Evaluation of candidal species among individuals with oral potentially malignant disorders and oral squamous cell carcinoma

Nanotherapeutics for the delivery of antifungal drugs

The treatment of fungal infections is challenging with high death rates reported among immunocompromised patients. The currently available antifungals suffer from poor bioavailability and solubility, pharmacokinetics, and drug resistance, with limited cellular uptake. The clinical pipeline of new antifungals is dry. The incorporation of antifungal drugs into polymer-based nanocarriers to form nanotherapeutics is a promising approach to enhance the therapeutic outcomes of the available antifungal drugs. This review summarizes different polymer-based nanotherapeutics strategies that have been explored for the delivery of antifungals, resulting in enhanced therapeutic outcomes, such as improved pharmacokinetics, targeted/sustained delivery, prolonged drug circulation, retention of the drugs at the localized site of action, and overcoming drug resistance when compared with the free antifungal drugs.

Real-Time PCR Detection of Candida Species in Biopsy Samples from Non-Smokers with Oral Dysplasia and Oral Squamous Cell Cancer: A Retrospective Archive Study

The impact of Candida sp. in the development of oral cancer remains uncertain and requires sensitive analytical approaches for clarification. Given the invasive capabilities of these microorganisms in penetrating and invading host tissues through hyphal invasion, this study sought to detect the presence of five Candida sp. in oral biopsy tissue samples from non-smoker patients. Samples were obtained from patients at varying stages of oral carcinogenesis, including dysplasia, carcinoma in situ, OSCC, and histologically benign lesions, and analyzed using Real-Time PCR. Oral tissue samples from 80 patients (46 males and 34 females) were included. Significantly higher C. albicans presence was detected in the mild/moderate dysplasia group compared to the healthy (p = 0.001), carcinoma in situ (p = 0.031) and OSCC groups (p = 0.000). Similarly, C. tropicalis carriage was higher in tissues with mild/moderate dysplasia compared to healthy (p = 0.004) and carcinoma in situ (p = 0.019). Our results showed a significant increase in the presence of C. albicans and C. tropicalis within the mild/moderate dysplasia group compared to other cohorts. Coexistence of these two microorganisms was observed, suggesting a potential transition from a commensal state to an opportunistic pathogen, which could be particularly linked to the onset of oral neoplasia.

Presence of Candida and its associated factors in participants attending oral cancer screening in the lower northeastern area of Thailand

BACKGROUND

Certain evidence indicated high prevalence of Candida in oral potentially malignant disorders (OPMDs) and oral cancer (OC). This study was aimed to investigate the presence of Candida and its associated factors in participants who attended the oral cancer screening program in the lower northeastern districts of Thailand.

METHODS

Convenient participants residing in the lower northeastern districts of Thailand who attended the oral cancer screening were enrolled. A questionnaire retrieving demographic characteristics, risk factors of oral cancer, and risk of having Candida was completed. Oral examination was performed by oral medicine specialists or oral surgeons. The participants were categorized into 4 groups according to their clinical diagnosis, namely normal oral mucosa (NOM), OPMDs/OC, non-OPMDs/OC and clinically suspected oral candidiasis (CSOC). Stimulated saliva flow rate was measured. Dip-slide test was performed in each participant to evaluate the presence of Candida. The levels of Candida were categorized into high and low levels according to the score received from the dip-slide test. Factors associated with high levels of Candida were identified using multivariate logistic regression analysis.

RESULTS

A total of 577 participants were recruited. High levels of Candida were found in 31.3%, 24.7%, 25.9% and 18.1% in the OPMDs/OC, the non-OPMDs/OC, the CSOC and the NOM groups, respectively. According to multivariate logistic regression analysis, age above 60 years, female gender, betel quid chewing habit, use of denture, hyposalivation, and being in the CSOC group were found to be significantly associated with high levels of Candida.

CONCLUSION

Higher number of participants in the OPMDs/OC group was found to have high levels of Candida. Increasing age, female gender, betel quid chewing habit, use of denture, hyposalivation and having CSOC lesions were associated with high levels of Candida.

