Changing practice patterns of adjuvant radiation among elderly women with early stage breast cancer in the United States from 2004 to 2014

The effect of adjuvant radiotherapy after breast-conserving surgery in elderly women with T1-2N0 estrogen receptor-negative breast cancer

PURPOSE

To evaluate whether adjuvant radiotherapy (RT) following breast-conserving surgery (BCS) results in better survival among women ≥ 70 years with T1-2N0 estrogen receptor (ER)-negative breast cancer.

METHODS

In this retrospective cohort study, we included patients who met the inclusion criteria between 2010 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) program. Univariate and Multivariate Cox proportional analysis were used to identify the risk factors for overall survival (OS) and breast cancer-specific survival (BCSS). Kaplan-Meier survival analysis was used to compare the prognosis of patients with or without adjuvant RT. Propensity score matching (PSM) was applied to perform a 1:1 matched case-control analysis.

RESULTS

A total of 4201 women were included in this study, with a median follow-up time of 64 months (range: 0-107 months). Of these patients, 2811 (66.9%) received adjuvant RT, while 1390 (33.1%) did not. Patients who did not receive adjuvant RT were more likely to be aged ≥ 80 years old, have a single marital status, larger tumors, and HER2-positive status (p < 0.05). Multivariate Cox proportional analysis indicated that receiving adjuvant RT was an independent factor associated with better OS and BCSS before and after PSM (P < 0.001). The survival curves before and after PSM showed that patients achieved an improved OS and BCSS from adjuvant RT (P < 0.005). In the subgroup analysis, there was no survival benefit trend from adjuvant RT in patients who were ≥ 80 years, or those with T1mic+T1a, T1b tumors.

CONCLUSIONS

The use of RT following BCS in older women with T1-2N0 ER-negative breast cancer is associated with improve OS and BCSS. However, the potential benefit may be relatively limited for patients ≥ 80 years, or those with T1mic+T1a, T1b tumors.

Physicians’ Opinion on Intraoperative Radiotherapy as a Therapeutic De-Escalation Option in Older Women with Early Breast Cancer

Background: Intraoperative radiotherapy (IORT) is a therapeutic de-escalation option in older women with low-risk early breast cancer (EBC). A qualitative study was implemented to describe EBC physicians’ points of view on IORT as a de-escalation option. Methods: Recorded face-to-face and telephone semi-structured interviews were conducted among diverse physicians from seven French comprehensive cancer centers. Interview transcripts were grouped as corpus to construct a typology. Thematic analysis was performed. Results: Positions toward IORT were contrasted between the 16 participating physicians. Five fully supported IORT as a de-escalation option, four were not in favor, and seven had a more reserved or neutral opinion. Points of divergence concerned treatment efficacy, treatment duration, side effects and sequelae, psychological impact, compliance with adjuvant endocrine therapy, logistical constraints, financial cost, and availability of other techniques of partial breast irradiation. Physicians in favor of IORT emphasized direct benefits for the patient, and those against pointed the lack of specific guidelines, risk of lost opportunity in older women with long life expectancy, and challenges of shared decision making. Conclusions: Despite national policies to preserve cancer patients’ quality of life and increase their participation in medical decision making, therapeutic de-escalation using IORT is not consensual among physicians. Further efforts are needed to promote patient-centered care.

Long-Term Adherence to Adjuvant Endocrine Therapy Following Various Radiotherapy Modalities in Early Stage Hormone Receptor Positive Breast Cancer

INTRODUCTION

We compared the rates of long-term adjuvant endocrine therapy (AET) adherence after various radiation therapy (RT) modalities among patients with early stage breast cancer.

MATERIALS AND METHODS

Medical records from patients with stage 0, I, or IIA (tumors ≤3 cm), hormone receptor (HR) positive breast cancer that received adjuvant radiation therapy (RT) from 2013 to 2015 at a single institution were retrospectively reviewed. All patients received breast conserving surgery (BCS) followed by adjuvant RT via one of the following modalities: whole breast radiotherapy (WBI), partial breast irradiation (PBI) with either external beam radiation therapy (EBRT) or fractionated intracavitary high-dose rate (HDR) brachytherapy, or single fraction HDR-brachytherapy intraoperative-radiation therapy (IORT).

