Risk of seizures in a population of women with BRCA-positive metastatic breast cancer from an electronic health record database in the United States

Table 2 Seizure incidence and occurrence rates in BRCA+ patients overall and by phenotype

	N	Number of patients with seizures	Median follow-up duration to seizure (days)	% patients with at least one seizure	Incidence person-years*	Incidence rate** (95% CI)	Total Occurrences	Occurrence frequency	Occurrence person-years^†	Occurrence rate**
Overall	7941	2207	161	27.80%	18655	11.83 (11.35,12.33)	15029	6.80	7468	201.30
HER2+/HR+	1039	298	193.5	28.68%	2443	12.20 (10.89,13.66)	2492	8.36	1051	237.13
HER2+/HR-	378	124	176.5	32.80%	860	14.43 (12.10,17.20)	1191	9.60	471	252.74
HER2−/HR+	3182	848	147	26.65%	7749	10.94 (10.23,11.71)	5212	6.15	2917	178.66
HER2−/HR-	1340	447	149	33.36%	2656	16.83 (15.34,18.46)	3171	7.09	1312	241.72

HER2 = human epidermal growth factor receptor 2; HR = hormone receptor; TNBC = triple negative breast cancer
*Date of metastasis to first seizure date or end of follow-up for those without a seizure
**Per 100 person-years
†Date of metastasis to the end of follow-up among patients with a seizure

ISSN: 1471-2407