Endocrine Treatment for 5 Years or Radiation for 5 Days for Patients With Early Breast Cancer Older Than 65 Years: Can We Do It Right?

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.

Avoiding Locoregional Overtreatment in Older Adults With Early-Stage Breast Cancer

Advances in the treatment of older women with early-stage breast cancer, particularly opportunities for de-escalation of therapy, have afforded patients and providers opportunity to individualize care. As the majority of women ≥65 have estrogen receptor-positive, HER2-negative disease, locoregional therapy (surgery and/or radiation) may be tailored based on a patient's physiologic age to avoid either over- or undertreatment. To determine who would derive benefit from more or less intensive therapy, an accurate assessment of an older patient's physiologic age and incorporation of patient-specific values are paramount. While there now exist well-validated geriatric assessment tools whose use is encouraged by the American Society of Clinical Oncology when considering systemic therapy, these instruments have not been widely integrated into the locoregional breast cancer care model. This review aims to highlight the importance of assessing frailty and the concepts of and over- and undertreatment, in the context of trial data supporting opportunities for safe deescalation of locoregional therapy, when treating older women with early-stage breast cancer.

Radiation Oncologists' Views on Adjuvant Radiotherapy for Early-Stage Breast Cancer in the Elderly: Comparisons between Japan and the United States

PURPOSE

To understand perspective on breast cancer using a survey.

MATERIALS & METHODS

Questionnaire was distributed to 304 Japanese radiation oncologists (RadOncs) (response rate: 64.1%). Result was compared with a similar US survey.

RESULTS

In a scenario with an 81-year-old patient with comorbidities, while most US RadOncs chose to tell that radiation might not be necessary, 2% of Japanese chose it. In a scenario with a healthy 65-year-old breast cancer patient with lumpectomy, while most US RadOncs chose to discuss omission of radiation, 24.5% of Japanese chose it.

CONCLUSIONS

Differences were observed on radiotherapy for older early-stage breast cancer.

Omission of radiation therapy after breast conserving surgery for older women at low-risk of local recurrence: One option among many

This editorial discusses the evolving landscape of early-stage breast cancer treatment, emphasizing the need to tailor therapies based on disease biology and genomic approaches. The focus is on the reconsideration of postoperative radiation therapy (RT) for older patients with low-risk, hormone receptor-positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) breast cancer. Recent trials show modest long-term local recurrence rates with the omission of RT after BCS in certain cases, challenging the traditional approach. The commentary calls for continued research on predictive tests for treatment response and advocates for a multidisciplinary approach to decision-making, considering factors like quality of life. The nuanced risk/benefit ratio of RT in older patients is explored, emphasizing the importance of comprehensive assessment for optimal therapy.

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.

Update on Accelerated Whole Breast Irradiation

Since the advent of breast conservation, adjuvant radiation therapy (RT) has been standard of care following breast conserving surgery (BCS). Radiation therapy following BCS has traditionally been whole breast irradiation (WBI); studies comparing breast conservation to mastectomy utilized standard fractionation WBI, which delivers treatment daily over 5 to 7 weeks (1.8-2 Gy/fraction) and was the standard for decades. More recently, multiple randomized trials have compared standard fractionation WBI to moderately hypofractionated WBI (2.66 Gy/fraction, 15-16 fractions), which allows for completion of treatment in 3 to 4 weeks. Results have demonstrated no difference in local control between these two approaches with comparable toxicity and cosmetic outcomes with long-term follow-up. As such, moderately hypofractionated WBI represents the standard of care approach for most patients with early-stage breast cancer following BCS at this time. In the past few years, ultra-hypofractionated WBI (5.2-5.7 Gy/fraction, 5 fractions) has emerged with promising outcomes; 5-year outcomes from the FAST-Forward randomized trial demonstrated noninferiority between ultra-hypofractionated WBI and moderately hypofractionated WBI. Moving forward, long-term outcomes from ultra-hypofractionated WBI studies are expected, as well as the potential for incorporating moderately hypofractionated regimens into patients requiring regional nodal irradiation following BCS. Finally, the advent of ultra-short regimens may allow clinicians to re-evaluate treatment de-intensification in early-stage breast cancer to consider radiation therapy alone following BCS in lieu of endocrine therapy.