy. Fractionation schema were defined as 1) standard fractionation, 1.8-2 Gy; 2) hypofractionation, 2.5-2.67 Gy; 3) accelerated partial breast irradiation (APBI), 3.4 Gy - 4.25 Gy, and 4) intraoperative radiation therapy, single dose of 20 Gy. Stage was recorded using TNM staging. The χ2 test and a multivariable multinomial logistic regression model were used to assess whether patient characteristics, such as age, race, or stage influenced fractionation schemes. Results with 2-sided P values < .05 were considered statistically significant.

Results

Racial composition of the study was 13.8% Asian, 22% Black, 29%, White, and 35.1% Hispanic. Mean age was 61 and was divided into 4 age range groups: 30 to 49 (n = 160), 50 to 59 (n = 231), 60 to 69 (n = 294), and ≥70 years (n = 216). In addition, 501 patients (56%) received hypofractionation, 342 (38.8%) received standard fractionation, and 58 (7.1%) received APBI, respectively. For all groups, hypofractionation became more common over time. Age ≥70 years was associated with 9 times higher odds of APBI and 14 times higher odds of hypofractionation, compared with age 30 to 49 years. After adjusting for the other predictors in a multivariable multinomial logistic regression model, the race distribution differed among the 3 groups (P = .03), with a smaller percentage of Hispanics and higher percentage of blacks in the standard group.

Conclusions

This study of a diverse cohort of patients with breast cancer failed to identify treatment differences associated by race. The study found an association between age and hypofractionation.

Feasibility of Intraoperative Radiotherapy Tumor Bed Boost in Patients with Breast Cancer after Neoadjuvant Chemotherapy

PURPOSE

This study aimed to assess the feasibility and safety of administering intraoperative radiotherapy (IORT) as a boost during breast-conserving surgery (BCS) following neoadjuvant chemotherapy for patients at high risk of breast cancer recurrence.

MATERIALS AND METHODS

Patients who underwent neoadjuvant chemotherapy received a single 20-Gy dose of IORT during BCS, followed by external beam radiotherapy 4-6 weeks after surgery.

RESULTS

The median follow-up duration was 31.0 months (range, 18.0-59.0 months). Initial tumor sizes had a median of 2.6 cm (range: 0.8-5.3 cm), reducing to 0.3 cm (range: 0-4.0 cm) after neoadjuvant chemotherapy. The most common neoadjuvant chemotherapy regimen was doxorubicin and cyclophosphamide, followed by paclitaxel (n=42, 73.7%). Among 57 patients who received neoadjuvant chemotherapy before BCS and IORT, 2 patients (3.5%) required secondary surgery to achieve negative resection margins due to initially positive margins. Regional lymph node irradiation was performed in 37 (64.9%) patients. There was no grade 3 or higher adverse events, with 4 patients (7.0%) experiencing grade 2 acute radiation dermatitis and 3 (5.3%) having less than grade 2 breast edema. Binary correlation analysis did not reveal statistically significant associations between applicator size or radiation therapy modality and the risk of treatment-related toxicity. Furthermore, chi-square analysis showed that the grade of treatment-related toxicity was not associated with the fractionated regimen (p=0.375).

CONCLUSION

Most patients successfully received IORT as a tumor bed boost after neoadjuvant chemotherapy. Thus, IORT may be a safe and feasible option for patients with advanced-stage breast cancer receiving neoadjuvant chemotherapy.

Prospective Evaluation of Limited-Stage Small Cell Lung Cancer Radiotherapy Fractionation Regimen Usage and Acute Toxicity in a Large Statewide Quality Collaborative

PURPOSE

National guidelines on limited-stage small cell lung cancer (LS-SCLC) treatment give preference to a hyperfractionated regimen of 45 Gy in 30 fractions delivered twice daily; however, use of this regimen is uncommon compared with once-daily regimens. The purpose of this study was to characterize the LS-SCLC fractionation regimens used throughout a statewide collaborative, analyze patient and treatment factors associated with these regimens, and describe real-world acute toxicity profiles of once- and twice-daily radiation therapy (RT) regimens.

METHODS AND MATERIALS

Demographic, clinical, and treatment data along with physician-assessed toxicity and patient-reported outcomes were prospectively collected by 29 institutions within the Michigan Radiation Oncology Quality Consortium between 2012 and 2021 for patients with LS-SCLC. We modeled the influence of RT fractionation and other patient-level variables clustered by treatment site on the odds of a treatment break specifically due to toxicity with multilevel logistic regression. National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0, incident grade 2 or worse toxicity was longitudinally compared between regimens.

