Table 1.

CTC markers of melanoma.

Marker(s)	Detection method	Study group(s)	Detection Rate	Sensitivity, Specificity, PPV	Disease recurrence	References
Tyrosinase	RT-PCR	Stage I–IV (n = 212)	Stage I–II: 14% Stage III–IV: 48%	Sensitivity: 22%	88% of relapsed patients had positive markers, 39% of relapsed patients had negative markers over 36 month follow-up period in stage III patients.	(30)
Tyrosinase	RT-PCR	Control (n = 52) Stage I–II (n = 177) Stage III–IV (n = 122)	Control: 0% Stage I–II: 53%* Stage III–IV: 82%*	Sensitivity: 65%* Specificity: 100% PPV: 100%	No correlation was noted between relapse and marker positivity.	(28)
MLANA/MART-1	RT-PCR	Control (n = 52) Stage I–II (n = 120) Stage III–IV (n = 91)	Control: 0% Stage I-II: 18%* Stage III–IV: 33%*	Sensitivity: 25%* Specificity: 100% PPV: 100%	No correlation was noted between relapse and marker positivity.	(28)
Tyrosinase or MART1	RT-PCR	Control (n = 89) Stage I–II (n = 236)	Tyrosinase (initial): Control: 0% Stage I-II: 5%	Tyrosinase or MART1 over follow-up period: Sensitivity: 60% Specificity: 98% PPV: 99%	40% of relapsed patients had positive markers over median 36 month follow-up period.	(31)
			MART1 (initial): Control: 2% Stage I-II: 7%
MLANA ABCB5 TGF-β2 PAX3d MCAM	qRT-PCR	Control (n = 152) Stage 0–II (n = 154) Stage III-IV (n = 76)	2 or more markers: Control: 17% Melanoma: 72%	2 or more markers: Sensitivity: 71% Specificity: 83% PPV: 86%	MLANA + ABCB5 PPV: 56%, positive in 26% of pts with relapse. 48% of Stage III–IV relapsed patients had MLANA. No correlation for stage 0-II over 45 month follow-up period.	(32)
CD146 antibodies	CellSearch Circulating Melanoma Cell Assay	Control (n = 91) Stage III (n = 243)	Control: 2% Stage III: 59%	Sensitivity: 59% Specificity: 98% PPV: 99%	48% of relapsed patients had positive markers within 54 month follow-up period (median 17 m)	(24)

^*Figures derived from positivity rates within individual groups provided in the study.