Hypofractionated irradiation in 794 elderly breast cancer patients: An observational study.

To assess the efficacy, and the acute and late toxicity of hypofractionated radiotherapy (Hypo-RT), and the impact of age and comorbidities on disease progression and death in elderly breast cancer (BC) patients. Women aged ≥65 years who received Hypo-RT (42.4 Gy in 16 fractions, plus a boost for high-risk patients) were considered for the present analysis. Competing risk analysis was used to estimate the 5-year cumulative incidence of BC progression and BC-related death, calculating the adjusted subhazard ratios (SHR) with 95% confidence intervals (95%CI) in relation to age, hypertension-augmented Charlson Comorbidity Index (hCCI), tumor characteristics, and chemotherapy. The sample included 794 patients with a median age of 74 years (range 65-91 years). At the baseline, 70% of these patients had at least one comorbidity. With a median follow-up of 48.3 months, the 5-year cumulative incidence of BC progression and BC-related death was 6.7% (95%CI 4.8%-9.2%) and 2.3% (95%CI 1.2%-3.9%), respectively. Old age (≥80 years) and a high burden of comorbidity (hCCI ≥ 2) were independently associated with BC progression. Hypo-RT is safe in elderly BC patients, but age and comorbidities influence BC progression. Further studies are warranted.

Discontinuation of hormone therapy for elderly breast cancer patients after hypofractionated whole-breast radiotherapy.

The purpose of the study was to examine adherence to hormone therapy (HT) in elderly breast cancer patients (≥ 65 years old) treated with hypofractionated radiotherapy. We analyzed data on 550 ER-positive breast cancer patients given hypofractionated whole-breast radiotherapy from June 2009 to September 2016. Baseline comorbidities considered in the hypertension-augmented Charlson Comorbidity Index (hCCI) were retrospectively retrieved. Total hCCI scores were classified as no comorbidity (hCCI = 0), low burden of comorbidity (hCCI = 1), and high burden of comorbidity (hCCI ≥ 2). Competing risk analysis was used to estimate the 5-year cumulative incidence of HT discontinuation. Fine and Gray models were used to estimate the adjusted subhazard ratio (SHR) of HT discontinuation by hCCI score. HT was initially prescribed for 85.6% of patients and almost all of them (468/471) took it for at least one month. It was subsequently discontinued by 45 patients (9.6%), for an overall 5-year cumulative incidence of 11.7%. The 5-year cumulative incidence of HT discontinuation rose from 3.9% in the youngest age group (65-69 years) to 23.3% in the oldest (≥ 80 years) (p = 0.005). Baseline comorbidity had some effect on the likelihood of discontinuing HT, but only among patients with a low burden of comorbidity (hCCI = 1, SHR 2.00, 95%CI 0.95-4.20). Adherence to HT was better in our sample than in the literature, probably because patients were selected and motivated to continue HT. This confirms the importance of communication with patients to improve adherence to HT. We confirmed the association between HT discontinuation and older age, while comorbidity had a limited influence.

Hypofractionated Whole-Breast Irradiation With or Without Boost in Elderly Patients: Clinical Evaluation of an Italian Experience.

PURPOSE: To examine local control, disease-free survival (DFS), and toxicity in elderly (≥ 65 years) breast cancer patients treated with hypofractionated radiotherapy (hypo-RT) with or without a boost to the tumor bed. PATIENTS AND METHODS: The study was conducted on 752 patients treated from April 2009 to February 2017. Patients received 42.4 Gy in 16 daily fractions (2.65 Gy per fraction). A boost was only administered in cases of grade 3 primary tumor and close or positive margins. Acute and late toxicity was prospectively assessed during and after hypo-RT, based on the Radiation Therapy Oncology Group scale. DFS and local recurrence-free survival were estimated by the Kaplan-Meier method for cumulative probability. Log-rank tests were used to identify differences by subtype. Cox proportional hazard models were used to investigate the impact of various factors on the risk of disease progression. RESULTS: Among the 752 patients treated, 41 (5.5%) experienced disease progression, including 7 (17.1%) exclusively local recurrences; 1 (2.4%) local and nodal recurrence; 1 (2.4%) local and nodal recurrence plus metastasis; 7 (17.1%) nodal recurrences plus metastases; and 25 (61%) exclusively distant metastases. The 5-year DFS, local recurrence-free survival, breast cancer-specific survival, and overall survival rates were 91.8% (95% confidence interval [CI], 88.6-94.2), 98.0% (95% CI, 96.1-99.1), 98.2% (95% CI, 96.5-99.1), and 87.5% (95% CI, 83.8-90.5), respectively. On univariate analysis, the administration of a boost, disease grade (grades 1 and 2 vs. 3), and molecular subtype (triple negative or human epidermal growth factor receptor 2 [HER2] positive, or luminal B vs. luminal A) significantly affected disease progression (P < .01). These findings were confirmed by multivariate analysis. CONCLUSION: Hypo-RT is effective and well tolerated in the elderly population, and the routine use of a boost for patients over 65 years is not justified. Further studies on the boost issue are strongly advocated.

