Table 4.
Pooled Multivariable HRs for Incident Melanoma by Subgroup According to Frequency of Grapefruit Consumption*
| Risk | Grapefruit Serving Category |
Ptrend | |||
|---|---|---|---|---|---|
| Never | < Once per Week | Once per Week | ≥ Twice per Week | ||
| No. of person-years | 515,163 | 647,023 | 354,732 | 485,515 | |
| Risk of overall melanoma on body sites with higher continuous sun exposure (head, neck, extremities) | |||||
| No. of cases | 175 | 374 | 224 | 381 | |
| Multivariable-adjusted HR (95% CI) | 1.00 | 1.36 (1.12 to 1.65) | 1.45 (1.16 to 1.81) | 1.58 (1.28 to 1.95) | < .001 |
| Risk of overall melanoma on body sites with lower continuous sun exposure (truncal sites) | |||||
| No. of cases | 121 | 198 | 118 | 177 | |
| Multivariable-adjusted HR (95% CI) | 1.00 | 1.04 (0.78 to 1.38) | 1.13 (0.76 to 1.69) | 1.14 (0.88 to 1.49) | .22 |
| Risk of melanoma in situ on body sites with higher continuous sun exposure (head, neck, extremities) | |||||
| No. of cases | 87 | 187 | 117 | 206 | |
| Multivariable-adjusted HR (95% CI) | 1.00 | 1.32 (1.00 to 1.75) | 1.50 (1.07 to 2.11) | 1.61 (1.13 to 2.30) | .03 |
| Risk of melanoma in situ on body sites with lower continuous sun exposure (truncal sites) | |||||
| No. of cases | 46 | 93 | 47 | 79 | |
| Multivariable-adjusted HR (95% CI) | 1.00 | 1.13 (0.78 to 1.63) | 1.14 (0.74 to 1.75) | 1.16 (0.78 to 1.74) | .59 |
| Risk of invasive melanoma on body sites with higher continuous sun exposure (head, neck, extremities) | |||||
| No. of cases | 88 | 187 | 107 | 175 | |
| Multivariable-adjusted HR (95% CI) | 1.00 | 1.40 (1.06 to 1.84) | 1.37 (1.00 to 1.88) | 1.53 (1.13 to 2.06) | .03 |
| Risk of invasive melanoma on body sites with lower continuous sun exposure (truncal sites) | |||||
| No. of cases | 75 | 105 | 71 | 98 | |
| Multivariable-adjusted HR (95% CI) | 1.00 | 0.96 (0.52 to 1.77) | 1.15 (0.69 to 1.91) | 1.10 (0.62 to 1.95) | .33 |
Abbreviation: HR, hazard ratio.
Multivariable analyses were adjusted for age, family history of melanoma, natural hair color, No. of arm moles, sunburn susceptibility as child or adolescent, No. of lifetime blistering sunburns, cumulative ultraviolet flux since baseline, average time spent in direct sunlight since high school, body mass index, physical activity, smoking status, and intake of total energy, alcohol, coffee, vitamin C from supplements, and other individual citrus products (grapefruit juice, oranges, and orange juice). Analyses for women were also adjusted for menopausal status and postmenopausal hormone use. Table 2 footnote provides additional details on these variables. Results among women and men were pooled using random-effects model.