RESULTS

There were 78 patients (15.6% overall) treated with twice-daily RT and 421 patients treated with once-daily RT. Patients receiving twice-daily RT were more likely to be married or living with someone (65% vs 51%; P = .019) and to have no major comorbidities (24% vs 10%; P = .017). Once-daily RT fractionation toxicity peaked during RT, and twice-daily toxicity peaked within 1 month after RT. After stratifying by treatment site and adjusting for patient-level variables, once-daily treated patients had 4.11 (95% confidence interval, 1.31-12.87) higher odds of treatment break specifically due to toxicity than twice-daily treated patients.

CONCLUSIONS

Hyperfractionation for LS-SCLC remains infrequently prescribed despite the lack of evidence demonstrating superior efficacy or lower toxicity of once-daily RT. With peak acute toxicity after RT and lower likelihood of a treatment break with twice-daily fractionation in real-word practice, providers may start using hyperfractionated RT more frequently.

Building Better Patient Care in Mississippi Radiation Oncology: Why Mississippi Needs a Collaborative Quality Initiative

OBJECTIVES

Cancer is an insidious and devastating disease that affects many people. Progress in mortality rate has not been realized universally across the United States, and challenges remain in how to best make up the ground that has been lost in these areas, one of which is Mississippi. Radiation therapy is a significant contributor to cancer control rates and certain challenges exist specifically regarding this treatment modality.

METHODS

The challenges of radiation oncology in Mississippi have been reviewed and discussed, with the proposal of a potential collaboration between clinical practitioners and payors to provide optimal and cost-effective radiation therapy to patients in Mississippi.

RESULTS

A similar model to that proposed has been reviewed and evaluated. This model is discussed based on its potential validity and usefulness in Mississippi.

CONCLUSIONS

Significant barriers exist in the state of Mississippi to patients receiving a consistent standard of care, regardless of their location and socioeconomic status. A collaborative quality initiative has been shown to be a boon to this endeavor elsewhere and stands to have a similar impact in Mississippi.

Breast Cancer Disparities in Asian Women: The Need for Disaggregated Research

Asian (AZN) women are a heterogeneous group, comprising a wide array of cultural beliefs, languages, and healthcare needs. Yet, studies of breast cancer (BCa) risks and outcomes predominately consider AZNs in aggregate, assuming that the distinct ethnicities have similar disease profiles and homogeneous responses to treatment. This stereotypical portrayal of AZNs as a homogenous group tends to mask disparities. For example, healthcare-seeking behaviors and attitudes of medical providers toward AZN BCa patients frequently differ within this group and from other races. Misconceptions may arise that significantly influence the prevention, detection, treatment, and post-therapeutic care of AZN women. In addition to low BCa screening rates among AZN women, disparities also exist in various stages of BCa treatment-omission of radiation after breast-conserving surgery, less access to hypofractionation, underutilization of hormonal therapy, and higher-cost treatment owing to high HER2+ incidence. In this perspective, we highlight the need for disaggregated research of BCa among AZN women and advocate for comprehensive, culturally sensitive strategies to address health disparities in this priority population. Improving BCa literacy and awareness, access to care, and equitable recruitment into clinical trials are a few amelioratory goals to consider in the future.

Mediators of Racial Disparities in Heart Dose Among Whole Breast Radiotherapy Patients

BACKGROUND

Racial disparities in survival of patients with cancer motivate research to quantify treatment disparities and evaluate multilevel determinants. Previous research has not evaluated cardiac radiation dose in large cohorts of breast cancer patients by race nor examined potential causes or implications of dose disparities.

METHODS

We used a statewide consortium database to consecutively sample 8750 women who received whole breast radiotherapy between 2012 and 2018. We generated laterality- and fractionation-specific models of mean heart dose. We generated patient- and facility-level models to estimate race-specific cardiac doses. We incorporated our data into models to estimate disparities in ischemic cardiac event development and death. All statistical tests were 2-sided.

RESULTS

Black and Asian race independently predicted higher mean heart dose for most laterality-fractionation groups, with disparities of up to 0.42 Gy for Black women and 0.32 Gy for Asian women (left-sided disease and conventional fractionation: 2.13 Gy for Black women vs 1.71 Gy for White women, P < .001, 2-sided; left-sided disease and accelerated fractionation: 1.59 Gy for Asian women vs 1.27 Gy for White women, P = .002). Patient clustering within facilities explained 22%-30% of the variability in heart dose. The cardiac dose disparities translated to estimated excesses of up to 2.6 cardiac events and 1.3 deaths per 1000 Black women and 0.7 cardiac events and 0.3 deaths per 1000 Asian women vs White women.

