Radiotherapy or tamoxifen after conserving surgery for breast cancers of excellent prognosis: British Association of Surgical Oncology (BASO) II trial

Can De-Escalation of Adjuvant Therapy Be Considered for Older Adults with Breast Cancer?

AbstractThe trimodal approach of lumpectomy, radiotherapy, and endocrine therapy may represent overtreatment for certain older patients with early-stage breast cancer. Treatment guidelines permit adjuvant endocrine monotherapy, based on older randomized trials comparing adjuvant endocrine therapy with radiotherapy versus without radiotherapy. There are limited data on radiotherapy with endocrine therapy versus without endocrine therapy, and therefore, the incremental benefits versus burdens of endocrine therapy, specifically in older (≥70 years of age) women with favorable-risk breast cancer are unknown. With the routine use of molecular genomic assays that identify low-risk breast cancer and advances in radiotherapy delivery that have reduced treatment burden, many older women might consider radiotherapy alone without endocrine therapy if offered. This article reviews the relevant literature and proposes a trial to inform the de-escalation of adjuvant therapy in older patients with estrogen receptor-positive, human epidermal growth factor receptor type 2-negative breast cancer.

Long-Term Outcomes of Radiation Monotherapy Versus Combined Radiation Monotherapy + Hormone Therapy in Low-Risk Early-Stage Breast Cancer Patients 70 Years or Older After Breast-Conserving Surgery

PURPOSE

Standard therapy for breast cancer after breast-conserving surgery is radiation therapy (RT) plus hormone therapy (HT). For patients with a low-risk of recurrence, there is an interest in deescalating therapy.

METHODS AND MATERIALS

A retrospective study was carried out for patients treated at the Swedish Cancer Institute from 2000 to 2015, aged 70 years or older, with pT1N0 or pT1NX estrogen receptor-positive and ERBB2-negative unifocal breast cancer without positive surgical margins, high nuclear grade, or lymphovascular invasion.

RESULTS

Patient numbers were sufficient to carry out analyses for RT + HT (n = 307) and RT alone (n = 148). The median follow-up was 9.6 years. There were no statistically significant differences in adjusted overall survival (OS), disease-specific death, progression-free survival (PFS), distant recurrence, and second primary cancers with RT monotherapy compared with RT + HT. Cumulative rates of all of these outcomes were <5%, even at 15 years of follow-up, regardless of treatment, greatly outweighed by the incidence of death from other causes in this elderly population. In matched analysis, we calculated a hazard ratio of 1.12 (95% CI, 0.82-1.53) for RT versus RT + HT for OS and a hazard ratio of 1.12 (95% CI, 0.82-1.53) for RT versus RT + HT for PFS.

CONCLUSIONS

Our data suggest that elderly, low-risk breast cancer patients have similarly high OS and PFS with low rates of local recurrence, distant recurrence, and death from breast cancer with much higher rates of death from competing causes, whether treated with RT or HT + RT. These patients are likely to die of other causes without disease recurrence, regardless of which of these treatments is used. Thus, they may benefit from the administration of more modern forms of breast irradiation without the need for adjuvant systemic hormone therapy. A detailed analysis of which clinical, pathologic, genomic, and comorbidity variables are needed to select these patients.

Reimagining Deintensification for Low-Risk Breast Cancer

As outcomes for low-risk breast cancer continue to improve, research and clinical paradigms are increasingly focused on appropriate deintensification with the goal of improving the therapeutic ratio of breast cancer treatment. These deintensification approaches span across disciplines including breast surgery, radiation therapy, and systemic therapy. With regard to breast surgery, studies have continued to push deintensification when it comes to surgical margins with breast conservation, reducing re-excision rates, whereas deintensification of axillary surgery has reduced the rates of axillary lymph node dissection and increasingly the need for any axillary surgery, including sentinel lymph node biopsy for low-risk patients. With regard to radiation therapy, studies have allowed for a drastic reduction in treatment duration, whereas approaches that reduce the target of treatment have led to a change from from treatment daily for 5-7 weeks to many low-risk patients completing treatment in just five treatments. With regard to systemic therapy, use of genomic assays and tumor biology has led to reduced utilization of cytotoxic chemotherapy, with studies also allowing for dose reduction of endocrine therapy for patients with ductal carcinoma in situ. Moving forward, greater focus should be placed on interdisciplinary deintensification approaches such as the consideration of radiation therapy alone as compared with endocrine therapy alone for low-risk breast cancers.

Omitting Radiotherapy after Breast-Conserving Surgery in Luminal A Breast Cancer: The LUMINA Study

The modern generation of trials evaluating the role of adjuvant radiation have turned to genomic profiling as a further risk stratification tool. The LUMINA trial by Whelan and colleagues, published in the New England Journal of Medicine , applied Ki67 testing to identify those with luminal A disease and evaluated locoregional outcomes with breast-conserving surgery and endocrine therapy alone. This article was reviewed at the Canadian Association of General Surgeons' "Evidence-Based Reviews in Surgery" webinar series. Here, we present the Evidence-Based Reviews in Surgery panel's methodologic review and clinical commentary. The LUMINA study demonstrated very low rates of local recurrence in low-risk patients with luminal A biologic subtype treated with breast-conserving surgery and endocrine therapy alone without radiation. Although the LUMINA study was rigorously designed and executed, there are significant pragmatic limitations to the implementation of the proposed approach using their protocol. We advocate that there is no "one-size-fits-all" approach to early estrogen receptor + breast cancer. The choice of treatment strategy should strongly consider patient goals and preferences, with the need for incorporation of quality of life and patient-reported endpoints into future studies evaluating this population to help guide these nuanced decisions.

Adjuvant radiotherapy in postmenopausal women with early-stage ER-positive breast cancer: A systematic review and meta-analysis

BACKGROUND

The management of early breast cancer (BC) includes breast-conserving surgery (BCS), postoperative radiation therapy (PORT) and systemic therapy. Therefore, we aim at evaluating all the efficacy endpoints for PORT compared to no PORT in older women with early-stage BC.

METHOD

We searched PubMed, Web of Science, Cochrane, and Scopus databases from inception up to May 2024 for randomized controlled trials (RCTs) where patients were randomized into either PORT vs no PORT. The following outcomes were studied: any local recurrence, nodal recurrence, contralateral BC, distant relapse, all-causes and cancer-specific mortality.

RESULT

Seven eligible RCTs with a total of 4860 patients were included; 2435 of them received PORT; and 2425 did not. All patients had a node-negative disease, with 84.4% older than 60 years and only 10.4% had tumors larger than 2 cm. Patients in both treatment arms were offered adjuvant endocrine therapy e.g. tamoxifen and anastrozole. The median follow-up was 9.7 years (95% CI: 5.1-11.3). The survival risk for any local recurrence for patients with no radiotherapy was significantly higher than for those who used PORT (HR: 6.3; 95% CI: 4.17-9.52). Also, patients in the PORT arm had a significantly lower risk of nodal recurrence (risk of recurrence (RR): 0.28, 95% CI: 0.11-0.72, P = .009). However, PORT was not associated with a significant reduction in the risk of contralateral BC, distant relapse, BC-specific mortality or all-cause mortality (RR: 0.883, 1.52, 1.12, 0.995, respectively).

CONCLUSION

Postoperative radiotherapy significantly reduces local and regional recurrence following BCS in early estrogen receptor-positive elderly BC with limited value on distant recurrence or mortality. The risk-benefit ratio should be determined for every patient to avoid overtreatment of a significant proportion of patients.

De-escalation of surgical and radiation treatment in elderly luminal breast cancer patients, single institution report and review of the evidence

BACKGROUND

De-intensification of anti-cancer therapy without significantly affecting outcomes is an important goal. Omission of axillary surgery or breast radiation is considered a reasonable option in elderly patients with early-stage breast cancer and good prognostic factors. Data on avoidance of both axillary surgery and radiation therapy (RT) is scarce and inconclusive.

METHODS

A retrospective cohort study comprising all women aged 70 years and older diagnosed with early, hormone receptor (HR) positive, HER2-negative breast cancer treated with breast-conserving surgery (BCS) without sentinel lymph node biopsy (SLNB) and RT in a large tertiary center (between 2016 and 2021). Data on patient and tumor characteristics as well as outcomes including local recurrence, loco-regional recurrence, distant metastases, and death were extracted. Disease free survival (DFS) was assessed by Kaplan-Meier analysis. The Cox proportional hazard regression model was performed to identify factors (demographic and clinical characteristics of the patients) that predict the disease recurrence or death.