RESULTS

One hundred fourteen patients were reviewed. Thirty patients received WBI, 41 PBI, and 43 IORT with a median follow up of 64.2, 72.0, and 58.6 months, respectively. For the entire cohort, AET adherence was approximately 64% at 2 years and 56% at 5 years. Among patients in the IORT clinical trial, adherence to AET was approximately 51% at 2 years and 40% at 5 years. After controlling for additional factors, DCIS histology (vs invasive disease) and IORT (compared to other radiation modalities) were associated with decreased endocrine therapy adherence (P < 0.05).

CONCLUSION

DCIS histology and receipt of IORT were associated with lower rates of adherence to AET at 5 years. Our findings suggest that examination of the efficacy of RT interventions such as PBI and IORT in patients who do not receive AET is warranted.

The addition of radiotherapy to breast-conserving surgery improves survival for elderly patients with early breast cancer

Purpose

To evaluate whether adjuvant radiotherapy (RT) after breast-conserving surgery (BCS) was associated with better survival among elderly (≥70 years) breast cancer patients with T1-2N0 and estrogen receptor (ER) positive disease.

Methods

We included patients who met the inclusion criteria between 2010 and 2014 from the Surveillance, Epidemiology, and End Results program. Patients were subdivided into three groups based on surgery and RT: BCS alone, BCS plus RT, and refusal of RT. The primary outcomes were breast cancer-specific survival (BCSS) and overall survival (OS). Chi-squared tests, Kaplan-Meier method, and Multivariate Cox regression analysis were used for statistical analysis. Propensity score matching (PSM) was performed to minimize the potential selection bias.

Results

A total of 26586 patients were included in this analysis. The median follow-up was 66 months. Of these patients, 15591 (58.6%) patients received RT, RT was recommended but not performed due to patient refusal for 1270 (4.8%) patients, and RT was not recommended for 9725 (36.6%) patients. The 5-year BCSS was 98.3% for patients receiving RT, 97.1% for patients refusal of RT, and 96.4% for patients not recommended RT (P<0.001). The 5-year OS was 88.6% for patients receiving RT, 77.6% for patients who refused RT, and 72.1% for patients not recommended RT (P<0.001). Multivariate Cox regression analyses showed that patients who received adjuvant RT after BCS had significantly better BCSS (hazard ratio [HR] 0.523, 95%confidence interval [CI] 0.447-0.612, P<0.001) and OS (HR 0.589, 95%CI 0.558-0.622, P<0.001) compared to those without RT. A total of 7721 pairs of patients were matched successfully between those with and without RT using PSM. The results also showed that patients who received RT after BCS had significantly better BCSS (HR 562, 95%CI 0.467-0.676, P<0.001) and OS (HR 0.612, 95%CI 0.0.575-0.652, P<0.001) compared to those without RT.

Conclusions

These data suggest that individual counseling is important for treatment decision-making in elderly breast cancer patients with T1-2N0 and ER-positive disease. Given the relatively lower toxicity of modern RT techniques, adjuvant RT should be recommended in patients with high life expectancy.

Contemporary Cancer Program Practice Profile Report (CP3R) Compliance Rates for Breast Cancer: A National Cancer Database Analysis

INTRODUCTION

The Commission on Cancer (CoC) issues Cancer Program Practice Profile Reports (CP3R) that set standards for high-quality care. Three metrics for breast cancer include radiation within 1 year for women < 70 years of age receiving breast-conserving surgery, radiation within 1 year after mastectomy for women with four or more positive lymph nodes (MASTRT), and hormonal therapy within 1 year of a stage IB-III hormone receptor-positive breast cancer (HT). Our study evaluates national trends in quality metric compliance.

METHODS

The National Cancer Database was queried from 2004 to 2014 to identify patients who met the criteria for the three quality metrics. National trends in compliance were compared.

