BRAFV600 variant allele frequency predicts outcome in metastatic melanoma patients treated with BRAF and MEK inhibitors

BACKGROUND

The prognostic impact of variant allele frequency (VAF) on clinical outcome in BRAFV600 mutated metastatic melanoma patients (MMPs) receiving BRAF (BRAFi) and MEK inhibitors (MEKi) is unclear.

MATERIALS AND METHODS

A cohort of MMPs receiving first line BRAFi and MEKi was identified by inspecting dedicated databases of three Italian Melanoma Intergroup centres. VAF was determined by next generation sequencing in pre-treatment baseline tissue samples. Correlation between VAF and BRAF copy number variation was analysed in an ancillary study by using a training and a validation cohort of melanoma tissue samples and cell lines.

RESULTS

Overall, 107 MMPs were included in the study. The VAF cut-off determined by ROC curve was 41.3%. At multivariate analysis, progression-free survival (PFS) was significantly shorter in patients with M1c/M1d [HR 2.25 (95% CI 1.41-3.6, p < 0.01)], in those with VAF >41.3% [HR 1.62 (95% CI 1.04-2.54, p < 0.05)] and in those with ECOG PS ≥1 [HR 1.82 (95% CI 1.15-2.88, p < 0.05)]. Overall survival (OS) was significantly shorter in patients with M1c/M1d [HR 2.01 (95% CI 1.25-3.25, p < 0.01)]. Furthermore, OS was shorter in patients with VAF >41.3% [HR 1.46 (95% CI 0.93-2.29, p = 0.06)] and in patients with ECOG PS ≥1 [HR 1.52 (95% CI 0.94-2.87, p = 0.14)]. BRAF gene amplification was found in 11% and 7% of samples in the training and validation cohort, respectively.

CONCLUSIONS

High VAF is an independent poor prognostic factor in MMP receiving BRAFi and MEKi. High VAF and BRAF amplification coexist in 7%-11% of patients.

External Validation of Three Available Grading Systems for Medullary Thyroid Carcinoma in a Single Institution Cohort

Medullary thyroid carcinoma (MTC) is a rare thyroid carcinoma with a variable clinical behavior. Potential clinical and pathological prognostic markers have been investigated, but studies are limited and controversial. In neuroendocrine neoplasms of various other sites, necrosis and proliferation (mitotic activity and/or Ki67 index) are integrated to provide a histological grade. Recently, an International Medullary Thyroid Carcinoma Grading System (IMTCGS) has been designed to define high- or low-grade MTC by combining proliferative activity and necrosis. This proposal integrates two previously published grading schemes by American (2-tiered grading, low- and high-grade MTC) and Australian authors (3-tiered grading, low-, intermediate-, and high-grade MTC). To validate the clinical role of these systems, their prognostic impact was evaluated in an independent cohort of 111 MTCs. Necrosis, which was the only parameter integrated into the 3 grading systems, proved to be individually correlate with tumor relapse, while no association was found with the proliferation (mitotic count and Ki67 index); however, by combining the different parameters according to all three grading systems, "high-grade" MTCs turned out to be significantly associated with the disease recurrence (p < 0.005) in all systems. In disease-free survival analysis, the IMTCGS stratification was the only one that demonstrated a significant impact at Cox regression analysis (p = 0.004), further confirmed by the Kaplan-Meier curves (p = 0.002). Similar findings were also reproduced when analysis was restricted to sporadic MTCs (68 cases). In conclusion, our results confirm the prognostic role of IMTCGS, supporting the importance of incorporating this information into the pathology report. However, none of the systems proved to predict the overall survival in this validation cohort.

The lobular neoplasia enigma: management and prognosis in a long follow-up case series

BACKGROUND

Many oncologists debate if lobular neoplasia (LN) is a risk factor or an obligatory precursor of more aggressive disease. This study has three aims: (i) describe the different treatment options (surgical resection vs observation), (ii) investigate the upgrade rate in surgically treated patients, and (iii) evaluate the long-term occurrences of aggressive disease in both operated and unoperated patients.

METHODS

A series of 122 patients with LN bioptic diagnosis and follow-up information were selected. Clinical, radiological, and pathological data were collected from medical charts. At definitive histology, either invasive or ductal carcinoma in situ was considered upgraded lesions.