RESULTS

A total of 100 women were included, median age of patients was 81. All patients had clinically node-negative disease with a median tumor size was 13 mm. Five (5%) women had lymphovascular invasion. At a median follow-up of 3.9 years, there were 7 (7%) recurrences, 4 local, 2 local-regional, and one distant. The median DFS for the entire group was 42 months (11-128). Eight patients (8%) died, 5 of them for reasons unrelated to breast cancer (3 of unknown reason). Tumor size larger than 13 mm was associated with significantly worse DFS (HR = 4.02, 95% CI 1.08-14.99, p = 0.04).

CONCLUSION

Omission of both SLNB and adjuvant RT is feasible in elderly, early breast cancer patients with small luminal tumors.

Single-modality endocrine therapy versus radiotherapy after breast-conserving surgery in women aged 70 years and older with luminal A-like early breast cancer (EUROPA): a preplanned interim analysis of a phase 3, non-inferiority, randomised trial

BACKGROUND

Optimal therapy following breast-conserving surgery in older adults with low-risk, early-stage breast cancer remains uncertain. The EUROPA trial aims to compare the effects of radiotherapy and endocrine therapy as single-modality treatments on health-related quality of life (HRQOL) and ipsilateral breast tumour recurrence (IBTR) outcomes in this population.

METHODS

This non-inferiority, phase 3, randomised study was conducted at 18 academic hospitals across Italy (17 centres) and Slovenia (one centre). Eligible patients were women aged 70 years or older with histologically confirmed, stage I, luminal A-like breast cancer, who had undergone breast-conserving surgery and had an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients were randomly assigned (1:1) to receive single-modality endocrine therapy or radiotherapy. Endocrine therapy consisted of daily oral aromatase inhibitors or tamoxifen, for a total planned duration of 5-10 years as per clinical discretion, while radiotherapy was administered as either whole breast or partial breast irradiation, delivered in 5-15 fractions. Randomisation was stratified by health status according to the Geriatric 8 (G8) screening tool and by age, with allocation concealed and no blinding. The co-primary endpoints were the change in HRQOL, assessed by the global health status (GHS) scale of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire 30-item core module at 24 months, and 5-year IBTR rates (not reported here). This preplanned interim analysis was performed once at least 152 patients completed the 24-month GHS HRQOL assessment. The safety population comprised patients who received the study intervention at least once after randomisation. The study is registered with ClinicalTrials.gov, NCT04134598, and is ongoing and actively recruiting.

FINDINGS

Between March 4, 2021, and June 14, 2024, 731 women were randomly assigned to receive radiotherapy (n=365) or endocrine therapy (n=366). This analysis included 104 patients in the radiotherapy group and 103 in the endocrine therapy group, with a median follow-up of 23·9 months (IQR 22·9-24·2). Patients were predominantly White (204 [99%] of 207) and the median age was 75·0 years (IQR 73·0-80·0) in the radiotherapy group and 74·0 years (72·0-80·0) in the endocrine therapy group. 86 patients in the radiotherapy group and 75 in the endocrine therapy group completed the 24-month HRQOL assessment. The mean baseline GHS score was 71·9 (SD 19·1) in the radiotherapy group and 75·5 (19·3) in the endocrine therapy group. At 24 months, the age-adjusted, G8 score-adjusted mean change from baseline in GHS was -3·40 (95% CI -7·82 to 1·03; p=0·13) in the radiotherapy group and -9·79 (-14·45 to -5·13; p<0·0001) in the endocrine therapy group, with an adjusted mean difference of 6·39 (0·14 to 12·65; p=0·045) favouring radiotherapy. Treatment-related adverse events were less frequent in the radiotherapy group (65 [67%] of 97 patients) compared with the endocrine therapy group (76 [85%] of 89). The most common grade 3-4 adverse events were arthralgia (six [7%] of 89 in the endocrine therapy group vs 0 of 97 in the radiotherapy group), pelvic organ prolapse (three [3%] vs 0), fatigue, hot flashes, myalgia, bone pain, and fractures (two [2%] vs 0 for each). Serious adverse events were reported in 15 (15%) patients in the radiotherapy group and 13 (15%) in the endocrine therapy group. There were no treatment-related deaths in either group.

INTERPRETATION

Endocrine therapy was associated with a greater reduction in HRQOL, as measured by GHS, compared with radiotherapy at 24 months. While these interim results suggest radiotherapy might better preserve HRQOL in older women with low-risk early breast cancer, further data on disease control outcomes and final patient accrual are needed to draw definitive conclusions.

FUNDING

Fondazione Radioterapia Oncologica.

Early-Stage Breast Cancer: A Critical Review of Current and Emerging Practice

Breast-conserving surgery followed by adjuvant radiation to reduce the risk of ipsilateral breast tumor recurrence is the mainstay of treatment for early-stage breast cancer (ESBC). However, improved understanding of the heterogeneity of the clinical and molecular characteristics of ESBC has led to greater efforts to personalize approaches to treatment. Furthermore, advances in the understanding of the radiobiology of breast cancer have led to several practice-changing trials on the effectiveness and tolerability of moderate and ultrahypofractionated radiation. Here, we review the recent evidence and ongoing research in the radiotherapeutic management of ESBC, including the use of boost for high-risk disease and opportunities for accelerated fractionation, partial breast irradiation, and radiation omission for low-risk disease. We also discuss how molecular profiling can inform decision-making and new opportunities for primary radiation therapy and reirradiation.

"When Less is More": Paradigm Shifts in Radiation Treatment for Early-Stage Breast Cancer

OPINION STATEMENT

Recent advancements in the treatment of early-stage breast cancer have significantly shifted the radiotherapy landscape. Traditionally, the standard of care included lumpectomy followed by endocrine therapy and 3-5 weeks of adjuvant radiation targeting the entire unilateral breast. This review summaries modern trials, emphasizing data reported since 2019 that have changed radiation treatment paradigms. Ultra-hypofractionated treatment regimens have enabled radiation oncologists to deliver the total radiation dose in as few as 5 treatments over 1 week for select patients. Partial breast irradiation, treating only the breast tissue nearest to the lumpectomy cavity, has also emerged as an effective and well-tolerated treatment. Furthermore, a growing body of evidence supports the safety of omitting radiation completely for certain older adults with low-risk disease. Ongoing research in areas such as precision cancer care, treatment de-escalation, and toxicity prevention and management reflects a broader shift toward shared decision-making in medicine and individually tailored treatment paradigms. As research progresses, treatment options will continue to evolve. Advances in radiation oncology will give the oncology team a growing array of tools to custom treatment plans to individual patient risks and toxicity concerns. Knowledge of radiation advances should be used to facilitate shared decisions with patients about the balance of treatment efficacy, toxicity, and quality of life, with the ultimate goal of promoting high-quality, personalized, and patient-centered cancer care.

21-gene recurrence score predictive of the benefit of postoperative radiotherapy after breast-conserving surgery for elderly patients with T1N0 and luminal breast cancer

PURPOSE

To assess the predictive value of the 21-gene recurrence score (RS) on the survival outcomes of postoperative radiotherapy (PORT) in elderly patients with T1N0 luminal breast cancer after breast-conserving surgery.

METHODS

We retrospectively included patients aged ≥ 70 years and diagnosed with T1N0 luminal BC between 2004 and 2015 using the data from the Surveillance, Epidemiology, and End Results. The RS groups were categorized using the TAILORx criteria as follows: low risk (RS < 11) (LR), intermediate risk (RS 11-25) (IR), and high risk (RS > 25) (HR). Kaplan-Meier analysis, propensity score matching (PSM), and Cox proportional hazards analysis were used for statistical analysis.

RESULTS

We included 5901 patients in the analysis. Of the patients, 4492 (76.1%) underwent PORT, while 1409 (23.9%) did not receive PORT. There were 1588 (26.9%), 3613 (61.2%), and 700 (12.0%) patients classified as LR, IR, and HR, respectively. There were 1182 (74.4%), 2773 (76.8%), and 537 (76.7%) patients in the LR, IR, and HR groups receiving PORT, respectively (P = 0.182). A total of 1353 pairs of patients were completely matched using PSM. PORT was independently associated with better overall survival (OS) (P < 0.001) and breast cancer-specific survival (BCSS) (P = 0.015) in the entire cohort. The sensitivity analyses showed that the receipt of PORT was not associated with OS (P = 0.887) and BCSS (P = 0.861) in the LR group. However, the receipt of PORT was associated with OS (P < 0.001) and BCSS in the IRHR group (P = 0.026).

