Can older women with early breast cancer avoid radiation?

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.

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.

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.).

Adjuvant radiation therapy for older women with early-stage breast cancer: a propensity-matched SEER analysis

INTRODUCTION

The purpose was to evaluate the effect of adjuvant radiation therapy on the survival prognosis of older women with early-stage breast cancer under different surgical treatments.

METHODS

We collected patients from the Surveillance, Epidemiology and End Results (SEER) database. Elderly female patients (≥ 70 years) with stage I-IIB diagnosed with invasive carcinoma in 1988-2017 were included. After propensity score matching (PSM), the prognosis of patients who underwent breast-conserving surgery or mastectomy was calculated separately. The effects of radiotherapy on the survival of three special population groups (breast-conserving surgery + T1N0M0 + ER positive, mastectomy + T3N0M0 and mastectomy + T1-2N1M0) were analyzed selectively.

RESULTS

Of 106,553 older women with early-stage breast cancer were identified. 48,630 patients had received radiotherapy, while 57,923 patients had not. After PSM, older women undergoing breast-conserving surgery benefited significantly from radiotherapy (both OS and BCSS p < 0.001), for patients with T1N0M0 and ER-positive breast cancer (both OS and BCSS p < 0.001). In the subgroup of T1-2N1M0 breast cancer treated by mastectomy, patients undergoing radiotherapy had a worse survival as well (OS p < 0.001; BCSS p = 0.0907). While in the subgroup of T3N0M0 breast cancer treated by mastectomy, survival analyses showed no statistical differences between patients receiving radiation or not (OS p = 0.1778, BCSS p = 0.6957).

CONCLUSIONS

This study indicated the clinical effects of radiation on older women who received different surgical treatments. Our study suggested that radiotherapy should be omitted in older women undergoing mastectomy + T3N0M0 or T1-2N1M0 and radiotherapy could be considered in women with T1N0M0 + ER-positive undergoing breast-conserving surgery.

Effects of Adjuvant Endocrine Therapy Adherence and Radiation on Recurrence and Survival Among Older Women with Early-Stage Breast Cancer

BACKGROUND

The Cancer and Leukemia Group-B 9343 (CALGB 9343) trial demonstrated that women aged ≥ 70 years with early-stage breast cancer can safely omit radiation therapy (RT) and be treated with breast-conserving surgery (BCS) and adjuvant endocrine therapy (AET) alone. AET adherence is low, leaving an undertreated cohort who may be at increased risk of recurrence and death. We hypothesized that AET adherence and adjuvant treatment choice impact recurrence and survival among CALGB 9343 eligible women.

PATIENTS AND METHODS

SEER-Medicare was used to identify CALGB 9343 eligible women who underwent BCS between 2007 and 2016. Medicare claims were used to identify AET use, and the proportion of days covered by AET was used to categorize adherent (PDC ≥ 0.80) versus nonadherent patients (PDC < 0.80). Recurrence-free, cancer-specific, and overall survival were assessed using Cox proportional hazards models.

RESULTS

In total, 10,719 women were identified, of whom 780 (7.3%) underwent BCS alone, 1490 (13.9%) underwent BCS + RT, 1663 (15.5%) underwent BCS + AET, and 6786 (63.3%) had BCS + RT + AET. Among women treated with BCS + AET, adherent patients had lower recurrence than did nonadherent patients (HR = 0.65, 95% CI: 0.50-0.85). With respect to adjuvant treatment combinations, there was no recurrence difference between the BCS + RT + AET group and BCS + AET group (HR = 0.81, 95% CI: 0.54-1.21). There was equivalent cancer-specific but worse overall survival in the BCS + AET group versus the BCS + AET + RT group.

CONCLUSIONS

While BCS + RT + AET may represent overtreatment for some, AET nonadherent women who omit RT are at risk for worse outcomes. Treatment decisions regarding RT omission should be tailored to the individual patient, taking into consideration the chances of AET nonadherence and the patients' own risk tolerance.