Fungi and cancer

The microbiome may impact cancer development, progression and treatment responsiveness, but its fungal components remain insufficiently studied in this context. In this review, we highlight accumulating evidence suggesting a possible involvement of commensal and pathogenic fungi in modulation of cancer-related processes. We discuss the mechanisms by which fungi can influence tumour biology, locally by activity exerted within the tumour microenvironment, or remotely through secretion of bioactive metabolites, modulation of host immunity and communications with neighbouring bacterial commensals. We examine prospects of utilising fungi-related molecular signatures in cancer diagnosis, patient stratification and assessment of treatment responsiveness, while highlighting challenges and limitations faced in performing such research. In all, we demonstrate that fungi likely constitute important members of mucosal and tumour-residing microbiomes. Exploration of fungal inter-kingdom interactions with the bacterial microbiome and the host and decoding of their causal impacts on tumour biology may enable their harnessing into cancer diagnosis and treatment.

Host's Immunity and Candida Species Associated with Denture Stomatitis: A Narrative Review

Denture-related Candida stomatitis, which has been described clinically in the literature, is either localized or generalized inflammation of the oral mucosa in connection with a removable prosthesis. During this inflammatory process, the mycobacterial biofilm and the host’s immune response play an essential role. Among microorganisms of this mixed biofilm, the Candida species proliferates easily and changes from a commensal to an opportunistic pathogen. In this situation, the relationship between the Candida spp. and the host is influenced by the presence of the denture and conditioned both by the immune response and the oral microbiota. Specifically, this fungus is able to hijack the innate immune system of its host to cause infection. Additionally, older edentulous wearers of dentures may experience an imbalanced and decreased oral microbiome diversity. Under these conditions, the immune deficiency of these aging patients often promotes the spread of commensals and pathogens. The present narrative review aimed to analyze the innate and adaptive immune responses of patients with denture stomatitis and more particularly the involvement of Candida albicans sp. associated with this pathology.

Evaluation of Candidiasis in Upper-Aerodigestive Squamous Cell Carcinoma Patients—A Clinico-Mycological Aspect

Candida is a commensal yeast. It can be infective when the host’s defense mechanism is weakened, as in the case of squamous cell carcinoma patients. We aimed to evaluate the prevalence and clinical mycological manifestation of candidiasis in 150 cancer cases comprised of preoperative and post-operative (with or without radiotherapy) upper aerodigestive squamous cell carcinoma. A total of 150 patients suffering from squamous cell carcinoma of the Upper Aero-Digestive Tract (UADT) were divided into preoperative (n = 48), post-operative without radiotherapy (n = 29) and post-operative with radiotherapy (n = 73). Samples were collected using cotton swabs and cultured. Candida species were identified according to color pigmentation on Candida Differential Agar (CDA) plate. The clinico-mycological association of patients was evaluated by the chi-square test, and 98 out of 150 patients showed the presence of various Candida species. The major species isolated was Candida albicans (53%), followed by Candida tropicalis (16%). There was a significant statistical difference between patients who showed mycological associations and patients who did not have any such association (p = 0.0008). The prevalence of oral candidiasis was found to be 65.33% among total cases of upper aero-digestive squamous cell carcinoma. Chronic erythematous cases of candidiasis were mainly seen in preoperative squamous cell carcinoma cases, whereas the acute erythematous type of candidiasis was mainly seen in post-operative cases who received radiotherapy. The clinicomycological assessment can help to correlate the signs and symptoms with the presence of candidiasis in upper aerodigestive squamous cell carcinoma patients. Meticulous testing and examination can help in the early detection of candidiasis. Future studies are needed to develop advance scientific preventive strategies for high-risk cases.

Evaluation of the Distribution of Candida Species in Patients with Dysplastic and Nondysplastic Oral Lichen Planus Lesions

