Table 1.
Age-adjusted female adenoid cystic carcinoma of the breast incidence rates and incidence rate ratios
| Total | ||||
|---|---|---|---|---|
| Characteristic | n | IR | IRR | 95% CI |
| Total | 338 | 0.92 | NA | |
| Race | ||||
| Whites | 295 | 0.97 | 1.00 | Reference |
| Blacks | 20 | 0.59 | 0.61 | 0.37 to 0.96 |
| Other/unspecified | 23 | ~ | ~ | ~ |
| Calendar period | ||||
| 1977 to 1986 | 79 | 0.78 | 1.00 | Reference |
| 1987 to 1996 | 121 | 1.02 | 1.30 | 0.97 to 1.76 |
| 1997 to 2006 | 138 | 0.96 | 1.23 | 0.93 to 1.65 |
| Age | ||||
| <50 years | 59 | 0.25 | 1.00 | Reference |
| ≥50 years | 279 | 2.70 | 11.02 | 8.31 to 14.87 |
| Laterality | ||||
| Right | 164 | 0.45 | 1.00 | Reference |
| Left | 173 | 0.47 | 1.06 | 0.85 to 1.32 |
| Not specified | 1 | ~ | ~ | ~ |
| Site | ||||
| Upper outer quadrant | 105 | 0.29 | 1.00 | Reference |
| Upper inner quadrant | 29 | 0.08 | 0.28 | 0.18 to 0.43 |
| Lower outer quadrant | 23 | 0.06 | 0.22 | 0.13 to 0.35 |
| Lower inner quadrant | 14 | ~ | ~ | ~ |
| Nipple/central | 28 | 0.08 | 0.27 | 0.17 to 0.41 |
| Overlapping | 89 | 0.24 | 0.83 | 0.62 to 1.11 |
| Not specified | 50 | 0.14 | 0.47 | 0.33 to 0.67 |
| Stage | ||||
| Localized | 320 | 0.87 | 1.00 | Reference |
| Regional | 14 | ~ | ~ | ~ |
| Distant | 1 | ~ | ~ | ~ |
| Unstaged | 3 | ~ | ~ | ~ |
| LN and sizea | ||||
| LN negative, ≤2 cm | 126 | 0.50 | 1.00 | Reference |
| LN negative, >2 cm | 67 | 0.26 | 0.52 | 0.38 to 0.71 |
| LN positive, ≤2 cm | 2 | ~ | ~ | ~ |
| LN positive, >2 cm | 3 | ~ | ~ | ~ |
| Other/not specified | 46 | 0.18 | 0.36 | 0.25 to 0.51 |
| Hormone receptorsb | ||||
| ER-negative/PR-negative | 128 | 0.56 | 1.00 | Reference |
| ER-negative/PR-positive | 6 | ~ | ~ | ~ |
| ER-positive/PR-positive | 21 | 0.09 | 0.16 | 0.10 to 0.25 |
| ER-positive/PR-negative | 12 | ~ | ~ | ~ |
| Other/not specified | 55 | 0.24 | 0.42 | 0.30 to 0.59 |
Data from the nine cancer registry areas of the Surveillance, Epidemiology and End Results Program, 1977 to 2006. Incidence rates are age-adjusted to the 2000 US standard population and are expressed per 1 million person-years. Incidence rate ratios are based on unrounded rates. n, number of cases; IR, incidence rate; IRR, incidence rate ratio; CI, confidence interval; NA, not applicable; ~, IRs and IRRs not calculated for fewer than 16 cases or other/unspecified race; LN, regional lymph nodes; ER, estrogen receptor; PR, progesterone receptor. aLimited to cases with localized/regional stage diagnosed in 1988 or later. bLimited to cases diagnosed in 1990 or later.