Increase in Distant Stage Breast Cancer Incidence Rates in US Women Aged 25–49 Years, 2000–2011: The Stage Migration Hypothesis

Table 1

Age-standardized incidence rate for women aged 25–39 years and 40–49 years with invasive breast cancer in SEER registries: annual percent change (APC) by stage at diagnosis^a,b.

Stage	2000		2011		2000–2011
	Number	Rate (CL)	Number	Rate (CL)	Number	Rate (CL)	APC, % (CL)
Age 25–39 years
Distant	123	1.4 (1.2, 1.7)	204	2.5 (2.2, 2.9)	1935	1.9 (1.8, 2.0)	5.4 (3.7, 7.2)^*
Regional	1356	15.4 (14.6, 16.3)	1249	15.4 (14.5, 16.3)	15,251	15.2 (14.9, 15.4)	−0.4 (−1.1, +0.3)
IIIC^b	174	2.0 (1.7, 2.3)	94	1.1 (0.9, 1.4)	1541	1.5 (1.5, 1.6)	−4.5 (−5.5, −3.4)^*
IIIB	88	1.0 (0.8, 1.2)	67	0.8 (0.6, 1.1)	911	0.9 (0.8, 1.0)	−0.9 (−2.3, +0.5)
IIIA	324	3.7 (3.3, 4.1)	324	4.0 (3.6, 4.4)	3773	3.8 (3.6, 3.9)	0.5 (−0.9, +2.1)
IIA, IIB	693	7.9 (7.3, 8.5)	704	8.7 (8.1, 9.4)	8296	8.3 (8.1, 8.4)	0.2 (−0.6, +0.9)
Localized	1338	15.3 (14.5, 16.1)	1309	16.1 (15.3, 17.1)	15,813	15.8 (15.5, 16.0)	0.2 (−0.3, +0.8)
Age 40–49 years
Distant	341	5.7 (5.1, 6.3)	475	7.7 (7.0, 8.4)	4817	6.4 (6.2, 6.6)	3.6 (2.2, 5.1)^*
Regional	3634	60.3 (58.3, 62.3)	3396	54.5 (52.7, 56.4)	43,479	57.7 (57.1, 58.2)	−0.9 (−1.2, −0.5)^*
IIIC^b	375	6.2 (5.6, 6.9)	263	4.2 (3.7, 4.8)	3795	5.0 (4.9, 5.2)	−3.7 (−4.9, −2.5)^*
IIIB	206	3.4 (3.0, 3.9)	168	2.7 (2.3, 3.1)	2361	3.1 (3.0, 3.3)	−1.4 (−2.9, +0.2)
IIIA	809	13.4 (12.5, 14.4)	840	13.5 (12.6, 14.5)	9916	13.2 (12.9, 13.4)	0.0 (−0.6, +0.6)
IIA, IIB	2083	34.6 (33.1, 36.1)	2015	32.3 (30.9, 33.8)	25,314	33.6 (33.2, 34.0)	−0.6 (−1.1, −0.1)^*
Localized	5078	84.2 (81.9, 86.5)	5603	89.4 (87.1, 91.8)	64,881	85.8 (85.1, 86.4)	0.8 (0.3, 1.2)^*

^aSummary stage 2000 (1988+) [7] (see text).
^bSEER breast-adjusted AJCC 6th edition stages IIIC, IIIB, and IIA-B, within regional summary stage cancers [11] (see text).
CL: confidence limits (95%), lower and upper, on rate or on APC.
SEER: Surveillance, Epidemiology, and End Results Program of the National Cancer Institute.
^*CL do not include zero.