Radiation Therapy After Breast-Conserving Surgery in Women 70 Years of Age and Older: How Wisely Do We Choose?

Frequency of use and characterization of frailty assessments in observational studies on older women with breast cancer: a systematic review

BACKGROUND

Breast cancer and frailty frequently co-occur in older women, and frailty status has been shown to predict negative health outcomes. However, the extent to which frailty assessments are utilized in observational research for the older breast cancer population is uncertain. Therefore, the aim of this review was to determine the frequency of use of frailty assessments in studies investigating survival or mortality, and characterize them, concentrating on literature from the past 5 years (2017-2022).

METHODS

MEDLINE, EMBASE and Cochrane Library were systematically queried to identify observational studies (case-control, cohort, cross-sectional) published from 2017-2022 that focus on older females (≥ 65 years) diagnosed with breast cancer, and which evaluate survival or mortality outcomes. Independent reviewers assessed the studies for eligibility using Covidence software. Extracted data included characteristics of each study as well as information on study design, study population, frailty assessments, and related health status assessments. Risk of bias was evaluated using the appropriate JBI tool. Information was cleaned, classified, and tabulated into review level summaries.

RESULTS

In total, 9823 studies were screened for inclusion. One-hundred and thirty studies were included in the final synthesis. Only 11 (8.5%) of these studies made use of a frailty assessment, of which 4 (3.1%) quantified frailty levels in their study population, at baseline. Characterization of frailty assessments demonstrated that there is a large variation in terms of frailty definitions and resulting patient classification (i.e., fit, pre-frail, frail). In the four studies that quantified frailty, the percentage of individuals classified as pre-frail and frail ranged from 18% to 29% and 0.7% to 21%, respectively. Identified frailty assessments included the Balducci score, the Geriatric 8 tool, the Adapted Searle Deficits Accumulation Frailty index, the Faurot Frailty index, and the Mian Deficits of Accumulation Frailty Index, among others. The Charlson Comorbidity Index was the most used alternative health status assessment, employed in 56.9% of all 130 studies. Surprisingly, 31.5% of all studies did not make use of any health status assessments.

CONCLUSION

Few observational studies examining mortality or survival outcomes in older women with breast cancer incorporate frailty assessments. Additionally, there is significant variation in definitions of frailty and classification of patients. While comorbidity assessments were more frequently included, the pivotal role of frailty for patient-centered decision-making in clinical practice, especially regarding treatment effectiveness and tolerance, necessitates more deliberate attention. Addressing this oversight more explicitly could enhance our ability to interpret observational research in older cancer patients.

Association between adjuvant radiation treatment and breast cancer-specific mortality among older women with comorbidity burden: A comparative effectiveness analysis of SEER-MHOS

BACKGROUND

The National Comprehensive Cancer Network suggested that older women with low-risk breast cancer (LRBC; i.e., early-stage, node-negative, and estrogen receptor-positive) could omit adjuvant radiation treatment (RT) after breast-conserving surgery (BCS) if they were treated with hormone therapy. However, the association between RT omission and breast cancer-specific mortality among older women with comorbidity is not fully known.

METHODS

1105 older women (≥65 years) with LRBC in 1998-2012 were queried from the Surveillance, Epidemiology, and End Results-Medicare Health Outcomes Survey data resource and were followed up through July 2018. Latent class analysis was performed to identify comorbidity burden classes. A propensity score-based inverse probability of treatment weighting (IPTW) was applied to Cox regression models to obtain subdistribution hazard ratios (HRs) and 95% CI for cancer-specific mortality considering other causes of death as competing risks, overall and separately by comorbidity burden class.

RESULTS

Three comorbidity burden (low, moderate, and high) groups were identified. A total of 318 deaths (47 cancer-related) occurred. The IPTW-adjusted Cox regression analysis showed that RT omission was not associated with short-term, 5- and 10-year cancer-specific death (p = 0.202 and p = 0.536, respectively), regardless of comorbidity burden. However, RT omission could increase the risk of long-term cancer-specific death in women with low comorbidity burden (HR = 1.98, 95% CI = 1.17, 3.33), which warrants further study.

CONCLUSIONS

Omission of RT after BCS is not associated with an increased risk of cancer-specific death and is deemed a reasonable treatment option for older women with moderate to high comorbidity burden.

Omitting Radiotherapy after Breast-Conserving Surgery in Luminal A Breast Cancer

BACKGROUND

Adjuvant radiotherapy is prescribed after breast-conserving surgery to reduce the risk of local recurrence. However, radiotherapy is inconvenient, costly, and associated with both short-term and long-term side effects. Clinicopathologic factors alone are of limited use in the identification of women at low risk for local recurrence in whom radiotherapy can be omitted. Molecularly defined intrinsic subtypes of breast cancer can provide additional prognostic information.

