Genetic polymorphisms may influence the vertical growth rate of melanoma

CDKN2A Polymorphism in Melanoma Patients in Colombian Population: A Case-Control Study

Introduction

Melanoma is the most aggressive type of skin cancer, with poor prognosis in advanced stages. The incidence and mortality rates have increased in recent years. Single nucleotide polymorphisms p.R24P, p.M53I, p.G101W, p.V126D, and p.A148T in the CDKN2A (HGNC ID: 1787) gene have been associated with the development of melanoma in different populations; however, this association has not been studied in Colombia.

Methods

Cutaneous melanoma patients and healthy controls (85 cases and 166 controls) were included in this study. These subjects were screened through HRM-qPCR assay and detected variants in exon 1 and 2 of CDKN2A gene and confirmed with Sanger sequencing. Chi-square test was used to compare allele and genotype distributions between cases and controls. Odds ratio (OR) with 95% confidence interval (CI) was calculated to determine the association between polymorphisms and haplotypes with melanoma susceptibility. Statistical and haplotype analyses were performed using Stata® and R-Studio®.

Results

Fifty-four percent of women were identified both in cases and controls. The frequencies of melanoma subtypes were 36,47% lentigo maligna, 24,71% acral lentiginous, 23,53% superficial extension, and 15,29% nodular. Variants in the CDKN2A gene were 11.76% in cases and 8.43% in controls. The most frequent was p.A148T in 5.88% of cases and in 4.82% of controls. GGTTG haplotype showed statistically significant differences between cases and controls (p value = 0.04).

Conclusion

CDKN2A polymorphisms p.G101W, p.R24P, p.M53I, and A148T are not associated with melanoma susceptibility in the Colombian population; further studies regarding genetic interaction and additive effects between more variants are required.

Solar UV Exposure and Mortality from Skin Tumors: An Update

Solar UV exposure is critical and complex in the etiology and prognosis of skin cancer, particularly cutaneous malignant melanoma. Sun exposure and one of its "derivatives," vitamin D, have been implicated in protection against mortality from melanoma. However, the relationships are inconsistent. At this time, it is not possible to make clear recommendations for or against sun exposure in relationship to melanoma prognosis. However, this relationship deserves continued exploration.