Validity of self-reported breast cancer characteristics in a nationwide cohort of women with a family history of breast cancer

Table 2 Positive Predictive Values (PPV) of self-reported breast cancer characteristics, Sister Study 2003-2014^a

Breast cancer characteristic	Medical record (%)^b	Self-report^b	PPV (%)
Invasiveness
Invasive	1533 (76)	1191 (63)	99.3
In situ	472 (24)	711 (37)	64.2
Unknown	3	106
Location^c
Ductal (any)	1804 (90)	1562 (88)	98.9
Lobular only	190 (10)	215 (12)	75.7
Unknown	9	226
Stage
0	471 (24)	563 (32)	71.1
I	1035 (52)	712 (41)	92.1
II	380 (19)	352 (20)	67.9
III/IV	117 (6)	128 (7)	71.1
Unknown	5	253
Among medically confirmed invasive cases:^d
ER
Positive	1277 (85)	1104 (83)	99.1
Negative	217 (15)	234 (17)	83.0
Unknown	39	195
PR
Positive	1081 (73)	643 (62)	98.9
Negative	404 (27)	402 (38)	71.6
Unknown	48	488
HER2
Positive	167 (12)	232 (22)	66.1
Negative	1271 (88)	845 (78)	99.1
Unknown	95	456

Abbreviation: ER estrogen receptor, PR progesterone receptor, HER2 human epidermal growth factor receptor 2, PPV positive predictive value
^aExcludes 43 who did not complete the questionnaire about breast cancer characteristics and 3 who reported on a different breast cancer event than the one abstracted from her medical records
^bData are reported as number (percentage) of women. Totals may not always equal 100% because of rounding
^cExcludes 5 cases that are not of ductal or lobular origin (phyllodes tumors)
^dER, PR, and HER2 analyses are restricted to 1533 cases confirmed as invasive breast cancer by medical records

ISSN: 1471-2407