METHODS

We performed a prospective cohort study involving women who were at least 55 years of age, had undergone breast-conserving surgery for T1N0 (tumor size <2 cm and node negative), grade 1 or 2, luminal A-subtype breast cancer (defined as estrogen receptor positivity of ≥1%, progesterone receptor positivity of >20%, negative human epidermal growth factor receptor 2, and Ki67 index of ≤13.25%), and had received adjuvant endocrine therapy. Patients who met the clinical eligibility criteria were registered, and Ki67 immunohistochemical analysis was performed centrally. Patients with a Ki67 index of 13.25% or less were enrolled and did not receive radiotherapy. The primary outcome was local recurrence in the ipsilateral breast. In consultation with radiation oncologists and patients with breast cancer, we determined that if the upper boundary of the two-sided 90% confidence interval for the cumulative incidence at 5 years was less than 5%, this would represent an acceptable risk of local recurrence at 5 years.

RESULTS

Of 740 registered patients, 500 eligible patients were enrolled. At 5 years after enrollment, recurrence was reported in 2.3% of the patients (90% confidence interval [CI], 1.3 to 3.8; 95% CI, 1.2 to 4.1), a result that met the prespecified boundary. Breast cancer occurred in the contralateral breast in 1.9% of the patients (90% CI, 1.1 to 3.2), and recurrence of any type was observed in 2.7% (90% CI, 1.6 to 4.1).

CONCLUSIONS

Among women who were at least 55 years of age and had T1N0, grade 1 or 2, luminal A breast cancer that were treated with breast-conserving surgery and endocrine therapy alone, the incidence of local recurrence at 5 years was low with the omission of radiotherapy. (Funded by the Canadian Cancer Society and the Canadian Breast Cancer Foundation; LUMINA ClinicalTrials.gov number, NCT01791829.).

Recent Advances in Optimizing Radiation Therapy Decisions in Early Invasive Breast Cancer

Adjuvant whole breast irradiation after breast-conserving surgery is a well-established treatment standard for early invasive breast cancer. Screening, early diagnosis, refinement in surgical techniques, the knowledge of new and specific molecular prognostic factors, and now the standard use of more effective neo/adjuvant systemic therapies have proven instrumental in reducing the rates of locoregional relapses. This underscores the need for reliably identifying women with such low-risk disease burdens in whom elimination of radiation from the treatment plan would not compromise oncological safety. This review summarizes the current evidence for radiation de-intensification strategies and details ongoing prospective clinical trials investigating the omission of adjuvant whole breast irradiation in molecularly defined low-risk breast cancers and related evidence supporting the potential for radiation de-escalation in HER2+ and triple-negative clinical subtypes. Furthermore, we discuss the current evidence for the de-escalation of regional nodal irradiation after neoadjuvant chemotherapy. Finally, we also detail the current knowledge of the clinical value of stromal tumor-infiltrating lymphocytes and liquid-based biomarkers as prognostic factors for locoregional relapse.

Breast-Conserving Surgery with or without Irradiation in Early Breast Cancer

BACKGROUND

Limited level 1 evidence is available on the omission of radiotherapy after breast-conserving surgery in older women with hormone receptor-positive early breast cancer receiving adjuvant endocrine therapy.

METHODS

We performed a phase 3 randomized trial of the omission of irradiation; the trial population included women 65 years of age or older who had hormone receptor-positive, node-negative, T1 or T2 primary breast cancer (with tumors ≤3 cm in the largest dimension) treated with breast-conserving surgery with clear excision margins and adjuvant endocrine therapy. Patients were randomly assigned to receive whole-breast irradiation (40 to 50 Gy) or no irradiation. The primary end point was local breast cancer recurrence. Regional recurrence, breast cancer-specific survival, distant recurrence as the first event, and overall survival were also assessed.

RESULTS

A total of 1326 women were enrolled; 658 were randomly assigned to receive whole-breast irradiation and 668 to receive no irradiation. The median follow-up was 9.1 years. The cumulative incidence of local breast cancer recurrence within 10 years was 9.5% (95% confidence interval [CI], 6.8 to 12.3) in the no-radiotherapy group and 0.9% (95% CI, 0.1 to 1.7) in the radiotherapy group (hazard ratio, 10.4; 95% CI, 4.1 to 26.1; P<0.001). Although local recurrence was more common in the group that did not receive radiotherapy, the 10-year incidence of distant recurrence as the first event was not higher in the no-radiotherapy group than in the radiotherapy group, at 1.6% (95% CI, 0.4 to 2.8) and 3.0% (95% CI, 1.4 to 4.5), respectively. Overall survival at 10 years was almost identical in the two groups, at 80.8% (95% CI, 77.2 to 84.3) with no radiotherapy and 80.7% (95% CI, 76.9 to 84.3) with radiotherapy. The incidence of regional recurrence and breast cancer-specific survival also did not differ substantially between the two groups.

