Evaluation of self-assessed melanoma growth rate in a Mediterranean patient population

Synchronous primary cutaneous melanomas: a descriptive study of their clinical features, histology, genetic background of the patients and clinical outcomes

BACKGROUND

Around 0.5% cutaneous melanoma (CM) patients will present with synchronous melanomas when first seen. Moreover, 26%-40% of patients with multiple primary melanomas present with synchronous lesions.

OBJECTIVES

To assess the prevalence, clinical and histopathological characteristics, germline mutations and outcome in patients with synchronous melanoma.

METHODS

Clinical and histopathological data from 4703 melanoma patients were included. Clinical, histological and genetic mutational status information was analyzed. Kaplan-Meier curves were used to investigate survival outcomes.

RESULTS

A total of 144 patients (3.06%) presented simultaneously with 2 or more primary melanomas. During follow-up, 25.7% of patients with synchronous melanoma developed a new primary melanoma compared to 8.6% of patients diagnosed with single melanoma (p < 0.001). Germinal CDKN2A mutations were identified in 10.7% of patients with synchronous melanomas and genetic variants in MC1R in 72%. No significant differences in all survival outcomes between patients with synchronous melanomas and single melanomas were found.

CONCLUSION

Synchronous melanomas are more frequent than previously reported and are more frequent in older patients compared to single melanomas. Moreover, these patients have a higher risk of developing a new primary melanoma during follow-up and have higher rates of germline susceptibility variants. Nevertheless, these findings were not associated with worse outcomes.

Measuring the horizontal and vertical growth rates of superficial spreading melanoma: a pilot study with sequential digital dermoscopy

BACKGROUND

Some authors have hypothesized that the initial kinetics of the primary melanoma (MM) growth could reflect its biologic aggressiveness. The aim of this study was to pilot a measure of the horizontal vs. vertical growth of superficial spreading melanomas (SSM).

METHODS

The dermoscopic images of twenty-three consecutive MMs (17 SSMs and 6 MMs in situ), excised after digital sequential dermoscopy, were reviewed. We built up two indexes: 1) dROG (digital Rate of Growth) defined as Breslow thickness/(t1-tR), where t1 was the reported time of the first dermoscopic image acquisition and tR was the reported time of the acquisition before the lesion excision; 2) lHGR (linear Horizontal Growth Rate) took into account the greater axis of the lesion at two time points, at the time (t1) of the first image acquisition (D1) and before (tR) lesion excision (DR). The index was computed as (DR-D1)/(t1-tR). We built up the Composite Rate of Growth index (cROG) calculated as dROG/lHRG. If the value of cROG is <1 the superficial growth is prevalent on the vertical growth, and if the value is >1 the vertical growth is prevalent on the superficial growth.

RESULTS

In 82.6% of lesions the horizontal growth was prevalent on the vertical growth, and in 17.4% of cases the vertical growth was equal or prevalent on the superficial growth.

CONCLUSIONS

A small proportion of SSMs with a slow horizontal growth could have a precocious vertical growth. Other larger studies are needed to confirm this observation.

An observational study regarding the rate of growth in vertical and radial growth phase superficial spreading melanomas

