Comparison between the use of hypofractionated and conventionally fractionated radiotherapy in early breast cancer: A single-center real-world study in Taiwan.

BACKGROUND/PURPOSE: This study aimed to analyze the long-term outcomes of hypofractionated whole-breast irradiation (WBI) (HF-WBI) compared with those of conventionally fractionated WBI (CF-WBI) for early breast cancer treated with breast-conservation surgery (BCS) and adjuvant WBI in Taiwan. METHODS: This study included patients treated at our institution between 2012 and 2016. All patients with early breast cancer received BCS (pT1-2, pN0, M0) and adjuvant WBI through one of two treatment schemes. Propensity score matching analysis was conducted to create comparable cohorts. The major result is ipsilateral breast tumor recurrence (IBTR) rates and overall survival rates. RESULTS: A total of 869 patients with early-stage breast cancer received adjuvant HF-WBI or CF-WBI were included. After matching, 718 patients were separated into two groups of the same number. With a median follow-up of 66 months, seven cases of IBTR were noted (three for CF, four for HF). There were no significant differences between the HF-WBI and CF-WBI groups in 5-year IBTR rates (0.9% vs 0.6%, P = 0.3887, 95% CI [0.25-7.79]) and 5-year overall survival rates (98.1% vs 98.9%, P = 0.4702, 95% CI [0.32-3.49]). In our institution, the use of HF-WBI increased significantly from 5% before 2012 (Q3) to 92% in 2016 (Q4). There was no significant difference in grade 1-2 toxicity between the two treatment groups. Fewer cases of grade 3 skin toxicity noted in the HF-WBI group (zero vs four events). CONCLUSION: HF-WBI had similar IBTR, OS and toxicity to CF-WBI.

Stereotactic body radiotherapy and checkpoint inhibitor for locally recurrent unresectable nasopharyngeal carcinoma.

The treatment of local recurrence of nasopharyngeal carcinoma (NPC) is challenging, and the role of reirradiation is controversial regarding the high risk for severe toxicity. Stereotactic body radiotherapy (SBRT) is a high-precision radiation technique that can spare surrounding normal tissues. Studies have demonstrated the high activity and low toxicity of both SBRT and anti-programmed-cell-death-1 immune checkpoint inhibitors for head and neck cancers. There has been preclinical and clinical evidence suggesting synergy between radiotherapy and checkpoint inhibitors. We report two patients with locally recurrent unresectable rT4 NPC both involving the retro-orbital areas. They received the same treatment with low-dose SBRT (28 Gy in 5 fractions) and pembrolizumab, and showed a remarkable tumour response without untoward radiation toxicity. SBRT plus an immune checkpoint inhibitor may provide a new treatment option for locally recurrent NPC. We propose further investigation with a formal clinical trial.

A new clinical-genomic model to predict 10-year recurrence risk in primary operable breast cancer patients.

This study aimed to validate the long-term prognostic value of a new clinical-genomic model, Distant Genetic Model-Clinical Variable Model 6 (DGM-CM6), developed in Asia as a prognostic panel for all subtypes of breast cancer. We included 752 operable stage I-III breast cancer patients representing all subtypes treated from 2005 to 2014 as the validation cohort. The median follow-up was 95.8 months. The low- and high-risk patients classified by DGM-CM6 (RI-DR) had significant differences in 10-year distant recurrence-free interval (DRFI) (94.1% vs. 85.0%, P < 0.0001) and relapse-free survival (RFS) (90.0% vs. 80.5%, P = 0.0003). External validation using EMTAB-365 dataset showed similar observation (P < 0.0001). DGM-CM6 was an independent prognostic factor by multivariate analysis with hazard ratios of 3.1 (1.6-6.0) for RFS (P = 0.0009) and 3.8 (1.6-9.0) for DRFI (P = 0.0028). Comparing the C-index of DGM-CM6 and PAM50-ROR scores, the former performed better than the latter in predicting long-term DRFI and RFS, especially in N0, ER/PR-positive, and HER2-negative patients.