CONCLUSIONS

Omission of radiotherapy was associated with an increased incidence of local recurrence but had no detrimental effect on distant recurrence as the first event or overall survival among women 65 years of age or older with low-risk, hormone receptor-positive early breast cancer. (Funded by the Chief Scientist Office of the Scottish Government and the Breast Cancer Institute, Western General Hospital, Edinburgh; ISRCTN number, ISRCTN95889329.).

The Effect of Surgeon Referral and a Radiation Oncologist Productivity-Based Metric on Radiation Therapy Receipt Among Elderly Women With Early Stage Breast Cancer: Analysis From a Tertiary Cancer Network

Purpose

: Guidelines for early-stage breast cancer allow for radiation therapy (RT) omission after breast conserving surgery among older women, though high utilization of RT persists. This study explored surgeon referral and the effect of a productivity-based bonus metric for radiation oncologists in an academic institution with centralized quality assurance review.

Methods and materials

: We evaluated patients ≥70 years of age treated with breast conserving surgery for estrogen receptor (ER)+ pT1N0 breast cancer at a single tertiary cancer network between 2015 and 2018. The primary outcomes were radiation oncology referral and RT receipt. Covariables included patient and physician characteristics and treatment decisions before versus after productivity metric implementation. Univariable generalized linear effects models explored associations between these outcomes and covariables.

Results

: Of 703 patients included, 483 (69%) were referred to radiation oncology and 273 (39%) received RT (among those referred, 57% received RT). No difference in RT receipt pre- versus post-productivity metric implementation was observed (P = .57). RT receipt was associated with younger patient age (70-74 years; odds ratio [OR], 2.66; 95% confidence interval [CI], 1.54-4.57) and higher grade (grade 3; OR, 7.75; 95% CI, 3.33-18.07). Initial referral was associated with younger age (70-74; OR, 5.64; 95% CI, 3.37-0.45) and higher performance status (Karnofsky performance status ≥90; OR, 5.34; 95% CI, 2.63-10.83).

Conclusions

: Nonreferral to radiation oncology accounted for half of RT omission but was based on age and Karnofsky performance status, in accordance with guidelines. Lack of radiation oncologist practice change in response to misaligned financial incentives is reassuring, potentially reflecting incentive design and/or centralized quality assurance review. Multi-institutional studies are needed to confirm these findings.

Trends in surgical treatment of early-stage breast cancer reveal decreasing mastectomy use between 2003 and 2016 by age, race, and rurality

PURPOSE

To examine trends in the surgical treatment of breast cancer by age, rurality, and among Black women in a populous, racially diverse, state in the Southeastern United States of America.

METHODS

We identified women diagnosed with localized or regional breast cancer between 2003 and 2016 in the North Carolina Central Cancer Registry (n = 86,776). Using Joinpoint regression we evaluated the average annual percentage change in proportion of women treated with mastectomy versus breast-conserving surgery overall, by age group, among Black women, and for women residing in rural areas.

RESULTS

Overall, the rate of mastectomy usage in the population declined 2.5% per year between 2003 and 2016 (95% CI - 3.2, - 1.7). Over this same time interval, breast-conserving surgery increased by 1.6% per year (95% CI 0.9, 2.2). These temporal trends in surgery were also observed among Black women and rural residing women. Trends in surgery type varied by age group: mastectomy declined over time among women > 50 years, but not among women aged 18-49 at diagnosis.

DISCUSSION

In contrast to national studies that reported increasing use of mastectomy, we found declining mastectomy rates in the early 2000s in a Southern US state with a racially and geographically diverse population. These decreasing trends were consistent among key subgroups affected by cancer inequities, including Black and White rural women.

Breast surgical oncology in elderly and unfit patients: a systematic review

INTRODUCTION

Breast cancer treatment in elderly women remains a complex issue due to pre-existing comorbidities, therapy-related toxicities, and the lack of evidence-based data in this population, leading to both overtreatment and undertreatment.

EVIDENCE ACQUISITION

The aim was to investigate the literature on breast surgical oncology in the older woman as a major therapeutic challenge: the 86 more consistent articles amongst 1440 potential citations according to PRISMA guidelines were retained.