CONCLUSIONS

Depending on laterality and fractionation, Asian women and Black women experience higher cardiac doses than White women. This may translate into excess radiation-associated ischemic cardiac events and deaths. Solutions include addressing inequities in baseline cardiac risk factors and facility-level availability and use of radiation technologies.

Identifying Patients Whose Symptoms Are Underrecognized During Treatment With Breast Radiotherapy

Importance

Understanding whether physicians accurately detect symptoms in patients with breast cancer is important because recognition of symptoms facilitates supportive care, and clinical trials often rely on physician assessments using Common Toxicity Criteria for Adverse Events (CTCAE).

Objective

To compare the patient-reported outcomes (PROs) of patients with breast cancer who received radiotherapy from January 1, 2012, to March 31, 2020, with physicians' CTCAE assessments to assess underrecognition of symptoms.

Design, Setting, and Participants

This cohort study included a total of 29 practices enrolled in the Michigan Radiation Oncology Quality Consortium quality initiative. Of 13 725 patients with breast cancer who received treatment with radiotherapy after undergoing lumpectomy, 9941 patients (72.4%) completed at least 1 PRO questionnaire during treatment with radiotherapy and were evaluated for the study. Of these, 9868 patients (99.3%) were matched to physician CTCAE assessments that were completed within 3 days of the PRO questionnaires.

Exposures

Patient and physician ratings of 4 symptoms (pain, pruritus, edema, and fatigue) were compared.

Main Outcomes and Measures

We used multilevel multivariable logistic regression to evaluate factors associated with symptom underrecognition, hypothesizing that it would be more common in racial and ethnic minority groups.

Results

Of 9941 patients, all were female, 1655 (16.6%) were Black, 7925 (79.7%) were White, and 361 (3.6%) had Other race and ethnicity (including American Indian/Alaska Native, Arab/Middle Eastern, and Asian), either as self-reported or as indicated in the electronic medical record. A total of 1595 (16.0%) were younger than 50 years, 2874 (28.9%) were age 50 to 59 years, 3353 (33.7%) were age 60 to 69 years, and 2119 (21.3%) were 70 years or older. Underrecognition of symptoms existed in 2094 of 6781 (30.9%) observations of patient-reported moderate/severe pain, 748 of 2039 observations (36.7%) of patient-reported frequent pruritus, 2309 of 4492 observations (51.4%) of patient-reported frequent edema, and 390 of 2079 observations (18.8%) of patient-reported substantial fatigue. Underrecognition of at least 1 symptom occurred at least once for 2933 of 5510 (53.2%) of those who reported at least 1 substantial symptom. Factors independently associated with underrecognition were younger age (younger than 50 years compared with 60-69 years: odds ratio [OR], 1.35; 95% CI, 1.14-1.59; P < .001; age 50-59 years compared with 60-69 years: OR, 1.19; 95% CI, 1.03-1.37; P = .02), race (Black individuals compared with White individuals: OR, 1.56; 95% CI 1.30-1.88; P < .001; individuals with Other race or ethnicity compared with White individuals: OR, 1.52; 95% CI, 1.12-2.07; P = .01), conventional fractionation (OR, 1.26; 95% CI, 1.10-1.45; P = .002), male physician sex (OR, 1.54; 95% CI, 1.20-1.99; P = .002), and 2-field radiotherapy (without a supraclavicular field) (OR, 0.80; 95% CI, 0.67-0.97; P = .02).

Conclusions and Relevance

The results of this cohort study suggest that PRO collection may be essential for trials because relying on the CTCAE to detect adverse events may miss important symptoms. Moreover, since physicians in this study systematically missed substantial symptoms in certain patients, including younger patients and Black individuals or those of Other race and ethnicity, improving symptom detection may be a targetable mechanism to reduce disparities.

Hypofractionated Radiation Therapy for Breast Cancer: Financial Risk and Expenditures in the United States, 2008 to 2017

PURPOSE

Rising cancer care expenditures and technological advancement of shorter radiation therapy regimens have drawn significant attention to the use of hypofractionated radiation therapy in clinical care. We examine the costs of hypofractionated whole breast irradiation (HF-WBI) compared with conventional whole breast irradiation (CF-WBI) in the United States and investigate the influences of patient characteristics and commercial insurance on HF-WBI use.

