PRIME II
Breast-conserving surgery with or without irradiation in women aged 65 years or older with early breast cancer
Phase 3N = 1,326
- Population
- Women aged 65 years or older with low-risk early breast cancer: hormone receptor-positive, axillary node-negative, T1-T2 up to 3 cm, clear margins (grade 3 or lymphovascular invasion, but not both, permitted).
- Design
- Phase 3 randomised trial at 76 centres in four countries, April 2003 to December 2009; stratified by centre; patients had breast-conserving surgery and were receiving adjuvant endocrine treatment; randomised to whole-breast radiotherapy (40-50 Gy) or no radiotherapy. Primary report at median follow-up of 5 years; 10-year report at median follow-up of 9.1 years.
- Primary endpoint
- IBTR
- Arms
- Whole-breast radiotherapy (control, n = 658): Whole-breast radiotherapy, 40-50 Gy, plus adjuvant endocrine treatment
- No radiotherapy (experimental, n = 668): No radiotherapy; adjuvant endocrine treatment
- People
- Kunkler IH
IBTRHR 5.19 (95% CI 1.99–13.52)Δ IBTR+2.8 pointsΔ 60-month OS0 pointsLocal recurrenceHR 10.4 (95% CI 4.1–26.1)Δ Local recurrence+8.6 pointsΔ Distant recurrence as first event−1.4 points
Show the numbers
| Endpoint | Analysis | No radiotherapy | Whole-breast radiotherapy | Effect |
|---|---|---|---|---|
| IBTRIpsilateral breast tumour recurrence at 5 years | primarymedian follow-up 5 yearsKunkler 2015 | 4.1% (2.4–5.7%) | 1.3% (0.2–2.3%) | HR 5.19 (95% CI 1.99–13.52)P=0.0002Hazard ratio is univariate, no radiotherapy versus radiotherapy, p=0.0007. The published erratum (Lancet Oncol 2015;16:e105) corrects only the first sentence of the Interpretation; these values are unchanged. |
| OS | primarymedian follow-up 5 yearsKunkler 2015 | 93.9% at 5 y (91.8–96.0%) | 93.9% at 5 y (91.8–96.0%) | P=0.34 |
| Local recurrenceRandomised women (1326)Cumulative incidence of local breast cancer recurrence within 10 years (primary endpoint, as worded in the 2023 abstract) | long term-updatemedian follow-up 9.1 yearsKunkler 2023 | 9.5% (6.8–12.3%) | 0.9% (0.1–1.7%) | HR 10.4 (95% CI 4.1–26.1)P<0.001Direction of the hazard ratio is not stated in the abstract; read as no radiotherapy versus radiotherapy because recurrence was more common without radiotherapy. |
| Distant recurrence as first eventRandomised women (1326)10-year incidence of distant recurrence as the first event | long term-updatemedian follow-up 9.1 yearsKunkler 2023 | 1.6% (0.4–2.8%) | 3% (1.4–4.5%) | — |
| OSRandomised women (1326) | long term-updatemedian follow-up 9.1 yearsKunkler 2023 | 80.8% at 10 y (77.2–84.3%) | 80.7% at 10 y (76.9–84.3%) | — |
| Endpoint | Analysis | No radiotherapy | Whole-breast radiotherapy | Effect |
|---|---|---|---|---|
| IBTRIpsilateral breast tumour recurrence at 5 years | primarymedian follow-up 5 yearsKunkler 2015 | 4.1% (2.4–5.7%) | 1.3% (0.2–2.3%) | HR 5.19 (95% CI 1.99–13.52)P=0.0002Hazard ratio is univariate, no radiotherapy versus radiotherapy, p=0.0007. The published erratum (Lancet Oncol 2015;16:e105) corrects only the first sentence of the Interpretation; these values are unchanged. |
| OS | primarymedian follow-up 5 yearsKunkler 2015 | 93.9% at 5 y (91.8–96.0%) | 93.9% at 5 y (91.8–96.0%) | P=0.34 |
| Local recurrenceRandomised women (1326)Cumulative incidence of local breast cancer recurrence within 10 years (primary endpoint, as worded in the 2023 abstract) | long term-updatemedian follow-up 9.1 yearsKunkler 2023 | 9.5% (6.8–12.3%) | 0.9% (0.1–1.7%) | HR 10.4 (95% CI 4.1–26.1)P<0.001Direction of the hazard ratio is not stated in the abstract; read as no radiotherapy versus radiotherapy because recurrence was more common without radiotherapy. |
| Distant recurrence as first eventRandomised women (1326)10-year incidence of distant recurrence as the first event | long term-updatemedian follow-up 9.1 yearsKunkler 2023 | 1.6% (0.4–2.8%) | 3% (1.4–4.5%) | — |
| OSRandomised women (1326) | long term-updatemedian follow-up 9.1 yearsKunkler 2023 | 80.8% at 10 y (77.2–84.3%) | 80.7% at 10 y (76.9–84.3%) | — |
Data table
| Endpoint | HR | 95% CI |
|---|---|---|
| IBTR | 5.19 | 1.99–13.52 |
| Local recurrence | 10.4 | 4.1–26.1 |
Appears in
Sources
Kunkler IH, Williams LJ, Jack WJ, Cameron DA, Dixon JM. Breast-conserving surgery with or without irradiation in women aged 65 years or older with early breast cancer (PRIME II): a randomised controlled trial. Lancet Oncol. 2015;16(3):266-73.
Kunkler IH, Williams LJ, Jack WJL, Cameron DA, Dixon JM. Breast-Conserving Surgery with or without Irradiation in Early Breast Cancer. N Engl J Med. 2023;388(7):585-594.