Familial and sporadic melanoma: different clinical and histopathological features in the Italian population - a multicentre epidemiological study - by GIPMe (Italian Multidisciplinary Group on Melanoma)

Cutaneous Melanoma Classification: The Importance of High-Throughput Genomic Technologies

Cutaneous melanoma is an aggressive tumor responsible for 90% of mortality related to skin cancer. In the recent years, the discovery of driving mutations in melanoma has led to better treatment approaches. The last decade has seen a genomic revolution in the field of cancer. Such genomic revolution has led to the production of an unprecedented mole of data. High-throughput genomic technologies have facilitated the genomic, transcriptomic and epigenomic profiling of several cancers, including melanoma. Nevertheless, there are a number of newer genomic technologies that have not yet been employed in large studies. In this article we describe the current classification of cutaneous melanoma, we review the current knowledge of the main genetic alterations of cutaneous melanoma and their related impact on targeted therapies, and we describe the most recent high-throughput genomic technologies, highlighting their advantages and disadvantages. We hope that the current review will also help scientists to identify the most suitable technology to address melanoma-related relevant questions. The translation of this knowledge and all actual advancements into the clinical practice will be helpful in better defining the different molecular subsets of melanoma patients and provide new tools to address relevant questions on disease management. Genomic technologies might indeed allow to better predict the biological - and, subsequently, clinical - behavior for each subset of melanoma patients as well as to even identify all molecular changes in tumor cell populations during disease evolution toward a real achievement of a personalized medicine.

Differences in Risk Factors for Melanoma in Young and Middle-aged Higher-risk Patients

BACKGROUND/AIM

Differences in risk factors for melanoma between young adults (18-39 years) and middle-aged (40-60 years) are not well documented. In this study, we aimed to determine differences in risk factors and characteristics of melanoma between these groups.

PATIENTS AND METHODS

This retrospective study is a review on 330 patients, including 250 middle-aged and 80 young adults, during the period 2006-2016 in the Tampere university hospital, in Finland.

RESULTS

Forty-one per cent of middle-aged and 47% of young adults were defined as higher-risk patients. High nevus count was the most common host risk factor in both groups. Young were more likely to have a family history of melanoma. Middle-aged had more often excessive intermittent sun exposure and a history of sunburn. Host risk characteristics were less commonly associated with thicker melanomas.

CONCLUSION

A high number of patients have host risk factors for melanoma. Several differences exist in risk factors and characteristics of melanomas between young adults and middle-aged patients.

Host Characteristics and Risk of Incident Melanoma by Breslow Thickness

BACKGROUND

Several host characteristics, including pigmentary traits (hair color, sunburn susceptibility and tanning ability), number of common nevi (moles), and family history of melanoma, have been associated with risk of melanoma.

METHODS

We prospectively examined the associations between host characteristics and risk of incident melanoma by Breslow thickness (≤1 mm, thin melanoma; or >1 mm, "thicker melanoma") based on the Nurses' Health Study (NHS, n = 86,380 women), NHS II (n = 104,100 women), and Health Professionals Follow-up Study (HPFS, n = 46,934 men).

RESULTS

During 22-30 years' follow-up, a total of 1,813 incident melanoma cases were identified with information on Breslow thickness, 1,392 (76.8%) of which had thin melanoma. No significant differences were observed for thin and thicker melanoma in associations with hair color, sunburn susceptibility, and tanning ability. However, we found significant differences for the association with family history of melanoma, with a higher risk estimate for thicker melanoma [HR = 2.55; 95% confidence interval (CI): 1.91-3.42] than thin melanoma (HR = 1.59; 95% CI: 1.21-2.08; P heterogeneity = 0.02). Interestingly, women and men displayed differential associations between nevi count and risk of melanoma by Breslow thickness, with the association appearing stronger for thicker melanoma than thin melanoma in men (P heterogeneity = 0.01), but not in women.

CONCLUSIONS

Individuals with family history of melanoma may be more likely to develop thicker melanoma. Men with high number of common nevi may tend to develop thicker melanoma, which was not found for women.

IMPACT

The findings further stress the risk of thicker melanoma for individuals with a family history of melanoma and men with a high nevi count.

Hereditary melanoma: a five-year study of Brazilian patients in a cancer referral center - phenotypic characteristics of probands and pathological features of primary tumors

BACKGROUND

Approximately five to 10% of all melanomas occur in families with hereditary predisposition and the main high-risk melanoma susceptibility gene is the CDKN2A.

OBJECTIVES

To describe, after a five-years study, the clinical data of patients (probands) from familial melanoma kindreds, and the pathological characteristics of their melanoma.

METHODS

The inclusion criteria were melanoma patients with a family history of melanoma or pancreatic cancer (first- or second-degree relatives) or patients with multiple primary melanomas (MPM).

RESULTS

A total of 124 probands were studied, where 64 were considered familial cases and 60 MPM. Mean age at diagnosis was 50 years. Our results show that the following characteristics were prevalent: skin phototype I/II (89.5%), sunburn during childhood (85.5%), total number of nevi ≥50 (56.5%), Breslow thickness ≤1.0mm (70.2%), tumors located on the trunk (53.2%) and superficial spreading melanomas (70.2%).

STUDY LIMITATIONS

Analyses of probands' relatives will be demonstrated in future publication.

CONCLUSIONS

Our findings are in agreement with previous familial melanomas reports. Fifteen new melanomas in 11 patients were diagnosed during follow up, all of which were ≤1.0 mm. This is the largest dataset of Brazilian melanoma prone kindreds to date, thus providing a complete database for future genetic studies.

