The Absolute Effect / Evidence / DBCG 82b
Breast Cancer · Radiation Oncology · Locoregional Disease
DBCG 82b
Clinical question
Does postmastectomy radiotherapy improve outcomes in high-risk premenopausal stage II/III breast cancer?
Trial context
Population
1,708 premenopausal women with high-risk stage II/III breast cancer
Intervention
Mastectomy + postmastectomy RT + systemic therapy vs mastectomy + systemic therapy
Key endpoint
10-year overall survival
Time horizon / follow-up
10 years
Absolute Effect
What changes for patients?
DBCG 82b increased 10-year overall survival from 45% to 54%, an absolute improvement of 9 percentage points (NNT 12). Ten-year locoregional recurrence fell from 32% to 9%, an absolute reduction of 23 points (NNT 5). NNT for OS is based on 10-year survival.
NNT: 12
Treatment burden / harm
Radiotherapy toxicity
NNH: Not quantifiable from the selected long-term endpoint
Relative effect
OS absolute benefit: 10-year OS 54% vs 45%
P<.001
Clinical interpretation
The absolute survival and locoregional-control gains support postmastectomy radiotherapy for appropriately selected high-risk node-positive breast cancer.
Primary publication
- Overgaard M, et al. N Engl J Med. 1997;337:949–955.
- Overgaard M, et al. Acta Oncol. 2007;46:533–551.
- Primary publication / source