Table 1.
Characteristics of the patients.
| Characteristics of patients | Total No. | % of all cases | Total N(0) | % of all cases | Total N(+) | % of all cases |
| Patient number | 83804 | 100.0% | 58139 | 69.4% | 25665 | 30.6% |
| SEER area: | ||||||
| East (Connecticut, Detroit, Atlanta) | 31795 | 37.9% | 21683 | 25.9% | 10112 | 12.1% |
| Central (Iowa, New Mexico, Utah) | 20459 | 24.4% | 14202 | 16.9% | 6257 | 7.5% |
| West (San Francisco-Oakland, Hawaii, Seattle) | 31550 | 37.6% | 22254 | 26.6% | 9296 | 11.1% |
| Year of diagnosis: | ||||||
| 1988–89 | 15390 | 18.4% | 10424 | 12.4% | 4966 | 5.9% |
| 1990–91 | 16660 | 19.9% | 11589 | 13.8% | 5071 | 6.1% |
| 1992–93 | 17042 | 20.3% | 11894 | 14.2% | 5148 | 6.1% |
| 1994–95 | 17072 | 20.4% | 11897 | 14.2% | 5175 | 6.2% |
| 1996–97 | 17640 | 21.0% | 12335 | 14.7% | 5305 | 6.3% |
| Age at diagnosis (years): | ||||||
| 20–39 | 5869 | 7.0% | 3396 | 4.1% | 2473 | 3.0% |
| 40–49 | 16231 | 19.4% | 10262 | 12.2% | 5969 | 7.1% |
| 50–59 | 18051 | 21.5% | 12362 | 14.8% | 5689 | 6.8% |
| 60–69 | 20703 | 24.7% | 15110 | 18.0% | 5593 | 6.7% |
| 70–79 | 17161 | 20.5% | 12802 | 15.3% | 4359 | 5.2% |
| 80+ | 5789 | 6.9% | 4207 | 5.0% | 1582 | 1.9% |
| Race: | ||||||
| White and Other | 78025 | 93.1% | 54572 | 65.1% | 23453 | 28.0% |
| Black | 5779 | 6.9% | 3567 | 4.3% | 2212 | 2.6% |
| Marital status at diagnosis: | ||||||
| Single, widowed, other | 33224 | 39.6% | 23171 | 27.6% | 10053 | 12.0% |
| Married | 50580 | 60.4% | 34968 | 41.7% | 15612 | 18.6% |
| Topography: | ||||||
| Inner quadrant | 12537 | 15.0% | 9726 | 11.6% | 2811 | 3.4% |
| Others | 71267 | 85.0% | 48413 | 57.8% | 22854 | 27.3% |
| Histology: | ||||||
| Ductal | 64370 | 76.8% | 43924 | 52.4% | 20446 | 24.4% |
| Others | 19434 | 23.2% | 14215 | 17.0% | 5219 | 6.2% |
| Grade: | ||||||
| Poor/undifferentiated | 25161 | 30.0% | 15265 | 18.2% | 9896 | 11.8% |
| Others | 58643 | 70.0% | 42874 | 51.2% | 15769 | 18.8% |
| ER/PR status (+ includes unspecified): | ||||||
| ER+ and PR+ | 63306 | 75.5% | 44332 | 52.9% | 18974 | 22.6% |
| ER+ and PR- | 7001 | 8.4% | 4852 | 5.8% | 2149 | 2.6% |
| ER- and PR+ | 2554 | 3.0% | 1696 | 2.0% | 858 | 1.0% |
| ER- and PR- | 10943 | 13.1% | 7259 | 8.7% | 3684 | 4.4% |
| Tumor size (mm) (T stage): | ||||||
| < = 5 (T1a) | 3349 | 4.0% | 3069 | 3.7% | 280 | 0.3% |
| > 5 and < = 10 (T1b) | 16997 | 20.3% | 14691 | 17.5% | 2306 | 2.8% |
| > 10 and < = 20 (T1c) | 36754 | 43.9% | 26443 | 31.6% | 10311 | 12.3% |
| > 20 and < = 50 (T2) | 26704 | 31.9% | 13936 | 16.6% | 12768 | 15.2% |
| Number of nodes examined: | ||||||
| 1–9 | 14225 | 17.0% | 10525 | 12.6% | 3700 | 4.4% |
| 10–14 | 27004 | 32.2% | 19210 | 22.9% | 7794 | 9.3% |
| 15–19 | 23102 | 27.6% | 15820 | 18.9% | 7282 | 8.7% |
| 20+ | 19473 | 23.2% | 12584 | 15.0% | 6889 | 8.2% |
| Number of nodes involved: | ||||||
| 0 | 58139 | 69.4% | 58139 | 69.4% | 0 | 0.0% |
| 1–3 | 16778 | 20.0% | 0 | 0.0% | 16778 | 20.0% |
| 4+ | 8887 | 10.6% | 0 | 0.0% | 8887 | 10.6% |
| Breast conserving surgery/Radiotherapy | ||||||
| no/no | 46862 | 55.9% | 31752 | 37.9% | 15110 | 18.0% |
| no/yes | 3972 | 4.7% | 1024 | 1.2% | 2948 | 3.5% |
| yes/no | 4438 | 5.3% | 2946 | 3.5% | 1492 | 1.8% |
| yes/yes | 28532 | 34.0% | 22417 | 26.7% | 6115 | 7.3% |
ER = estrogen receptor, N(0) = node negative, N(+) = node positive, PR = progesterone receptor, SEER = Surveillance, Epidemiology, and End Results Program.