Table 1.
Factors associated with the accuracy of an algorithm to identify date of second breast cancer events.
| Absolute difference in date of true and predicted second breast cancer event date (in days)
|
||||
|---|---|---|---|---|
| <30 days N = 272 (76.0%) |
31–60 days N = 23 (6.4%) |
61–90 days N = 8 (2.2%) |
>90 days N = 55 (15.4%) |
|
| Age, mean (SD), y | 60.3 (13.4) | 60.2 (15.5) | 54.6 (15.2) | 61.7 (15.5) |
| Study follow-up, mean (SD), y | 7.6 (3.9) | 7.7 (3.8) | 7.6 (3.8) | 5.8 (3.6) |
|
| ||||
| n (row %) | n (row %) | n (row %) | n (row %) | |
|
| ||||
| Characteristics of second breast cancer event
|
||||
| Type | ||||
| Recurrence | 185 (70.3) | 18 (6.8) | 8 (3.0) | 52 (19.8) |
| Second primary | 87 (91.6) | 5 (5.3) | 0 (0) | 3 (3.2) |
| Method of diagnosis | ||||
| Clinical | 60 (71.4) | 5 (6.0) | 2 (2.4) | 17 (20.2) |
| Pathological | 171 (74.7) | 15 (6.6) | 6 (2.6) | 37 (16.2) |
| Extent of second breast cancer event | ||||
| In situ | 23 (95.8) | 0 (0) | 0 (0) | 1 (4.2) |
| Local | 94 (85.5) | 11 (10.0) | 0 (0) | 5 (4.5) |
| Regional | 19 (48.7) | 2 (5.1) | 2 (5.1) | 16 (41.0) |
| Distant | 132 (72.9) | 10 (5.5) | 6 (3.3) | 33 (18.2) |
| Year of second breast cancer event | ||||
| 1993–1995 | 5 (55.6) | 0 (0) | 0 (0) | 4 (44.4) |
| 1996–1999 | 49 (64.5) | 5 (6.6) | 4 (5.3) | 18 (23.7) |
| 2000–2003 | 95 (79.8) | 10 (8.4) | 1 (0.8) | 13 (10.9) |
| 2004–2006 | 64 (73.6) | 7 (8.0) | 3 (3.4) | 13 (14.9) |
| 2007–2011 | 59 (88.1) | 1 (1.5) | 0 (0) | 7 (10.4) |
| Age at second breast cancer event, y | ||||
| 20–29 | 0 (0) | 0 (0) | 1 (100) | 0 (0) |
| 30–39 | 7 (63.6) | 1 (9.1) | 0 (0) | 3 (27.3) |
| 40–49 | 31 (73.8) | 3 (7.1) | 0 (0) | 8 (19.0) |
| 50–59 | 68 (77.3) | 5 (5.7) | 4 (4.5) | 11 (12.5) |
| 60–69 | 62 (78.5) | 6 (7.6) | 1 (1.3) | 10 (12.7) |
| 70–79 | 59 (77.6) | 3 (3.9) | 2 (2.6) | 12 (15.8) |
| ≥80 | 45 (73.8) | 5 (8.2) | 0 (0) | 11 (18.0) |
| Characteristics first primary cancer
|
||||
| Year of primary diagnosis, n (%) | ||||
| 1993–1995 | 68 (73.9) | 5 (5.4) | 2 (2.2) | 17 (18.5) |
| 1996–1999 | 105 (77.8) | 11 (8.1) | 4 (3.0) | 15 (11.1) |
| 2000–2003 | 72 (73.5) | 6 (6.1) | 1 (1.0) | 19 (19.4) |
| 2004–2006 | 27 (81.8) | 1 (3.0) | 1 (3.0) | 4 (12.1) |
| Age at first primary breast cancer diagnosis, y | ||||
| 20–29 | 0 (0) | 0 (0) | 1 (33.3) | 2 (66.7) |
| 30–39 | 13 (76.5) | 2 (11.8) | 0 (0) | 2 (11.8) |
| 40–49 | 51 (78.5) | 4 (6.2) | 2 (3.1) | 8 (12.3) |
| 50–59 | 68 (77.3) | 5 (5.7) | 2 (2.3) | 13 (14.8) |
| 60–69 | 64 (79.0) | 5 (6.2) | 1 (1.2) | 11 (13.6) |
| 70–79 | 52 (73.2) | 5 (7.0) | 2 (2.8) | 12 (16.9) |
| ≥80 | 24 (72.7) | 2 (6.1) | 0 (0) | 7 (21.2) |
| Stage† | ||||
| Local | 199 (80.6) | 19 (7.7) | 1 (0.4) | 28 (11.3) |
| Regional | 73 (65.8) | 4 (3.6) | 7 (6.3) | 27 (24.3) |
| Distant | ||||
| Tumor size† | ||||
| ≤20 mm | 178 (82.0) | 16 (7.4) | 3 (1.4) | 20 (9.2) |
| 21–49 mm | 88 (65.7) | 7 (5.2) | 5 (3.7) | 34 (25.4) |
| ≥50 mm | 6 (85.7) | 0 (0) | 0 (0) | 1 (14.3) |
| Positive node† | ||||
| No nodes examined | 28 (70.0) | 4 (10.0) | 0 (0) | 8 (20.0) |
| All negative | 175 (82.2) | 15 (7.0) | 1 (0.5) | 22 (10.3) |
| Positive | 69 (65.7) | 4 (3.8) | 7 (6.7) | 25 (23.8) |
| ER and PR status† | ||||
| ER positive | 200 (78.7) | 15 (5.9) | 6 (2.4) | 33 (13.0) |
| Both ER and PR negative | 55 (67.1) | 8 (9.8) | 2 (2.4) | 17 (20.7) |
| Other | 17 (77.3) | 0 (0) | 0 (0) | 5 (22.7) |
| Surgery, n (%)† | ||||
| No surgery | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| Lumpectomy | 170 (79.1) | 15 (7.0) | 3 (1.4) | 27 (12.6) |
| Mastectomy | 102 (71.3) | 8 (5.6) | 5 (3.5) | 28 (19.6) |
| Unknown surgery type | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| Radiation therapy† | ||||
| No | 99 (70.7) | 8 (5.7) | 4 (2.9) | 29 (20.7) |
| Yes | 171 (79.2) | 15 (6.9) | 4 (1.9) | 26 (12.0) |
| Unknown | 2 (100) | 0 (0) | 0 (0) | 0 (0) |
| Chemotherapy† | ||||
| No | 158 (79.0) | 13 (6.5) | 3 (1.5) | 26 (13.0) |
| Yes | 113 (72.0) | 10 (6.4) | 5 (3.2) | 29 (18.5) |
| Unknown | 1 (100) | 0 (0) | 0 (0) | 0 (0) |
| Adjuvant Hormonal therapy† | ||||
| No | 144 (73.1) | 16 (8.1) | 4 (2.0) | 33 (16.8) |
| Yes | 125 (79.1) | 7 (4.4) | 4 (2.5) | 22 (13.9) |
| Unknown | 3 (100) | 0 (0) | 0 (0) | 0 (0) |
SD = standard deviation; ER = estrogen receptor; PR = progesterone receptor; SEER = Surveillance, Epidemiology and End Results program of the National Cancer Institute
*
Second breast cancer event status (second primary breast cancer or recurrent breast cancer) was determined by medical chart review.
†
Ascertained from SEER cancer registry data.