RESULTS

Overall, 1,094,264 patients qualified for BCSRT (n = 534,147), MASTRT (n = 66,291), or HT (n = 493,826). In 2014, 91.1% of patients met BCSRT, 88.4% met MASTRT, and 90.7% met HT. BCSRT, MASTRT, and HT compliance rates were lower in community hospitals compared with Integrated Network Cancer Programs (INCP) (BCSRT: 89.0% vs. 92.8%, p < 0.01; MASTRT: 85.5% vs. 90.6%, p < 0.01; HT: 87.3% vs. 93.7%, p < 0.01). On multivariate analysis, patients receiving care at an INCP facility [odds ratio (OR) 1.47, 95% confidence interval (CI) 1.37-1.58] and insured patients (OR 1.70, 95% CI 1.54-1.87) had higher odds of BCSRT compliance, and minorities (OR 0.76, 95% CI 0.73-0.80) had lower odds. Similar results were seen for MASTRT and HT.

CONCLUSION

In more recent years, overall compliance rates for breast cancer quality metrics of BCSRT and HT by Comprehensive Community Cancer Programs, Academic/Research Programs, and INCPs have increased to meet the 90% CoC standards, while MASTRT has regressed. Community programs were least compliant with meeting the CoC standards.

Predicting adjuvant endocrine therapy initiation and adherence among older women with early-stage breast cancer

PURPOSE

The CALGB 9343 trial demonstrated that women age 70 or older with early-stage, estrogen receptor positive (ER +) breast cancer (BC) may safely forgo radiation therapy (RT) and be treated with breast conserving surgery followed by adjuvant endocrine therapy (AET) alone. However, most patients in this population still undergo RT in part because AET adherence is low. We sought to develop a predictive model for AET initiation and adherence in order to improve decision-making with respect to RT omission.

METHODS

Women ages 70 and older with early-stage, ER + BC were identified using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. Comorbidities, socioeconomic measures, prescription medications, and demographics were collected as potential predictors. Bivariate analysis was performed to identify factors associated with AET initiation and adherence. Stepwise selection of significant predictors was used to develop logistic regression classifiers for initiation and adherence. Model performance was evaluated using the c-statistic and other measures.

RESULTS

11,037 patients met inclusion criteria. Within the cohort, 8703 (78.9%) patients initiated AET and 6685 (60.6%) were adherent to AET over 1 year. Bivariate predictors of AET initiation were similar to predictors of adherence. The best AET initiation and adherence classifiers were poorly predictive with c-statistics of 0.65 and 0.60, respectively.

CONCLUSIONS

The best models in the present study were poorly predictive, demonstrating that the reasons for initiation and adherence to AET are complex and individual to the patient, and therefore difficult to predict. Initiation and adherence to AET are important factors in decision-making regarding whether or not to forgo adjuvant RT. In order to better formulate treatment plans for this population, future work should focus on improving individual prediction of AET initiation and adherence.

Does persistent use of radiation in women > 70 years of age with early-stage breast cancer reflect tailored patient-centered care?

PURPOSE

Randomized controlled trials demonstrate that omission of radiation therapy (RT) in older women with early-stage cancer undergoing breast conserving surgery (BCS) is an "acceptable choice." Despite this, high RT rates have been reported. The objective was to evaluate the impact of patient- and system-level factors on RT rates in a contemporary cohort.

METHODS

Through the National Cancer Data Base, we identified women with clinical stage I estrogen receptor-positive breast cancer who underwent BCS (n = 84,214). Multivariable logistic regression identified patient, tumor, and system-level factors associated with RT. Joinpoint regression analysis calculated trends in RT use over time stratified by age and facility-type, reporting annual percent change (APC).

RESULTS

RT rates decreased from 2004 (77.2%) to 2015 (64.3%). The decline occurred earliest and was most pronounced in older women treated at academic facilities. At academic facilities, the APC was - 5.6 (95% CI - 8.6, - 2.4) after 2009 for women aged > 85 years, - 6.4 (95% CI - 9.0, - 3.8) after 2010 for women aged 80 -  < 85 years, - 3.7 (95% CI - 5.6, - 1.9) after 2009 for women aged 75 -  < 80, and - 2.4 (95% CI, - 3.1, - 1.6) after 2009 for women aged 70 -  < 75. In contrast, at community facilities rates of RT declined later (2011, 2012, and 2013 for age groups 70-74, 75-79, and 80-84 years).

CONCLUSIONS

RT rates for older women with early-stage breast cancer are declining with patient-level variation based on factors related to life expectancy and locoregional recurrence. Facility-level variation suggests opportunities to improve care delivery by focusing on barriers to de-implementation of routine use of RT.