TABLE 4.
Estimates of lung cancer risk associated with metformin use, by histologic type
| Metformin Use | Adenocarcinoma
|
Squamous Cell Carcinoma
|
Small Cell Carcinoma
|
|||
|---|---|---|---|---|---|---|
| No. of events | Adjusteda HR (95% CI) | No. of events | Adjusteda HR (95% CI) | No. of events | Adjusteda HR (95% CI) | |
| Never | 121 | 1.00 (reference) | 88 | 1.00 (reference) | 62 | 1.00 (reference) |
| Ever | 80 | 0.88 (0.62-1.25) | 52 | 1.09 (0.71-1.68) | 36 | 1.23 (0.74-2.04) |
| Total duration, years | ||||||
| <2.0 | 26 | 0.92 (0.59-1.45) | 16 | 0.94 (0.54-1.66) | 14 | 1.23 (0.66-2.29) |
| 2.0 - 4.9 | 30 | 0.99 (0.63-1.54) | 16 | 1.10 (0.60-2.01) | 8 | 0.88 (0.39-1.98) |
| ≥5.0 | 24 | 0.69 (0.40-1.17) | 20 | 1.46 (0.76-2.79) | 14 | 1.82 (0.85-3.91) |
| Recency of use | ||||||
| Former | 23 | 0.99 (0.59-1.67) | 12 | 1.10 (0.54-2.23) | 8 | 1.45 (0.61-3.40) |
| Recent | 11 | 0.94 (0.49-1.79) | 3 | 0.52 (0.16-1.69) | 8 | 2.29 (1.03-5.07) |
| Current | ||||||
| <5.0 years | 31 | 0.93 (0.60-1.43) | 23 | 1.17 (0.71-1.95) | 11 | 0.84 (0.42-1.67) |
| ≥5.0 years | 15 | 0.61 (0.33-1.13) | 14 | 1.30 (0.65-2.62) | 9 | 1.58 (0.68-3.69) |
| Cumulative dose (mg), quartiles | ||||||
| ≤750,000 | 21 | 0.79 (0.49-1.28) | 18 | 1.14 (0.66-1.95) | 11 | 1.08 (0.55-2.14) |
| 750,001 – 2,300,000 | 31 | 1.12 (0.72-1.74) | 11 | 0.80 (0.41-1.58) | 8 | 0.94 (0.42-2.09) |
| 2,300,001 – 4,930,000 | 19 | 0.80 (0.46-1.39) | 12 | 1.17 (0.58-2.37) | 9 | 1.59 (0.70-3.61) |
| >4,930,000 | 9 | 0.61 (0.28-1.30) | 11 | 2.03 (0.90-4.55) | 8 | 3.11 (1.22-7.95) |
a
Stratified on age and adjusted for gender, race/ethnicity, birth year, diabetes duration, BMI, alcohol use, Charlson comorbidity index, smoking history (status and pack-years), education, income level, creatinine level, HbA1c level, and use of other diabetes medications