METHODS AND MATERIALS

In a retrospective study using private employer-sponsored insurance claims, a pooled cross-sectional evaluation of radiation therapy in patients with commercial insurance was performed from 2008 to 2017. The study population included female patients with early-stage breast cancer treated with lumpectomy and whole breast irradiation.

RESULTS

A total of 15,869 women received HF-WBI, and 59,328 received CF-WBI. HF-WBI use increased from 2008 to 2017. Community-level factors such as a higher proportion of college graduates and greater mixed racial composition were associated with increased HF-WBI use. Mean insurer-paid radiation therapy expenditures were significantly lower for HF-WBI versus CF-WBI (adjusted difference, $6375; 95% confidence interval, $6147-$6603). Mean patient out-of-pocket expenditure for HF-WBI was $139 less than that for CF-WBI. Geographic variation existed across the United States in HF-WBI use (range, 9.6%-36.2%), with no consistent relationship between HF-WBI use and corresponding average cost differences between HF-WBI and CF-WBI.

CONCLUSIONS

If trends continue, HF-WBI will soon become the dominant form of radiation treatment in the United States. Although HF-WBI represents significant savings to the health care system and individual patients, no evidence indicated that a financial disincentive had slowed adoption of HF-WBI. Therefore, multilevel approaches, including individuals, the community, and health policy, should be used to promote cost-effective cancer care. Innovations to policies on cost-effective radiation therapy treatment might consider non-financial incentives to promote HF-WBI use.

Effect of education and standardization of cardiac dose constraints on heart dose in lung cancer patients receiving definitive radiation therapy across a statewide consortium

PURPOSE/OBJECTIVES

Cardiac radiation exposure is associated with an increased rate of adverse cardiac events in patients receiving radiation therapy for locally advanced non-small cell lung carcinoma (NSCLC). Previous analysis of practice patterns within XXXX revealed 1 in 4 patients received a mean heart dose >20 Gy and significant heterogeneity existed among treatment centers in using cardiac dose constraints. The purpose of this study is to analyze the effect of education and initiation of standardized cardiac dose constraints on heart dose across a statewide consortium.

MATERIALS/METHODS

From 2012 to 2020, 1681 patients from 27 academic and community centers who received radiation therapy for locally advanced NSCLC were included in this analysis. Dosimetric endpoints including mean heart dose (MHD), mean lung dose, and mean esophagus dose were calculated using data from dose-volume histograms. These dose metrics were grouped by year of treatment initiation for all patients. Education regarding data for cardiac dose constraints first occurred in small lung cancer working group meetings and then consortium-wide starting in 2016. In 2018, a quality metric requiring mean heart dose <20 Gy while maintaining dose coverage (D95) to the target was implemented. Dose metrics were compared before (2012-2016) versus after (2017-2020) initiation of interventions targeting cardiac constraints. Statistical analysis was performed using the Wilcoxon Rank Sum test.

RESULTS

Following education and implementation of the heart dose performance metric, mean MHD declined from an average of 12.2 Gy pre-intervention to 10.4 Gy post-intervention (p < 0.0001), and the percentage of patients receiving MHD >20 Gy reduced from 21.1% to 10.3% (p < 0.0001). Mean lung dose and mean esophagus dose did not increase, and target coverage remained unchanged.

CONCLUSIONS

Education and implementation of a standardized cardiac dose quality measure across a statewide consortium was associated with a reduction of mean heart dose in patients receiving radiation therapy for locally advanced NSCLC. These dose reductions were achieved without sacrificing target coverage, increasing mean lung dose, or increasing mean esophagus dose. Analysis of the clinical ramifications of the reduction in cardiac doses is ongoing.

European Society for Radiotherapy and Oncology Advisory Committee in Radiation Oncology Practice consensus recommendations on patient selection and dose and fractionation for external beam radiotherapy in early breast cancer

High-quality randomised clinical trials testing moderately fractionated breast radiotherapy have clearly shown that local control and survival is at least as effective as with 2 Gy daily fractions with similar or reduced normal tissue toxicity. Fewer treatment visits are welcomed by patients and their families, and reduced fractions produce substantial savings for health-care systems. Implementation of hypofractionation, however, has moved at a slow pace. The oncology community have now reached an inflection point created by new evidence from the FAST-Forward five-fraction randomised trial and catalysed by the need for the global radiation oncology community to unite during the COVID-19 pandemic and rapidly rethink hypofractionation implementation. The aim of this paper is to support equity of access for all patients to receive evidence-based breast external beam radiotherapy and to facilitate the translation of new evidence into routine daily practice. The results from this European Society for Radiotherapy and Oncology Advisory Committee in Radiation Oncology Practice consensus state that moderately hypofractionated radiotherapy can be offered to any patient for whole breast, chest wall (with or without reconstruction), and nodal volumes. Ultrafractionation (five fractions) can also be offered for non-nodal breast or chest wall (without reconstruction) radiotherapy either as standard of care or within a randomised trial or prospective cohort. The consensus is timely; not only is it a pragmatic framework for radiation oncologists, but it provides a measured proposal for the path forward to influence policy makers and empower patients to ensure equity of access to evidence-based radiotherapy.