CONCLUSION

Our study highlights the possible role of the 21-gene RS in predicting the survival outcomes of PORT following BCS in elderly patients with T1N0 luminal breast cancer.

Re-Evaluating the Omission of Radiation Therapy in Low-Risk Patients With Early-Stage Breast Cancer

Traditionally, management of early-stage breast cancer has required adjuvant radiation therapy following breast conserving surgery, due to decreased local recurrence and breast cancer mortality. However, over the past decade, there has been an increasing emphasis on potential overtreatment of patients with early-stage breast cancer. This has given rise to questions of how to optimize deintensification of treatment in this cohort of patients while maintaining clinical outcomes. A multitude of studies have focused on identification of a subset of patients with invasive breast cancer who were at low risk of local recurrence based on clinicopathologic features and therefore suitable for RT omission. These studies have failed to identify a subset that does not from RT with respect to local control. Several ongoing trials are evaluating alternative approaches to deintensification while focusing on tumor biology. With regards to ductal carcinoma in situ (DCIS), the role of RT has been questioned since breast conservation was utilized. Paralleling invasive disease studies, studies have sought to use clinicopathologic features to identify low risk patients suitable for RT omission but have failed to identify a subset that does not from RT with respect to local control. Use of new assays in patients with DCIS may represent the ideal approach for risk stratification and appropriate deintensification. At this time, when considering deintensification, individualizing treatment decisions with a focus on shared decision making is paramount.

Quality of Life Outcomes Associated With Optimization of Treatment by Omitting Radiotherapy in Early Breast Cancer

PURPOSE

Improved prognosis of early breast cancer (EBC) has created opportunities for treatment optimization but reducing morbidity should not inadvertently compromise quality of life (QoL). PROSPECT1 used pre-operative MRI and pathology findings to identify women suitable for radiotherapy (RT) omission following breast conserving surgery. We retrospectively explored the association between de-escalation by omission of RT and QoL in women with EBC.

MATERIALS AND METHODS

Three groups were recruited: PROSPECT participants who omitted RT following preoperative MRI (A); participants who received RT following preoperative MRI (B); and women who received usual care - No MRI, received RT (C). Measures included the EORTC QLQ-C30 and BR23, BCTOS, DASS-21 and a measure of decision regret. Between group differences were assessed using ANOVA or nonparametric equivalents. Semi-structured interviews were analyzed with qualitative description (n = 44).

RESULTS

Data from 400 women were analyzed (125A, 102B, 173C). Group A had fewer symptoms and better body image (breast symptoms: A-B P = .003, A-C P = <.001; arm symptoms: A-B P = .004, A-C P = .011; body image: A-C P = .041) and fewer differences between the treated and untreated breasts (cosmetic: A-B P < .001, A-C P < .001; functional: A-C P = .011; breast specific pain: A-B P < .001, A-C P < .001). Two qualitative themes were found: Treatment with the biggest impact on QoL, and Specific impact of RT on QoL.

CONCLUSIONS

Omission of RT was associated with better QoL and functional and cosmetic outcomes. It was highly acceptable to patients. Clinicians should consider the potential for preserved QoL associated with treatment optimization via omission of RT in treatment planning for patients with EBC.

Omission of adjuvant radiotherapy in low-risk elderly males with breast cancer

PURPOSE

Randomized clinical trials demonstrate that lumpectomy + hormone therapy (HT) without radiation therapy (RT) yields equivalent survival and acceptable local-regional outcomes in elderly women with early-stage, node-negative, hormone-receptor positive (HR +) breast cancer. Whether these data apply to men with the same inclusion criteria remains unknown.

METHODS

The National Cancer Database was queried for male patients ≥ 65 years with pathologic T1-2N0 (≤ 3 cm) HR + breast cancer treated with breast-conserving surgery with negative margins from 2004 to 2019. Adjuvant treatment was classified as HT alone, RT alone, or HT + RT. Male patients were matched with female patients for OS comparison. Survival analysis was performed using Cox regression and Kaplan - Meier method. Inverse probability of treatment weighting (IPTW) was applied to adjust for confounding.

RESULTS

A total of 523 patients met the inclusion criteria, with 24.4% receiving HT, 16.3% receiving RT, and 59.2% receiving HT + RT. The median follow-up was 6.9 years (IQR: 5.0-9.4 years). IPTW-adjusted 5-yr OS rates in the HT, RT, and HT + RT cohorts were 84.0% (95% CI 77.1-91.5%), 81.1% (95% CI 71.1-92.5%), and 93.0% (95% CI 90.0-96.2%), respectively. On IPTW-adjusted MVA, relative to HT, receipt of HT + RT was associated with improvements in OS (HR: 0.641; p = 0.042). RT alone was not associated with improved OS (HR: 1.264; p = 0.420).

CONCLUSION

Among men ≥ 65 years old with T1-2N0 HR + breast cancer, RT alone did not confer an OS benefit over HT alone. Combination of RT + HT demonstrated significant improvements in OS. De-escalation of treatment through omission of either RT or HT at this point should be done with caution.

Radiation therapy of breast cancer in the Nahe Breast Center: first results of an analysis in the context of health services research

BACKGROUND

The first evaluation of radiotherapy results in patients with breast cancer treated as part of a multimodal oncologic therapy in the Nahe Breast Center is presented. Analysis of the results was performed using an in-practice registry.

PATIENTS AND METHODS

From September 2016 to December 2017, 138 patients (median age 62.5 years; range 36-94 years) with breast cancer (right side, n = 67; left side, n = 71) received adjuvant radiation therapy. Of these, 103 patients received gyneco-oncologic care at the Nahe Breast Center, and 35 were referred from outside breast centers. The distribution into stages was as follows: stage I, n = 48; stage II, n = 68; stage III, n = 19; stage IV, n = 3. Neoadjuvant chemotherapy was given to 19 and adjuvant chemotherapy to 50 patients. Endocrine treatment was given to 120 patients. Both 3D conformal (n = 103) and intensity-modulated (n = 35) radiotherapy were performed with a modern linear accelerator.

RESULTS

With a median follow-up of 60 months (1-67), local recurrence occurred in 4/138 (2.9%) and distant metastasis in 8/138 (5.8%) patients; 7/138 (5.1%) patients died of their tumors during the follow-up period. The actuarial 5‑year local recurrence-free survival of all patients was 97.1%, and the actuarial 5‑year overall survival of all patients was 94.9%. We observed no grade 3 or 4 radiogenic side effects.

CONCLUSION

The results of radiotherapy for breast carcinoma at the Nahe Breast Center are comparable to published national and international results. In particular, the local recurrence rates in our study, determined absolutely and actuarially, are excellent, and demonstrate the usefulness of radiotherapy.

Hype or hope? A review of challenges in balancing tumor control and treatment toxicity in breast cancer from the perspective of the radiation oncologist

The aim of this article is to discuss the challenges and new strategies in managing breast cancer patients, with a specific focus on radiation oncology and the importance of balancing oncologic outcomes with quality of life and post-treatment morbidity. A comprehensive literature review was conducted to identify advances in the management of breast cancer, exploring de-escalation strategies, hypofractionation schemes, predictors and tools for reducing toxicity (radiation-induced lymphocyte apoptosis, deep inspiration breath-hold, adaptive radiotherapy), enhancer treatments (hyperthermia, immunotherapy) and innovative diagnostic modalities (PET-MRI, omics). Balancing oncologic outcomes with quality of life and post-treatment morbidity is crucial in the era of personalized medicine. Radiotherapy plays a critical role in the management of breast cancer patients. Large randomized trials are necessary to generalize some practices and cost remains the main obstacle for many innovations that are already applicable.

