Radiation therapy utilization and outcomes for older women with breast cancer: Impact of molecular subtype and tumor grade

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Personalized Radiation Therapy for Breast Cancer

Breast cancer is diagnosed in nearly 3 million people worldwide. Radiation therapy is an integral component of disease management for patients with breast cancer, and is used after breast-conserving surgery or a mastectomy to reduce the risk of a local recurrence. The following review describes the methods used to personalize radiation therapy by optimizing patient selection, using advanced treatment techniques to lessen the radiation dose to normal organs, and using hypofractionation in order to shorten the duration of radiation treatment.

MMR Deficiency Defines Distinct Molecular Subtype of Breast Cancer with Histone Proteomic Networks

Mismatch repair (MMR) alterations are important prognostic and predictive biomarkers in a variety of cancer subtypes, including colorectal and endometrial. However, in breast cancer (BC), the distinction and clinical significance of MMR are largely unknown. This may be due in part to the fact that genetic alterations in MMR genes are rare and only seen to occur in around 3% of BCs. In the present study, we analyzed TCGA data using a multi-sample protein–protein interaction (PPI) analysis tool, Proteinarium, and showed a distinct separation between specific MMR-deficient and -intact networks in a cohort of 994 BC patients. In the PPI networks specific to MMR deficiency, highly connected clusters of histone genes were identified. We also found the distribution of MMR-deficient BC to be more prevalent in HER2-enriched and triple-negative (TN) BC subtypes compared to luminal BCs. We recommend defining MMR-deficient BC by next-generation sequencing (NGS) when any somatic mutation is detected in one of the seven MMR genes.

Can Radiotherapy After Breast-Conserving Surgery be Omitted in Elderly Patients with Early-Stage, Hormone-Receptor Negative Breast Cancer? A Population-Based Study and Proposed Nomogram

INTRODUCTION

We aimed to evaluate whether radiotherapy (RT) after breast-conserving surgery (BCS) can be omitted in elderly patients with early-stage, hormone receptor-negative breast cancer.

METHODS

Patients aged 65 years and older with T1-2N0-1, hormone receptor-negative breast cancer in 2010-2015 were extracted from the Surveillance, Epidemiology, and End Results program. Propensity score matching was used to balance the baseline of different groups. Survival analysis was performed using Kaplan-Meier plot and log-rank test. Independent risk factors were identified by multivariate Cox analysis. A nomogram predicting breast cancer-specific survival (BCSS) and a risk stratification model were constructed and validated.

RESULTS

A total of 4465 patients were included and 27.7% (1237/4465) patients did not receive postoperative RT. RT was significantly associated with improved overall survival (OS) (HR = 0.552 P < 0.001) and BCSS (HR = 0.559, P < 0.001) in the matched cohort. The same results were found after adjusting independent risk factors by multivariate analysis. On the basis of the nomogram predicting BCSS of patients without RT by incorporating independent risk factors (age, race, HER2 status, T stage, and N stage), we built a risk stratification model which indicated that RT improved OS (HR = 0.511, P < 0.001) and BCSS (HR = 0.517, P < 0.001) in the high-risk group (total score > 150), but not in the low-risk group (total score ≤ 120). The C-index and all calibration curves demonstrated sufficient accuracies and good predictive capabilities.

CONCLUSIONS

RT is indeed beneficial for the whole cohort in this study. However, it may be omitted in the low-risk subgroup without significantly sacrificing survival. For patients in the high-risk group, RT following BCS remained beneficial. This study highlights the need for prospective randomized trials to study RT de-escalation strategies.

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

INTRODUCTION

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

EVIDENCE ACQUISITION

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

EVIDENCE SYNTHESIS

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

CONCLUSIONS

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

Radiotherapy and radiosensitization in breast cancer: Molecular targets and clinical applications

Relatively poor survival outcomes are observed in advanced or metastatic breast cancer, where local control of the primary or metastatic disease may be achieved by surgical resection, local ablative and radiation therapies. Radioresistance, poses a major challenge in achieving durable oncologic outcomes, mandating development of novel management strategies. Although multimodality approaches that combine radiotherapy with chemotherapy, or systemic agents, are utilized for radiosensitization and treatment of various malignancies, this approach has not yet found its clinical application in breast cancer. Some agents for breast cancer treatment can serve as radiosensitizers, creating an opportunity to enhance effects of radiation while providing systemic disease control. Hence, combination of radiotherapy with radiosensitizing agents have the potential to improve oncologic outcomes in advanced or metastatic breast cancer. This review discusses molecular targets for radiosensitization and novel systemic agents that have potential for clinical use as radiosensitizers in breast cancer.

The Role of Radiation Therapy in the Older Patient

PURPOSE OF REVIEW

Older patients represent a unique subgroup of the cancer patient population for which the role of radiation therapy (RT) requires special consideration. This review will discuss many of these considerations as well as various radiation treatment techniques in the context of a variety of disease sites.

RECENT FINDINGS

Several recent studies give insight into the management of older cancer patients considering their age, performance status, comorbid conditions, quality of life, genetics, cost, and individual goals. RT plays an evolving and pivotal role in providing optimal care for this population. Recent advances in RT technique allow for more precise treatment delivery and reduced toxicity. Studies evaluating the use of radiation therapy in breast, brain, lung, prostate, rectal, pancreatic, esophageal, and oligometastatic cancer are summarized and discussed in the context of treating the older patient population. Individual age, performance and functional status, comorbid conditions, and patients' objectives and goals should all be considered when presenting treatment options for older patients and age alone should not disqualify patients from curative intent treatments. When possible, hypofractionated courses should be utilized as outcomes are often equivalent and toxicities are reduced. In many cases, RT may be preferable to other treatment options due to decreased toxicity profile and acceptable disease control.

