3.

Univariate and multivariate analyses of predictive factors for PFS in patients with SCLC

Variables	Univariate*				Multivariate*
	HR	95% CI	P		HR	95% CI	P
PFS, progression-free survival; SCLC, small-cell lung cancer; PS, performance score; CTC, circulating tumor cell; WBMTV, whole-body metabolic tumor volume; HR, hazard ratio; 95% CI, 95% confidence interval; *, Cox regression analysis with enter method; **, Cox regression analysis with stepwise method. CTCs at baseline and WBMTV before the initiation of therapy treatment are the only two predictors in the final Cox multivariate proportional-hazards model with stepwise method.
Age (median 59 years)	0.86	0.66−1.54	0.49		1.00	0.99−1.02	0.77
Sex (male vs. female)	1.01	0.66−1.54	0.98		0.98	0.64−1.48	0.91
PS (≤3)	1.25	0.80−1.95	0.03		0.57	0.13−2.40	0.44
Chemotherapy regimen utilized	1.16	0.66−2.04	0.62		1.14	0.63−2.04	0.67
CTCs at baseline	2.05	1.32−3.18	<0.01		2.37**	1.05−6.33	<0.01
CTCs after one cycle of chemotherapy	1.69	1.29−2.22	<0.01		0.99	0.68−1.45	0.39
CTCs after four cycles of chemotherapy	0.87	0.63−1.20	0.39		1.13	0.47−2.77	0.92
WBMTV before treatment	1.90	1.23−2.95	<0.01		6.11**	3.47−10.96	<0.01