Choosing Wisely in radiation therapy for breast cancer: Time lag in adoption of hypofractionated radiation therapy in Victoria

INTRODUCTION

To evaluate the adoption of hypofractionated radiotherapy (HFRT) for breast cancer (BC) in Victoria, Australia.

METHODS

This is a population-based cohort of women with BC who had breast RT as captured in the Victorian Radiotherapy Minimum Data Set between 2012 and 2017. We defined HFRT as < 25 fractions of RT. The pattern of HFRT use over time was evaluated with the Cochrane-Armitage test for trend. Factors associated with HFRT were identified using multivariable logistic regression.

RESULTS

12,717 women were included in the study. Overall, 6,653 (52%) patients had HFRT. HFRT use increased from 35% in 2012 to 66% in 2017 (P-trend < 0.001). Older women were more likely to have HFRT (74% for women aged ≥ 70 years vs. 27% for women aged < 50 years; P < 0.001). Women who had nodal irradiation were less likely to have HFRT compared with those who did not (13% vs. 57%; P < 0.001). HFRT use was more common in public than private institutions (57% vs. 46%, P < 0.001), and in metropolitan than regional centres (54% vs. 46%, P < 0.001). In multivariable analyses, the progressive increase in HFRT use over time was independent of other covariates - women treated in 2017 were 7.3 times (95% CI = 6.3-8.6, P < 0.001) more likely to be treated with HFRT than in 2012. Age at RT, nodal irradiation, area of residence and institutional type and locations were all independently associated with HFRT use.

CONCLUSION

This large Australian contemporary population-based study demonstrates increasing use of HFRT for BC. However, large sociodemographic and institutional provider-related variations in practice still exist.

Toward Improving Patients' Experiences of Acute Toxicity From Breast Radiotherapy: Insights From the Analysis of Patient-Reported Outcomes in a Large Multicenter Cohort

PURPOSE

Understanding acute toxicities after whole-breast radiotherapy is important to inform patients, guide treatment decisions, and target supportive care. We evaluated patient-reported outcomes prospectively collected from a cohort of patients with breast cancer.

METHODS

We describe the maximal toxicity reported by 8,711 patients treated between 2012 and 2019 at 27 practices. Multivariable models identified characteristics associated with (1) breast pain, (2) bother from itching, stinging/burning, swelling, or hurting of the treated breast, and (3) fatigue within 7 days of completing whole-breast radiotherapy.

RESULTS

Moderate or severe breast pain was reported by 3,233 (37.1%): 1,282 (28.9%) of those receiving hypofractionation and 1,951 (45.7%) of those receiving conventional fractionation. Frequent bother from at least one breast symptom was reported by 4,424 (50.8%): 1,833 (41.3%) after hypofractionation and 2,591 (60.7%) after conventional fractionation. Severe fatigue was reported by 2,008 (23.1%): 843 (19.0%) after hypofractionation and 1,165 (27.3%) after conventional fractionation. Among patients receiving hypofractionated radiotherapy, younger age (P < .001), higher body mass index (BMI; P < .001), Black (P < .001) or other race (P = .002), smoking status (P < .001), larger breast volume (P = .002), lack of chemotherapy receipt (P = .004), receipt of boost treatment (P < .001), and treatment at a nonteaching center predicted breast pain. Among patients receiving conventionally fractionated radiotherapy, younger age (P < .001), higher BMI (P = .003), Black (P < .001) or other race (P = .002), diabetes (P = .001), smoking status (P < .001), and larger breast volume (P < .001) predicted breast pain.

CONCLUSION

In this large observational data set, substantial differences existed according to radiotherapy dose fractionation. Race-related differences in pain existed despite controlling for multiple other factors; additional research is needed to understand what drives these differences to target potentially modifiable factors. Intensifying supportive care may be appropriate for subgroups identified as being vulnerable to greater toxicity.