Table 1

The numbers and the causes of withdrawals among women selected, and the medical records obtained in the case-control study of the risk for breast cancer death or subsequent invasive breast cancer after a primary diagnosis of DCIS

Causes of withdrawalBreast cancer deathSubsequent invasive breast cancer
Cases selected/obtained 113/109Controls selected/obtained 452/427Cases selected/obtained 162/154Controls selected/obtained 638/591
Invasive cancer in the primary lesion27291146
Diagnosis made by cytology only17020
History of earlier breast cancer216033
Lobular CIS2572537
Benign lesion only15013
Recurrence before case1
No control available02
No case available240146
Cause of death other than breast cancer21
Bilateral or generalized recurrence5