Table 1.

Selected characteristics of incident cases of esophageal cancer and their matched controls in each cohort study

ACS CPS-II NC CohortPLCO Cohort
CharacteristicsCasesControlsCasesControls
Matching variablesN = 51N = 153PN = 74N = 219P
 Age at mouthwash collection; mean (SD)71.4 (6.1)71.4 (6.0)0.9765.2 (5.6)65.3 (5.5)0.82
 Months from mouthwash collection to diagnosis (cases) or riskset (controls); mean (SD)35.3 (24.5)35.3 (24.3)1.0052.6 (30.1)53.3 (29.9)0.85
 Gender; n %1.000.97
  Female8 (15.7)24 (15.7)15 (20.3)44 (20.1)
  Male43 (84.3)129 (84.3)59 (79.7)175 (79.9)
 Race/ethnicity; n %1.000.99
  Caucasian50 (98.0)150 (98.0)67 (90.5)198 (90.4)
  African American/other1 (2.0)3 (2.0)7 (9.5)21 (9.6)
Unmatched variables
 BMI group (kg/m2); n (%)0.380.89
  <2522 (43.1)50 (32.7)18 (24.3)55 (25.1)
  25–29.918 (35.3)63 (41.2)37 (50.0)113 (51.6)
  ≥305 (9.8)26 (17.0)17 (23.0)48 (21.9)
  Missing6 (11.8)14 (9.1)2 (2.7)3 (1.4)
 Smoking status; n (%)0.010.01
  Never11 (21.6)60 (39.2)20 (27.0)99 (45.2)
  Former32 (62.7)86 (56.2)44 (59.5)108 (49.3)
  Current8 (15.7)7 (4.6)10 (13.5)12 (5.5)
 Pack-years, former and current smokers; mean (SD)31.5 (26.7)31.9 (31.9)0.9454.0 (30.4)36.2 (28.3)0.0002
 Alcohol consumption; n (%)
  None16 (31.4)55 (35.9)0.5523 (31.1)73 (33.3)0.72
  Drinker35 (68.6)98 (64.1)51 (68.9)146 (66.7)
   Drinks/week; median (IQR)5.7 (2.1–18.1)3.4 (1.0–9.1)0.105.8 (1.1–14.6)2.4 (1.1–7.0)0.13
 Education; n %0.940.41
  <12 grade3 (5.9)12 (7.8)2 (2.7)17 (7.8)
  High school/vocational15 (29.4)39 (25.5)30 (40.5)77 (35.2)
  Some college10 (19.6)33 (21.5)10 (13.5)38 (17.4)
  College graduate10 (19.6)29 (19.0)13 (17.6)39 (17.8)
  Graduate degree12 (23.5)39 (25.5)18 (24.3)48 (21.9)
  Missing1 (2.0)1 (0.7)1 (1.4)
 Marital status; n %0.480.85
  Married40 (78.4)113 (73.9)60 (81.1)175 (79.9)
  Separated/divorced2 (1.3)7 (9.5)20 (9.1)
  Widowed2 (3.9)12 (7.8)4 (5.4)18 (8.2)
  Never married2 (2.7)6 (2.7)
  Missing9 (17.6)26 (17.0)1 (1.4)
Tumor histology; n (%)
  Adenocarcinoma31 (60.8)N/A49 (66.2)N/A
  Squamous cell carcinoma12 (23.5)N/A16 (21.6)N/A
  Other8 (15.7)N/A9 (12.2)N/A
  • Abbreviations: IQR: interquartile range; SD: standard deviation.