Ipsilateral breast tumor recurrence in early stage breast cancer patients treated with breast conserving surgery and adjuvant radiation therapy: Concordance of biomarkers and tumor location from primary tumor to in-breast tumor recurrence

Table 1 Clinicopathologic characteristics of primary tumors in patients who experienced an ipsilateral breast tumor recurrence

	Overall	DCIS	Invasive
n	37	19	18
Age [years, mean (SD)]	63.08 (14.52)	65.74 (11.49)	60.28 (17.05)
Race (%)
White	27 (73.0)	13 (68.4)	14 (77.8)
African American	7 (18.9)	3 (15.8)	4 (22.2)
Asian	1 (2.7)	1 (5.3)	0 (0.0)
Declined	2 (5.4)	2 (10.5)	0 (0.0)
ER Positive (%)	26 (70.3)	14 (73.7)	12 (66.7)
PR Positive (%)	24 (64.9)	12 (63.2)	12 (66.7)
ILC	2 (5.4)		2 (11.1)
IDC	15 (40.5)		15 (83.3)
Mixed invasive	1 (2.7)		1 (5.6)
Invasive only: DCIS present (%)
No			3 (16.7)
Yes			15 (83.3)
Invasive only: HER-2 Status (%)
Negative			14 (77.8)
Positive			3 (16.7)
Not performed			1 (5.6)
Invasive only: Pathologic grade (%)
1			4 (22.2)
2			4 (22.2)
3			10 (55.6)
Invasive only: Ki 67 Status (%)
Low (< 10)			8 (44.4)
High (≥ 10)			8 (44.4)
Not performed			2 (11.1)
Invasive only: LVI (%)
Not present			12 (66.7)
Present			5 (27.8)
Close			1 (5.6)
DCIS only: Nuclear grade (%)
Grade 1		0 (0)
Grade 2		10 (52.6)
Grade 3		9 (47.3)
T - stage (%)
0	19 (51.4)	19 (100.0)	0 (0.0)
1	11 (29.7)	0 (0.0)	11 (61.1)
2	7 (18.9)	0 (0.0)	7 (38.9)
Positive margins (%)	8 (21.6)	6 (31.6)	2 (11.1)
Chemotherapy (%)	11 (29.7)	0 (0.0)	11 (61.1)
Hormone therapy (%)	18 (48.6)	7 (36.8)	11 (61.1)
Tumor axis/quadrant (%)
3:00	1 (2.7)	1 (5.3)	0 (0.0)
6:00	1 (2.7)	0 (0.0)	1 (5.6)
9:00	1 (2.7)	1 (5.3)	0 (0.0)
Central	2 (5.4)	1 (5.3)	1 (5.6)
LIQ	1 (2.7)	0 (0.0)	1 (5.6)
LOQ	3 (8.1)	2 (10.5)	1 (5.6)
UIQ	6 (16.2)	2 (10.5)	4 (22.2)
UOQ	22 (59.5)	12 (63.2)	10 (55.6)

DCIS: Ductal carcinoma in situ; ER: Estrogen receptor; PR: Progesterone receptor; ILC: Invasive lobular carcinoma; IDC: Invasive ductal carcinoma; LVI: Lymphovascular invasion; LIQ: Lower inner quadrant; LOQ: Lower outer quadrant; UIQ: Upper inner quadrant; UOQ: Upper outer quadrant.

Table 2 Clinicopathologic characteristics of recurrences

Median time to IBTR (years IQR)	1.97 (1.03-3.5)
Invasive (%)	18 (45.9)
DCIS (%)	19 (51.4)
DCIS to invasive conversion (%)	5 (26.3)
Invasive to DCIS conversion (%)	5 (27.8)
In-situ component in invasive histology (%)	10 (55.6)
Concordant with original receptor subtype (%)
Yes	25/32 (78.1)
No	7/32 (21.9)
Unknown	5/37 (13.5)
ER concordance (%)
Same	25 (75.8)
Change from + to -	5 (15.2)
Change from - to +	2 (6.1)
PR concordance (%)
Same	22 (66.7)
Change from + to -	8 (24.2)
Change from - to +	2 (6.0)
HER-2 concordance (%)
Same	16 (100)
Change from + to -	0 (0)
Change from - to +	0 (0)
Concordant with original location (%)
Yes	23 (62.2)
No	14 (37.8)
Salvage surgery (%)	32 (86.5)
Bilateral mastectomy	16 (43.2%)
Unilateral mastectomy	9 (24.3)
Local excision	6 (16.2%)
Salvage systemic therapy (%)
Chemotherapy only	3 (8.1)
Hormone therapy only	11 (29.7)
Both	5 (13.5)
Re-irradiation of ipsilateral breast	6 (16.2%)

IBTR: Ipsilateral breast tumor recurrence; IQR: Interquartile range; DCIS: Ductal carcinoma in situ; ER: Estrogen receptor; PR: Progesterone receptor.

Table 3 Results of univariate Cox model assessing the association of clinical variables with risk of the first ipsilateral breast tumor recurrence

Clinical variable	Hazard ratio (95%CI)	P value
Patient age (continuous)	1.004 (0.98-1.02)	0.73
ER negative	1	-
ER positive	0.53 (0.26-1.11)	0.093
PR negative	1	-
PR positive	0.75 (0.38-1.50)	0.423
Tumor grade: Low	1	-
Tumor grade: Intermediate	0.791 (0.25-2.5)	0.689
Tumor grade: High	1.624 (0.54-4.8)	0.385
Margins negative	1	-
Margins positive	0.793 (0.36-1.75)	0.565
No chemotherapy	1	-
Chemotherapy up-front	1.282 (0.63-2.6)	0.499
No endocrine therapy up-front	1	-
Endocrine therapy up-front	0.362 (0.18-0.73)	0.004
Biomarker not concordant	1	-
Biomarker concordant	1.04 (0.95-1.10)	0.92
Location not concordant	1	-
Location concordant	1.265 (0.63-2.53)	0.506
Size < 1.5 cm	1	-
Size ≥ 1.5 cm	0.442 (0.22-0.90)	0.023
Invasive primary tumors
LVI none	1	-
LVI present	0.617 (0.20-1.92)	0.404
HER2 negative/equivocal	1	-
HER2 positive	0.837 (0.28-2.55)	0.754
Ki-67 (continuous)	1.002 (0.99-1.02)	0.745

IBTR: Ipsilateral breast tumor recurrence; HR: Hormone receptor; ER: Estrogen receptor; PR: Progesterone receptor; LVI: Lymphovascular invasion.