Table 2. The association between betel quid use and risk of head and neck cancer overall and by sites.
| Characteristics | Controls N = 617 n (%) | All head and neck cancer N = 487 n (%) | OR (95% CI)a | Oral cavity N = 313 n (%) | OR (95% CI)a | Pharynx N = 119 n (%) | OR (95% CI)a | Larynx N = 55 n (%) | OR (95% CI)a |
|---|---|---|---|---|---|---|---|---|---|
| Betel quid chewing status | |||||||||
| Never | 446 (72.3) | 127 (26.1) | Referent | 67 (21.4) | Referent | 31 (26.1) | Referent | 29 (52.7) | Referent |
| Former | 105 (17.0) | 192 (39.4) | 4.20 (2.97–5.95) | 133 (42.5) | 6.43 (4.25–9.73) | 43 (36.1) | 2.87 (1.61–5.13) | 16 (29.1) | 1.24 (0.57–2.71) |
| Current | 66 (10.7) | 168 (34.5) | 6.09 (4.08–9.08) | 113 (36.1) | 8.05 (5.10–12.71) | 45 (37.8) | 4.80 (2.57–8.99) | 10 (18.2) | 2.38 (0.94–6.06) |
| Ever (former + current) | 171 (27.7) | 360 (73.9) | 4.85 (3.54–6.64) | 246 (78.6) | 7.03 (4.81–10.28) | 88 (73.9) | 3.54 (2.09–5.98) | 26 (47.3) | 1.53 (0.76–3.07) |
| Types of betel quid chewed | |||||||||
| Never | 446 (72.3) | 127 (26.1) | Referent | 67 (21.4) | Referent | 31 (26.0) | Referent | 29 (52.7) | Referent |
| With betel leaf (Betel quid) | 70 (11.3) | 147 (30.2) | 4.73 (3.19–7.01) | 96 (30.7) | 6.31 (3.98–10.00) | 36 (30.3) | 3.39 (1.80–6.35) | 15 (27.3) | 2.74 (1.17–6.41) |
| With betel inflorescence (Lao-hwa) | 21 (3.4) | 39 (8.0) | 4.42 (2.44–7.98) | 28 (8.9) | 6.72 (3.48–12.99) | 9 (7.6) | 3.65 (1.40–9.47) | 2 (3.6) | 0.34 (0.10–2.53) |
| Both types | 79 (12.8) | 172 (35.4) | 5.10 (3.52–7.41) | 122 (39.0) | 7.81 (5.07–12.04) | 41 (34.4) | 3.47 (1.90–6.34) | 9 (16.4) | 1.24 (0.50–3.07) |
| Unknown | 1 (0.2) | 2 (0.3) | -- | 0 (0.0) | -- | 2 (1.7) | -- | 0 (0.0) | -- |
| Betel pack-yearsb | |||||||||
| Never | 446 (72.3) | 127 (26.1) | Referent | 67 (21.4) | Referent | 31 (26.0) | Referent | 29 (52.7) | Referent |
| 0.1–9.9 pack-years | 56 (9.1) | 70 (14.4) | 3.28 (2.14–5.04) | 52 (16.6) | 5.01 (3.07–8.18) | 14 (11.8) | 2.00 (0.94–4.22) | 4 (7.3) | 0.94 (0.29–3.02) |
| 10.0–19.9 pack-years | 31 (5.0) | 59 (12.1) | 4.69 (2.83–7.79) | 45 (14.4) | 7.19 (4.10–12.61) | 11 (9.2) | 2.33 (1.00–5.44) | 3 (5.4) | 1.00 (0.26–3.89) |
| 20.0–29.9 pack-years | 27 (4.4) | 55 (11.3) | 4.63 (2.68–7.99) | 27 (8.6) | 4.67 (2.43–8.96) | 19 (16.0) | 5.82 (2.61–12.98) | 9 (16.4) | 3.13 (1.09–9.00) |
| 30.0 or more pack-years | 55 (8.9) | 158 (32.4) | 6.41 (4.22–9.76) | 106 (33.9) | 9.51 (5.82–15.52) | 43 (36.2) | 5.51 (2.86–10.61) | 9 (16.4) | 1.54 (0.60–3.96) |
| Unknown | 2 (0.3) | 18 (3.7) | -- | 16 (5.1) | -- | 1 (0.8) | -- | 1 (1.8) | -- |