EVIDENCE SYNTHESIS

Studies demonstrated that despite low-grade tumor types, lower incidence of axillary lymph node involvement, ER+ disease, and less aggressive tumor biology, elderly breast cancer patients often receive less than the standard-of-care when compared to their younger counterparts. The surgery omission in elderlies and the preference for the primary endocrine treatment is associated with worse survival, especially in patients aged 80 years or over - a cohort with no specific recommendations concerning breast and axillary surgical procedures. On the other hand, a higher mastectomy rate is still considered the standard treatment in older women with higher T2:T1 tumor ratio and greater difficulties to attend radiotherapy due to severe comorbidities. Surgical de-escalation procedures even in an-ambulatory setting are recognized as a feasible option in these patients to prevent or palliate breast or chest wall symptoms.

CONCLUSIONS

Benefits and disadvantages from surgery only or coupled with adjuvant therapies for elderly women were analyzed in literature, outlining a growing need for a proper geriatric assessment and short-stay surgical programs which are feasible today owing to the availability of less invasive approaches.

Surgical Axillary Staging Before Neoadjuvant Chemotherapy: Who Gets It and Why We Should Avoid It

BACKGROUND

Surgical axillary staging demonstrating positive nodal disease before neoadjuvant chemotherapy (NAC) necessitates axillary lymph node dissection (ALND) post-NAC. Despite evidence supporting post-NAC surgical staging, we hypothesized that there is persistent use of pre-NAC staging and that it is associated with aggressive clinicopathologic features and a higher rate of subsequent ALND.

PATIENTS AND METHODS

Stage I-III breast cancer patients who underwent lymph node staging surgery and received NAC between 2013 and 2017 in the National Cancer Database were included. Sequence of staging surgery and chemotherapy administration was determined. Multivariable regression was used to assess characteristics associated with pre-NAC staging. Rate of ALND was compared between those who had pre- and post-NAC surgical axillary staging.

RESULTS

In total, 120,538 met inclusion; 68% received NAC first and 32% had pre-NAC staging. Pre-NAC staging surgery was associated with younger age (age < 30 versus 40-49 years, HR 1.1) and decreased with older age (ages 70-79/80+ versus 40-49 years, HR 0.86 and 0.73). Advancing clinical T stage, lobular subtype, higher grade, and HR+/HER2- subtype were also associated with pre-NAC surgical staging. Women who underwent pre-NAC surgical staging were more likely to undergo ALND.

CONCLUSIONS

Over 30% of women underwent surgical axillary staging prior to NAC, resulting in higher rates of ALND in this cohort. While certain features suggestive of aggressive behavior (grade and T stage) were associated with pre-NAC surgical axillary staging, women with more aggressive tumor subtypes (triple negative/HER2+) were less likely to undergo pre-NAC surgical axillary staging. Pre-NAC surgical axillary staging should be performed only in rare circumstances to avoid unnecessary ALND.

Impact of Choosing Wisely Recommendations on Sentinel Lymph Node Biopsy and Postoperative Radiation Rates in Women Over Age 70 Years with Hormone-Positive Breast Cancer

BACKGROUND

In 2016, the Society of Surgical Oncology released a Choosing Wisely guideline recommending sentinel lymph node biopsy (SLNB) omission in females ≥70 years of age with early-stage, hormone-positive, clinically node-negative invasive breast cancer. This study investigated the impact of this guideline on SLNB and radiotherapy rates, in addition to assessing temporal trends of nodal biopsy and factors associated with recurrence.

METHODS

The study involved a retrospective review of women who met the guideline criteria and underwent partial mastectomy at a single institution between 2009 and 2018. Using the same inclusion criteria, the National Cancer Database was queried to obtain a separate dataset. Statistical analyses included univariate comparisons, and multivariate logistic regression modeling to predict radiotherapy delivery.

RESULTS

In our institutional series, 487 patients were included, 274 (56.3%) of whom received radiotherapy. There were 414 patients (85.0%) who underwent SLNB, with a nodal positivity rate of 11%. SLNB correlated with higher rates of radiotherapy (63.5% vs. 15.1%, p < 0.001). Age <80 years was an independent predictor of radiotherapy receipt (odds ratio 3.0, 95% confidence interval 0.22-0.52). SLNB performance decreased after 2016 (88.4% vs. 78.4%, p = 0.003). Median follow-up was 4.8 years, with 19 (3.9%) documented recurrences. SLNB performance was not associated with recurrence (2.9% vs. 5.5%, p = 0.279), whereas radiotherapy resulted in reduced recurrence (1.1% vs. 6.1%, p = 0.002). One (0.2%) disease-related mortality was observed.

CONCLUSION

Recurrence rates and disease-related mortality remain low in this demographic regardless of treatment rendered. Omission of SLNB and radiotherapy should remain a consideration, and efforts in both patient and physician education should continue.

