Table 1.
Trials for low-risk breast cancer.
| Research Question | Trial | Accrual Period | Control Arm |
Comparison Arm |
Age | Tumours | Tumour Size | Receptor Status | Median FU | LRR | OS |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Omission of WBRT in BCS | CALGB 9343 | 1994–1999 | WBRT | No WBRT | ≥70 | Invasive | ≤2 cm | ER+ (100%) | 12.6 Years | 2% vs. 10% * | 67% vs. 66% |
| PRIME II | 2003–2009 | WBRT | No WBRT | ≥65 | Invasive | ≤3 cm | ER+ (100%) | 7.3 Years | 1.4% vs. 13.1% * | 81% vs. 80.4% | |
| APBI in BCS | NSABP B39-RTOG 0413 | 2005–2013 | WBRT | APBI (3DCRT/Brachytherapy) | ≥18 | Invasive + DCIS | ≤3 cm | ER+ (80%) | 10.2 Years | 3.9% vs. 4.6% | 91.3% vs. 90.6% |
| Ontario RAPID | 2006–2011 | WBRT | APBI (3DCRT) | ≥40 | Invasive + DCIS | ≤3 cm | ER+ (90%) | 8.6 Years | 2.8% vs. 3.9% | 94.3% vs. 93.6% | |
| RT dose for WBRT | Ontario | 1993–1996 | 50 Gy | 42.56 Gy | ≥18 | Invasive | ≤5 cm | ER+ (73.9%) | 10 Years | 6.7% vs. 6.2% | 84.4% vs. 84.6% |
| UK START_B | 1999–2002 | 50 Gy | 40 Gy | ≥18 | Invasive | ≤3 cm | NR | 9.9 Years | 5.5% vs. 4.3% | 80.8% vs. 84.1% *,** | |
| FAST_Forward | 2011–2014 | 40 Gy | 26 Gy, 27 Gys | ≥40 | Invasive | ≤5 cm (98%) | ER+ (70%) | 6 Years | 2.3% vs. 1.5% *** | 94.6% vs. 94.4% |
Abbreviations: WBRT, Whole Breast Radiotherapy; BCS, Breast Conserving Surgery; APBI, Partial Breast Irradiation; RT, Radiotherapy; Gy, Gray; 3DCRT, 3D Conformal Radiotherapy; DCIS, Ductal Carcinoma in Situ; ER, Estrogen Receptor; NR, Not Reported; FU, Follow-up; LRR, Locoregional Recurrence; OS, Overall Survival. * Values in bold represent a significant difference; ** Converted from All-Cause Mortality; *** Result for 40 Gy vs. 26 Gy arm only.