Older age and comorbidity in breast cancer: is RT alone the new therapeutic frontier?

AIM: To assess the impact of age, comorbidities and endocrine therapy (ET) in older breast cancer (BC) patients treated with hypofractionated radiotherapy (Hypo-RT). METHODS: From June 2009 to December 2017, we enrolled in this study 735 ER-positive BC patients (stage pT1-T2, pNx-1, M0 and age ≥ 65 years) receiving hypo-RT and followed them until September 2019. Baseline comorbidities included in the hypertension-augmented Charlson Comorbidity Index were retrospectively retrieved. Logistic regression model estimated adjusted-odds ratios (ORs) of ET prescription in relation to baseline patient and tumor characteristics. Competing risk analysis estimated 5-year cumulative incidence function (CIF) of ET discontinuation due to side effects (with BC progression or death as competing events), and its effect on locoregional recurrence (LRR) and distant metastasis (DM) (with death as competing event). RESULTS: ET has been prescribed in 89% patients. In multivariable analysis, the odds of ET prescription was significantly reduced in older patients (≥ 80 years, OR 0.08, 95% CI 0.03-0.20) and significantly increased in patients with moderate comorbidity. Patients ≥ 80 years discontinued the prescribed therapy earlier and more frequently than younger (65-69 years) patients (p = 0.060). Five-year CIF of LLR, DM and death from causes other that BC were 1.7%, 2.2% and 7.5%, respectively. Patients who discontinued ET had higher chance of LRR (p = 0.004). ET use did not impact on OS in any of the analyzed groups. CONCLUSIONS: In older patients, ET did not show a benefit in terms of overall survival. Further studies focusing on tailored treatment approaches are warranted to offer the best care in terms of adjuvant treatment to these patients.

VMAT partial-breast irradiation: acute toxicity of hypofractionated schedules of 30 Gy in five daily fractions.

PURPOSE: To report acute toxicities in breast cancer (BC) patients (pts) recruited in a prospective trial and treated with accelerated partial-breast irradiation (APBI) using Volumetric Modulated Arc Therapy (VMAT) delivered with a hypofractionated schedule. METHODS: From March 2014 to June 2019, pts with early-stage BC (Stage I), who underwent breast conservative surgery (BCS), were recruited in a prospective study started at the National Cancer Institute of Milan. Pts received APBI with a hypofractionated schedule of 30 Gy in five daily fractions. Radiotherapy treatment (RT) was delivered using VMAT. Acute toxicity was assessed according to RTOG/EORTC criteria at the end of RT. RESULTS: Between March 2014 and June 2019, 151 pts were enrolled in this study. 79 Pts had right-side and 72 had left-side breast cancer. Median age was 69 (range 43-92). All pts presented with pathological stage IA BC, molecular classification was Luminal A in 128/151 (85%) and Luminal B in 23/151 (15%) cases. Acute toxicity, assessed at the end of RT, consisted of G1 erythema in 37/151 (24. 5%) pts and skin toxicities higher than G1, did not occur. Fibrosis G1 and G2 were reported in 41/151 (27. 1%) pts and in 2/151 pts (1. 3%), respectively. Edema G1 occurred in 8/151 (5. 3%) pts and asthenia G1 occurred in 1/151 (0. 6%) pts. CONCLUSIONS: APBI with VMAT proved to be feasible and can be a valid alternative treatment option after BCS in selected early breast cancer pts according to ASTRO guidelines. A longer follow-up is needed to assess late toxicity.