Table V. Effect of T stage and N stage on survival in patients with gallbladder adenocarcinoma without distant metastases – interaction model adjusted for age, sex, race, ethnicity, radiation therapy, extent of surgery, era of operation and tumor grade. Data entries are hazard ratios (95% CI).

	Full study cohort		Pathologically confirmed LN
	N0	N1	N0	N1
T1	1.0*	1.80 (1.37–2.37)	1.0*	2.84 (1.99–4.04)
T2	1.21 (1.05–1.39)	1.44 (1.14–1.83)	0.92 (0.64–1.31)	2.26 (1.63–3.13)
T3	2.29 (2.02–2.59)	2.35 (1.97–2.77)	2.13 (1.55–2.91)	3.75 (2.82–4.97)
T4	3.81 (3.14–4.62)	3.85 (2.76–5.37)	3.23 (1.97–5.31)	6.77 (4.48–10.23)

*HR 1.0 for T1N0 used as reference.