Trastuzumab and Hypofractionated Whole Breast Radiotherapy: A Victorious Combination?

INTRODUCTION: The purpose of this study was to examine the impact of trastuzumab on acute skin and cardiac toxicity in patients with breast cancer treated with chemotherapy with or without trastuzumab and adjuvant whole breast hypofractionated radiotherapy (hypo-RT). MATERIALS AND METHODS: The study was conducted on 727 patients treated from April 2009 to October 2016. Patients received 42.4 Gy in 16 daily fractions (2.65 Gy per fraction). A boost was only administered in cases with grade (G) 3 primary tumor and close or positive margins. Acute and late toxicity was assessed prospectively during and after hypo-RT, based on the Radiation Therapy Oncology Group scale. Multivariable logistic regression models were used to examine the onset of acute skin toxicity (≥ G2) in the whole study population, and the impact of trastuzumab on the onset of acute skin (≥ G2) or cardiac toxicity in the subgroup of 176 patients given chemotherapy. RESULTS: A total of 176 patients received chemotherapy with anthracycline and taxane, and 51 (29%) of them were also treated with trastuzumab. Acute G1, G2, and G3 skin toxicity occurred, respectively, in 56.8%, 27.3%, and 1.1% of the patients given chemotherapy alone, and in 64.7%, 19.6%, and 0% of those given trastuzumab as well. Among the patients given chemotherapy, left ventricular ejection fraction (LVEF) toxicity developed with a severity of G1 (LVEF < 60%-50%) in 12 (6.8%) patients, G2 (LVEF < 50%-40%) in 2 (1.1%) patients, and G3 (LVEF < 40%) in 1 (0.6%) patient. Among the patients also given trastuzumab, 7 (13.7%) patients had G1 LVEF toxicity, and 1 (2%) patient had G2 LVEF toxicity. We found that patients given trastuzumab were at higher risk of cardiac toxicity ≥ G1 (odds ratio, 4.3; P = .01), and at lower risk of acute skin toxicity ≥ G2 (odds ratio, 0.4; P = .03) than patients given chemotherapy alone. CONCLUSIONS: This analysis showed that trastuzumab with adjuvant hypo-RT for patients with breast cancer was generally well-tolerated in routine clinical practice. A longer follow-up will be necessary to assess late cardiac toxicity.

Axillary coverage by whole breast irradiation in 1 to 2 positive sentinel lymph nodes in breast cancer patients.

PURPOSE: To evaluate the dosimetric coverage of axillary levels I, II, and III obtained with standard whole breast irradiation in 1 to 2 positive sentinel lymph nodes (SLNs) patients not submitted to axillary lymph nodes dissection (ALND), and to compare the lymph nodes areas coverage obtained with 3D conformal radiation therapy, intensity-modulated radiotherapy (IMRT), and volumetric modulated arc therapy (VMAT). METHODS: Patients with 1 to 2 positive SLNs undergoing breast-conserving therapy, without ALND, were included in the analysis. For each patient, 3 treatment plans were performed: a 3D conventional tangential plan, a static IMRT plan, and a volumetric IMRT, designed to encompass the entire breast parenchyma. The volumes of axillary levels I, II, and III receiving 90% and 95% (V90, V95) of the whole breast prescribed dose were evaluated. Dose-volume histograms were compared by means of the Friedman test. RESULTS: Ten patients were enrolled. All defined breast volumes received >95% of the prescribed dose with the 3 techniques. Median V95 for axillary level I was 26.4% (range 4.7%-61.3%) for 3D plans, 8.6% (range 0.64%-19.1%) for static IMRT plans, and 2.6% (range 0.4%-4.7%) for volumetric IMRT plans (p<0.001). Median V95 for axillary level II was 5.4% (range 0%-14.6%), 1.9% (range 0%-15%), and 2.6% (range 0.4%-4.7%) for 3D, static IMRT, and volumetric IMRT, respectively (p<0.001). CONCLUSIONS: Results of our analysis showed that standard 3D tangential whole breast irradiation failed to deliver a therapeutic dose to axillary levels I and II. The coverage was even lower using static and volumetric IMRT techniques.