Effect of PRAME and p21 expression on diagnosis and prognosis in melanoma

Melanoma is the most lethal skin cancer with an increasing annual incidence. While melanoma can be treated with surgery in the early stages, the life expectancy in metastatic lesions decreases dramatically. Therefore, early diagnosis and treatment of these patients is very important for a good prognosis. Recent studies have shown that the genetic map of malignant melanoma is quite heterogeneous, and in recent years, the diagnostic and therapeutic role of these genetic disorders has gained a key role in melanoma as in other cancers.PRAME expression was not detected in any of the intradermal nevus cases (n= 46). PRAME staining was not detected in 38 (90.5%) of the dysplastic nevus cases (n= 42). PRAME expression was seen in varying degrees in 112 (92.6%) of the invasive melanoma cases (n= 121). When PRAME expression levels were compared between nevi and invasive melanoma cases, a statistically significant relationship was found (p<0.001). p21 was negative in 29 (63%) and 1 positive in 17 (37%) of the nevus . In dysplastic nevus cases, 19 (45.2%) showed negative, 22 (52.4%) showed 1 positive, and one (2.4%) showed 2 positive p21 expression. Only two (1.7%) of melanoma cases showed negative with p21, 37 (30.6%) showed 1 positive , 29 (24%) showed 2 positive , 32 (26.4%) showed 3 positive and 21 (17.4%) showed 4 positive p21 expression. No statistically significant relationship was found between clinicopathological parameters and PRAME and p21 expression. When the general metastatic group and the non-metastatic group were compared, no significant relationship was found with PRAME staining, whereas p21 3 and 4 positive staining was more common in the metastatic group (p=0.024).In our study, we found that high PRAME expression is a reliable auxiliary antibody in melanoma diagnosis. We observed that p21 positivity plays a role in nevus-to-dysplasia and melanoma progression and also metastasis, and its diagnostic reliability is lower than PRAME. The prognostic significance of PRAME and p21 is controversial. In our study, expression of over 50% was associated with shorter mean survival, but statistical significance could not be demonstrated. We believe that supporting these molecules with studies including larger case series on their effects on prognosis and treatment will contribute to the literature. Keywork: Malign melanoma, PRAME, p21