Patient views and correlates of radiotherapy omission in a population-based sample of older women with favorable-prognosis breast cancer

BACKGROUND

The omission of radiotherapy (RT) after lumpectomy is a reasonable option for many older women with favorable-prognosis breast cancer. In the current study, we sought to evaluate patient perspectives regarding decision making about RT.

METHODS

Women aged 65 to 79 years with AJCC 7th edition stage I and II breast cancer who were reported to the Georgia and Los Angeles County Surveillance, Epidemiology, and End Results registries were surveyed (response rate, 70%) regarding RT decisions, the rationale for omitting RT, decision-making values, and understanding of disease recurrence risk. We also surveyed their corresponding surgeons (response rate, 77%). Patient characteristics associated with the omission of RT were evaluated using multilevel, multivariable logistic regression, accounting for patient clustering within surgeons.

RESULTS

Of 999 patients, 135 omitted RT (14%). Older age, lower tumor grade, and having estrogen receptor-positive disease each were found to be strongly associated with omission of RT in multivariable analyses, whereas the number of comorbidities was not. Non-English speakers were more likely to omit RT (adjusted odds ratio, 5.9; 95% confidence interval, 1.4-24.5). The most commonly reported reasons for RT omission were that a physician advised the patient that it was not needed (54% of patients who omitted RT) and patient choice (41%). Risk of local disease recurrence was overestimated by all patients: by approximately 2-fold among those who omitted RT and by approximately 8-fold among those who received RT. The risk of distant disease recurrence was overestimated by approximately 3-fold on average.

CONCLUSIONS

To some extent, decisions regarding RT omission are appropriately influenced by patient age, tumor grade, and estrogen receptor status, but do not appear to be optimally tailored according to competing comorbidities. Many women who are candidates for RT omission overestimate their risk of disease recurrence. Cancer 2018;124:2714-2723. © 2018 American Cancer Society.

Controversial issues in the management of older adults with early breast cancer

It is well recognized that the incidence of breast cancer increases significantly with age. Despite this, older people remain under-represented in many clinical trials and their management relies on extrapolation of data from younger patients. Providing an aggressive intervention can be challenging, particularly in less fit older patients where a conservative approach is commonly perceived to be more appropriate. The optimal management of this population is unknown and treatment decision should be personalized. This review article will discuss several controversial issues in managing older adults with early breast cancer in a multidisciplinary setting, including the role of surgical treatment of the axilla in clinically node negative disease, radiotherapy after breast conservation surgery in low-risk tumours, personalizing adjuvant systemic therapy, and geriatric assessments in breast cancer treatment decisions.

Low risk of recurrence in elderly patients treated with breast conserving therapy in a single institute

OBJECTIVES

To guide decision making in preventing over- or under-treatment in older breast cancer patients who have undergone breast conserving surgery, we analyzed prognostic factors and risk of recurrence in a consecutive series of patients ≥ 65 years old with breast cancer and identified subgroups that may benefit or not from more intensive treatment.

METHODS

Patients ≥65 years of age with breast cancer (pT1-2/pN0-2) treated with breast conserving surgery and postoperative radiation therapy at the Netherlands Cancer Institute (NKI) between 1980 and 2008 were identified. Endpoints were locoregional recurrence (LRR), distant metastasis (DM) and overall survival (OS). Multivariable analyses were performed using Cox proportional hazards models.

RESULTS

1922 patients with a median age of 70 years were analyzed. The 5- and 10- years LRR rates were 2% and 3% respectively. In multivariable analysis there was no significant factor influencing LRR risk. Patients with low risk tumors (node negative patients with T1 and ER positive, grade 1 or 2) had lower risk of DM (HR 0.26) and better OS (HR 0.65) compared to patients with higher risk tumors (grade 3 and/or node positive).

CONCLUSION

In elderly breast cancer patients the risk of LRR and DM is low. In patients with less favorable characteristics the risk of LRR is equally low, with a higher risk to develop DM and worse OS. Treatment in the low risk group may be minimized, while for the higher risk group adjuvant treatment could be intensified.