Treatment of Primary and Metastatic Multifocal Mucosal Melanoma of the Oral Cavity with Imatinib

Primary oral and sinonasal mucosal melanomas in Latin America: a systematic review

Primary oral and sinonasal mucosal melanomas (POSNMMs) are aggressive neoplasms with limited therapeutic alternatives. The aim of this review was to characterize the demographic, clinical, immunohistochemical, and molecular information regarding these tumors in the Latin American population. Articles published in English, Spanish, or Portuguese (1990-2022) retrieved from the PubMed/MEDLINE, Scopus, CAS, Web of Science, EBSCO, and Google Academic databases were included. Thirty-three studies, with a total of 1212 cases, were identified. Clinicopathological data were available for 870 cases and immunohistochemical and/or molecular information for 342. Nineteen studies (57.6%) reported cases of oral melanoma, three (9.1%) sinonasal melanoma, and 11 (33.3%) oral and sinonasal melanoma. Fifteen studies (45.5%) provided only clinicopathological data, 12 (36.4%) reported only immunohistochemical data, two (6.1%) shared clinicopathological and immunohistochemical data, one (3.0%) offered clinicopathological, immunohistochemical, and molecular data, one (3.0%) provided immunohistochemical and molecular data, one (3.0%) clinicopathological and molecular data, and one (3.0%) only molecular data. The mean age of individuals with POSNMMs was 58 years, and slightly more were male (male 51.3%, female 48.7%). In Latin America, POSNMMs are a rare but aggressive malignancy with a poor prognosis and limited treatment options. Although molecular data and targeted therapy are still being researched, data from Latin America indicate the need for multicenter collaborative clinical trials to unite individual and isolated efforts.

Canine oral melanoma with suspected pulmonary metastasis: Combination of immunotherapy and tyrosine kinase inhibitor treatment

This case report follows a 10-year-old castrated male Miniature Schnauzer dog presented with a history of incomplete surgical resection of an oral malignant melanoma (amelanotic type) on the right mandible. Melanoma vaccine therapy was administered due to incomplete surgical resection, however, new masses were detected on the contralateral mandible and suspected pulmonary metastasis occurred at 2 weeks and 7 months, respectively, following the first melanoma vaccination. At the time of detecting the pulmonary metastasis, targeted chemotherapy was initiated with the owner's consent using imatinib (10 mg/kg/day, p.o.), a tyrosine kinase inhibitor (TKI). The patient did not show any significant adverse events related to both anticancer treatments. Three months following the first dose of imatinib, the absence of the suspected pulmonary metastatic nodules on radiography indicated complete remission. In conclusion, this report describes the achievement of clinical remission of suspected pulmonary metastatic oral malignant melanoma and an extension of survival time in a dog given a combination treatment of immunotherapy and tyrosine kinase inhibitor.

Using nanoparticles for in situ vaccination against cancer: mechanisms and immunotherapy benefits

Immunotherapy to treat cancer is now an established clinical approach. Immunotherapy can be applied systemically, as done with checkpoint blockade antibodies, but it can also be injected directly into identified tumors, in a strategy of in situ vaccination (ISV). ISV is designed to stimulate a strong local antitumor immune response involving both innate and adaptive immune cells, and through this generate a systemic antitumor immune response against metastatic tumors. A variety of ISVs have been utilized to generate an immunostimulatory tumor microenvironment (TME). These include attenuated microorganisms, recombinant proteins, small molecules, physical disruptors of TME (alternating magnetic and focused ultrasound heating, photothermal therapy, and radiotherapy), and more recently nanoparticles (NPs). NPs are attractive and unique since they can load multiple drugs or other reagents to influence immune and cancer cell functions in the TME, affording a unique opportunity to stimulate antitumor immunity. Here, we describe the NP-ISV therapeutic mechanisms, review chemically synthesized NPs (i.e., liposomes, polymeric, chitosan-based, inorganic NPs, etc.), biologically derived NPs (virus and bacteria-based NPs), and energy-activated NP-ISVs in the context of their use as local ISV. Data suggests that NP-ISVs can enhance outcomes of immunotherapeutic regimens including those utilizing tumor hyperthermia and checkpoint blockade therapies.

CD117 immunoexpression in oral and sinonasal mucosal melanoma does not correlate with somatic driver mutations in the MAPK pathway

BACKGROUND

Mutations on KIT and downstream genes of MAPK pathway that overstimulate cellular proliferation have been associated with primary oral and sinonasal melanomas (POSNM), but there is limited information that allows the use of personalized therapy. Thus, the aim of the present study was to determine a possible association between the C-KIT immunohistochemical expression with the presence of somatic driver mutations in NRAS, BRAF, KIT, MITF and PTEN on POSNM.

METHODS

A retrospective study included 62 tumour samples of an oncological reference centre in Mexico City (17-year period). Immunohistochemistry stain of C-KIT was carried out. Genomic DNA was obtained and used to assess hotspot mutations of KIT, NRAS, BRAF, MITF and PTEN through qPCR. Chi-square, Fisher's exact and the Mann-Whitney U tests were applied when necessary. The significance was set at P < 0.05.

RESULTS

Sixty-two cases were included, 74% were positive for C-KIT immunoexpression, all exhibited moderate/strong intensity. Ten (16.1%) samples harboured at least one mutation, 6.4% and 6.6% for NRAS^{Q 61R} and BRAF^{V 600E} , respectively, followed by KIT^K624E (3.2%). No KIT^{L 576P} , MITF or PTEN mutations were identified. No significant correlation was observed between mutations and immunostaining (rs = -0.057, P = 0.765).

CONCLUSIONS

Regardless of the high immunoexpression of C-KIT, there was no association with the MAPK mutations among POSNM samples. Thus, C-KIT immunohistochemistry is not a reliable tool to detect POSNM candidates for biological therapy.