Table 1.

Patient characteristics of the training set

ParametersControls (n = 109)Cases (n = 146)Total (n = 255)
Demographic characteristics
Age, mean ± SD, range (y)59.8 ± 14.3, 25–9059.8 ± 10.7, 32–8959.5 ± 12.4, 25–90
Male sex (%)78 (71.6)136 (93.2)214 (83.9)
BMI, mean ± SD, range (kg/m2)23.0 ± 3.5, 17.0–33.122.1 ± 3.4, 15.6–34.322.5 ± 3.5, 15.6–34.3
Lifestyle risk factors (%)57 (52.3)133 (91.1)190 (74.5)
 Levels of alcohol drinking
  Never70 (64.2)24 (16.4)94 (36.9)
  Light to moderate26 (23.9)36 (24.7)62 (24.3)
  Heavy13 (11.9)86 (58.9)99 (38.8)
 Levels of betel quid chewing
  Never92 (84.4)65 (44.5)157 (61.6)
  Light to moderate7 (6.4)30 (20.6)37 (14.5)
  Heavy10 (9.2)51 (34.9)61 (23.9)
 Levels of cigarette smoking
  Never68 (62.4)24 (16.5)92 (36.1)
  Light to moderate20 (18.3)56 (38.3)76 (29.8)
  Heavy21 (19.3)66 (45.2)87 (34.1)
Genetic polymorphisms (%)
 Encoding enzymes in the metabolism of alcohol
  ALDH2 genotype41 (37.6)128 (87.7)169 (66.3)
   ALDH2*1/2*1, fast15 (36.6)36 (28.1)51 (30.2)
   ALDH2*1/2*2 or 2*2/2*2, slow26 (63.4)92 (71.9)118 (69.8)
  ADH1B genotype39 (35.8)128 (87.7)167 (65.5)
   ADH1B*1/*1, slow4 (10.3)37 (28.9)41 (24.6)
   ADH1B*1/*2 or *2/*2, fast35 (89.7)91 (71.1)126 (75.4)
  ADH1C genotype38 (34.9)126 (86.3)164 (57.3)
   ADH1C*1/*1, fast34 (89.5)101 (80.2)135 (82.3)
   ADH1C*1/*2 or *2/*2, slow4 (10.5)25 (19.8)29 (17.7)
 Encoding enzymes in the metabolism of xenobiotics
  GSTP1 genotype36 (33.0)121 (82.9)157 (61.6)
   ile/ile, slow31 (86.1)90 (74.4)121 (77.1)
   ile/val or val/val, fast5 (13.9)31 (25.6)36 (22.9)
  GSTM1 genotype40 (36.7)128 (87.7)168 (65.9)
   present, active19 (47.5)54 (42.2)73 (43.5)
   null, inactive21 (52.5)74 (57.8)95 (56.5)
  GSTT1 genotype41 (37.6)128 (87.7)169 (66.3)
   present, active20 (48.8)62 (48.4)82 (48.5)
   null, inactive21 (51.2)66 (51.6)87 (51.5)
Serological markers
 MCV, mean ± SD, range (fL)89.3 ± 8.3, 63.5–104.193.0 ± 6.9, 67.1–111.592.0 ± 7.7, 63.5–111.5
H. pylori infections (%)40/103 (38.8)70/141 (49.7)110/244 (45.1)
 Human papillomavirus infections (%)7/41 (17.1)30/128 (23.4)37/169 (21.9)
Endoscopic findings (%)
 Negative study1090109 (42.7)
 Head and neck SCC049 (33.6)49 (19.2)
 Esophageal SCC091 (62.3)91 (35.7)
 Synchronous head and neck and esophageal SCC06 (4.1)6 (2.4)
 Presence of numerous LVLs in the background mucosae6 (10.5)68 (48.6)74 (29.0)