Adjuvant breast radiotherapy, endocrine therapy, or both after breast conserving surgery in older women with low-risk breast cancer: Results from a population-based study

Geriatric Breast Cancer: Staging, Molecular Surrogates, and Treatment. A Review & Meta-analysis

Breast cancer (BC) is one of the most frequent cancers in females across the globe. Treatment recommendations for BC patients are primarily driven by patient age, staging and tumor molecular subtype. Thus, we updated the general overview of BC staging, molecular surrogates, and treatment choices for women >70 years based on a systematic study encompassing the years 2013-2023. A PRISMA guidelines and PICO framework were followed, and relevant research articles were searched using different data bases (Web of Sciences, PubMed, MEDLINE, and Scopus). Mixed Methods Appraisal Tool was used for studies quality assessment. The research articles that made it into the systematic review were compiled using qualitative criteria. In the meanwhile, heterogeneity was determined using meta-analysis with RevMan 5.4. We applied a random effects model with a 0.05 significance level. Overall, there were 4151 research articles, after screening only 17 articles with 39,906 patients were included. Conclusion: Elderly patients with breast cancer should be treated differently in an adapted way. The treatment should not be the same worldwide due to different health systems. Molecular surrogates are different in geriatric patients. Surgery is the best option for treatment in this subset of patients. We need to have therapeutic decision appointments for elderly patients with breast cancer. The guidelines and medical authority should be used in the best decision.

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.

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.

Avoiding Overtreatment of Women ≥70 With Early-Stage Breast Cancer: A Provider-Level Deimplementation Strategy

INTRODUCTION

National guidelines recommend against routine axillary staging with sentinel lymph node biopsy (SLNB) and adjuvant radiotherapy (RT) in women ≥70 y with early-stage, hormone receptor-positive, HER2-negative breast cancer and clinically negative axilla; however, these practices remain common.

METHODS

We conducted a prospective pilot study from August 2021 to 2022 using an intervention targeting breast surgeons and radiation oncologists in Michigan that aimed to reduce SLNB and RT in eligible patients. The intervention consisted of (1) a geriatric assessment, (2) an assessment of the patient's medical maximizing-minimizing preferences, and (3) a tailored script with counterpoints to reasons patients commonly seek SLNB or RT. At the end of the study period, participants completed a survey providing feedback with the primary outcomes being: acceptability, appropriateness, feasibility, and intention and motivation to use the materials based on validated measures.

RESULTS

Participants (n = 23) included 15 breast surgeons and 8 radiation oncologists. Collectively, the materials were used with 115 patients. Considering all materials holistically, acceptability, appropriateness, and feasibility of the intervention were high; participants also intended and were motivated to use the intervention. Scores across all measures were highest for the geriatric assessment and lowest for the tailored script. The major barriers to using the intervention were limited time and instances of disagreement on treatment recommendations among surgeons and radiation oncologists.

CONCLUSIONS

The omission of SLNB and adjuvant RT should be discussed in appropriately selected patients. A multifaceted provider-level deimplementation strategy may be an effective means for achieving this goal.

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.

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.

Comparative cost-effectiveness of radiotherapy among older women with hormone receptor positive early-stage breast cancer

OBJECTIVE

The aim was to examine the real-world cost-effectiveness of breast-conserving surgery (BCS) plus hormonal therapy with radiotherapy, compared to hormonal therapy alone among women 66 and older with hormone receptor positive early-stage breast cancer in the United States (US).

METHODS

This study was conducted from a U.S. Centers for Medicare and Medicaid Services perspective and an eight-year time horizon. Both costs (2020 US$) and health utilities (quality-adjusted life years, QALYs) were obtained from retrospective studies using the SEER linked with Medicare and Medicare Health Outcomes Survey, respectively. The incremental cost-effectiveness ratio (ICER) of the addition of radiotherapy to hormonal therapy versus hormonal therapy alone after BCS was estimated by an unbiased doubly robust estimator. Sensitivity analyses were conducted through bootstrapping to estimate credible intervals.

RESULTS

The addition of radiotherapy to hormonal therapy after BCS yielded the highest clinical benefits (2.66 QALYs) and costs ($19,424.27) compared to its hormonal therapy alone after BCS (0.77 QALYS; $2,028.58). The ICER was estimated to be $9,174.94/QALY. Sensitivity analyses did not change the direction of the findings.

CONCLUSIONS

The results implicated that the combination of radiotherapy and hormonal therapy is cost-effective in the US.