Omission of radiation therapy post breast conserving surgery

Radiation therapy (RT) after breast conserving surgery decreases the risks of local recurrence and breast cancer mortality in the multidisciplinary management of patients with breast cancer. However, breast cancer is a heterogeneous disease, and the absolute benefit of post-operative RT in individual patients varies substantially. Clinical trials aiming to identify patients with low-risk early breast cancer in whom post-operative RT may be safely omitted, based on conventional clinical-pathologic variables alone, have not provided sufficiently tailored information on local recurrence risk assessment to guide treatment decisions. The majority of patients with early breast cancer continue to be routinely treated with RT after breast conserving surgery. This approach may represent over-treatment for a substantial proportion of the patients. The clinical impact of genomic signatures on local therapy decisions for early breast cancer has been remarkably modest due to the lack of high-level evidence supporting their clinical validity for assessment of the risk of local recurrence. Efforts to personalise breast cancer care must be supported by high level evidence to enable balanced, informed treatment decisions. These considerations underpin the importance of ongoing biomarker-directed clinical trials to generate the high-level evidence necessary for setting the future standard of care in personalised local therapy for patients with early breast cancer.

LUMINA: Using molecular biomarkers to guide decision making for breast radiotherapy

In this opinion piece, we respond to comments about the LUMINA trial by Meattini and colleagues in the Journal. LUMINA was a prospective cohort study which evaluated the omission of radiotherapy after breast conserving surgery (BCS) in patients treated with endocrine therapy with low risk clinico-pathologic features and luminal A breast cancer. We address their areas of concern including the single cohort design that required careful patient selection, the relatively short follow-up period of 5 years, and the limited follow-up on younger patients. The Ki67 biomarker was key to defining the luminal A phenotype. We clarify the evidence supporting the Ki67 criteria used. The compliance with endocrine therapy was high and similar to other contemporary trials. Based on the results of LUMINA, and mounting evidence from other trials, we feel comfortable offering our patients the option of no radiotherapy after BCS if they fit the trial eligibility criteria from LUMINA and have decided to receive adjuvant endocrine therapy. We concur that a patient-centered approach to treatment decision making should be used to make patients aware of all available information including the results of the LUMINA trial when deciding on post-operative breast radiotherapy.

Optimal adjuvant therapy in older (≥70 years of age) women with low-risk early-stage breast cancer

Older women are under-represented in breast cancer (BC) clinical trials, and treatment guidelines are primarily based on BC studies in younger women. Studies uniformly report an increased incidence of local relapse with omission of breast radiation therapy. Review of the available literature suggests very low rates of distant relapse in women ≥70 years of age. The incremental benefit of endocrine therapy in decreasing rate of distant relapse and improving disease-free survival in older patients with low-risk BC remains unclear. Integration of molecular genomic assays in diagnosis and treatment of estrogen receptor positive BC presents an opportunity for optimizing risk-tailored adjuvant therapies in ways that may permit treatment de-escalation among older women with early-stage BC. The prevailing knowledge gap and lack of risk-specific adjuvant therapy guidelines suggests a compelling need for prospective trials to inform selection of optimal adjuvant therapy, including omission of adjuvant endocrine therapy in older women with low risk BC.

Comparison of adverse events in partial- or whole breast radiotherapy: investigation of cosmesis, toxicities and quality of life in a meta-analysis of randomized trials

PURPOSE/OBJECTIVE

Adjuvant whole breast radiotherapy and systemic therapy are part of the current evidence-based treatment protocols for early breast cancer, after breast-conserving surgery. Numerous randomized trials have investigated the therapeutic effects of partial breast irradiation (PBI) compared to whole breast irradiation (WBI), limiting the treated breast tissue. These trials were designed to achieve equal control of the disease with possible reduction in adverse events, improvements in cosmesis and quality of life (QoL). In this meta-analysis, we aimed to investigate the differences between PBI and WBI in side effects and QoL.

MATERIAL/METHODS

We performed a systematic literature review searching for randomized trials comparing WBI and PBI in early-stage breast cancer with publication dates after 2009. The meta-analysis was performed using the published event rates and the effect-sizes for available acute and late adverse events. Additionally, we evaluated cosmetic outcomes as well as general and breast-specific QoL using the EORTC QLQ-C30 and QLQ-BR23 questionnaires.

RESULTS

Sixteen studies were identified (n = 19,085 patients). PBI was associated with a lower prevalence in any grade 1 + acute toxicity and grade 2 + skin toxicity (OR = 0.12; 95% CI 0.09-0.18; p < 0.001); (OR = 0.16; 95% CI 0.07-0.41; p < 0.001). There was neither a significant difference in late adverse events between the two treatments, nor in any unfavorable cosmetic outcomes, rated by either medical professionals or patients. PBI-technique using EBRT with twice-daily fractionation schedules resulted in worse cosmesis rated by patients (n = 3215; OR = 2.08; 95% CI 1.22-3.54; p = 0.007) compared to WBI. Maximum once-daily EBRT schedules (n = 2071; OR = 0.60; 95% CI 0.45-0.79; p < 0.001) and IORT (p = 0.042) resulted in better cosmetic results grade by medical professionals. Functional- and symptom-based QoL in the C30-scale was not different between PBI and WBI. Breast-specific QoL was superior after PBI in the subdomains of "systemic therapy side effects" as well as "breast-" and "arm symptoms".

CONCLUSION

The analysis of multiple randomized trials demonstrate a superiority of PBI in acute toxicity as well breast-specific quality of life, when compared with WBI. Overall, late toxicities and cosmetic results were similar. PBI-technique with a fractionation of twice-daily schedules resulted in worse cosmesis rated by patients.

Effect of adjuvant radiotherapy after breast-conserving surgery in elder women with early-stage breast cancer: a propensity-score matching analysis

Purpose

The study aimed to explore the role of adjuvant radiotherapy (RT) after breast-conserving surgery (BCS) in elder women with early-stage breast cancer (BC).

Methods

BC patients with 70-79 years of age, stage T1-2N0-1M0, undergoing BCS were screened in the Surveillance, Epidemiology and End Results (SEER) database between 2010 and 2015. The clinicopathological characteristics were balanced with propensity-score matching (PSM) method. Kaplan-Meier curves and Cox regression analyses were performed to determine the impact of adjuvant RT on BC patients.

Results

Ultimately, 12,310 patients treated with adjuvant RT and 4837 patients treated with no RT, were involved in the analysis. Overall, patients treated with adjuvant RT was associated with a better breast cancer-specific survival (BCSS) (HR: 1.980 [1.596- 2.456], P < 0.001) and overall survival (OS) (HR: 2.214 [1.966- 2.494], P < 0.001) than those who did not undergo RT. After 1:1 PSM, adjuvant RT still performed advantage in both BCSS (HR: 1.918 [1.439- 2.557], P < 0.001) and OS (HR: 2.235 [1.904- 2.624], P < 0.001). In the multivariate COX analysis of BCSS, widowed, divorced and separated patients, tumor grade III, T2 stage, N1 stage, no RT, molecular subtypes with luminal B and triple negative were associated with a shorter BCSS (P < 0.05). In the multivariate COX analysis of OS, age ≥74 years, widowed, divorced and separated patients, tumor grade II/III, T2 stage, no RT, no chemotherapy, molecular subtypes with triple negative were associated with a shorter OS (P < 0.05). Furthermore, the advantages of adjuvant RT were observed in all subgroup analysis.

Conclusion

Adjuvant RT after BCS can improve both BCSS and OS in elderly patients with early-stage BC. Additionally, all subgroups analysis-derived BCSS and OS were in support of RT.

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.

Whole Breast Irradiation in Comparison to Endocrine Therapy in Early Stage Breast Cancer-A Direct and Network Meta-Analysis of Published Randomized Trials

BACKGROUND

Multiple randomized trials have established adjuvant endocrine therapy (ET) and whole breast irradiation (WBI) as the standard approach after breast-conserving surgery (BCS) in early-stage breast cancer. The omission of WBI has been studied in multiple trials and resulted in reduced local control with maintained survival rates and has therefore been adapted as a treatment option in selected patients in several guidelines. Omitting ET instead of WBI might also be a valuable option as both treatments have distinctly different side effect profiles. However, the clinical outcomes of BCS + ET vs. BCS + WBI have not been formally analyzed.

METHODS

We performed a systematic literature review searching for randomized trials comparing BCS + ET vs. BCS + WBI in low-risk breast cancer patients with publication dates after 2000. We excluded trials using any form of chemotherapy, regional nodal radiation and mastectomy. The meta-analysis was performed using a two-step process. First, we extracted all available published event rates and the effect sizes for overall and breast-cancer-specific survival (OS, BCSS), local (LR) and regional recurrence, disease-free survival, distant metastases-free interval, contralateral breast cancer, second cancer other than breast cancer and mastectomy-free interval as investigated endpoints and compared them in a network meta-analysis. Second, the published individual patient data from the Early Breast Cancer Trialists' Collaborative Group (EBCTCG) publications were used to allow a comparison of OS and BCSS.