| Ordinalc | 1.58 (1.43–1.75) | 1.67 (1.49–1.87) | 1.55 (1.32–1.81) | 1.18 (0.95–1.46) | |||||
| Test for trendc | <0.0001 | <0.0001 | <0.0001 | 0.14 | |||||
| Total time chewed (Thousand minutes) | |||||||||
| 0 | 446 (72.3) | 127 (26.1) | Referent | 67 (21.4) | Referent | 31 (26.0) | Referent | 29 (52.7) | Referent |
| <200 | 42 (6.8) | 39 (8.0) | 2.59 (1.57–4.26) | 29 (9.3) | 3.74 (2.14–6.53) | 8 (6.7) | 1.62 (0.67–3.92) | 2 (3.6) | 0.85 (0.19–3.88) |
| 201–399 | 20 (3.2) | 38 (7.8) | 5.15 (2.83–9.37) | 25 (8.0) | 6.62 (3.42–12.82) | 9 (7.6) | 3.41 (1.35–8.66) | 4 (7.3) | 3.04 (0.88–10.56) |
| 401–599 | 19 (3.1) | 25 (5.1) | 3.66 (1.90–7.05) | 18 (5.7) | 4.79 (2.34–9.83) | 5 (4.2) | 2.10 (0.69–6.36) | 2 (3.6) | 1.76 (0.35–8.86) |
| 600 or more | 83 (13.5) | 220 (45.2) | 6.43 (4.53–9.13) | 143 (45.7) | 8.20 (5.46–12.33) | 61 (51.3) | 5.56 (3.21–9.63) | 16 (29.1) | 3.20 (1.49–6.89) |
| Unknown | 7 (1.1) | 38 (7.8) | -- | 31 (9.9) | -- | 5 (4.2) | -- | 2 (3.6) | -- |
| Ordinalc | 1.58 (1.45–1.72) | 1.65 (1.50–1.82) | 1.51 (1.32–1.73) | 1.35 (1.12–1.64) | |||||
| Test for trendc | <0.0001 | <0.0001 | <0.0001 | 0.002 | |||||
| Time since quitting | |||||||||
| Current chewer | 66 (10.7) | 168 (34.5) | Referent | 113 (36.1) | Referent | 45 (37.8) | Referent | 10 (18.2) | Referent |
| 0.0–9.9 years | 56 (9.1) | 103 (21.2) | 0.69 (0.44–1.07) | 67 (21.4) | 0.72 (0.44–1.17) | 28 (23.5) | 0.74 (0.39–1.42) | 8 (14.6) | 0.62 (0.22–1.81) |
| 10.0–19.9 years | 23 (3.7) | 63 (12.9) | 1.10 (0.62–1.97) | 48 (15.3) | 1.42 (0.77–2.61) | 9 (7.6) | 0.63 (0.24–1.61) | 6 (10.9) | 0.73 (0.19–2.71) |
| 20.0 years or more | 25 (4.0) | 23 (4.7) | 0.27 (0.13–0.53) | 15 (4.8) | 0.34 (0.16–0.73) | 6 (5.0) | 0.26 (0.09–0.78) | 2 (3.6) | 0.20 (0.04–1.08) |
| Never chewer | 446 (72.3) | 127 (26.1) | 0.16 (0.11–0.24) | 67 (21.4) | 0.12 (0.08–0.20) | 31 (26.1) | 0.20 (0.11–0.38) | 29 (52.7) | 0.41 (0.16–1.05) |
| Unknown | 1 (0.2) | 3 (0.6) | -- | 3 (1.0) | -- | 0 (0.0) | -- | 0 (0.0) | -- |
| Ordinalc,d | 0.83 (0.67–1.02) | 0.87 (0.70–1.09) | 0.72 (0.52–0.99) | 0.74 (0.44–1.24) | |||||
| Test for trendc,d | 0.08 | 0.23 | 0.04 | 0.25 | |||||
| Every 1 yeard | 0.972 (0.950–0.995) | 0.976 (0.952–1.001) | 0.967 (0.933–1.001) | 0.955 (0.901–1.011) |
Abbreviations: N = number; CI = confidence interval; OR = odds ratio
a OR and 95% CI were calculated using unconditional logistic regression, adjusted for age, education, cigarette smoking (pack-year categories), and alcohol drinking (frequency)
b 1 pack year = 20 betel quids/per day x 1 year
c Those with an unknown value were excluded from the analysis.
d Never betel quid chewers were excluded from the analysis