Table 2.
Cancer incidencea and hazard ratios in the study groups (1984–2002) for common cancer sites, cancers by sex, obesity-related cancers, and nonobesity-related cancers
| Surgery N = 6,596 |
Control N = 9,442 |
|||||
|---|---|---|---|---|---|---|
| Cancer siteb | Number of cases | Rates/1,000 person years | Number of cases | Rates/1,000 person years | Hazard ratioc (95% CI) | P value |
| All cancers | 254 | 3.13 | 477 | 4.28 | 0.76 (0.65–0.89) | 0.0006 |
| All cancers, male | 39 | 3.73 | 65 | 3.83 | 1.02 (0.69–1.52) | 0.91 |
| All cancers, female | 215 | 3.04 | 412 | 4.36 | 0.73 (0.62–0.87) | 0.0004 |
| Obesity-related cancersd | 104 | 1.28 | 253 | 2.27 | 0.62 (0.49–0.78) | <0.0001 |
| Nonobesity-related cancerse | 150 | 1.85 | 224 | 2.01 | 0.91 (0.73–1.12) | 0.37 |
| Oral cavity and pharynx (20010–20100) | 3 | 0.04 | 9 | 0.08 | 0.46 (0.12–1.75) | 0.25 |
| Esophagus (21010) | 3 | 0.04 | 4 | 0.04 | 0.98 (0.21–4.66) | 0.98 |
| Stomach (21020) | 2 | 0.02 | 2 | 0.02 | 1.70 (0.24–12.2) | 0.59 |
| Small intestine (21030) | 1 | 0.01 | 4 | 0.04 | 0.38 (0.04–3.47) | 0.39 |
| Colorectal (21041–51052) | 25 | 0.31 | 52 | 0.47 | 0.70 (0.43–1.15) | 0.15 |
| Liver (21071) | 1 | 0.01 | 1 | 0.01 | 1.69 (0.10–27.80) | 0.71 |
| Gallbladder (21080) | 0 | 0 | 2 | 0.02 | — | — |
| Pancreas (21100) | 9 | 0.11 | 8 | 0.07 | 1.75 (0.66–4.63) | 0.26 |
| Other digestive (21130) | 0 | 0 | 1 | 0.01 | — | — |
| Larynx (22020) | 1 | 0.01 | 2 | 0.02 | 0.81 (0.07–9.03) | 0.87 |
| Lung and bronchus (22030) | 5 | 0.06 | 11 | 0.10 | 0.71 (0.25–2.08) | 0.53 |
| Other respiratory (22010, 22020, 22050) | 1 | 0.01 | 3 | 0.03 | 0.51 (0.05–4.97) | 0.56 |
| Trachea (22060) | 0 | 0 | 2 | 0.02 | — | — |
| Soft tissue including heart (24000) | 4 | 0.05 | 4 | 0.04 | 1.13 (0.26–5.00) | 0.87 |
| Melanoma of skin (25010) | 17 | 0.21 | 29 | 0.26 | 0.71 (0.38–1.34) | 0.30 |
| Other nonepithelial skin (25020) | 4 | 0.05 | 2 | 0.02 | 2.37 (0.40–14.0) | 0.34 |
| Breast (26000) | 73 | 0.90 | 107 | 0.96 | 0.91 (0.67–1.24) | 0.54 |
| Premenopausal female breast | 49 | 0.60 | 65 | 0.58 | 0.93 (0.63–1.37) | 0.69 |
| Postmenopausal female breast | 24 | 0.30 | 40 | 0.36 | 0.96 (0.57–1.63) | 0.89 |
| Cervix uteri (27010) | 9 | 0.11 | 14 | 0.13 | 0.88 (0.37–2.08) | 0.78 |
| Corpus and uterus NOS (27020–27030) | 14 | 0.17 | 98 | 0.88 | 0.22 (0.13–0.40) | <0.0001 |
| Ovary (27040) | 7 | 0.09 | 19 | 0.17 | 0.19 (0.23–1.34) | 0.19 |
| Vulva (27060) | 9 | 0.11 | 2 | 0.02 | 6.15 (1.30–29.2) | 0.02 |
| Prostate (28010) | 17 | 0.21 | 17 | 0.15 | 1.71 (0.87–3.36) | 0.12 |
| Urinary bladder (29010) | 4 | 0.05 | 3 | 0.03 | 1.98 (0.43–9.06) | 0.38 |
| Kidney and renal pelvis (29020) | 11 | 0.14 | 13 | 0.12 | 1.22 (0.54–2.78) | 0.63 |
| Brain and CNS (31010–31040) | 6 | 0.07 | 10 | 0.09 | 0.69 (0.24–2.02) | 0.50 |
| Thyroid (32010) | 10 | 0.12 | 20 | 0.18 | 0.64 (0.29–1.41) | 0.27 |
| Hodgkin’s lymphoma (33011–33012) | 1 | 0.01 | 2 | 0.02 | 0.73 (0.06–8.78) | 0.80 |
| Non-Hodgkin’s lymphoma (33041–33042) | 7 | 0.09 | 17 | 0.15 | 0.54 (0.22–1.37) | 0.20 |
| Myeloma (34000) | 2 | 0.02 | 4 | 0.04 | 0.46 (0.06–3.28) | 0.44 |
| Leukemia (35011–35043) | 4 | 0.05 | 7 | 0.06 | 0.37 (0.08–1.64) | 0.19 |
| Other | 4 | 0.05 | 8 | 0.07 | — | — |
CI, 95% confidence interval; CNS, central nervous system; NOS, not otherwise specified.
Incidence is defined as cancers diagnosed after gastric bypass surgery for the surgical group and following application for driver’s license or identification card for the severely obese controls.
The SEER (Surveillance Epidemiology and End Results) site-specific coding is included within the parentheses. Menopause assumed to occur at age 50 for breast cancer analysis.
Analyses are adjusted for sex, age, and BMI. For gender-specific sites, analyses are adjusted for age and BMI.
Obesity-related cancers included esophageal adenocarcinomas, colorectal, pancreas, postmenopausal breast, corpus and uterus, kidney, non-Hodgkin lymphoma, leukemia, multiple myeloma, liver and gallbaldder.
All cancers that are not included as obesity-related cancers.