Outcomes After Sentinel Lymph Node Biopsy and Radiotherapy in Older Women With Early-Stage, Estrogen Receptor-Positive Breast Cancer

IMPORTANCE

Overtreatment of early-stage breast cancer with favorable tumor biology in older patients may be harmful without affecting recurrence and survival. Guidelines that recommend deimplementation of sentinel lymph node biopsy (SLNB) (Choosing Wisely) and radiotherapy (RT) (National Comprehensive Cancer Network) have been published.

OBJECTIVE

To describe the use rates and association with disease recurrence of SLNB and RT in older women with breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study obtained patient and clinical data from an integrated cancer registry and electronic health record of a single health care system in Pennsylvania. The cohort was composed of consecutive female patients 70 years or older who were diagnosed with early-stage, estrogen receptor-positive, ERBB2 (formerly HER2)-negative, clinically node-negative breast cancer from January 1, 2010, to December 31, 2018, who were treated at 15 community and academic hospitals within the health system.

EXPOSURES

Sentinel lymph node biopsy and adjuvant RT.

MAIN OUTCOMES AND MEASURES

Primary outcomes were 5-year locoregional recurrence-free survival (LRFS) rate and disease-free survival (DFS) rate after SLNB and after RT. Secondary outcomes included recurrence rate, subgroups that may benefit from SLNB or RT, and use rate of SLNB and RT over time. Propensity scores were used to create 2 cohorts to separately evaluate the association of SLNB and RT with recurrence outcomes. Cox proportional hazards regression model was used to estimate hazard ratios (HRs).

RESULTS

From 2010 to 2018, a total of 3361 women 70 years or older (median [interquartile range {IQR}] age, 77.0 [73.0-82.0] years) with estrogen receptor-positive, ERBB2-negative, clinically node-negative breast cancer were included in the study. Of these women, 2195 (65.3%) received SLNB and 1828 (54.4%) received adjuvant RT. Rates of SLNB steadily increased (1.0% per year), a trend that persisted after the 2016 adoption of the Choosing Wisely guideline. Rates of RT decreased slightly (3.4% per year). To examine patient outcomes and maximize follow-up time, the analysis was limited to cases from 2010 to 2014, identifying 2109 patients with a median (IQR) follow-up time of 4.1 (2.5-5.7) years. In the propensity score-matched cohorts, no association was found between SLNB and either LRFS (HR, 1.26; 95% CI, 0.37-4.30; P = .71) or DFS (HR, 1.92; 95% CI, 0.86-4.32; P = .11). In addition, RT was not associated with LRFS (HR, 0.33; 95% CI, 0.09-1.24; P = .10) or DFS (HR, 0.99; 95% CI, 0.46-2.10; P = .97). Subgroup analysis showed that stratification by tumor grade or comorbidity was not associated with LRFS or DFS. Low absolute rates of recurrence were observed when comparing the groups that received SLNB (3.5%) and those that did not (4.5%) as well as the groups that received RT (2.7%) and those that did not (5.5%).

CONCLUSIONS AND RELEVANCE

This study found that receipt of SLNB or RT was not associated with improved LRFS or DFS in older patients with ER-positive, clinically node-negative breast cancer. Despite limited follow-up time and wide 95% CIs, this study supports the continued deimplementation of both SLNB and RT in accordance with the Choosing Wisely and National Comprehensive Cancer Network guidelines.

Patients Older 65 Years With Early Breast Cancer Prefer Intraoperative Radiation as a Locoregional Treatment Choice

BACKGROUND

Patients 65 years old or older with early endocrine-responsive breast cancer have many treatment options, including no radiation. This study aimed to evaluate treatment preference when intraoperative radiation therapy (IORT) is offered in this population.

METHODS

The study reviewed patients 65 years old or older with a diagnosis of early-stage endocrine-responsive breast cancer in 2016-2019 at a single hospital in a large integrated health care system. Electronic medical records of multidisciplinary breast tumor board discussion, treatment options documented by the treatment team, and final treatment offered were reviewed. Variables including age at biopsy, language, endocrine treatment, and comorbidities were collected. Regression analysis was used to evaluate for variables associated with patients' choice regarding radiation treatment.

RESULTS

The institutional IORT guidelines were met by 63 patients in the described age group who had a documented offer of all radiation treatment options. The median age of the patients was 70 years (interquartile range 63-77 years). Overall, 74.6% of the patients chose IORT, and 14.3% opted for whole-breast irradiation. Only 4.8% chose to omit radiation after breast-conserving surgery, and 6.3% chose mastectomy. The patients who chose IORT were more likely to receive endocrine treatment (odds ratio 3.70; p = 0.03). Age, race, language, and comorbidities were not associated with preference for IORT (p < 0.05).

CONCLUSIONS

Patients 65 years old or older with early-stage endocrine-responsive breast cancer preferred to have IORT despite counsel about the lack of survival benefit. This study suggests that local cancer control with the convenient radiation delivery method is important to the described patient population.