The natural history of superficial spreading melanomas (SSMs) involves the progression from a radial growth phase (RGP) to a vertical growth phase (VGP). Currently, a patient's history represents the only method to estimate the rate of tumor growth. The present study aimed to verify whether the estimated rate of growth (ROG) of SSMs with a RGP or VGP exhibited any differences, and to evaluate the possible implications for the most important prognostic determinants. ROG was quantified as the ratio between Breslow's thickness in millimeters (mm) and the time of tumor growth in months, defined as the time between the date that the patient had first noticed the lesion in which melanoma subsequently developed and the date on which the patient first felt this lesion changed. A total of 105 patients (58 male and 47 female) were studied. Of these, 66 had VGP-SSMs, whilst 39 had RGP-only SSMs (RGP-SSMs). No significant differences in age and gender were observed between these groups. The mean Breslow's thickness in patients with VGP-SSMs was significantly greater than in patients with RGP-SSMs (0.78±0.68 vs. 0.48±0.22 mm, P=0.0096). Similarly, the ROG was observed to be higher in VGP-SSM vs. RGP-SSM patients (0.13±0.16 vs. 0.065±0.09 mm/month, P=0.0244). In patients with VGP-SSMs, Breslow's thickness and ROG were significantly higher for tumors with a mitotic rate of ≥1 mitosis/mm² compared with those with <1 mitosis/mm² (1.15±0.96 vs. 0.56±0.30 mm, P=0.0005; and 0.188±0.20 vs. 0.09±0.12 mm/month, P=0.0228, respectively). According to these results, two subsets of SSMs exist: The first is characterized by the presence of mitosis and a higher ROG, while the second exhibits a more indolent behavior and is characterized by an RGP only. Given the differences in the Breslow's thickness and ROG, clinicians must be aware of the possible diagnostic delay in these subsets of melanoma that, differently from true nodular melanomas, generally fulfill the classical ABCD clinical criteria.

Impact of oncogenic BRAF mutations and p16 expression on the growth rate of early melanomas and naevi in vivo

BACKGROUND

It is important to know what drives and arrests melanocytic growth in vivo but observations linking oncogenic mutations to growth rates of melanocytic neoplasms in vivo are sparse.

OBJECTIVES

To clarify the relationship between BRAF(V) (600E) mutations and p16 expression and the growth rate of melanocytic neoplasms in vivo.

METHODS

We measured the growth rate of 54 melanocytic lesions (26 melanomas, 28 naevi) in vivo with digital dermatoscopy and correlated it with BRAF(V) (600E) and p16 expression, and with dermatoscopic and histological patterns.

RESULTS

Melanomas grew faster than naevi (mean 2·7 vs. 0·8 mm(2) /year; P < 0·001) and the growth rate was faster in lesions with more nests (> 25% nests: 2·0 mm(2) /year vs. < 25% nests: 1·0 mm(2) /year; P = 0·036). Melanomas with the BRAF(V) (600E) mutation grew significantly faster than melanomas without the mutation (mean 3·36 vs. 1·60 mm(2) /year, P = 0·018). This effect of the BRAF(V) (600E) mutation on the growth rate was not observed in melanocytic naevi (mean 1·01 vs. 0·47 mm(2) /year, P = 0·274). Histopathologically, extensive nesting, larger nests and larger cell sizes were more common in melanocytic neoplasms with the BRAF(V) (600E) mutation than in those without the mutation. Melanomas expressing p16 had a slower growth rate than melanomas without p16 expression (2·27 vs. 4·34 mm(2) /year, P = 0·047). This effect was not observed in naevi (0·81 vs. 0·68 mm(2) /year, P = 0·836).

CONCLUSIONS

The expression of BRAF(V) (600E) and the loss of p16 accelerate the growth rate of early melanomas in vivo but not in melanocytic naevi. In comparison to melanocytic proliferations that lack the mutation, the epidermal melanocytes in lesions that harbour BRAF(V) (600E) mutations are larger and more frequently arranged in large nests.

Defining the dermoscopic characteristics of fast-growing cutaneous melanomas

A high growth rate in melanomas has been associated with a more aggressive phenotype and worse survival. The aim of this study was to define the dermoscopic characteristics associated with this type of cutaneous melanoma. We carried out a retrospective study of 132 cutaneous melanomas, analyzing certain clinical characteristics and the most important dermoscopic variables related to the melanomas. Fast-growing melanomas were considered to be those with a growth rate of more than 0.5 mm per month. Fast-growing melanomas more often lacked an atypical network, were symmetrical, presented ulceration, and were hypopigmented. The dermoscopic vascular pattern often showed atypical irregular vessels and milky-red areas. The association of these two is a specific characteristic. Fast-growing melanomas have a characteristic phenotype and dermoscopy can be useful for their identification.