Table 4.

Invasive Breast Cancer Characteristics and Stages by Thyroid Disorder

	No thyroid disorder (n = 111,740)		Hyperthyroidism (n = 1695)			Hypothyroidism (n = 19,735)
	No. of cases	Incidencea	No. of cases	Incidencea	Age-adjusted HR [95% CI]	No. of cases	Incidencea	Age-adjusted HR [95% CI]
SEER stageb
Localized	5103	31.68	92	38.61	1.03 [0.84–1.27]	898	31.57	1.01 [0.94–1.08]
Regional	1563	9.70	20	8.39	0.96 [0.61–1.49]	289	10.16	1.03 [0.91–1.18]
Distant	103	0.64	2	0.84	1.23 [0.29–5.25]	12	0.42	1.15 [0.61–2.15]
Histologyb
Ductal	199	1.24	2	0.84	0.59 [0.15–2.39]	37	1.30	0.99 [0.70–1.42]
Lobular	118	0.73	2	0.84	0.96 [0.23–3.94]	21	0.74	1.01 [0.63–1.63]
Ductal and lobular	442	2.74	3	1.26	0.86 [0.27–2.68]	82	2.88	1.03 [0.81–1.30]
Missing or unknown	155	0.96	4	1.68	1.23 [0.45–3.35]	20	0.70	1.16 [0.72–1.85]
Morphology, gradeb
Well differentiated	1761	10.93	28	11.75	1.06 [0.73–1.55]	316	11.11	1.03 [0.91–1.16]
Moderately differentiated	2858	17.74	40	16.79	1.03 [0.75–1.41]	498	17.51	1.08 [0.98–1.19]
Poorly differentiated	1500	9.31	33	13.85	0.96 [0.68–1.36]	283	9.95	0.96 [0.84–1.09]
Anaplastic	119	0.74	3	1.26	0.37 [0.12–1.22]	14	0.49	1.01 [0.58–1.76]
Missing or unknown	531	3.30	10	4.20	0.74 [0.40–1.39]	79	2.78	0.92 [0.72–1.16]
Receptor statusb
ER
Positive	5448	33.82	80	33.57	1.01 [0.81–1.27]	977	34.35	1.04 [0.97–1.11]
Negative	930	5.77	27	11.33	0.89 [0.61–1.30]	151	5.31	0.93 [0.79–1.11]
Borderline	8	0.05	1	0.42	9.84 [0.31–309.45]	1	0.04	0.39 [0.04–4.22]
Unknown	271	1.68	5	2.10	0.81 [0.34–1.98]	47	1.65	1.16 [0.85–1.59]
PR
Positive	4587	28.48	61	25.60	1.01 [0.78–1.30]	831	29.22	1.05 [0.97–1.13]
Negative	1694	10.52	45	18.88	0.96 [0.71–1.29]	284	9.98	0.96 [0.85–1.09]
Borderline	36	0.22	0	0.00	—	5	0.18	0.80 [0.30–2.10]
Unknown	335	2.08	7	2.94	0.95 [0.45–2.00]	55	1.93	1.10 [0.83–1.47]
HER2
Positive	703	4.36	19	7.97	0.99 [0.62–1.56]	124	4.36	0.95 [0.79–1.15]
Negative	4477	27.79	71	29.80	1.02 [0.81–1.29]	776	27.28	1.03 [0.96–1.11]
Borderline	52	0.32	1	0.42	0.89 [0.12–6.55]	8	0.28	1.33 [0.54–3.30]
Unknown	437	2.71	6	2.52	0.92 [0.41–2.06]	85	2.99	0.97 [0.77–1.23]
Triple negative
No	6291	39.05	96	40.29	1.03 [0.84–1.26]	1117	39.27	1.03 [0.97–1.10]
Yes	478	2.97	18	7.55	0.92 [0.57–1.47]	73	2.57	0.85 [0.66–1.08]

Mixed thyroid disorder excluded.

^aIncidence per 10,000 person-years follow-up.

^bInvasive breast cancer only.

SEER, Surveillance, Epidemiology, and End Results.