Long-term outcome and axillary recurrence in elderly women (≥70 years) with breast cancer: 10-years follow-up from a matched cohort study

BACKGROUND AND OBJECTIVES

The oncological benefit of axillary surgery (AS), with sentinel lymph node biopsy (SLNB) or axillary dissection (ALND), in elderly women affected by breast cancer (BC) is controversial. We evaluated AS trends over a 10-year follow-up period as well as locoregional and survival outcomes in this subset of patients.

METHODS

Patients aged 70 years or older, treated between 1994 and 2008, were selected and divided in two groups, depending on whether or not AS was performed. A (1:1) matched analysis for all relevant clinicopathological features was performed. Outcomes were analyzed using the Kaplan-Meier method and univariate Cox-proportional hazard ratio analysis.

RESULTS

A total of 1.748 patients were identified and stratified by age (70-74, 75-79, 80-84). A matched analysis was performed for 252 patients: 122 who underwent AS and 122 who did not. At 10-year follow-up, ipsilateral breast tumor recurrence, distant metastasis and contralateral BC were similar, p = 0.83, p = 0.42 and p = 0.28, respectively. In the no-AS group, a significant increased risk of axillary lymph-node recurrence was identified at 5- and confirmed at 10-years (p = 0.038), without impact on overall survival at 5- and 10-years (p = 0.52). In the non-AS group, higher rate of axillary recurrence at 10-years was observed in patients with poorly differentiated (24.1%, 95% CI 7.2-46.2), highly proliferative (Ki67 ≥ 20%: 17.1%, 95% CI 0.6-33.3) and luminal B tumors (16.8%, 95% CI 5.9-35.5).

CONCLUSIONS

Axillary staging in elderly women does not impact long-term survival. Tailoring surgery according to tumor biology and age may improve locoregional outcome.

Breast-conserving Surgery Without Radiation Therapy for Invasive Cancer

Radiotherapy (RT) after breast-conserving surgery (BCS) halves the risk of local recurrence, and it is considered the standard of care for the vast majority of patients with early invasive breast cancer. However, the majority of patients treated with BCS will not recur locally, even in the absence of RT. Over the past several decades, the improved and widespread use of systemic therapy has significantly decreased the rate of local recurrence. This has stimulated interest in identifying favorable patient subsets not requiring RT. Randomized controlled trials have shown in women aged ≥ 70 years with stage I estrogen receptor-positive (ER⁺) tumors, RT can be safely omitted. To better identify patients with favorable prognosis, ongoing trials have incorporated biological markers and genomic assays. Despite great research efforts to de-escalate locoregional treatment, real-world data indicate that omission of RT in low-risk patients is inconsistent. Better decision-making is warranted to reduce overtreatment and financial toxicity.

Effects of Radiation Therapy and Comorbidity on Health-Related Quality of Life and Mortality Among Older Women With Low-Risk Breast Cancer: Protocol for a Retrospective Cohort Study

Background

The National Comprehensive Cancer Network Breast Cancer Guidelines Committee suggests that the omission of adjuvant radiation therapy (RT) after breast-conserving surgery can be a reasonable option among older women with low-risk breast cancer (early-stage, estrogen receptor-positive, and node-negative) if they are treated with endocrine therapy. However, RT usage in this group of women still exceeds 50%. Conversely, older women tend to forego RT (even when necessary) due to cost, inconvenience, and potential adverse responses associated with RT. Understanding health-related quality of life (HRQOL) change with receipt of RT among older women in the modern era is limited due to the under-representation of this population in clinical trials.

Objective

The proposed study aims to examine the associations of RT with HRQOL trajectories as well as survival outcomes among older women with 5-10 years of follow-up. We will also assess whether prediagnosis comorbidity burden influences receipt of RT and whether the associations between RT and HRQOL trajectory and survival outcomes are modified by the comorbidity burden.

Methods

We will use a retrospective cohort study design with the population-based Surveillance, Epidemiology, and End-Results database linked to the Medicare Health Outcomes Survey (SEER-MHOS). Older women (≥65 years) who were diagnosed with low-risk breast cancer in 1998-2014, received breast-conserving surgery, and participated in MHOS 1998-2016 are eligible for this analysis. The latent class analysis clustering method will be used to identify each patient’s prediagnosis comorbidity burden, and HRQOL will be evaluated using the Short Form 36/Veterans RAND 12-Item Health Survey scales. The inverse-weighted estimates of the probability of treatment will be included to control for treatment selection bias and confounding effects in subsequent analysis. The association of RT with HRQOL trajectory will be evaluated using inverse-weighted multilevel growth mixture models. The inverse-weighted Cox regression model will be used to obtain hazard ratios with 95% CIs for the association of RT with survival outcomes. Differential effects of RT on both outcomes according to comorbidity burden class will also be evaluated.

