Loading
This is the trial that ended the routine mastectomy. Twenty years on, women who kept their breast lived exactly as long as those who lost it, and the radiotherapy that went with breast conservation cut the chance of the cancer coming back in that breast from about two in five to about one in seven.
Bernard Fisher opened NSABP B-06 in 1976 to ask a question the surgical profession regarded as settled: whether removing the lump was as good as removing the breast. 1,851 women with tumours of 4 cm or less were randomised three ways, to total mastectomy, to lumpectomy alone, or to lumpectomy followed by breast irradiation; all node-positive women received chemotherapy.
At twenty years the cumulative incidence of a recurrence in the treated breast was 14.3 percent after lumpectomy with irradiation against 39.2 percent after lumpectomy alone (p<0.001). That gap is the case for radiotherapy. The case for conservation is what did not differ: there was no significant difference between the three groups in disease-free survival, distant-disease-free survival or overall survival. The hazard ratio for death after lumpectomy alone against total mastectomy was 1.05 (95 percent confidence interval 0.90 to 1.23, p=0.51), and after lumpectomy with irradiation 0.97 (0.83 to 1.14, p=0.74).
One detail is easy to miss and matters for how radiotherapy is discussed today. Among women with tumour-free margins, irradiation gave a hazard ratio for death of 0.91 (0.77 to 1.06, p=0.23): a marginally significant fall in breast cancer deaths that was partly offset by a rise in deaths from other causes. The benefit of breast radiotherapy is real, and it is not free.
The condition Fisher attached to the conclusion is still the condition today: conservation is appropriate provided the margins are clear and an acceptable cosmetic result can be obtained.
Numbers are from the trial as recorded here; see the source links in the table below. This is orientation, not medical advice: ask your team how closely the trial population matches you.
1,851 analysed.
| Endpoint | Arm | n | Value | HR (95% CI) | p | Source |
|---|---|---|---|---|---|---|
| Cumulative incidence of recurrent tumour in the ipsilateral breast at 20 yearsprimary | Lumpectomy plus breast irradiation | - | 14.3% | - | <0.001 | link |
| Lumpectomy alone | - | 39.2% | ||||
| Death from any cause at 20 years, lumpectomy alone against total mastectomy | Lumpectomy alone against total mastectomy | - | 1.05 hazard ratio | 1.05 (0.9 to 1.23) | 0.51 | link |
| Death from any cause at 20 years, lumpectomy with irradiation against total mastectomy | Lumpectomy plus irradiation against total mastectomy | - | 0.97 hazard ratio | 0.97 (0.83 to 1.14) | 0.74 | link |
Shares Leaving radiotherapy out, EORTC 10801, Lumpectomy (breast-conserving surgery), Resection margins (R0 / R1 / R2).
Shares Milan I (quadrantectomy against radical mastectomy), Breast conservation or mastectomy, Lumpectomy (breast-conserving surgery), Mastectomy.
Shares EORTC 10801, Lumpectomy (breast-conserving surgery), Resection margins (R0 / R1 / R2), HER2-positive breast cancer.
Shares Leaving radiotherapy out, NSABP B-04, Mastectomy, HER2-positive breast cancer.
Shares NSABP B-04, NSABP Foundation, NRG Oncology, HER2-positive breast cancer.
Shares Breast conservation or mastectomy, Lumpectomy (breast-conserving surgery), Mastectomy, HER2-positive breast cancer.
Shares NSABP Foundation, HER2-positive breast cancer, Triple-negative breast cancer (TNBC), HR-positive / HER2-negative breast cancer.
Shares NSABP Foundation, NRG Oncology, HER2-positive breast cancer, Breast cancer (all types).