Table A2.

Investigation for Potential Nonlinearity in Dose Response, Interaction Between Exposures, Effect of Age at Exposure, Time Elapsed Since Exposure,and Genetic Susceptibility

Exposures Included in the Model by Tumor Type	Analysis
	Deviance	df	LRT P
Meningioma
Null model	127.54	92
Radiation linear in continuous dose	50.83	91	< .001*
Plus quadratic in continuous dose	50.82	90	.954†
Plus cubic in continuous dose	50.72	89	.748†
Plus quartic in continuous dose	50.47	88	.618†
Radiation linear in continuous dose + intrathecal methotrexate linear in continuous dose	44.87	90	.015†
Plus quadratic in continuous dose of intrathecal methotrexate	43.67	89	.274‡
Plus cubic in continuous dose of intrathecal methotrexate	35.48	88	.004‡
Plus quartic in continuous dose of intrathecal methotrexate	35.48	87	.931‡
Radiation linear in continuous dose + intrathecal methotrexate linear in continuous dose + modification by genetic susceptibility	44.78	89	.780‡
Radiation linear in continuous dose + intrathecal methotrexate linear in continuous dose + interaction	44.69	89	.676‡
Radiation linear in continuous dose + intrathecal methotrexate linear in continuous dose + modification by age at exposure	44.57	89	.583‡
Radiation linear in continuous dose + intrathecal methotrexate linear in continuous dose + modification by time since exposure	44.19	89	.539‡
Radiation linear in continuous dose + intrathecal methotrexate linear in continuous dose + first primary cancer group	35.02	81	.362‡
Glioma/PNET
Null model	81.79	59
Radiation linear in continuous dose	69.58	58	< .001*
Plus quadratic in continuous dose	67.12	57	.117†
Plus cubic in continuous dose	65.45	56	.197†
Plus quartic in continuous dose	64.64	55	.367†
Radiation linear in continuous dose + modification by genetic susceptibility	63.77	57	.016†
Radiation linear in continuous dose + modification by age at exposure	65.05	57	.033†
Radiation linear in continuous dose + modification by time since exposure	68.74	57	.359†

NOTE. Radiation dosed in Gy; chemotherapeutic drugs dosed in milligrams per meter squared.

Abbreviations: df, degrees of freedom; LRT, likelihood ratio test; PNET, primitive neuroectodermal tumor.

^*LRT P value relative to null model.

^†LRT P value relative to model with radiation fitted as a linear trend in continuous dose.

^‡LRT P value relative to model with radiation and intrathecal methotrexate each fitted as a linear trend in continuous dose.