Table 2.

Impact of prognostic factors on overall survival and disease control

			UVA		MVA*
Outcome	Factor	Dichotomization	HR	p value	HR	p value
OS	pGTV	(>32.79 vs. ≤32.79)	4.40	< 0.0001†	3.74	0.0003†
	nGTV	(>19.04 vs. ≤19.04)	1.68	0.07	0.99	0.97
	T-stage	(3–4 vs. 1–2)	2.25	0.004†	1.46	0.2
	N-stage	(N2–3 vs. N0–1	3.39	0.005†	3.44	0.0073†
LF	pGTV	(>32.79 vs. ≤32.79)	6.01	0.004†	‡	‡
	T-stage	(T3–4 vs T1–2)	2.59	0.03†	‡	‡
RF	nGTV	(>19.04 vs. ≤19.04)	1.55	0.36	‡	‡
	N-stage	(N2–3 vs. N0–1)	6.98	0.055	‡	‡
DMF	pGTV	(>32.79 vs. ≤32.79)	3.03	0.0008†	3.01	0.0008†
	nGTV	(> 19.04 vs. ≤19.04)	1.78	0.64	NS	NS
	T-stage	(T3–4 vs. T1–2)	1.33	0.36	NS	NS
	N-stage	(N2–3 vs. N0–1)	9.42	0.002†	9.24	0.002†

Abbreviations: DMF = distant metastatic failure; HR = hazard ratio; LF = local failure; MVA = multivariate analysis; OS = overall survival; nGTV = nodal gross tumor volume; pGTV = primary gross tumor volume; NS = not significant; RF = regional failure; UVA = univariate analysis.

^*Variables with a p value ≤0.10 in univariate analysis were considered for initial multivariate analysis model with backward elimination.

^†p Values were significant.

^‡Excluded from analysis because of insufficient number of events for MVA to be reliably run.