Differences in telomere length between sporadic and familial cutaneous melanoma

BACKGROUND

Several pieces of evidence indicate that a complex relationship exists between constitutional telomere length (TL) and the risk of cutaneous melanoma. Although the general perception is that longer telomeres increase melanoma risk, some studies do not support this association. We hypothesize that discordant data are due to the characteristics of the studied populations.

OBJECTIVES

To evaluate the association of TL with familial and sporadic melanoma.

MATERIALS AND METHODS

TL was measured by multiplex quantitative polymerase chain reaction in leukocytes from 310 patients with melanoma according to familial/sporadic and single/multiple cancers and 216 age-matched controls.

RESULTS

Patients with sporadic melanoma were found to have shorter telomeres compared with those with familial melanoma. In addition, shorter telomeres, while tending to reduce the risk of familial melanoma regardless of single or multiple tumours, nearly trebled the risk of single sporadic melanoma.

CONCLUSIONS

This is the first time that TL has been correlated to opposite effects on melanoma risk according to the presence or absence of familial predisposition. Individual susceptibility to melanoma should be taken into account when assessing the role of TL as a risk factor.

Epidemiological and genetic factors underlying melanoma development in Italy

Among human cancers, melanoma remains one of the malignancies with an ever-growing incidence in white populations. Recent advances in biological and immunological therapeutic approaches as well as increased efforts for secondary prevention are contributing to improve the survival rates. It is likely that a significant fall in mortality rates for melanoma will be achieved by further increase of the early detection through a more accurate selection of the higher-risk individuals (i.e., carriers of predisposing genetic alterations). A similar scenario occurs in Italy. In the present review, we have considered data on incidence, survival and mortality rates of melanoma in Italian population, including evaluation of the main risk factors and genetic mutations underlying disease susceptibility.

Age-related characteristics of cutaneous melanoma in a Spanish Mediterranean population

BACKGROUND

Melanoma is considered a heterogeneous tumor with genetic and environmental factors involved in its pathogenesis. The impact of these factors varies depending on age.

OBJECTIVE

The aim of this study was to characterize the epidemiological, phenotypic, and histological features of patients with melanoma according to three age groups: ≤40, 41-65, and >65 years.

METHODS

A total of 1122 consecutive patients with invasive melanoma definitively treated in our institution since January 2000 were selected from our melanoma database. Epidemiological, phenotypic, and histological data were retrieved and analyzed as a function of age.

RESULTS

Female patients predominated in the younger age group. The location of cutaneous malignant melanoma differed with age. In the younger and middle age groups, tumors presented mainly on the trunk, while in the older group they were mainly found on the head/neck. Signs of actinic damage such as actinic keratoses, solar lentigines, or other skin tumors increased with age, while genetic factors such as family history of melanoma or a high number of common melanocytic nevi were more frequent in the younger group.

CONCLUSION

Our results suggest that melanoma development in younger patients is the result of genetic factors, particularly related to multiple nevi, whereas in older patients environmental factors such as severe chronic sun exposure play a major role.

Histologic features of melanoma associated with CDKN2A genotype

BACKGROUND

Inherited susceptibility genes have been associated with histopathologic characteristics of tumors.

OBJECTIVE

We sought to identify associations between histology of melanomas and CDKN2A genotype.

METHODS

This was a case-control study design comparing 28 histopathologic tumor features among individuals with sporadic melanomas (N = 81) and cases from melanoma families with (N = 123) and without (N = 120) CDKN2A germline mutations.

RESULTS

Compared with CDKN2A(-) cases, mutation carriers tended to have histologic features of superficial spreading melanoma subtype including higher pigmentation (Ptrend = .02) and increased pagetoid scatter (Ptrend = .07) after adjusting for age at diagnosis, sex, and American Joint Committee on Cancer thickness category. Similar associations were observed when comparing mutation carriers with a combined group of CDKN2A(-) (wild type) and sporadic melanomas. The presence of spindle cell morphology in the vertical growth phase was also an important predictor of genotype. Of the 15 cases with this phenotype, none were observed to harbor a CDKN2A mutation.

LIMITATIONS

Our study examined rare mutations and may have been underpowered to detect small, but biologically significant associations between histology and genotype.

CONCLUSION

Familial melanomas with CDKN2A mutations preferentially express a histologic phenotype of dense pigmentation, high pagetoid scatter, and a non-spindle cell morphology in the vertical growth phase.

MC1R variation and melanoma risk in relation to host/clinical and environmental factors in CDKN2A positive and negative melanoma patients

Host, environmental and genetic factors differently modulate cutaneous melanoma (CM) risk across populations. Currently, the main genetic risk determinants are germline mutations in the major known high-risk susceptibility genes, CDKN2A and CDK4, and variants of the low-risk gene MC1R, which is key in the pigmentation process. This case-control study aimed at investigating the influence of the main host and environmental risk factors and of MC1R variation on CM risk in 390 CDKN2A-negative and 49 CDKN2A-positive Italian individuals. Multivariate analysis showed that MC1R variation, number of nevi and childhood sunburns doubled CM risk in CDKN2A-negative individuals. In CDKN2A-positive individuals, family history of CM and presence of atypical nevi, rather than MC1R status, modified risk (20.75- and 2.83-fold, respectively). Occupational sun exposure increased CM risk (three to sixfold) in both CDKN2A-negative and CDKN2A-positive individuals, reflecting the occupational habits of the Ligurian population and the geographical position of Liguria.