Results

As of October 2020, the study was approved by the institutional review board, and SEER-MHOS data were obtained from the National Cancer Institute. Women with low-risk breast cancer who met inclusion and exclusion criteria have been identified, and prediagnosis comorbidity burden class has been characterized using latent class analysis. Further data analysis will begin in November 2020, and the first manuscript will be submitted in a peer-reviewed journal in February 2021.

Conclusions

This research can potentially improve clinical outcomes of older women with low-risk breast cancer by providing them additional information on the HRQOL trajectories when they make RT treatment decisions. It will facilitate informed, shared treatment decision making and cancer care planning to ultimately improve the HRQOL of older women with breast cancer.

International Registered Report Identifier (IRRID)

DERR1-10.2196/18056

Radiation and/or endocrine therapy? Recurrence and survival outcomes in women over 70 with early breast cancer after breast-conserving surgery

PURPOSE

Women over 70 with early breast cancer treated with breast-conserving surgery are typically offered adjuvant endocrine and radiation therapy. Prior studies have supported the omission of adjuvant radiation in this low-risk population. We sought to compare the effect of adjuvant treatment with endocrine therapy alone, radiation therapy alone or both versus no adjuvant treatment on local control and survival in this population.

METHODS

Data were extracted on 1363 breast cancer patients over the age of 70 treated with a breast-conserving surgery from 2003 until 2018. 460 patients met inclusion criteria of pT1N0, invasive disease with negative margins and not treated with chemotherapy. The primary outcome of this population-based study was local recurrence-free survival at 5 and 10 years.

RESULTS

Patients receiving no adjuvant therapy had worse local recurrence-free, loco-regional recurrence-free and disease-free survival than patients receiving at least one form of adjuvant therapy (p < 0.05). 5-year local recurrence rates were 0.8% in patients receiving both endocrine and radiation therapy, 1.5% in those receiving radiation alone, 4.2% in those receiving endocrine therapy alone and 12% in those receiving no adjuvant therapy.

CONCLUSIONS

This study supports the benefit of some form of adjuvant therapy (radiation alone, endocrine therapy alone or both) in low-risk breast cancer patients over 70. Receiving no adjuvant therapy is associated with poorer outcomes. Many of these patients are candidates for Accelerated Partial Breast Irradiation which can be completed in less than a week. These patients should be offered radiation therapy, endocrine therapy or both.

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.

Trends in Surgical Axillary Management in Early Stage Breast Cancer in Elderly Women: Continued Over-Treatment

INTRODUCTION

In the past two decades, three prospective randomized trials demonstrated that elderly women with early stage hormone positive breast cancer had equivalent disease-specific mortality regardless of axillary surgery. In 2016, the Choosing Wisely campaign encouraged patients and providers to reconsider the role of axillary surgery in this population. We sought to identify factors that contribute to adopting non-operative management of the axilla in these patients.

MATERIALS AND METHODS

We performed a retrospective analysis of women ≥ 70 years old with cT1/T2, hormone positive invasive ductal carcinoma who underwent partial or total mastectomy, with/without axillary surgery, and did not receive adjuvant chemotherapy from the National Cancer Database from 2004 to 2015. We used multivariable log-binomial regression to model the risk of undergoing axillary surgery across region, care setting, and Charlson-Deyo scores, and analyzed temporal trends using Poisson regression. From 2004 to 2015, 87,342 of 99,940 women who met inclusion criteria (83%) had axillary surgery. Over time, axillary surgery increased from 78% to 88% (p < 0.001). This rise was consistent across region (p = 0.81) and care setting (p = 0.09), but flattened as age increased (p < 0.001). Omitting axillary surgery was more likely in patients treated in New England (RR 0.88, 95% CI 0.86, 0.89) and patients ≥ 85 (RR 0.66, 95% CI 0.65, 0.67).

CONCLUSIONS

Axillary surgery continues to be the preferred option of axillary management in elderly women with early stage, clinically node negative, hormone-positive, invasive breast cancer despite no survival benefit. Identifying factors to improve patient selection and dissemination of current recommendations can improve adoption of current evidence on axillary surgery in the elderly.

Nodal positivity decreases with age in women with early-stage, hormone receptor-positive breast cancer

BACKGROUND

Despite data demonstrating the safety of omitting axillary surgery in older women with early-stage breast cancer, the incidence of axillary surgery remains high. It was hypothesized that the prevalence of nodal positivity would decrease with advancing age.