RESULTS

Atypical lobular hyperplasia (ALH), lobular carcinoma in situ (LCIS), and high-grade LN (HG-LN) were diagnosed in 44, 63, and 15 patients, respectively. The median follow-up was 9.5 years. Ninety-nine patients were surgically treated, while 23 underwent clinical-radiological follow-up. An upgrade was observed in 28/99 (28.3%). Age ≥ 54 years (OR 4.01, CI 1.42-11.29, p = 0.009), Breast Imaging-Reporting and Data System (BI-RADS) categories 4-5 (OR 3.76, CI 1.37-10.1, p = 0.010), and preoperatory HG-LN diagnosis (OR 8.76, 1.82-42.27, p = 0.007) were related to upgraded/aggressive disease. During follow-up, 8 patients developed an ipsilateral malignant lesion, four of whom were not initially operated (4/23, 17%).

CONCLUSIONS

BI-RADS categories 4-5, HG-LN diagnosis, and age ≥ 54 years were features associated with an upgrade at definitive surgery. Moreover, 17% of unoperated cases developed an aggressive disease, emphasizing that LN patients need close surveillance due to the long-term risk of breast cancer.

Genetic mutations in primary malignant melanoma of the esophagus: case report and literature review

The most frequent genetic aberrations in mucosal melanoma are activating mutations of c-KIT. Primary malignant melanomas of esophagus (PMME) are uncommon entities, with aggressive biological behavior and poor prognosis. The better definition of their genotype could improve therapeutic options. We report a case of a 66 years old man with a PMME in the lower third of the esophagus. Analysis of c-kit, KRAS, NRAS and BRAF genes resulted negative for mutations. On the basis of a computerized (PuMed/Medline) bibliography search we retrieved a total of other 35 cases of PMME analyzed for genetic alterations in RAS, BRAF, and KIT. When we compared mutations frequency of PMME with those of other mucosal melanomas, it appeared that PMME are characterized by a relative higher percentage of NRAS mutations. PMME seem to show a specific pattern of genetic alterations suggesting that they could represent a distinct entity among mucosal melanomas.

The fragile X mental retardation protein regulates tumor invasiveness-related pathways in melanoma cells

The fragile X mental retardation protein (FMRP) is lacking or mutated in patients with the fragile X syndrome (FXS), the most frequent form of inherited intellectual disability. FMRP affects metastasis formation in a mouse model for breast cancer. Here we show that FMRP is overexpressed in human melanoma with high Breslow thickness and high Clark level. Furthermore, meta-analysis of the TCGA melanoma data revealed that high levels of FMRP expression correlate significantly with metastatic tumor tissues, risk of relapsing and disease-free survival. Reduction of FMRP in metastatic melanoma cell lines impinges on cell migration, invasion and adhesion. Next-generation sequencing in human melanoma cells revealed that FMRP regulates a large number of mRNAs involved in relevant processes of melanoma progression. Our findings suggest an association between FMRP levels and the invasive phenotype in melanoma and might open new avenues towards the discovery of novel therapeutic targets.

Expression pattern of chemokine receptors and chemokine release in inflammatory erythroderma and Sézary syndrome

BACKGROUND

Erythroderma can be caused by inflammatory dermatoses or cutaneous T-cell lymphoma. Even if chemokines and their receptors are involved in the skin-selective lymphocyte recruitment, their role in inflammatory erythroderma is yet unclear.

OBJECTIVE

To evaluate the chemokine release (TARC, MDC, IP-10) and to define the expression pattern of Th1- (CCR5, CXCR3) and Th2-related (CCR4) chemokine receptors in inflammatory erythroderma and Sézary syndrome (SS).

MATERIALS AND METHODS

Flow cytometry has been carried out on both circulating and skin-infiltrating T lymphocytes; serum chemokine levels have been evaluated using ELISA techniques.

RESULTS

CCR4, CCR5 and CXCR3 were expressed on about 40% of peripheral blood lymphocytes and on the majority of skin-infiltrating lymphocytes in the inflammatory erythroderma patients, whereas the leukemic CD4+CD26- subpopulation in SS was characterized by a high CCR4 expression without a concurrent increase in CCR5 or CXCR3. TARC, MDC and IP-10 serum levels were significantly increased in both erythrodermic and SS patients.

CONCLUSIONS

Our results confirm that SS is a Th2 disorder with a selective expression of CCR4, whereas inflammatory erythroderma shares an overexpression of both Th1- and Th2-related chemokine receptors, suggesting an activation of different pathways driving reactive lymphocytes to the skin.