RESULTS

We identified three studies, including a direct comparison of BCS + ET vs. BCS + WBI (n = 1059) and nine studies randomizing overall 7207 patients additionally to BCS only and BCS + WBI + ET resulting in a four-arm comparison. In the network analysis, LR was significantly lower in the BCS + WBI group in comparison with the BCS + ET group (HR = 0.62; CI-95%: 0.42-0.92; p = 0.019). We did not find any differences in OS (HR = 0.93; CI-95%: 0.53-1.62; p = 0.785) and BCSS (OR = 1.04; CI-95%: 0.45-2.41; p = 0.928). Further, we found a lower distant metastasis-free interval, a higher rate of contralateral breast cancer and a reduced mastectomy-free interval in the BCS + WBI-arm. Using the EBCTCG data, OS and BCSS were not significantly different between BCS + ET and BCS + WBI after 10 years (OS: OR = 0.85; CI-95%: 0.59-1.22; p = 0.369) (BCSS: OR = 0.72; CI-95%: 0.38-1.36; p = 0.305).

CONCLUSION

Evidence from direct and indirect comparison suggests that BCS + WBI might be an equivalent de-escalation strategy to BCS + ET in low-risk breast cancer. Adverse events and quality of life measures have to be further compared between these approaches.

Impact of non-adherence to endocrine therapy on recurrence risk in older women with stage I breast cancer after breast-conserving surgery

PURPOSE

We examined the impact of non-adherence to adjuvant endocrine therapy (ET) on the risk and site of recurrence among older women with early stage, hormone receptor positive (HR+) breast cancer (EBC).

METHODS

A population-based cohort of women age ≥ 65 years with T1N0 HR + EBC who were diagnosed between 2010 and 2016 and treated with breast-conserving surgery (BCS) + ET was identified. Treatment and outcomes were ascertained through linkage with administrative databases. ET non-adherence was examined as a time-dependent covariate in multivariable cause-specific Cox regression models to evaluate its effect on the risks of ipsilateral local recurrence (LR), contralateral breast cancer, and distant metastases.

RESULTS

The population cohort includes 2637 women; 73% (N = 1934) received radiation (RT) + ET and 27% (N = 703) received ET alone. At a median follow-up of 8.14 years, the first event was LR in 3.6% of women treated with ET alone and 1.4% for those treated with RT + ET (p < 0.001); the risk of distant metastases was < 1% in both groups. The proportion of time adherent to ET was 69.0% among those treated with RT + ET and 62.8% for those treated with ET alone. On multivariable analysis, increasing proportion of time non-adherent to ET was associated with increased risk of LR ((HR = 1.52 per 20% increase in time; 95%CI 1.25, 1.85; p < 0.001), contralateral BC (HR = 1.55; 95%CI 1.30, 1.84; p < 0.001), and distant metastases (HR = 1.44; 95%CI 1.08, 1.94; p = 0.01) but absolute risks were low.

CONCLUSION

Non-adherence to adjuvant ET was associated with an increased risk of recurrence, but absolute recurrence rates were low.

Adjuvant Therapy for Elderly Breast Cancer Patients after Breast-Conserving Surgery: Outcomes in Real World Practice

We aimed to evaluate the standard of care of adjuvant radiotherapy (RT) after breast-conserving surgery (BCS) in elderly female patients (≥65 years) treated outside of clinical trials and to identify potential factors related to the omission of RT and the interaction with endocrine therapy (ET). All women treated with BCS at two major breast centers between 1998 and 2014 were evaluated. Data were provided by the Tumor Registry Munich. Survival analyses were conducted using the Kaplan-Meier method. Prognostic factors were identified using multivariate Cox regression analysis. The median follow-up was 88.4 months. Adjuvant RT was performed in 82% (2599/3171) of patients. Irradiated patients were younger (70.9 vs. 76.5 years, p < 0.001) and were more likely to receive additional chemotherapy (p < 0.001) and ET (p = 0.014). Non-irradiated patients more often had non-invasive DCIS tumors (pTis: 20.3% vs. 6.8%, p < 0.001) and did not undergo axillary surgery (no axillary surgery: 50.5% vs. 9.5%, p < 0.001). Adjuvant RT was associated with improved locoregional tumor control after BCS in invasive tumors (10-year local recurrence-free survival (LRFS): 94.0% vs. 75.1%, p < 0.001, 10-year lymph node recurrence-free survival (LNRFS): 98.1% vs. 93.1%, p < 0.001). Multivariate analysis confirmed significant benefits for local control with postoperative RT. Furthermore, RT led to increased locoregional control even in patients who received ET (10-year LRFS 94.8% with ET + RT vs. 78.1% with ET alone, p < 0.001 and 10-year LNRFS: 98.2% vs. 95.0%, p = 0.003). Similarly, RT alone had significantly better locoregional control rates compared to ET alone (10-year LRFS 92.6% with RT alone vs. 78.1% with ET alone, p < 0.001 and 10-year LNRFS: 98.0% vs. 95.0%, p = 0.014). The present work confirms the efficacy of postoperative RT for breast carcinoma in elderly patients (≥65 years) treated in a modern clinical setting outside of clinical trials, even in patients who receive ET.

Pattern and risk factors of isolated local relapse among women with hormone receptor-positive and HER2-negative breast cancer and lymph node involvement: 10-year follow-up analysis of the PACS 01 and PACS 04 trials

PURPOSE

We aimed to determine the pattern of isolated local recurrences (ILR) in women with stage II-III hormone receptor-positive and human epidermal growth factor receptor 2 breast cancer (HR + /HER2-BC) after 10-year follow-up.

METHODS

UNICANCER-PACS 01 and PACS 04 trials included 5,008 women with T1-T3 and N1-N3 to evaluate the efficacy of different anthracycline ± taxanes-containing regimens after modified mastectomy or lumpectomy plus axillary lymph node dissection. We analyzed the data from 2,932 women with HR + /HER2- BC to evaluate the cumulative incidence of ILR and describe the factors associated with ILR.

RESULTS

After a median follow-up of 9.1 years (95% CI 9.0-9.2 years), the cumulative incidence of ILR increased steadily between 1 and 10 years from 0.2% to 2.5%. The multivariable analysis showed that older age (subhazard ratios [sHR] = 0.95, 95% CI 0.92-0.99) and mastectomy (sHR = 0.39, 95% CI 0.17-0.86) were associated with lower risk of ILR, and no adjuvant endocrine therapy (sHR = 2.73, 95% CI 1.32 7-5.67) with increased risk of ILR.

CONCLUSION

In this population of high-risk patients with localized HR + /HER2- BC, the risk of ILR was low but remained constant over 10 years. Younger age at diagnosis, breast-conserving surgery, and adjuvant endocrine therapy were independent risk factors of ILR.

Impact of de-escalating systemic therapy guided by 21-gene assay on locoregional recurrence after partial-breast irradiation

PURPOSE

Partial-breast irradiation (PBI) has been performed as alternative to whole-breast irradiation (WBI) in breast-conserving therapy (BCT). Recently, the 21-gene recurrence score (RS) was introduced to determine the adjuvant therapy for estrogen receptor (ER)-positive, and human epidermal growth factor receptor 2 (HER2)-negative diseases. However, the impact of RS-based systemic therapy on locoregional recurrence (LRR) following BCT with PBI remains uninvestigated.

METHODS AND MATERIALS

Patients with ER-positive, HER2-negative, and node-negative breast cancer who underwent BCT with PBI were examined during May 2012-March 2022. In addition to immunohistochemistry (IHC), RS was available to decide on adjuvant therapy.

RESULTS

In total, 431 patients were evaluated with a median followup of 48.6 months. The 4-year LRR-free survival rates were 97.3% and 96.4% in the IHC and RS cohorts, respectively (p = 0.50). Ki67 of >20% was significantly associated with LRR in the multivariate analysis (HR 4.39, p < 0.05). For patients with Ki67 > 20%, 29 of 71 (40.8%) and 46 of 59 (78.0%) patients received only endocrine therapy in the IHC and RS cohorts, respectively (p < 0.0001). For patients with Ki67 >20% who received only endocrine therapy, the 4-year LRR-free survival rates were 91.8% in the IHC cohort and 94.6% in the RS cohort (p = 0.29) CONCLUSIONS: Although the introduction of RS increased the number of patients receiving endocrine therapy alone for Ki67 >20% of disease by two times, the LRR-free survival after BCT with PBI could be maintained. However, further studies from multiple institutions with longer followup data are required.

