Malignant conversion of florid oral and labial papillomatosis during topical immunotherapy with imiquimod

Enhanced targeted liposomal delivery of imiquimod via aptamer functionalization for head and neck cancer therapy

The incidence of head and neck cancers, particularly those associated with Human Papillomavirus (HPV) infections, has been steadily increasing. Conventional therapies exhibit limitations and drawbacks, prompting the exploration of new strategies over the years, with nanomedicine approaches, especially liposomes gaining relevance. Additionally, the functionalization of liposomes with aptamers enables selective delivery to target cells. For instance, AT11 can serve as a targeting moiety for cancer cells due to its high affinity for nucleolin, a protein overexpressed on the cancer cell's surface. In this study, liposomes functionalized with AT11 are proposed as drug delivery systems for imiquimod (IQ), aiming to maximize its potential as an anticancer agent for HPV-related cancers. To this end, firstly liposomes were produced through the ethanol injection method, functionalized with AT11-TEG-Cholesteryl, and characterized using dynamic light scattering. The obtained liposomes presented suitable properties for cancer therapy (with sizes from 120 to 140 nm and low polydispersity PDI < 0.16) and were further evaluated in terms of potential anticancer effects. AT11 IQ-associated liposomes allowed a selective delivery of IQ towards a tongue cancer cell line (UPCI-SCC-154) relative to the non-malignant cell line (Het1A). Specifically, they induced a selective reduction of the cell viability (∼52 % versus ∼113 %; p < 0.0001), proliferation (∼68 % versus ∼102 %; p<0.0001) and increased cell death (∼7-fold increase; p < 0.0001)). Additionally, they decreased the migration (from ∼24 % to ∼8 %; p < 0.0001) and invasion (to 11 %; p = 0.0047) capacities of the cancer cells. In summary, the produced liposomes represent a promising approach to enhance the anticancer potential of IQ in head and neck cancer, particularly in tongue cancer.

How safe is off-label use of imiquimod in oral lesions?

DATA SOURCES

A comprehensive search was conducted on PubMed and Embase, adhering to the principles outlined in the PRISMA Extension for Scoping Reviews (PRISMA-ScR). The search strategy was subsequently registered on PROSPERO.

STUDY SELECTION

Articles were chosen based on an analysis of titles and abstracts, with no restrictions on publication date, language, or participant age. In vitro studies, animal studies, and literature reviews were excluded from consideration.

DATA EXTRACTION AND SYNTHESIS

Clinical trials in humans, case reports, or case series that reported the use of imiquimod for treating conditions in the oral or labial mucosa were included in this study. Results from duplicate articles were excluded from the analysis.

RESULTS

Out of a total of 601 references initially identified, only 28 studies were included in the review. These studies were classified based on the use of imiquimod into three groups: potentially malignant disorders and oral cancer, lesions related to HPV, and autoimmune conditions. In all cases presented in the article, there is an occurrence of both local and systemic side effects.

CONCLUSIONS

The study elucidated the off-label use of imiquimod in oral pathologies, whether potentially malignant, cancerous, autoimmune, or associated with HPV infection. However, it was observed that further research is warranted for the development of a specific formulation for the oral mucosa, ensuring the drug's sustained presence at its active site of action without interference from saliva and minimizing potential side effects.

Oral florid papillomatosis: Topical treatment with 5% imiquimod in orabase

Background

Florid oral papillomatosis is characterized by its tendency to local recurrence that requires multiple treatments, leading to important functional sequelae.

Methods

We present 74‐year‐old woman with oral florid papillomatosis (OFP) who refused a new surgical treatment, and was treated with imiquimod 5% in orabase on alternate days for 16 weeks. Treatment was complemented with application of hyaluronic acid gel.

Results

There were no side effects to the treatment, nor signs of local recurrence, in the treated area at 2 years of follow‐up.

