Prediction of positron emission tomography/computed tomography (PET/CT) positivity in patients with high-risk primary melanoma.

Positron emission tomography/computed tomography (PET/CT) is an important tool to identify occult melanoma metastasis. To date, it is controversial which patients with primary cutaneous melanoma should have staging PET/CT. In this retrospective analysis of more than 800 consecutive patients with cutaneous melanoma, we sought to identify factors predictive of PET/CT positivity in the setting of newly-diagnosed high-risk primary melanoma to determine those patients most appropriate to undergo a PET/CT scan as part of their diagnostic work up. 167 patients with newly-diagnosed high-risk primary cutaneous melanoma underwent a PET/CT scan performed as part of their initial staging. Clinical and histologic factors were evaluated as possible predictors of melanoma metastasis identified on PET/CT scanning using both univariate and multivariate logistic regression. In all, 32 patients (19.2%) had a positive PET/CT finding of metastatic melanoma. In more than half of these patients (56.3%), PET/CT scanning identified disease that was not detectable on clinical examination. Mitotic rate, tumor thickness, lymphadenopathy, and bleeding were significantly predictive of PET/CT positivity. A combinatorial index constructed from these factors revealed a significant association between number of high-risk factors observed and prevalence of PET/CT positivity, which increased from 5.8% (with the presence of 0-2 factors) to 100.0%, when all four factors were present. These results indicate that combining clinical and histologic prognostic factors enables the identification of patients with a higher likelihood of a positive PET/CT scan.

Is head and neck melanoma different from trunk and extremity melanomas with respect to sentinel lymph node status and clinical outcome?

BACKGROUND: Previous studies showed conflicting and inconsistent results regarding the effect of anatomic location of the melanoma on sentinel lymph node (SLN) positivity and/or survival. This study was conducted to evaluate and compare the effect of the anatomic locations of primary melanoma on long-term clinical outcomes. METHODS: All consecutive cutaneous melanoma patients (n=2,079) who underwent selective SLN dissection (SLND) from 1993 to 2009 in a single academic tertiary-care medical center were included. SLN positive rate, disease-free survival (DFS), and overall survival (OS) were determined. Kaplan-Meier survival, univariate, and multivariate analyses were performed to determine predictive factors for SLN status, DFS, and OS. RESULTS: Head and neck melanoma (HNM) had the lowest SLN-positive rate at 10.8% (16.8% for extremity and 19.3% for trunk; P=0.002) but had the worst 5-year DFS (P<0.0001) and 5-year OS (P<0.0001) compared with other sites. Tumor thickness (P<0.001), ulceration (P<0.001), HNM location (P=0.001), mitotic rate (P<0.001), and decreasing age (P<0.001) were independent predictive factors for SLN-positivity. HNM with T3 or T4 thickness had significantly lower SLN positive rate compared with other locations (P≤0.05). Also, on multivariate analysis, HNM location versus other anatomic sites was independently predictive of decreased DFS and OS (P<0.001). By Kaplan-Meier analysis, HNM was associated significantly with the worst DFS and OS. CONCLUSIONS: Primary melanoma anatomic location is an independent predictor of SLN status and survival. Although HNM has a decreased SLN-positivity rate, it shows a significantly increased risk of recurrence and death as compared with other sites.

Inoperable bulky melanoma responds to neoadjuvant therapy with vemurafenib.

A patient with a bulky inoperable stage IIIC melanoma involving the left axilla and neck from a primary of the left medial elbow received vemurafenib as neo-adjuvant treatment. Based on the molecular analysis, BRAF V600E mutation was present. After 4 months of vemurafinib treatment, the tumours shrank to less than 50% of original clinical size and allowed the surgeons to perform a left modified radical neck dissection and left radical axillary dissection. Pathological analysis of specimen revealed viable metastatic cells only in 1 of 40 nodes resected in the neck and axillary dissection, accounting for over 98% pathological response. Other lymph nodes had a mixture of foamy histiocytic inflammatory reaction fibrosis and islands of necrotic tissues. After recovery from surgery, vemurafenib was resumed and continued for 6 months. He remained disease free 6 months after surgery.