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.).

American Society of Clinical Oncology 2022 Annual Meeting Highlights for Radiation Oncologists

The American Society of Clinical Oncology annual meeting is the largest multidisciplinary oncology-focused conference in the world. With almost 5000 total abstracts in 2022, it is difficult for individuals to evaluate all the results. Here we present a review of 28 selected abstracts, across all disease sites, focusing on those of greatest relevance to radiation oncologists.

Accelerated Partial Breast Irradiation: An Opportunity for Therapeutic De-escalation

Partial breast irradiation (PBI) has been demonstrated to have comparable outcomes to whole breast irradiation based on multiple randomized trials with long-term follow-up. However, despite the strength of the data available, PBI remains underutilized despite being an appropriate option for many women diagnosed with early-stage breast cancer. This is significant, as PBI offers the potential to reduce toxicities and shorten treatment duration without impacting outcomes; in addition, for low-risk patients, PBI alone is being investigated as an alternative to endocrine therapy alone. Modern PBI can be delivered with multiple techniques, and advances in treatment planning have allowed for improved therapeutic ratios compared with earlier techniques; one such approach is utilizing stereotactic body radiation therapy approaches allowing for smaller target margins and therefore lower breast doses. Moving forward, studies are ongoing evaluating the use of radiation alone including PBI as compared with endocrine therapy alone, with prospective studies evaluating stereotactic body radiation therapy.

Cost-Effectiveness Analysis of Ultra-Hypofractionated Whole Breast Radiation Therapy Alone Versus Hormone Therapy Alone or Combined Treatment for Low-Risk ER-Positive Early Stage Breast Cancer in Women Aged 65 Years and Older

PURPOSE

The optimal management of early-stage, low-risk, hormone-positive breast cancer in older women remains controversial. Recent trials have shown that 5-fraction ultrahypofractionated whole-breast irradiation (U-WBI) has similar outcomes to longer courses, reducing the cost and inconvenience of treatment. We performed a cost-utility analysis to compare U-WBI to hormone therapy alone or their combination.

METHODS AND MATERIALS

We simulated 3 different treatment approaches for women age 65 years or older with pT1-2N0 ER-positive invasive ductal carcinoma treated with lumpectomy with negative margins using a Markov microsimulation model. The strategies were U-WBI performed with a 3-dimensional conformal technique over 5 fractions without a boost ("radiation therapy [RT] alone"), adjuvant hormone therapy (anastrozole for 5 years) without RT ("aromatase-inhibitor [AI] alone"), or the combination of the 2. The combination strategy was calibrated to match trial results, and the relative effectiveness of the RT alone and AI alone strategies were inferred from previous randomized trials. The primary endpoint was the cost-effectiveness of the 3 strategies over a lifetime horizon as measured by the incremental cost-effectiveness ratio (ICER), with a value of $100,000/quality-adjusted life-year deemed "cost-effective."

RESULTS

The model results compared with the prespecified target outcomes. On average, RT alone was the least expensive strategy ($14,775), with AI alone slightly more ($14,998), and combination therapy the costliest ($19,802). RT alone dominated AI alone (the incremental cost-effectiveness ratio [ICER] -$5089). Combination therapy, compared with RT alone, was slightly more expensive than our definition of cost-effective (ICER $113,468) but was cost-effective compared with AI alone (ICER $54,451). Probabilistic sensitivity analysis demonstrated RT alone to be cost-effective in 50% of trials, with combination therapy in 36% and AI alone in 14%.

CONCLUSIONS

U-WBI alone appears the more cost-effective de-escalation strategy for these low-risk patients, compared with AI alone. Combining U-WBI and AI appears more costly but may be preferred by some patients.

Optimizing Adjuvant Treatment Recommendations for Older Women with Biologically Favorable Breast Cancer: Short-Course Radiation or Long-Course Endocrine Therapy?

Omission of radiotherapy among older women taking 5 years of adjuvant endocrine therapy following breast conserving surgery for early-stage, hormone sensitive breast cancers is well-studied. However, endocrine therapy toxicities are significant, and many women have difficulty tolerating endocrine therapy, particularly elderly patients with comorbidities. Omission of endocrine therapy among women receiving adjuvant radiation is less well-studied, but available randomized and non-randomized data suggest that this approach may confer equivalent local control and survival for select patients. Herein we review available randomized and non-randomized outcome data for women treated with radiation monotherapy and emphasize the need for future prospective, randomized studies of endocrine therapy omission.

[The place of radiotherapy]

Radiation therapy (RT) is a key component of the management of elderly breast cancer patients. However, level I evidence in elderly patients is limited. Patient selection should include comorbidities and geriatric assessment. Advances in radiation planning and delivery are improving target coverage, reducing toxicity, and expanding treatment eligibility. Some alternative techniques, such as treatment in the lateral or prone position, may reduce the risk of toxicity. Shorter cycles of hypofractionated whole breast RT are safe and effective. In some cases, partial breast irradiation may be an option.

Ways to improve breast cancer patients' management and clinical outcome: The 2020 Assisi Think Tank Meeting

We report on the third Assisi Think Tank Meeting (ATTM) on breast cancer, a brainstorming project which involved European radiation and clinical oncologists who were dedicated to breast cancer research and treatment. Held on February 2020, the ATTM aimed at identifying key clinical questions in current clinical practice and "grey" areas requiring research to improve management and outcomes. Before the meeting, three key topics were selected: 1) managing patients with frailty due to either age and/or multi-morbidity; 2) stereotactic radiation therapy and systemic therapy in the management of oligometastatic disease; 3) contralateral breast tumour prevention in BCRA-mutated patients. Clinical practice in these areas was investigated by means of an online questionnaire. In the lapse period between the survey and the meeting, the working groups reviewed data, on-going studies and the clinical challenges which were then discussed in-depth and subjected to intense brainstorming during the meeting; research protocols were also proposed. Methodology, outcome of discussions, conclusions and study proposals are summarized in the present paper. In conclusion, this report presents an in-depth analysis of the state of the art, grey areas and controversies in breast cancer radiation therapy and discusses how to confront them in the absence of evidence-based data to guide clinical decision-making.

Accelerated Partial Breast Irradiation with Intraoperative Radiotherapy Is Effective in Luminal Breast Cancer Patients Aged 60 Years and Older

Adjuvant whole breast irradiation (AWBI) improves local control and survival in breast cancer patients after breast-conserving surgery. Between 2010 and 2017, 823 patients ≥ 60 years with ER-positive, Her-2 negative, clinically N0 breast cancer underwent breast-conserving surgery (BCS) at the West Pomeranian Oncology Center. Intraoperative radiotherapy (IORT) with kV photons was applied to 199 (24.2%) patients according to the IORT protocol, and AWBI only was applied to 624 (75.8%). IORT patients in cases with lymph node metastasis, lobular type presence, extensive in situ components, lymphatic vessel invasion, or resection margin < 2 mm, additionally underwent AWBI. Median follow-up was 74 months. There were two (1%) breast relapses in the IORT protocol group and one (0.2%) in the AWBI-only group. In each group, one axillary lymph node relapse was diagnosed (0.5% and 0.2%, respectively). There were two local relapses in the IORT-only group, and they were treated further with BCS and AWBI. Although locoregional relapse-free survival differed between the AWBI-only and IORT protocol groups (98.5% vs. 99.7%, p = 0.048), the local control, distant metastasis-free survival, and breast cancer-specific survival were similar. IORT is a reasonable option to avoid AWBI in ER-positive, Her-2 negative, cN0 women with breast cancer aged ≥ 60 years.

Implicaciones de la pandemia en la radioterapia para el cáncer de mama. Omisión de la radioterapia

La pandemia actual por el nuevo coronavirus (SARS-CoV-2) exige que los sistemas de salud rápidamente adopten medidas encaminadas a mitigar la crisis, lo que implica redistribuir los recursos económicos, sociales y la fuerza laboral, para que aquellos sectores de la población más afectados puedan ser atendidos de forma óptima y oportuna. En los pacientes con carcinoma mamario in situ e invasivo de bajo riesgo, la radioterapia postoperatoria no ofrece ningún beneficio en supervivencia global, lo que hace atractiva la idea de omitir este recurso oncológico. En este artículo, se realizó una revisión de la literatura sobre los criterios para omitir la radioterapia adyuvante en los pacientes con neoplasias mamarias de bajo riesgo. Adicionalmente, se resumen las recomendaciones emitidas por algunas sociedades científicas internacionales durante la contingencia actual, y se analizan determinadas razones por las cuales los médicos se rehúsan a cambiar conductas clínicas que ofrecen ventajas limitadas, muchas veces contrarrestadas por los riesgos y los efectos adversos asociados.