Conclusions

After reviewing the literature and according to our knowledge, this is the first published case of oral florid papillomatosis treated topically with imiquimod 5% successfully. Topical treatment with imiquimod 5% in orabase may be a valid alternative for patients with recurrent OFP located in the anterior area of the oral cavity who refuse surgical treatment, although we must closely monitor the patient for the possibility of recurrence or malignant degeneration.

Human papillomavirus vaccine trials and tribulations: Clinical perspectives

Human papillomavirus (HPV) affects hundreds of millions of people worldwide and is associated with both benign and malignant neoplasms in men and women. It is a double-stranded DNA virus with an icosahedral capsid. Forty HPV types are known to infect mucosal keratinocytes. If not cured by the immune system, the infection can lead to genital warts, mucosal dysplasia, or cancer. The most common oncogenic types are 16 and 18. The vaccine to prevent HPV and its associated morbidity and mortality has existed since 2006. Several variations protect against an increasing number of HPV types. The recommended vaccination age is before sexual exposure; administration of the vaccine to children has been controversial. This continuing medical education review evaluates the current HPV vaccines available to clinicians. Part I focuses on the debate over who should be vaccinated, at what age, and in which populations.

Verrucous papillary lesions: dilemmas in diagnosis and terminology

Verrucous papillary lesions (VPLs) of oral cavity are diagnostically challenging as they include a spectrum of benign, potentially malignant, and frankly malignant lesions. A majority of the benign VPLs have viral aetiology and include commonly occurring squamous papilloma along with verruca vulgaris, focal epithelial hyperplasia, and condyloma. Current understanding of potentially malignant VPLs is perplexing and is primarily attributed to the use of confusing and unsatisfactory terminology. Clinically and histologically oral verrucous hyperplasia, a potentially malignant disorder, resembles oral verrucous carcinoma and may be indistinguishable from one another. The most reliable way to separate these entities on routine haematoxylin-eosin stained tissue sections is to recognize the exophytic growth patterns of oral verrucous hyperplasia from the combined exophytic and endophytic growth patterns associated with verrucous carcinoma. A review of the literature showed that there is a lot of confusion regarding the current clinical and histopathological guidelines to diagnose this potentially malignant entity. The criteria elaborated by different authors in establishing the diagnosis of oral verrucous hyperplasia are discussed in detail. A brief overview of the treatment modalities adopted is also discussed. The need for establishing a clear understanding of this potentially malignant entity is stressed as it may have far reaching implications on its management.

In vivo and in situ modulation of the expression of genes involved in metastasis and angiogenesis in a patient treated with topical imiquimod for melanoma skin metastases

There is a growing body of evidence to support the efficacy of topical imiquimod in the treatment of primary skin carcinomas. Conflicting data exist concerning the use of imiquimod for the treatment of skin melanoma metastases. To date, only the impact of imiquimod on cytokines involved in immunological processes has been studied extensively. We report a woman successfully treated with imiquimod (once daily for 8 weeks) for skin melanoma metastases in whom we investigated the expression of molecules involved in metastasis and angiogenesis. Before and after treatment, a skin lesion was biopsied and the expression of the following molecules was investigated using real-time reverse transcription-polymerase chain reaction: matrix metalloproteinase (MMP)-1, 2 and 9 and their inhibitors KiSS-1 and tissue inhibitor of metalloproteinase (TIMP)-1, vascular endothelial growth factor (VEGF), fibroblast growth factor-2, and angiogenesis inhibitors (thrombospondin-1 and 2). Interferon (IFN)-alpha was also investigated as an in vivo marker of imiquimod activity. IFN-alpha was upregulated by the treatment. Under imiquimod, the following molecules were upregulated: TIMP-1, KiSS-1 and MMP-1. MMP-2 expression was not modified. MMP-9 expression was dramatically decreased. The expression of angiogenesis inhibitors was slightly increased but VEGF expression remained at a basal level. These results suggest that imiquimod could downregulate metastasis invasion and angiogenesis. However, these data were obtained at a transcriptional level and from a single case, and further investigations should include migration assays and additional cases in order to confirm that imiquimod may be safely used for treatment of melanoma metastases.