Table 1. Clinicopathological characteristics of cases involving secondary ipsilateral breast tumours.

		Clinical characteristics							Pathological characteristics		Molecular characteristics
		First tumour				Second tumour			First tumour	Second tumour	HUMARA	GAMDDL
Case	Age	pTNM	Margin	Adjuvant therapy	Quadrant	Quadrant	Time to second tumour (M)	Outcome	IIS, HG/NG	IIS, HG/NG	First/second tumours	First/second tumours
Clinically recurrent:
1	43	T1Nx	5 mm		Right D	Right ECA	39	Alive	Luminal A, HGII	Luminal A, HGII	NP	Identical
2	47	T1N0M0	5 mm	CMF, Tam	Right C	Right CA	37	Alive	Luminal A, HGIII	Luminal A, HGIII	Same allele	Identical
3	45	T1N0M0	12 mm		Right BD	Right D	12	Alive	Luminal A, HGI	Luminal A, HGI	Same allele	Identical
4	51	T1N0M0	4 mm	IR, CMF	Left C	Left EBD	15	Alive	HER2, HGIII	HER2, HGIII	Same allele	No mutation
5	26	T2N2M0	10 mm	CMF, Gos, T	Left C	Left CD	36	Dead	Luminal B, HGIII	Luminal B, HGIII	Same allele	Different mutation
6	49	T1N0M0	5 mm	IR	Left D	Left BD	19	Alive	TNBC, HGII	TNBC, HGIII	Same allele	Different mutation
7	43	T1N0M0	< 1 mm		Left A	Left AC	45	Alive	BLBC, HGII	TNBC, HGII	Different allele	Different mutation
Clinically new primary:
8	66	T1N0M0	9 mm	IR, Tam	Right B	Right C	41	Dead	Luminal A, HGII	Luminal A, HGIII	Different allele	No mutation

Abbreviations: BLBC=basal-like breast cancer; CMF=CPM+methotrexate+5-FU; HG=histological grade I, II, and III; HUMARA=human androgen receptor; GAMDDL=gene alterations of mitochondrial DNA D-loop region; Gos=goserelin; IR=irradiation; IIS=immunohistochemical intrinsic subtype; M=months; NP=no polymorphism; Quadrant A=medial upper; Quadrant B=medial under; Quadrant C=lateral upper; Quadrant D=lateral under; Quadrant E=around nipple; T=trastuzumab; Tam=tamoxifen; TNBC=triple-negative breast cancer.