Accelerated Partial Breast Irradiation using External-Beam or Intraoperative Electron Radiotherapy: 5 year oncological outcomes of a prospective cohort study

PURPOSE

To evaluate the ipsilateral breast tumor recurrence (IBTR) after two accelerated partial breast irradiation (APBI) techniques (intraoperative electron radiotherapy, IOERT and external-beam APBI, EB-APBI) in patients with early stage breast cancer.

PATIENTS AND METHODS

Between 2011 and 2016, women ≥60 years with breast carcinoma or DCIS of ≤30mm and cN0 undergoing breast conserving therapy were included in a two-armed prospective multi-center cohort study. IOERT (1 × 23.3Gy prescribed at the 100% isodose line) was applied in one hospital and EB-APBI (10 × 3.85Gy daily) in 2 other hospitals. Primary endpoint was IBTR (all recurrences in the ipsilateral breast irrespective of localization) at 5 years after lumpectomy. A competing risk model was used to estimate the cumulative incidences of IBTR, which were compared using Fine and Gray's test. Secondary endpoints were locoregional recurrence rate (LRR), distant recurrence, disease specific survival and overall survival. Univariate Cox-regression models were estimated to identify risk factors for IBTR. Analyses were performed of the intention to treat (ITT) population (IOERT n=305; EB-APBI n=295), and sensitivity analyses were done of the per-protocol population (PP) (IOERT n=270; EB-APBI n=207).

RESULTS

Median follow up was 5.2 years (IOERT) and 5 years (EB-APBI). Cumulative incidence of IBTR in the ITT population at 5 years after lumpectomy was 10.6% (95% confidence interval 7.0-14.2%) after IOERT and 3.7% (95%CI 1.2-5.9%) after EB-APBI (p=0.002). LRR was significantly higher after IOERT than EB-APBI (12.1% vs 4.5%, p=0.001). There were no differences between groups in other endpoints. Sensitivity analysis showed similar results. For both groups, no significant risk factors for IBTR were identified in the ITT population. In the PP population surgical margin status was the only significant risk factor for developing IBTR in both treatment groups.

CONCLUSION

Ipsilateral breast tumor recurrences and locoregional recurrence rates were unexpectedly high in patients treated with IOERT, and acceptable in patients treated with EB-APBI.

Systematic review of the evidence sources applied to cost-effectiveness analyses for older women with primary breast cancer

OBJECTIVE

To appraise the sources of evidence and methods to estimate input parameter values in decision-analytic model-based cost-effectiveness analyses of treatments for primary breast cancer (PBC) in older patients (≥ 70 years old).

METHODS

Two electronic databases (Ovid Medline, Ovid EMBASE) were searched (inception until 5 September-2021) to identify model-based full economic evaluations of treatments for older women with PBC as part of their base-case target population or age-subgroup analysis. Data sources and methods to estimate four types of input parameters including health-related quality of life (HRQoL); natural history; treatment effect; resource use were extracted and appraised. Quality assessment was completed by reference to the Consolidated Health Economic Evaluation Reporting Standards.

RESULTS

Seven model-based economic evaluations were included (older patients as part of their base-case (n = 3) or subgroup (n = 4) analysis). Data from younger patients (< 70 years) were used frequently to estimate input parameters. Different methods were adopted to adjust these estimates for an older population (HRQoL: disutility multipliers, additive utility decrements; Natural history: calibration of absolute values, one-way sensitivity analyses; Treatment effect: observational data analysis, age-specific behavioural parameters, plausible scenario analyses; Resource use: matched control observational data analysis, age-dependent follow-up costs).

CONCLUSION

Improving estimated input parameters for older PBC patients will improve estimates of cost-effectiveness, decision uncertainty, and the value of further research. The methods reported in this review can inform future cost-effectiveness analyses to overcome data challenges for this population. A better understanding of the value of treatments for these patients will improve population health outcomes, clinical decision-making, and resource allocation decisions.

Omission of adjuvant radiotherapy for older adults with early-stage breast cancer particularly in the COVID era: A literature review (on the behalf of Italian Association of Radiotherapy and Clinical Oncology)

This review is aimed at evaluating whether radiation therapy (RT) can be omitted in older adult early-stage low-risk breast cancer (BC) patients. The published data are particularly relevant at present, during the COVID-19 pandemic emergency, to define a treatment strategy and to prioritize essential therapy. Cochrane Database of Systematic Reviews and PubMED were systematically researched from outset through April 2020 using Mesh terms. Only randomized controlled trials (RCT), with one arm without adjuvant whole-breast irradiation (WBI), were included in the analysis. Recent literature regarding the COVID pandemic and BC RT was assessed. The reported RCTs identified a group of BC patients (pT1-2N0M0 R0, grade 1-2, estrogen receptor (ER) positive, human epidermal growth factor receptor 2 (HER2) negative tumours) in which the absolute risk of local recurrence (LR) was considered low enough to omit RT. The most common risk factors were tumor diameter, nodal and receptor status. Adjuvant RT had a significant impact on LR but not on distant metastasis (DM) or death. During the COVID 19 pandemic, results from RTCs were re-considered to define treatment recommendations for BC patients. International scientific societies and radiation oncology experts suggested RT omission, whenever possible, in older adult early-stage BC patients. Adjuvant RT might be omitted in a highly selected group of older adult early-stage BC patients with favourable prognostic factors. Hypofractionated regimens should be the standard. RT omission, partial breast irradiation (PBI), and ultra- hypofractionated regimens could be considered in selected cases due to the pandemic.

Partial breast irradiation versus whole breast radiotherapy for early breast cancer

BACKGROUND

Breast-conserving therapy for women with breast cancer consists of local excision of the tumour (achieving clear margins) followed by radiotherapy (RT). Most true recurrences occur in the same quadrant as the original tumour. Whole breast radiotherapy (WBRT) may not protect against the development of a new primary cancer developing in other quadrants of the breast. In this Cochrane Review, we investigated the delivery of radiation to a limited volume of the breast around the tumour bed (partial breast irradiation (PBI)) sometimes with a shortened treatment duration (accelerated partial breast irradiation (APBI)).

OBJECTIVES

To determine whether PBI/APBI is equivalent to or better than conventional or hypofractionated WBRT after breast-conserving therapy for early-stage breast cancer.

SEARCH METHODS

On 27 August 2020, we searched the Cochrane Breast Cancer Group Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and three trial databases. We searched for grey literature: OpenGrey (September 2020), reference lists of articles, conference proceedings and published abstracts, and applied no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) without confounding, that evaluated conservative surgery plus PBI/APBI versus conservative surgery plus WBRT. Published and unpublished trials were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors (BH and ML) performed data extraction, used Cochrane's risk of bias tool and resolved any disagreements through discussion, and assessed the certainty of the evidence for main outcomes using GRADE. Main outcomes were local recurrence-free survival, cosmesis, overall survival, toxicity (subcutaneous fibrosis), cause-specific survival, distant metastasis-free survival and subsequent mastectomy. We entered data into Review Manager 5 for analysis.