Objectives. This study is aimed at identifying and determining the distribution of isolated Candida species in patients with dysplastic and nondysplastic oral lichen planus (OLP) lesions in comparison with those of healthy controls. Material and Methods. This study includes patients with OLP, aged (more than 18 years old), who have had informed consent. Samples of the oral, tongue, and buccal mucus by rubbing with a sterile swab and sterilely next to the lamp flame. Demographic information was obtained using patient records to determine the species of Candida in both groups, and two tests of fertile tube production by Candida albicans and dye production in the dye medium were used. A biopsy from OLP lesions has been taken from each patient after swab sampling and was sent to the pathology department for further histopathological analysis. In the end $p$ value, less than 0/05 was considered significant. Result. In this study, 40 lichen planus patients were compared with 32 control patients. The female/male ratio in OLP and healthy groups was 22/18 and 17/15, respectively. Among the OLP patients, 23 cases (56%) were dysplastic, and the other 17 (44%) patients were nondysplastic. The mean (±standard deviation (SD)) age of patients was 48.83 (±9.34) years, and the mean age of the control group was 40.21 (±10.32). There were no significant differences based on age ( $p>0.05$ ). The highest frequency was related to tongue in both groups (22 (55%)) and buccal mucosa was the least common. There was a significant relationship between the location of the lesion and OLP ( $p=0.05$ ). 18 (45%) were erosive, and 22 (55%) were nonerosive. However, no significant difference was observed between erosive and nonerosive types in the OLP group ( $p=0/07$ ). Regarding the type of Candida, all cases in the patient’s group were related to Candida albicans [40 (100%)], and the correlation was not found in this regard ( $p>0/05$ ). About colony count, the mean for the case and control groups was 26.68 and 23.25, respectively. Also, no significant relationship was found between colony count and groups in this study ( $p=0.3$ ). There was no significant difference between gender and dysplastic or nondysplastic ( $p>0.05$ ). Conclusion. According to the statistical studies performed in this study, the presence of Candida in patients with dysplastic and nondysplastic lichen planus is not significantly different, and this rate is not higher than healthy individuals and in cases where the results are positive. The predominant species of Candida is the Candida albicans. In this study, the highest frequency was related to tongue in both groups. There was only a significant relationship between the location of the lesion and OLP.

The oral mycobiome: Oral epithelial dysplasia and oral squamous cell carcinoma

Fungi, a diverse group of eukaryotic organisms, play distinct roles in health and disease. Recent advances in the field of mycobiology have enabled the characterization of the "human mycobiome." The human mycobiome has extensively been studied in various disease models. However, to date, the role of the oral mycobiome in oral carcinogenesis has yet to be elucidated. Candida albicans, the most common oral colonizer, has been speculated to display tumorigenic effects; however, the literature lacks consistent documentation from mechanistic studies on whether oral mycobiota act as drivers, facilitators, or passive colonizers of oral premalignancy and cancer. This review article provides an overview of existing hypothesis-driven mechanistic models that outline the complex interplay between the oral mycobiome and oral epithelial dysplasia as well as their potential clinical implications.

Candida albicans and Oral Carcinogenesis. A Brief Review

Current medical knowledge and research on patients’ management are still evolving, and several protocols on minimizing risk of infection by Candida spp. among the population have developed. The aim of this work is to review the epidemiological and biomolecular characteristics and the various histopathological carcinogenesis hypothesis mechanisms that can occur during Candida albicans infections. Current evidence from the literature on the role of C. albicans during potentially malignant oral disorders and oral cancer has been sought. Thus, these biomolecular processes can give or contribute to benign lesions, also in precancerous or cancerous situations. Alongside this, the physiological microorganism oral flora (microbiota) can play a crucial role in maintaining oral health during those infections and therefore avoid carcinogenesis.

Analyzing the Association between Candida Prevalence, Species Specificity, and Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis— Candida and OSCC

The present review is a qualitative and quantitative analysis of the overall prevalence of Candida, and its species specificity in oral squamous cell carcinoma (OSCC). PubMed, Scopus, and Web of Science databases were searched using the keywords ‘Candida and oral squamous cell carcinoma’. Only case-control observational studies in the English language evaluating the prevalence and species specificity of Candida in OSCC were included. 297 articles were identified (PubMed-106, Scopus-148, Web of Science-43) using the keywords. After screening the titles and abstracts, 206 articles were removed as they were duplicates (118) or irrelevant to the topic (88). Full text of the remaining 91 articles was assessed using the inclusion criteria, based on which only seven articles were included in the systematic review. For the quantitative analysis, the odds ratio and confidence interval were assessed and a forest plot was generated. Based on the meta-analysis, there is an association between the total Candida, Candida albicans (CA) and OSCC, while the association with non-Candida albicans (NCA) is relatively weak. The number of studies included in the meta-analysis was relatively low (four to five). Further, at least one of the studies included in the meta-analysis for the association of CA., NCA and total Candida with OSCC had a Newcastle–Ottawa score below 7. Thus, although the results showed an association, the quality and quantity of the evidence may not be sufficient for conclusive inference.