Table 1.
Cases and controls included in benign breast disease pathologic specimen collectiona
| Cases | Controls | Selection of participants |
| 1,080 | 4,353 | Participants initially selected |
| -29 | -85 | Participant died or withdrew from study subsequent to selection |
| -265 | -1,090 | We did not pursue collection of specimens, because: |
| • participant denied having biopsy or had cyst aspiration only | ||
| • participant could not recall hospital or hospital no longer exists | ||
| • participant denied permission to seek specimens | ||
| • biopsy contained cancer | ||
| -379 | -1,406 | We were unable to obtain requested samples |
| • specimens were no longer available or destroyed | ||
| • hospital had no record of the patient or biopsy | ||
| • hospital had no record of the patient or biopsy | ||
| -33 | -113 | Specimens received were not usable for study |
| • slides were not of good quality/not evaluable | ||
| • specimens did not contain breast tissue | ||
| • were from wrong person or incorrect date | ||
| 374 | 1,659 | Eligible participants for whom we collected usable specimens |
aNurses' Health Study I (1976 to 1994) and II (1989 to 1995).