Table 5.

Hazard ratio estimates for association between MGMT activity and PFS in AGs^a.

Tumor sample	Dichotomousb				Continuous
	N	HR	95% CI	P ≤	HR	95% CI	P≤
All alkylator-treated AG	84	2.57	[1.505; 4.39]	0.001	1.072	[1.039; 1.107]	0.001
Exclude outlier MGMTc	78	2.34	[1.343; 4.07]	0.003	1.109	[1.032; 1.192]	0.005
Exclude upper and lower 10% of PFS	68	1.88	[1.074; 3.28]	0.03	1.064	[1.025; 1.104]	0.01
Exclude 1p 19q deleted	71	2.94	[1.664; 5.19]	0.001	1.072	[1.038; 1.109]	0.001
Prior treatment
None and surgery or biopsy aloned	57	2.57	[1.309; 5.03]	0.006	1.124	[1.071; 1.180]	0.001
Surgery or biopsy followed by RT	27	2.26	[0.911; 5.63]	0.08	1.045	[0.933; 1.10]	0.09
By diagnosis
Anaplastic Astrocytoma	35	2.40	[1.102; 5.21]	0.027	1.050	[1.005; 1.097]	0.029
Anaplastic oligodendroglioma	24	3.58	[1.283; 9.92]	0.015	1.110	[1.027; 1.199]	0.008
Anaplastic oligo-astrocytoma	25	2.90	[1.010; 8.31]	0.048	1.130	[1.036; 1.234]	0.006
Progression after RT
No	45	2.50	[1.113; 5.62]	0.027	1.112	[1.027; 1.204]	0.009
Yese	39	3.51	[1.620; 7.61]	0.001	1.065	[1.027; 1.106]	0.001
Prior low-grade glioma
No	54	2.43	[1.252; 4.71]	0.009	1.061	[1.023; 1.100]	0.002
Yes	30	2.39	[1.000; 5.77]	0.054	1.127	[1.036; 1.225]	0.005
By alkylator treatment
PCV	42	3.72	[1.825; 7.58]	0.001	1.112	[1.051; 1.176]	0.001
All other alkylatorsf	42	2.07	[0.959; 4.85]	0.064	1.061	[1.019; 1.106]	0.004
None (i.e., RT only)	49	0.746	[0.357; 1.556]	0.43	0.985	[0.943; 1.029]	0.50
Overall survivalg	83	1.02	[0.614; 1.69]	0.94	1.028	[0.988; 1.070]	0.17

^aThe relationship between MGMT activity in AGs and PFS following alkylating agent therapy was examined by using Cox proportional hazards regression analysis.

^bTumor activity was dichotomized at the median of each diagnosis (Table 4).

^cLimiting activities within the 95% confidence interval for the data eliminated the 6 highest MGMT activities.

^dIncludes seven previously operated and 4 previously biopsied tumors.

^eIncludes the 27 tumors re-operated for recurrence after surgery or biopsy and RT.

^fIncludes 23 tumors treated with chemo-RT, 15 with TMZ and 4 with BCNU.

^gDate of initial surgery not available for one tumor.