CT	computed tomography
CDK4/6i	CDK4/6 inhibitors
ER	estrogen receptor
GATA3	GATA protein binding 3
HE	hematoxylin-eosin
HER2	human epidermal growth factor receptor 2
IHC	immunohistochemistry
MBC	metastatic breast cancer
MPM	multiple primary malignancies
NE	neuroendocrine
NSE	neuron-specific enolase
NST	no special type
PET-CT	positron emission tomography-computed tomography
PR	progesterone receptor
RT	radiotherapy
SCLC	small cell lung carcinoma
SEER	surveillance, epidemiology and end result
SPM	second primary malignancies
TNBC	triple negative breast cancer
TTF-1	thyroid transcription factor-1
WHO	World Health Organization