A biomarker panel predicts recurrence-free survival in ulcerated primary cutaneous melanoma

Figures & data

Table 1. Patient and pathological characteristics of 71 cases with ulcerated primary CMM.

	Recurrence (n = 34)	Recurrence free (n = 37)	p-Value^1
Age at diagnosis
Median (range)	73.5 (27–89)	69 (37–90)	0.931
Gender			0.549
Male	17	19
Female	17	18
Breslow (mm)
Median(range)	4.45 (0.8–18)	2.2 (0.4–15)	<0.001
Histological type			0.740
SSM	13 (38%)	19 (51%)
NM	14 (41%)	13 (35%)
LMM	1 (3%)	1 (3%)
UNS	6 (18%)	4 (11%)
BRAF mutation			0.66
wildtype	15 (44%)	20 (54%)
V600E	14 (41%)	10 (27%)
V600K	3 (9%)	4 (11%)
other	2 (6%)	3 (8%)

SSM: superficial spreading melanoma; NM: nodular melanoma; LMM: lentigo maligna melanoma; UNS: unclassifiable.

¹p-Values calculated using Fishers exact test for categorical data and Mann-Whitney test for continuous data to assess if any of the variables differ between the recurrence and recurrence free groups.

Figure 1. Representative hematoxylin-eosin slides of primary ulcerated CMMs demonstrating presence of TILs (a) and representative expression of protein Ki67 with immunohistochemistry demonstrating high proportion (b) and low proportion (c). Twenty-seven percent (10/37) of the recurrence-free patients and 61% (20/33) of the patients with a recurrence had primary tumours with high Ki67 staining (cut-off level 10%). Scale bar = 50 µm.

Table 2. Cox regression analysis.

Univariate analysis
Variable	HR	95% CI	p-value
Gender (F vs M)	0.94	0.48-1.85	0.86
Age at diagnosis	1.00	0.98-1.02	0.91
Breslow	1.13	1.04-1.22	0.002
TILs	0.48	0.24-0.98	0.045
BRAF mutation all	1.14	0.58-2.24	0.71
BRAF mutation high*	2.44	1.23-4.84	0.011
Ki67	2.66	1.32-5.35	0.006
At least 2 of 3**	0.28	0.14-0.56	< 0.001
Multivariate analysis
Variable	HR	95% CI	p-value
Breslow	1.15	1.05-1.26	0.003
TILs	0.59	0.28-1.22	0.16
BRAF mutation high*	1.57	0.73-3.37	0.25
Ki67	2.21	1.02-4.77	0.04
Variable	HR	95% CI	p-value
At least 2 of 3**	0.30	0.15-0.61	0.001
Breslow	1.13	1.03-1.23	0.008

*>35% BRAF mutation.

** Presence of TILs, BRAF wildtype/low proportion of BRAF mutated alleles, low Ki67.

Figure 2. Representative hematoxylin-eosin slides of ulcerated primary CMMs showing the proportion of tumour cell content in relation to proportion of BRAF mutated alleles (a). Box plots demonstrate the distribution of proportion of all BRAF mutated alleles (recurrence free n = 16; recurrence n = 19) and BRAF V600E only (recurrence free n = 10; recurrence n = 13), with no respect to BRAF wildtype samples and not either to non-BRAF V600E in the bottom graph. There is a statistically significant difference in the distribution between patients who had recurrence and those who were recurrence-free (b). (t-test p = 0.014 and p = 0.013 respectively). Scale bar = 250 µm.

Figure 3. The prognostic power of a panel consisting of potentially three favourable prognostic factors; including BRAF wildtype/low proportion of BRAF mutated alleles, low expression of Ki67 and presence of TILs. A statistically significant increase in the proportion of patients with no recurrence in association with the increase from one to three factors was observed (a). (Chi-square test for trend; p = 0.0004). Kaplan-Meier curves showing a statistically significantly longer RFS for patients with presence of at least two favourable prognostic factors (b) (Log-rank (Mantel-Cox) test; p < 0.0001) and number at risk. The marks on the lines represent censored points.