Table 2.
Distribution of Tumor Characteristics by Age and Screening Interval
| Age |
||||||||
|---|---|---|---|---|---|---|---|---|
| 40-49 y Screening Intervala | 50-59 y Screening Intervala | 60-69 y Screening Intervala | 70-85 y Screening Intervala | |||||
| Tumor Characteristic | Annual | Biennial | Annual | Biennial | Annual | Biennial | Annual | Biennial |
| No. of breast cancers (N=15,440) | 1,645 | 613 | 3,579 | 923 | 3,549 | 853 | 3,297 | 981 |
| DCIS, % (n=3,340) | 26.3 | 27.4 | 24.4 | 22.0 | 20.7 | 18.6 | 18.6 | 16.0 |
| Invasive, % (n=12,100) | 73.7 | 72.6 | 75.6 | 78.0 | 79.3 | 81.4 | 81.4 | 84.0 |
| AJCC stage | ||||||||
| No. of invasive cancers | 1,137 | 416 | 2,460 | 665 | 2,542 | 644 | 2,429 | 735 |
| Stage I, % | 54.9 | 51.0 | 57.2 | 56.4 | 62.3 | 64.0 | 68.2 | 65.7 |
| Stage IIA, % | 23.6 | 24.3 | 22.7 | 24.4 | 21.0 | 20.8 | 17.9 | 21.6 |
| Stage IIB, % | 12.3 | 13.2 | 10.9 | 9.6 | 8.9 | 7.5 | 7.3 | 6.4 |
| Stage III or IV, % | 9.2 | 11.5 | 9.2 | 9.6 | 7.8 | 7.8 | 6.6 | 6.3 |
| AJCC stage IIB or higherb | ||||||||
| No. of invasive cancers | 1,155 | 425 | 2,532 | 680 | 2,616 | 666 | 2,506 | 782 |
| Yes, % | 21.3 | 24.2 | 19.7 | 19.0 | 16.4 | 14.7 | 13.6 | 12.1 |
| No, % | 78.7 | 75.8 | 80.3 | 81.0 | 83.6 | 85.3 | 86.4 | 87.9 |
| Tumor Size | ||||||||
| No. of invasive cancers | 1,171 | 426 | 2,597 | 690 | 2,673 | 668 | 2,569 | 776 |
| <10 mm, % | 23.7 | 20.2 | 27.8 | 23.9 | 30.6 | 25.9 | 33.8 | 28.2 |
| 10 to <15 mm, % | 22.6 | 17.1 | 22.9 | 24.2 | 24.3 | 23.8 | 24.8 | 26.3 |
| 15 to 20mm, % | 23.0 | 28.6 | 21.0 | 24.1 | 20.4 | 26.2 | 20.0 | 24.2 |
| >20 mm, % | 30.7 | 34.0 | 28.2 | 27.8 | 24.8 | 24.1 | 21.4 | 21.3 |
| Lymph node | ||||||||
| No. of invasive cancers | 1,189 | 435 | 2,621 | 692 | 2,725 | 672 | 2,603 | 800 |
| Positive, % | 32.5 | 35.9 | 28.9 | 30.5 | 24.3 | 22.6 | 19.2 | 18.6 |
| Negative, % | 67.5 | 64.1 | 71.1 | 69.5 | 75.7 | 77.4 | 80.8 | 81.4 |
| Any one or more less-favorable characteristicc | ||||||||
| No. of invasive cancers | 1,171 | 425 | 2,545 | 685 | 2,627 | 662 | 2,505 | 774 |
| Any, % | 59.1 | 63.1 | 54.0 | 53.7 | 48.6 | 49.7 | 44.0 | 44.6 |
| None, % | 40.9 | 36.9 | 46.0 | 46.3 | 51.4 | 50.3 | 56.0 | 55.4 |
Abbreviation: DCIS, ductal carcinoma in situ; AJCC, American Joint Committee on Cancer.
a
Annual includes cancers diagnosed within 12 months of screening exam performed 11-14 months after prior mammogram; Biennial includes cancers diagnosed within 24 months of screening exam performed 23-26 months after prior mammogram.
b
AJCC stage IIB or higher was imputed based on tumor size or extension, nodal status, metastasis, or SEER summary stage, when available, for women missing AJCC stage.
c
Stage IIB or higher, tumor size >15 mm, or positive nodes.