METHODS

The National Cancer Data Base was used to construct a cohort of adult women with early-stage, clinically node-negative, estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative breast cancer treated between 2013 and 2015. Multivariable logistic regression was used to assess the relationship between age and nodal positivity, and this was stratified by the axillary surgery category. Modified Poisson regression was used to estimate the proportion of women receiving adjuvant therapy according to age and nodal status.

RESULTS

The incidence of axillary surgery among women aged 70 and older (n = 51,917) remained high nationwide (86%). There was a significant decrease in nodal positivity with advancing age in women with early-stage, ER+, clinically node-negative breast cancer from the youngest cohort up to patients aged 70 to 89 years, and this was independent of histologic subtype (ductal vs lobular), race, comorbidities, and socioeconomic factors. Overall, less than 10% of women aged 70 or older who underwent surgery had node-positive disease, regardless of axillary surgery type, and almost 95% of node-positive patients aged 70 or older were at pathological stage N1mi or N1.

CONCLUSIONS

Axillary surgery may be safely omitted for many older women with ER+, clinically node-negative, early-stage breast cancer. Nodal positivity declines with advancing age, and this suggests varied biology in older patients versus younger patients.

Accelerated partial breast irradiation in the elderly: 5-Year results of the single fraction elderly breast irradiation (SiFEBI) phase I/II trial

PURPOSE

To evaluate the clinical outcomes of a very-accelerated partial breast irradiation (vAPBI) in the elderly based on a single fraction of multicatheter interstitial high-dose rate brachytherapy (MIB). Mature results with a median follow-up of 5 years.

METHODS AND MATERIALS

From November 2012 to September 2014, 26 patients (pts) (≥70) with early breast cancer were enrolled in a prospective phase II trial (NCT01727011). After lumpectomy, intraoperative catheter implant was performed for postoperative APBI (single fraction 16 Gy). Surveillance was performed twice a year after APBI. Oncologic outcome (local [LRFS], metastasis-free survival, cancer-specific survival, and overall survival [OS]) as well as late toxicity and cosmetic outcome were investigated.

RESULTS

Median age was 77 years [69-89]. After a median follow-up of 63 months [60-68], 5-year LRFS, metastasis-free survival, cancer-specific survival, and overall survival rates were 100%, 95.5%, 100%, and 88.5%, respectively. Late toxicity was observed in 5 pts (19.2%) with a total of five events: 3 pts G1 (60%); and 2 pts G2 (40%). The observed late side effects were breast pain in 1 pt (G2 cytosteatonecrosis with occasional acetaminophen consumption), hypopigmentation (puncture site) in 2 pts (G1) and breast fibrosis in 2 pts (G1: 1 pt; G2: 1 pt). Cosmetic evaluation was excellent for 21 pts (81%) and good for 2 pts (19%).

CONCLUSION

For elderly with early breast cancer, a vAPBI using a single fraction of postoperative MIB (16 Gy) provides excellent oncologic results, mainly in terms of local control and cancer death. Late toxicity and cosmetic profile are acceptable.

Increasing omission of radiation therapy and sentinel node biopsy in elderly patients with early stage, hormone-positive breast cancer

Prospective evidence demonstrates that there is limited benefit of axillary staging with sentinel lymph node biopsy (SLNB) or radiation therapy (RT) in patients over age 70 with clinical stage I, hormone-positive breast cancer. The clinical impact of this literature is unknown. Our hypothesis is that omission of SLNB and RT has increased over time in these patients, and patient and tumor characteristics can predict when omission strategies are used. A single-center tumor registry was queried for all patients over age 70 with ER+, Her2/neu-negative, clinical T1N0 invasive breast cancer from 2009 to 2017, who underwent breast conservation (n = 141). Date of treatment, age, tumor characteristics, use of SLNB, and use of RT were evaluated. The trend of treatment strategy over time was evaluated. Multivariable analysis was performed on the subgroup of patients after publication of the long-term follow-up CALGB 9343 data¹ . Patients undergoing treatment with omission of RT and SLNB increased over the study period (P = .0006). Patients who did not receive RT were older (78.76 years ± 5.48 vs 73.37 ± 3.63, P < .01). There was no difference between tumor grade and size between uses of RT. Of patients who received SLNB (n = 84), only 3 (3.5%) had a positive LN. On multivariable analysis of patients who were treated after publication of the CALGB 9343 data (2014-2017), only age was predictive of being treated with RT (OR, 0.77; 95% CI, 0.67-0.88). Omission of both RT and SLNB are increasing in clinical practice in appropriately selected patients. The likelihood that patients are offered omission of these interventions increases with age. Low nodal positivity rates suggest that this strategy may be underutilized. Tumor grade and size were not predictive of omission of RT in this group of low-risk patients. Long-term data are needed as these approaches are increasingly adopted.