Evaluation of Adjuvant Treatments for T1 N0 M0 Triple-Negative Breast Cancer

IMPORTANCE

Adjuvant chemotherapy remains the only recommended treatment for patients with triple-negative breast cancer (TNBC). However, the existing evidence is not enough to recommend adjuvant therapies to patients with T1 N0 M0 TNBC.

OBJECTIVE

To evaluate the association of different adjuvant therapies with survival outcome in patients with T1 N0 M0 TNBC stratified by cancer stage and age.

DESIGN, SETTING, AND PARTICIPANTS

Postoperative patients diagnosed as having T1 N0 M0 TNBC between 2010 and 2015 who were enrolled in the Surveillance, Epidemiology, and End Results cancer registry program were included in this population-based cohort study. Data analysis was performed from March 27, 2019, to August 10, 2020.

EXPOSURES

Chemotherapy and radiotherapy.

MAIN OUTCOMES AND MEASURES

Kaplan-Meier curve and univariate and multivariable Cox proportional hazards regression analyses were performed to compare overall survival (OS) and breast cancer-specific survival (BCSS) between the different treatments.

RESULTS

A cohort of 7739 eligible patients (mean [SD] age, 59.5 [12.4] years; all female) were included in the present study. The 5-year OS of the total patients was 91.7% (95% CI, 90.9%-92.5%), and median follow-up was 45 months (95% CI, 44-46 months). Patients aged 70 years and older or with T1a TNBC were more likely to receive adjuvant radiotherapy than chemotherapy. Although any adjuvant therapy could improve OS in T1 N0 M0 TNBC, only chemotherapy was associated with significantly better breast cancer-specific survival (BCSS adjusted hazard ratio: 0.657; 95% CI, 0.460-0.939; P = .02). Adjuvant radiotherapy after breast-conserving surgery was associated with better OS and BCSS in patients aged 70 years and older but not in those younger than 70 years. For patients with T1c BC, chemotherapy after breast-conserving surgery or other surgery was associated with improved OS, whereas only chemotherapy after other surgery was associated with better BCSS.

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that adjuvant therapies could improve OS in patients with T1 N0 M0 TNBC, whereas only chemotherapy was associated with better BCSS. Older patients with early-stage TNBC may benefit from adjuvant radiotherapy. Administration of adjuvant therapies to patients with different ages and cancer stages should be discussed carefully, which necessitates guidance from updated guidelines.

Radiotherapy after breast-conserving surgery for elderly patients with early-stage breast cancer: A national registry-based study

Considerable controversies exist regarding whether elderly patients with early-stage breast cancer receiving breast-conserving surgery (BCS) should forgo radiotherapy. We utilized the National Cancer Database to analyze data of 115 516 women aged ≥70 years, treated with BCS for T1-2N0-1M0 breast cancer between 2004 and 2014. Multivariable Cox proportional hazards model was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for mortality 3, 5 and 10 years after 90 days of BCS associated with radiotherapy. Patients who received no radiotherapy had a higher mortality rate than those who received radiotherapy (5-year survival rate: 71.2% vs 83.8%), with multivariable-adjusted HRs of 1.65 (95% CI: 1.57-1.72) for 3-year mortality, 1.53 (1.47-1.58) for 5-year mortality and 1.43 (1.39-1.48) for 10-year mortality. The association held even for patients ≥90 years. This association was observed in all strata by reasons for radiotherapy omission, receipt of endocrine therapy or chemotherapy, calendar period and other clinical characteristics, with 40% to 65% increased 5-year mortality for patients without radiotherapy. This positive association persisted when analyses were restricted to patients with T1N0 and estrogen-receptor-positive disease who had received endocrine therapy (5-year mortality: HR 1.47 [1.39-1.57]) and in propensity score weighted analyses. Our study shows, in routine practice, elderly patients who received no post-BCS radiotherapy had higher total mortality than those who received radiotherapy. These findings suggest that the current recommendation of omission of post-BCS radiotherapy for elderly women with early-stage breast cancer may need to be reconsidered, particularly for those without contraindication.

The 2018 assisi think tank meeting on breast cancer: International expert panel white paper

We report on the second Assisi Think Tank Meeting (ATTM) on breast cancer which was held under the auspices of the European Society for RadioTherapy & Oncology (ESTRO). In discussing in-depth current evidence and practice it was designed to identify grey areas in diverse forms of the disease. It aimed at addressing uncertainties and proposing future trials to improve patient care. Before the meeting, three key topics were selected: 1) primary systemic therapy, mastectomy, breast reconstruction and post-mastectomy radiation therapy, 2) therapeutic options in ductal carcinoma in situ, and 3) therapy de-escalation in early stage breast cancer. Clinical practice in these areas was investigated by means of an online questionnaire. The time lapse period between the survey and the meeting was used to review the literature and on-going clinical trials. At the ATTM both were discussed in depth and research protocols were proposed.

Controversies of radiation therapy omission in elderly women with early stage invasive breast cancer

Early stage invasive breast cancer is a disease that is prevalent in the elderly population. Data regarding radiation omission for elderly population is based on patients’ age. Given the increased life expectancy, data on individualizing treatment decisions based on multiple tumor and patient related factors other than age only is emerging. This review aims to analyze published data to provide clinicians with a general oversight on approaching this question.