Outcome Validation

Confirmation of Breast Cancer Diagnosis

Self-reports are the main source of information on breast cancer and other outcomes in the Sister Study. Participants who develop breast cancer report their diagnosis through phone calls, email correspondence, or regularly scheduled questionnaire follow-ups at which time they are asked to provide a copy of their pathology report, if available. Approximately 6 months after their diagnosis, participants are asked to complete a brief breast cancer questionnaire and for permission to obtain relevant medical records. Medical records are abstracted to verify reported breast cancer diagnosis information as well as to obtain information on:

• tumor characteristics
• hormone receptor status
• lymph node involvement
• metastasis
• treatments

SISTER STUDY DATA RELEASE 5:

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Links to other Data Releases

Concordance of breast cancer characteristics among those with medical records (N = 2,324 incident breast cancer events confirmed by medical records, 81.1% of 2,865 total incident breast cancer events)*

As of release 5.0, the Sister Study has medical records for 81.1% of women that reported a breast cancer diagnosis. Among the 81% that have medical records, the Positive Predictive Value (PPV) of a self-reported breast cancer is 99.4%. PPVs for self-reported subtypes and characteristics can be found below.

Self-Report Type for any Breast Cancer and by Invasiveness	% Confirmed by Medical Records (PPV)
Breast Cancer	99.4%
Invasive (any) Invasive-Ductal (any)†‡    Invasive-Ductal (only)†‡ Invasive-Lobular (any)†‡    Invasive-Lobular (only)†‡ Invasive- Both Ductal/Lobular or Mixed†‡	99.3% 98.5% 96.3% 73.4% 73.1% 43.8%
In Situ (only) In Situ-Ductal or Both Ductal/Lobular‡    In Situ-Ductal (only)‡ In Situ-Lobular	64.9% 67.7% 67.8% 68.2%

 

Self-Report Type by Ductal or Lobular Status†‡	% Confirmed by Medical Records (PPV)
Ductal (Any) Ductal-Only	98.8% 96.4%
Both Ductal/Lobular or Mixed	39.0%
Lobular (Any) Lobular-Only	72.2% 75.8%

† Excludes n = 5 cases not of ductal or lobular origin (phyllodes tumors).
‡ Special subtypes of inflammatory or Paget’s were assigned accordingly to ductal or lobular categories. 

 

Hormone Receptor Characteristics Among those with Medically Confirmed Invasive Cancers [excludes those that did not complete Breast Cancer Follow-Up Form (asks about self-report of hormone receptor characteristics) and are missing hormone receptor data in medical records].

Self-Report Type	% Confirmed by Medical Records (PPV)
Estrogen Receptor (ER) Positive Negative	99.3% 83.1%
Progesterone Receptor (PR) Positive Negative	99.0% 71.3%
Human Epidermal Growth Factor Receptor 2 (HER2) Positive Negative	64.3% 99.0%

*Further excluded 2 women from concordance results who have medical confirmation of breast cancer but disavowed (refuted) their original self-report of breast cancer.

 

Other Data Releases:

Breast Cancer Validation — Data Release 3

Breast Cancer Validation — Data Release 4