TABLE II.

Observed brain cancer survival probabilities by diagnostic method and histology

Category	Pts (n)	Survival probability (95% CL) by years since diagnosis
		1 Year	2 Years	3 Years	4 Years	5 Years	6 Years
Overall	20,875	0.47 (0.46, 0.48)	0.34 (0.33, 0.35)	0.30 (0.29, 0.30)	0.27 (0.26, 0.27)	0.25 (0.24, 0.25)	0.23 (0.22, 0.24)
Diagnostic confirmation
Microscopic	15,975	0.51 (0.50, 0.51)	0.35 (0.34, 0.35)	0.30 (0.29, 0.30)	0.26 (0.26, 0.27)	0.24 (0.23, 0.25)	0.22 (0.21, 0.23)
Other	4,895	0.36 (0.34, 0.37)	0.31 (0.30, 0.33)	0.29 (0.28, 0.30)	0.28 (0.26, 0.29)	0.26 (0.25, 0.27)	0.25 (0.23, 0.26)
Histology
Glioblastoma multiforme	8,365	0.29 (0.28, 0.30)	0.10 (0.09, 0.11)	0.06 (0.05, 0.06)	0.04 (0.04, 0.05)	0.03 (0.03, 0.04)	0.03 (0.02, 0.03)
Anaplastic astrocytoma	610	0.50 (0.46, 0.54)	0.34 (0.30, 0.38)	0.27 (0.23, 0.31)	0.22 (0.19, 0.26)	0.17 (0.14, 0.21)	0.14 (0.11, 0.18)
Diffuse astrocytoma	2,310	0.45 (0.43, 0.47)	0.31 (0.29, 0.33)	0.26 (0.24, 0.27)	0.22 (0.20, 0.24)	0.19 (0.18, 0.21)	0.17 (0.15, 0.19)
Anaplastic oligodendroglioma	555	0.74 (0.70, 0.78)	0.56 (0.52, 0.60)	0.48 (0.44, 0.53)	0.42 (0.38, 0.47)	0.36 (0.32, 0.41)	0.33 (0.28, 0.38)
Oligoastrocytoma	720	0.76 (0.72, 0.79)	0.60 (0.57, 0.64)	0.54 (0.50, 0.58)	0.48 (0.44, 0.53)	0.41 (0.37, 0.46)	0.35 (0.31, 0.40)
Oligodendroglioma	955	0.88 (0.86, 0.90)	0.82 (0.79, 0.84)	0.78 (0.75, 0.81)	0.73 (0.70, 0.76)	0.66 (0.63, 0.70)	0.60 (0.57, 0.65)
Glioma (NOS)	1,050	0.52 (0.49, 0.55)	0.43 (0.40, 0.47)	0.40 (0.37, 0.43)	0.38 (0.35, 0.41)	0.35 (0.32, 0.38)	0.32 (0.29, 0.36)
All others	6,305	0.60 (0.59, 0.61)	0.55 (0.54, 0.56)	0.51 (0.50, 0.52)	0.48 (0.47, 0.50)	0.46 (0.45, 0.47)	0.45 (0.43, 0.46)

CL = confidence limits.