Table 1.
Characteristics of Head and Neck Cancer Cases and Controls in the International Head and Neck Cancer Epidemiology Consortium, 1981–2007a
| Characteristic | No. of Cases | % | No. of Controls | % |
|---|---|---|---|---|
| Total | 13,935 | 18,691 | ||
| Study location | ||||
| Aviano, Italy | 482 | 3.5 | 855 | 4.6 |
| Central Europe (multicenter) | 762 | 5.5 | 907 | 4.9 |
| Houston, Texas | 829 | 5.9 | 865 | 4.6 |
| IARC (international multicenter) | 881 | 6.3 | 992 | 5.3 |
| Iowa | 546 | 3.9 | 759 | 4.1 |
| Italy (multicenter) | 1,261 | 9.0 | 2,716 | 14.5 |
| Latin America (multicenter) | 2,191 | 15.7 | 1,706 | 9.1 |
| Los Angeles, California | 417 | 3.0 | 1,004 | 5.4 |
| Milan, Italy | 416 | 3.0 | 1,531 | 8.2 |
| New York State (multicenter) | 1,118 | 8.0 | 906 | 4.8 |
| New York, New York (MSKCC) | 133 | 1.0 | 168 | 0.9 |
| North Carolina | 180 | 1.3 | 202 | 1.1 |
| Puerto Rico | 350 | 2.5 | 521 | 2.8 |
| Rome, Italy | 361 | 2.6 | 396 | 2.1 |
| São Paulo, Brazil | 1,764 | 12.7 | 1,508 | 8.1 |
| Seattle, Washington | 407 | 2.9 | 607 | 3.2 |
| Switzerland | 516 | 3.7 | 883 | 4.7 |
| Tampa, Florida | 207 | 1.5 | 897 | 4.8 |
| United States (multicenter) | 1,114 | 8.0 | 1,268 | 6.8 |
| Race/ethnicityb | ||||
| Asian/Pacific Islander | 49 | 0.4 | 84 | 0.4 |
| Black | 581 | 4.2 | 674 | 3.6 |
| Hispanic/Latino | 213 | 1.5 | 429 | 2.3 |
| Latin American | 3,955 | 28.4 | 3,214 | 17.2 |
| Non-Hispanic white | 9,014 | 64.7 | 14,124 | 75.6 |
| Other | 123 | 0.9 | 166 | 0.9 |
| Age, years | ||||
| 17–39 | 502 | 3.6 | 1,356 | 7.3 |
| 40–44 | 766 | 5.5 | 1,345 | 7.2 |
| 45–49 | 1,508 | 10.8 | 2,042 | 10.9 |
| 50–54 | 2,169 | 15.6 | 2,808 | 15.0 |
| 55–59 | 2,537 | 18.2 | 3,108 | 16.6 |
| 60–64 | 2,340 | 16.8 | 2,827 | 15.1 |
| 65–69 | 1,936 | 13.9 | 2,408 | 12.9 |
| 70–74 | 1,341 | 9.6 | 1,774 | 9.5 |
| 75–96 | 836 | 6.0 | 1,023 | 5.5 |
| Sex | ||||
| Male | 11,108 | 79.7 | 13,025 | 69.7 |
| Female | 2,827 | 20.3 | 5,666 | 30.3 |
| Educational levelc | ||||
| No formal education | 280 | 2.0 | 190 | 1.0 |
| Less than junior high school | 5,656 | 40.6 | 7,081 | 37.9 |
| Some high school | 2,077 | 14.9 | 2,267 | 12.1 |
| High school graduate | 1,849 | 13.3 | 2,280 | 12.2 |
| Vocational school, some college | 2,068 | 14.8 | 3,456 | 18.5 |
| College graduate/postgraduate | 1,278 | 9.2 | 2,768 | 14.8 |
| Missing | 730 | 5.2 | 651 | 3.5 |
| Tumor site | ||||
| Head and neck (not otherwise specified) | 314 | 2.3 | ||
| Hypopharynx | 1,026 | 7.4 | ||
| Larynx | 3,461 | 24.8 | ||
| Oral cavity | 4,110 | 29.5 | ||
| Oral/pharynx (not otherwise specified) | 1,190 | 8.5 | ||
| Oropharynx | 3,834 | 27.5 |
Abbreviations: IARC, International Agency for Research on Cancer; MSKCC, Memorial Sloan-Kettering Cancer Center.
a All centers in the International Head and Neck Cancer Epidemiology Consortium studies (data version 1.2) were included except those in Boston, Massachusetts; France; Sudan; and India. The French center was not included because it enrolled only smokers. The Boston, Massachusetts, center was not included because its data are currently unpublished. The centers in Sudan and India from the International Agency for Research on Cancer's international multicenter study were not included because of differences in tobacco products in these regions.
b Information on race and ethnicity was not collected in the Central European and Latin American multicenter studies. All cases and controls were classified as non-Hispanic white for the Central European study and as Latin American for the Latin American study.
c Educational information in this table represents actual counts and percentages; however, because educational information was not collected in the Rome, Italy, study and was frequently missing in the Latin American study, we imputed educational levels during subsequent analyses. Three cases and 2 controls who were originally missing information on educational level were also missing imputed educational level and were therefore excluded from subsequent analyses.