Table 3.

Univariate and multivariate analysis of prognostic factors according to PFS in thymoma

	PFS	Univariate analysis		Multivariate analysis
Prognostic factors	n (%)	HR (95% CI)	P value	HR (95%CI)	P value
Tumor location (Superior/Inferior)	12 (44.4)/140 (83.8)	0.238 (0.126–0.449)	<0.001*	0.250 (0.117–0.533)	<0.001*
Age (continue)	‐	1.033 (1.009–1.058)	0.007 *	1.043 (1.015–1.071)	0.002*
Tumor diameter (continue)	‐	1.155 (1.061–1.258)	0.001*	1.098 (0.981–1.229)	0.105
Sex (Male/Female)	78 (79.6)/74 (77.1)	1.126 (0.614–2.065)	0.701	‐	‐
MG (Yes/No)	46 (71.9)/106 (81.5)	1.487 (0.806–2.744)	0.204	‐	‐
Anti‐AchR (Positive/Negative)§	45 (72.6)/107 (81.1)	1.395 (0.753–2.585)	0.290	‐	‐
WHO classification (A/ AB/B1/B2/B3)†	13 (76.5)/41(91.1)/51(74.0)/37(74.0)/10(55.6)	1.468 (1.097–1.963)	0.010 *	0.968 (0.710–1.322)	0.840
Masaoka stage (I/II/III/IV)‡	87 (88.8)/46(85.2)/14 (58.3)/5(27.8)	2.452 (1.863–3.227)	<0.001*	1.890 (1.223–2.922)	0.004*
MPMT (Yes/No)	18 (66.7)/134(80.2)	1.953 (0.928–4.111)	0.078	2.105 (0.918–4.829)	0.079
Surgical radicality (R0/non‐R0)¶	142 (80.7)/10(55.6)	4.421 (2.025–9.651)	<0.001*	2.303 (0.791–6.705)	0.126
Lymph node dissection (Yes/No)	28 (68.3)/124(81.0)	1.857 (0.965–3.574)	0.064	0.802 (0.389–1.655)	0.551
Preoperative therapy (Yes/No)	4 (44.4)/148(80.0)	4.122 (1.597–10.639)	0.003*	1.559 (0.473–5.136)	0.466
Postoperative therapy (Yes/No)	59 (74.7)/93(80.9)	1.083 (0.588–1.992)	0.798	‐	‐

^* P < 0.05.

^† Muller‐Hemelink et al., 1999.

^‡ Koga et al., 1994.

^§ Positive: The serum titer of anti‐AchR ≥0.3 nmol/L. Negative: The serum titer of anti‐AchR<0.3 nmol/L (Nakajima et al. 2008).

^¶ R0 resection: no residual tumor on microscopy; Non‐R0 resection: microscopic or macroscopic residual tumor.

PFS, progression‐free survival; HR, harzard ratio; CI, confidence interval; MG, myasthenia gravis; anti‐AchR, anti‐acetylcholine receptor; WHO, World Health Organization; MPMT, multiple primary malignant tumors.