Table 3.

Circulating miRNA as diagnostic, predictive, or prognostic biomarkers.

Type of miR	Expression	Biological fluid	TNBC stage	Relevance	Special features	References
miR-10b	Upregulated	Plasma/ serum	Early	Lymph node status	Identification of bone metastasis	(159–161)
miR-199a-5p	Downregulated	Plasma	T0–T1	Tumor growth	Level inversely proportional to disease stage	(161, 162)
miR-105	Upregulated	Plasma	Early	Predicts survival and choice of treatment, promotes metastasis	Promotes cisplatin resistance	(163)
miR-16	Downregulated	Plasma	Advanced	Marker for overall survival		(161, 162)
miR-489	Upregulated	Plasma				(164)
miR-93-3p	Upregulated	Plasma	Early	Predicts survival, informs choice of treatment	Promotes cisplatin resistance	(161, 163)
miR-195-5p	Upregulated	Plasma	Early	Early detection		(161)
miR-495	Downregulated	Plasma	Early	Early detection		(165)
miR-18a	Upregulated	Serum		Choice of treatment	Involved in paclitaxel resistance	(166)
miR-18b	Upregulated	Serum	Early	Diagnosis, prognosis		(161, 166)
miR-143	Downregulated	Serum	Early	Diagnosis		(166)
miR-153	Upregulated	Serum				(166)
miR-155	Upregulated	Serum	Early	Diagnosis, lymph node status, response to therapy	Possibly contributes to chemoresistance	(166, 167)
miR-373	Upregulated	Plasma	Early	Diagnosis, lymph node status	Correlated with CD44 expression	(159, 167)
miR-17	Downregulated	Serum	Advanced	Predicts recurrence, informs choice of treatment		(167, 168)
miR-19b	Upregulated	Serum				(168)
miR-200c	Downregulated	Plasma	Metastatic	Lymph node status, distant metastasis	Decreased levels of miR-200c were only observed in metastatic tumors	(160, 169)
miR-34a/c	Downregulated	Plasma	All stages	Predictive for OS	miR-34c is an independent factor predicting worse prognosis	(167, 170)