Retrospective analysis of the relationship between breslow thickness anddistant organ metastasis determined by positron emission tomography/computedtomography (PET/CT)

Skin cancer is one of the most frequent types of cancer in the world. Malignant melanoma is a type of cancer with the highest mortality among skin cancers. The most important prognostic factor for malignant melanoma is the Breslow thickness specified in the pathology report. Many imaging methods are available for metastasis screening in malignant melanoma. The most important one of these methods is PET/CT applied by nuclear medicine. Almost all metastases in the body can be detected by this imaging technique In this study, it was aimed to demonstrate the effect of the Breslow thickness, which is the most significant prognostic factor in patients with malignant melanoma, on distant metastasis detected by PET/CT. Nevertheless, we also intended to observe the effects of Clark's level, the presence of ulceration, and the number of mitoses specified in the pathology report on distant metastasis. The patients who were treated for malignant melanoma in our clinic between 2012 and 2017 and had PET/CT and whose Breslow thickness was mentioned in the pathology report were retrospectively examined.As a result of PET/CT, the Breslow thickness was found to be statistically significantly higher in the group with distant metastasis compared to the group without distant metastasis (p=0.025). In this study, it was aimed to demonstrate the importance of the Breslow thickness in the early diagnosis and treatment of metastatic melanomas with very few treatment options by demonstrating its effect on distant metastasis. Furthermore, we determined that Clark staging, which lost its importance compared to the Breslow thickness in determining the prognosis, was still important and worth considering Keywords: Malignant melanoma (MM), Breslow thickness, PET/CT.