Table 1.
Participant characteristics according to NPC status, by study population
| Case-control Study (N=350) (1991–1994) |
Prospective CSP Cohort (N=23,943) (1991–2002) |
Prospective TFS Cohort (N=2,557) (1996–2014) |
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|---|---|---|---|---|---|---|---|
|
| |||||||
| Prevalent NPC (N=175) |
Community Controls (N=175) |
Incident NPC (N=37) |
Disease-Free Individuals (N=117) |
Incident NPC (N=26) |
Unaffected Family members (N=77) |
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|
| |||||||
| N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | ||
|
|
|||||||
| Age at enrollment | |||||||
| <=40 | 62 (35.4) | 60 (34.3) | 7 (18.9) | 21 (18.0) | 11 (42.3) | 33 (42.9) | |
| 41–50 | 36 (20.6) | 48 (27.4) | 7 (18.9) | 26 (22.2) | 9 (34.6) | 27 (35.1) | |
| >50 | 77 (44.0) | 67 (38.3) | 23 (62.2) | 70 (59.8) | 6 (23.1) | 17 (22.1) | |
| Sex | |||||||
| Female | 55 (31.4) | 59 (33.7) | 8 (21.6) | 25 (21.4) | 6 (23.1) | 18 (23.4) | |
| Male | 120 (68.6) | 116 (66.3) | 29 (78.4) | 92 (78.6) | 20 (76.9) | 59 (76.6) | |
| Smoking | |||||||
| Never | 86 (49.1) | 100 (57.1) | -- | -- | 10 (38.5) | 42 (54.0) | |
| Former | 30 (17.1) | 15 (8.6) | -- | -- | 3 (11.5) | 6 (7.9) | |
| Current | 59 (33.7) | 60 (34.3) | -- | -- | 13 (50.0) | 29 (38.2) | |
| Lag time* | |||||||
| <2 years | 4 (10.8) | 4 (15.4) | |||||
| 2–5 years | 18 (48.6) | 7 (26.9) | |||||
| >5 years | 11 (29.7) | 12 (46.2) | |||||
| Not assigned | 4 (10.8) | 3 (11.5) | |||||
*
Lag time defined as the number of years between study enrollment blood draw and NPC diagnosis for incident cases from the prospective cohorts. In the case-control study, all cases had blood drawn after NPC diagnosis but prior to cancer treatment.