Table 3.
Risk of esophageal cancer following breast cancer according to esophageal cancer risk factors, overall and by esophageal cancer histology
| Risk factora | Cases | Controls | OR (95% CI)b | By esophageal cancer histology |
|||||
|---|---|---|---|---|---|---|---|---|---|
| Squamous cell carcinoma |
Adenocarcinoma |
||||||||
| Cases | Controls | OR (95% CI)b | Cases | Controls | OR (95% CI)b | ||||
| Cigarette smoking status | |||||||||
| Non-smoker | 47 | 125 | 1.0 (referent) | 29 | 85 | 1.0 (referent) | 11 | 23 | 1.0 (referent) |
| Former smoker | 12 | 25 | 1.0 (0.4–2.3) | 8 | 17 | 0.9 (0.3–2.6) | 1 | 5 | |
| Current smoker <1 pack/day | 23 | 46 | 0.8 (0.4–1.6) | 20 | 33 | 0.9 (0.4–2.1) | 1 | 6 | |
| Current smoker ≥1 pack/day | 23 | 18 | 2.4 (1.1–5.7) | 17 | 14 | 2.6 (0.9–7.5) | 4 | 2 | 4.5 (0.7–40) |
| Ptrend | 0.20 | 0.22 | 0.46 | ||||||
| Unknown | 147 | 274 | 1.0 (0.6–1.7) | 104 | 195 | 1.0 (0.5–2.0) | 17 | 31 | 1.3 (0.4–4.0) |
| Alcohol consumptionc | |||||||||
| Non-drinker | 16 | 61 | 1.0 (referent) | 8 | 43 | 1.0 (referent) | 5 | 14 | 1.0 (referent) |
| Light drinker | 16 | 50 | 1.0 (0.4–2.4) | 12 | 39 | 1.3 (0.4–4.0) | 1 | 2 | |
| Moderate drinker | 12 | 16 | 3.1 (1.1–8.5) | 8 | 13 | 4.4 (1.2–16) | 2 | 2 | 0.9 (0.1–6.5) |
| Heavy drinker | 14 | 6 | 6.9 (2.1–25) | 12 | 4 | 14 (3.1–77) | 0 | 2 | |
| Ptrend | <0.001 | <0.001 | >0.5 | ||||||
| Unknown | 194 | 355 | 2.3 (1.2–4.6) | 138 | 245 | 3.9 (1.6–10) | 26 | 47 | 1.8 (0.5–7.2) |
| First-degree relative with cancer | |||||||||
| By number of relatives | |||||||||
| 0 | 65 | 159 | 1.0 (referent) | 49 | 110 | 1.0 (referent) | 7 | 23 | 1.0 (referent) |
| 1 | 52 | 70 | 1.9 (1.2–3.0) | 40 | 49 | 1.8 (1.0–3.3) | 7 | 9 | 2.6 (0.7–10.4) |
| 2+ | 29 | 31 | 2.8 (1.6–5.2) | 20 | 24 | 2.3 (1.1–4.5) | 3 | 3 | 5.4 (0.7–52) |
| Ptrend | <0.001 | 0.008 | 0.06 | ||||||
| Unknown | 106 | 228 | 1.3 (0.9–1.9) | 69 | 161 | 1.1 (0.7–1.8) | 17 | 32 | 1.8 (0.7–5.0) |
| By cancer typed | |||||||||
| Breast | 22 | 41 | 1.1 (0.6–2.0) | 15 | 28 | 0.9 (0.4–2.0) | 2 | 4 | 1.2 (0.1–8.7) |
| Lung | 13 | 4 | 6.3 (2.0–24) | 8 | 3 | 4.4 (1.1–24) | 4 | 1 | ∼ |
| Upper GI | 13 | 12 | 2.6 (1.0–6.7) | 10 | 10 | 2.2 (0.7–6.5) | 1 | 1 | ∼ |
| Colorectal | 11 | 9 | 2.4 (0.9–6.8) | 8 | 5 | 2.0 (0.6–7.3) | 1 | 2 | ∼ |
| Other | 23 | 39 | 1.1 (0.6–2.0) | 17 | 30 | 1.0 (0.4–2.1) | 4 | 3 | 5.3 (0.8–46) |
| BMI (kg/m2)e | |||||||||
| 13.8–18.4 | 6 | 7 | 1.0 (0.3–3.3) | 0 | 2 | 1.0 (referent) | |||
| 18.5–24.9 | 54 | 75 | 1.0 (referent) | 4 | 19 | ||||
| 25.0–29.9 | 25 | 42 | 0.7 (0.4–1.3) | 2 | 7 | 2.1 (0.2–17) | |||
| 30.0–48.4 | 7 | 22 | 0.4 (0.1–1.0) | 5 | 2 | 20 (2.4–456) | |||
| Ptrend | 0.02 | 0.002 | |||||||
| Unknown | 86 | 198 | 0.5 (0.3–0.9) | 23 | 37 | 4.8 (1.3–23) | |||
BMI, body mass index; CI, confidence interval; OR, odds ratio.
aData on cigarette smoking, alcohol consumption, and family history of cancer were ascertained up to 1 year prior to esophageal cancer diagnosis (or comparable date for controls).
bAll risk estimates were adjusted for continuous radiation dose. Cigarette smoking and alcohol consumption were evaluated in the same analysis, thus each is also adjusted for the other.
cLight, moderate, and heavy alcohol consumption was defined as <7, 7–20, and ≥21 drinks per week, respectively.
dFamily history by cancer type was evaluated in a multivariate analysis. Upper GI cancer includes esophagus, stomach, and pancreas.
eBMI was computed from height and weight data within 5 years of breast cancer diagnosis. Risks are provided by histology only because of the substantially different effects.