Experiences and Perceptions of Older Adults with Lower-Risk Hormone Receptor-Positive Breast Cancer about Adjuvant Radiotherapy and Endocrine Therapy: A Patient Survey

Older patients with lower-risk hormone receptor-positive (HR+) breast cancer are frequently offered both radiotherapy (RT) and endocrine therapy (ET) after breast-conserving surgery (BCS). A survey was performed to assess older patients’ experiences and perceptions regarding RT and ET, and participation interest in de-escalation trials. Of the 130 patients approached, 102 eligible patients completed the survey (response rate 78%). The median age of respondents was 74 (interquartile range 71–76). Most participants (71%, 72/102) received both RT and ET. Patients felt the role of RT and ET, respectively, was to: reduce ipsilateral tumor recurrence (91%, 90/99 and 62%, 61/99) and improve survival (56%, 55/99 and 49%, 49/99). More patients had significant concerns regarding ET (66%, 65/99) than RT (39%, 37/95). When asked which treatment had the most negative effect on their quality of life, the results showed: ET (35%, 25/72), RT (14%, 10/72) or both (8%, 6/72). Participants would rather receive RT (57%, 41/72) than ET (43%, 31/72). Forty-four percent (44/100) of respondents were either, “not comfortable” or “not interested” in participating in potential de-escalation trials. Although most of the adjuvant therapy de-escalation trials evaluate the omission of RT, de-escalation studies of ET are warranted and patient centered.

Patterns and predictors of relapse in Merkel cell carcinoma: Results from a population-based study

BACKGROUND AND PURPOSE

Prospective data evaluating the role of adjuvant radiotherapy (RT) for Merkel Cell Carcinoma(MCC) is lacking. To better understand the efficacy of adjuvant RT, a population-based patterns of failure study was conducted.

METHODS

We identified MCC patients treated from 1988 to 2018.Primary outcome measures were recurrence-free survival (RFS), overall survival (OS) and MCC-specific survival (MCC-SS). Charlson Co-morbidity Index (CCI) was also calculated.

RESULTS

217 patients with mean age 79 (range: 33-96) were analyzed. The median follow-up was 40 months. Treatments were: surgery(S) alone (n = 101, 45%) or S + RT(n = 116, 55%).Local recurrence (LR) was low in stage I (n = 6, 6.5%) with clear margin of ≥1 cm, negative sentinel lymph node biopsy (SLNB) without high-risk factors, irrespective of adjuvant RT. Tumor size ≥ 2 cm (HR:2.95; p = 0.024) and immunosuppression(HR:3.98; p = 0.001) were associated with high risk of nodal failure. Adjuvant RT was associated with significant reduction in regional failure (HR:0.36; p = 0.002). Distant metastases (DM) were infrequent in stage I (4/90) and stage II (4/34), compared to stage III (32/93). Adjuvant RT improvedRFS but did not influence MCC-SS and OS. CCI was a significant predictor of OS.

CONCLUSIONS

Adjuvant RT improvedRFS, withoutimpact on MCC-SS and OS. Co-morbidity rather than RT influenced OS. Adjuvant RT may be avoided instage I patients with negative SLNB and no associated high-risk factors. Prophylactic RNI could be considered in stage II with high risk features, inspite of negative SLNB. Stage III patients benefited from adjuvant RNI, but no impact on prevention of DM.

ndocrine therapy with accelerated artial breast irradiatin or exclusive ultra-accelerated artial breast irradiation for women aged ≥ 60 years with arly-stage breast cancer (EPOPE): The rationale for a GEC-ESTRO randomized phase III-controlled trial

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Epidemiologic data confirm the increase of breast cancer incidence in the elderly.

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The risk of recurrence of breast cancer is basically low.

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De-escalation breast cancer adjuvant therapy is justified in selected elderly patients.

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Ultra-accelerated breast irradiation with endocrine therapy omission is under debate.

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Prospective randomized trial is warranted.

Purpose

Breast cancer in the elderly has become a public health concern; there is a need to re-design its treatment with a view to de-escalation. Our paper sets out the rationale for a phase 3 randomized trial to evaluate less burdensome adjuvant procedures that remain effective and efficient.

Materials and methods

For low-risk breast cancer in the elderly, adjuvant treatment has been adjusted in order to make it more suitable and efficient. Hypofractionated radiation therapy based on accelerated or non-accelerated regimens as well as accelerated and ultra-accelerated partial breast irradiation (APBI) protocols were reviewed. Withdrawal of radiation (RT) or endocrine therapies (ET) from the adjuvant procedure were also investigated. Based on molecular and APBI classifications, inclusion criteria were discussed.

Results

Phase 3 randomized trials which compared standard vs. accelerated/non-accelerated hypofractionated regimens confirmed that the latter were non-inferior in terms of local control. Similarly, except for intraoperative-based techniques, APBI achieved non-inferior local control rates compared to whole breast irradiation for low-risk breast cancer. In phase 2 prospective trials using ultra APBI, encouraging results were observed regarding oncological outcome and toxicity profile. In phase 3 trials, adjuvant ET without RT significantly increased the rate of local relapse with no impact on overall survival while RT alone proved effective. Elderly patients aged 60 or more with low-risk, luminal A breast cancer were chosen as the target population in a phase 3 randomized trial comparing APBI + 5-year ET vs. uAPBI (16 Gy 1f) alone.

Conclusion

To investigate de-escalation adjuvant treatment for elderly breast cancer patients, we have defined a road map for testing more convenient strategies. This EPOPE phase 3 randomized trial is supported by the GEC-ESTRO breast cancer working group.