MAIN RESULTS

We included nine RCTs that enrolled 15,187 women who had invasive breast cancer or ductal carcinoma in-situ (6.3%) with T1-2N0-1M0 Grade I or II unifocal tumours (less than 2 cm or 3 cm or less) treated with breast-conserving therapy with negative margins. This is the second update of the review and includes two new studies and 4432 more participants. Local recurrence-free survival is probably slightly reduced (by 3/1000, 95% CI 6 fewer to 0 fewer) with the use of PBI/APBI compared to WBRT (hazard ratio (HR) 1.21, 95% confidence interval (CI) 1.03 to 1.42; 8 studies, 13,168 participants; moderate-certainty evidence). Cosmesis (physician/nurse-reported) is probably worse (by 63/1000, 95% CI 35 more to 92 more) with the use of PBI/APBI (odds ratio (OR) 1.57, 95% CI 1.31 to 1.87; 6 studies, 3652 participants; moderate-certainty evidence). Overall survival is similar (0/1000 fewer, 95% CI 6 fewer to 6 more) with PBI/APBI and WBRT (HR 0.99, 95% CI 0.88 to 1.12; 8 studies, 13,175 participants; high-certainty evidence). Late radiation toxicity (subcutaneous fibrosis) is probably increased (by 14/1000 more, 95% CI 102 more to 188 more) with PBI/APBI (OR 5.07, 95% CI 3.81 to 6.74; 2 studies, 3011 participants; moderate-certainty evidence). The use of PBI/APBI probably makes little difference (1/1000 less, 95% CI 6 fewer to 3 more) to cause-specific survival (HR 1.06, 95% CI 0.83 to 1.36; 7 studies, 9865 participants; moderate-certainty evidence). We found the use of PBI/APBI compared with WBRT probably makes little or no difference (1/1000 fewer (95% CI 4 fewer to 6 more)) to distant metastasis-free survival (HR 0.95, 95% CI 0.80 to 1.13; 7 studies, 11,033 participants; moderate-certainty evidence). We found the use of PBI/APBI in comparison with WBRT makes little or no difference (2/1000 fewer, 95% CI 20 fewer to 20 more) to mastectomy rates (OR 0.98, 95% CI 0.78 to 1.23; 3 studies, 3740 participants, high-certainty evidence).

AUTHORS' CONCLUSIONS

It appeared that local recurrence-free survival is probably worse with PBI/APBI; however, the difference was small and nearly all women remain free of local recurrence. Overall survival is similar with PBI/APBI and WBRT, and we found little to no difference in other oncological outcomes. Some late effects (subcutaneous fibrosis) may be worse with PBI/APBI and its use is probably associated with worse cosmetic outcomes. The limitations of the data currently available mean that we cannot make definitive conclusions about the efficacy and safety or ways to deliver PBI/APBI. We await completion of ongoing trials.

De-escalating adjuvant therapies in older patients with lower risk estrogen receptor-positive breast cancer treated with breast-conserving surgery: A systematic review and meta-analysis

PURPOSE

Radiation therapy (RT) and endocrine therapy (ET) are standard treatments for hormone receptor-positive (HR+) breast cancer after breast-conserving surgery (BCS). However, many older patients are at greater risk of treatment-related toxicities and non-cancer related death, and less likely to benefit from these standard treatments. A systematic review was performed evaluating outcomes of omitting RT or ET in older patients aged ≥50 treated with BCS for lower-risk breast cancer.

METHODS

Medline, Embase, and the Cochrane Register of Controlled Trials were queried from 1980 to April 30th, 2020 for randomized controlled studies (RCTs) and prospective cohort studies (PCSs) evaluating omission of RT and/or ET compared to RT plus ET in patients. Meta-analysis was performed using random-effects models with findings reported as risk ratios (RR) with 95% confidence intervals (CI).

RESULTS

From 3860 citations, 10 prospective studies met eligibility criteria. Omission of RT alone was evaluated in 7 RCTs (n = 4604) and one PCS (n = 667); omission of ET alone was assessed in 1 PCS (n = 271); and omission of either ET or RT was compared to ET plus RT in 1 RCT (n = 495). Adjuvant RT compared to no RT reduced 5- and 10-year in-breast tumor recurrence [5-year: RR 0.16, 95 %CI 0.09-0.27 l 10-year: 0.28, 95 %CI 0.16-0.5], but had no effect on survival [5-year: RR 0.94, 95 %CI 0.77-1.15; 10-year: 1.01, 95 %CI 0.9-1.12].

CONCLUSION

The current body of evidence suggests that RT can be omitted in older patients with lower-risk disease. However, more trials on the omission of ET are required to better inform treatment decisions.

Comparing Local and Systemic Control between Partial- and Whole-Breast Radiotherapy in Low-Risk Breast Cancer-A Meta-Analysis of Randomized Trials

PURPOSE/OBJECTIVE

The standard treatment for localized low-risk breast cancer is breast-conserving surgery, followed by adjuvant radiotherapy and appropriate systemic therapy. As the majority of local recurrences occur at the site of the primary tumor, numerous trials have investigated partial-breast irradiation (PBI) instead of whole-breast treatment (WBI) using a multitude of irradiation techniques and fractionation regimens. This meta-analysis addresses the impact on disease-specific endpoints, such as local and regional control, as well as disease-free survival of PBI compared to that of WBI in published randomized trials.

MATERIAL AND METHODS

We conducted a systematic literature review and searched for randomized trials comparing WBI and PBI in early-stage breast cancer with publication dates after 2009. The meta-analysis was based on the published event rates and the effect sizes for available oncological endpoints of at least two trials reporting on them. We evaluated in-breast tumor recurrences (IBTR), local recurrences at the primary site and elsewhere in the ipsilateral breast, regional recurrences (RR), distant metastasis-free interval (DMFI), disease-free survival (DFS), contralateral breast cancer (CBC), and second primary cancer (SPC). Furthermore, we aimed to assess the impact of different PBI techniques and subgroups on IBTR. We performed all statistical analyses using the inverse variance heterogeneity model to pool effect sizes.

RESULTS

For the intended meta-analysis, we identified 13 trials (overall 15,561 patients) randomizing between PBI and WBI. IBTR was significantly higher after PBI (OR = 1.66; CI-95%: 1.07-2.58; p = 0.024) with an absolute difference of 1.35%. We detected significant heterogeneity in the analysis of the PBI technique with intraoperative radiotherapy resulting in higher local relapse rates (OR = 3.67; CI-95%: 2.28-5.90; p < 0.001). Other PBI techniques did not show differences to WBI in IBTR. Both strategies were equally effective at the primary tumor site, but PBI resulted in statistically more IBTRs elsewhere in the ipsilateral breast. IBTRs after WBI were more likely to be located at the primary tumor bed, whereas they appeared equally distributed within the breast after PBI. RR was also more frequent after PBI (OR = 1.75; CI-95%: 1.07-2.88; p < 0.001), yet we did not detect any differences in DMFI (OR = 1.08; CI-95%: 0.89-1.30; p = 0.475). DFS was significantly longer in patients treated with WBI (OR = 1.14; CI-95%: 1.02-1.27; p = 0.003). CBC and SPC were not different in the test groups (OR = 0.81; CI-95%: 0.65-1.01; p = 0.067 and OR = 1.09; CI-95%: 0.85-1.40; p = 0.481, respectively).

CONCLUSION

Limiting the target volume to partial-breast radiotherapy appears to be appropriate when selecting patients with a low risk for local and regional recurrences and using a suitable technique.

Cost-Effectiveness Modeling of Surgery Plus Adjuvant Endocrine Therapy Versus Primary Endocrine Therapy Alone in UK Women Aged 70 and Over With Early Breast Cancer

OBJECTIVES

Approximately 20% of UK women aged 70+ with early breast cancer receive primary endocrine therapy (PET) instead of surgery. PET reduces surgical morbidity but with some survival decrement. To complement and utilize a treatment dependent prognostic model, we investigated the cost-effectiveness of surgery plus adjuvant therapies versus PET for women with varying health and fitness, identifying subgroups for which each treatment is cost-effective.

METHODS

Survival outcomes from a statistical model, and published data on recurrence, were combined with data from a large, multicenter, prospective cohort study of over 3400 UK women aged 70+ with early breast cancer and median 52-month follow-up, to populate a probabilistic economic model. This model evaluated the cost-effectiveness of surgery plus adjuvant therapies relative to PET for 24 illustrative subgroups: Age {70, 80, 90} × Nodal status {FALSE (F), TRUE (T)} × Comorbidity score {0, 1, 2, 3+}.

RESULTS

For a 70-year-old with no lymph node involvement and no comorbidities (70, F, 0), surgery plus adjuvant therapies was cheaper and more effective than PET. For other subgroups, surgery plus adjuvant therapies was more effective but more expensive. Surgery plus adjuvant therapies was not cost-effective for 4 of the 24 subgroups: (90, F, 2), (90, F, 3), (90, T, 2), (90, T, 3).

CONCLUSION

From a UK perspective, surgery plus adjuvant therapies is clinically effective and cost-effective for most women aged 70+ with early breast cancer. Cost-effectiveness reduces with age and comorbidities, and for women over 90 with multiple comorbidities, there is little cost benefit and a negative impact on quality of life.