Table 1.

Summary of radiation effects compared with other treatments^*

	Outcomes
Treatment	Breast cancer mortality	Overall mortality	All events
Lumpectomy + radiation + tamoxifen vs lumpectomy + radiation	1 study (4)	1 study (4)	1 study (4)
	N = 1804	N = 1804	N = 1798
	Effect: 0.50 (0.17 to 1.46) NS	Effect: 0.95 (0.63 to 1.44) NS	Effect: 0.76 (0.63 to 0.91)
	Evidence: L	Evidence: L	Evidence: L
Lumpectomy + radiation vs lumpectomy	4 studies (2–5)	4 studies (2–5)	2 studies (2,4)
	N = 4678	N = 678	N = 1823
	Effect: 1.09 (0.67 to 1.79) NS	Effect: 0.96 (0.77 to 1.20) NS	Effect: 0.71(0.62 to 0.82)
	Evidence: H	Evidence: H	Evidence: M
	1 study (6)
	N = 706
	Effect: 7.73 (0.90 to 66.50) NS
	Evidence: L
Lumpectomy + radiation or Lumpectomy + radiation + tamoxifen vs lumpectomy or lumpectomy + tamoxifen	1 study (7)
	N = 1103
	Effect: 0.20 (0.04 to 0.88)
	Evidence: L
Lumpectomy + radiation vs lumpectomy + tamoxifen			1 study (8)
			N = 3409
			Effect: 0.32 (0.24 to 0.44)
			Evidence: L

^*NS = not significant. Bold = significant at 95% confidence interval. Level of evidence: L = low; M = moderate; H = high.