Table 6.

AG PFS dichotomized by median MGMT activity.

Tumor sample	N	PFS (mo)		P≤a
		< median MGMT	> median MGMT
All alkylator-treated AG	84	43	12	0.0003
Exclude outlier MGMT activitiesb	78	43	14	0.002
Exclude upper and lower 10% of PFS	68	22	13	0.025
Without 1p and/or 19q deleted AO/AOA	71	26	8	0.0001
Prior treatment
None and surgery or biopsy onlyc	57	48	12	0.004
Surgery or biopsy followed by RT	27	21	13	0.068
By diagnosis
Anaplastic astrocytoma	35	21	8	0.022
Anaplastic oligodendroglioma	24	47	12	0.009
Anaplastic oligo-astrocytoma	25	43	13	0.038
Prior treatment
None and surgery or biopsy onlyc	57	48	12	0.004
Surgery or biopsy followed by RT	27	21	13	0.068
Progression after RT
No	45	112	15	0.020
Yesd	39	22	7	0.0006
Prior low-grade glioma
No	54	47	8	0.006
Yes	30	24	19	0.044
Alkylator therapy
PCV	42	24	8	0.0001
Other than PCVe	42	26	13	0.055
None (i.e., RT only)	49	18	19	0.43
Overall survivalf	84	68	53	0.58

^aDetermined by log rank test.

^bLimiting activities to those within the 95% confidence interval for the data eliminated the 6 highest MGMT activities.

^cIncludes seven previously operated and 4 previously biopsied tumors.

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

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

^fDate of initial surgery not available for one tumor.