Table 1.

Summary of patient and tumor characteristics

Patient	Tissue	Diagnosis	ER(%)/PR(%)/HER2( +)	PAM50 Subtype	TIS Status	Treatment at the time of sample collection
1	Breast	IDC, DCIS	2/0/3	Luminal A	High	Gemcitabine and trastuzumab
1	Breast	Tumor emboli	N/A	Luminal A	High	Nab-paclitaxel and trastuzumab
1	Lung	Metastatic	0/0/3	HER2 enriched	High	Nab-paclitaxel and trastuzumab
2	Breast	ICD, DCIS	0/0/3	HER2 enriched	Low	None. Initial diagnosis
2	Breast	Residual IDC	0/0/N/A	HER2 enriched	High	TDM1, pertuzumab, doxorubicin and cyclophosphamide*
2	Soft tissue	Local recurrence	0/0/3	HER2 enriched	Low	Trastuzumab and pertuzumab
3	Brain	Metastatic	15/0/3	HER2 enriched	Low	None. Discontinued due to toxicities
4	Breast	IDC	0/0/3	Basal like	High	None. Initial diagnosis
4	Breast	Local recurrence	N/A	Luminal A	High	Doxorubicin, cyclophosphamide, paclitaxel and trastuzumab
5	Brain	Metastatic	0/0/3	Basal like	Low	TDM1 and anastrozole
6	Breast	IDC, DCIS	80/70/2**	Luminal A	High	None. Initial diagnosis
7	Breast	IDC, DCIS	0/0/3	HER2 enriched	High	None. Initial diagnosis
7	Breast	Local recurrence	N/A	Basal like	High	None. Completed neoadjuvant and adjuvant therapy
8	Breast	IDC, DCIS	10/15/1	Luminal A	Low	None. Initial diagnosis
8	Soft tissue	Local recurrence	0/0/3	Basal like	Low	Nab-paclitaxel and atezolizumab (previously had triple negative disease)

DCIS: ductal carcinoma in situ; DCIS: ductal carcinoma in situ; ER: estrogen receptor; HER2: human epidermal growth factor 2; IDC: invasive ductal carcinoma; IDC: invasive ductal carcinoma; PR: progesterone receptor; TDM1: ado-trastuzumab emtansine; TIS: tumor inflammation score

^*Neoadjuvant therapy in the ISPY2 clinical trial

^**HER2/CEP17 ratio: 2.13 (amplified by FISH)