mTOR inhibitor-associated stomatitis (mIAS) in three patients with cancer treated with everolimus

Anti-epidermal growth factor receptor targeted therapy-associated ulcerations

The well-studied role of epidermal growth factor receptor (EGFR) in metastatic colorectal cancer (mCRC) and non-small cell lung cancer (NSCLC) has enabled the development of drugs that target this molecule, including panitumumab for the former and osimertinib for the latter. Oral adverse events due to those agents are rarely described in the literature and their exact characterization is hampered by inadequate reporting and/or incorrect terminology used. We report two cases of panitumumab- and osimertinib-associated oral ulcerations with emphasis on their possible pathogenesis and optimal management.

p53 haploinsufficiency and increased mTOR signalling define a subset of aggressive hepatocellular carcinoma

BACKGROUND & AIMS

p53 mutations occur frequently in human HCC. Activation of the mammalian target of rapamycin (mTOR) pathway is also associated with HCC. However, it is still unknown whether these changes together initiate HCC and can be targeted as a potential therapeutic strategy.

METHODS

We generated mouse models in which mTOR was hyperactivated by loss of tuberous sclerosis complex 1 (Tsc1) with or without p53 haplodeficiency. Primary cells were isolated from mouse livers. Oncogenic signalling was assessed in vitro and in vivo, with or without targeted inhibition of a single molecule or multiple molecules. Transcriptional profiling was used to identify biomarkers predictive of HCC. Human HCC materials were used to corroborate the findings from mouse models.

RESULTS

p53 haploinsufficiency facilitates mTOR signalling via the PTEN/PI3K/Akt axis, promoting HCC tumorigenesis and lung metastasis. Inhibition of PI3K/Akt reduced mTOR activity, which effectively enhanced the anticancer effort of an mTOR inhibitor. ATP-binding cassette subfamily C member 4 (Abcc4) was found to be responsible for p53 haploinsufficiency- and Tsc1 loss-driven HCC tumorigenesis. Moreover, in clinical HCC samples, Abcc4 was specifically identified an aggressive subtype. The mTOR inhibitor rapamycin significantly reduced hepatocarcinogenesis triggered by Tsc1 loss and p53 haploinsufficiency in vivo, as well as the biomarker Abcc4.

CONCLUSIONS

Our data advance the current understanding of the activation of the PTEN/PI3K/Akt/mTOR axis and its downstream target Abcc4 in hepatocarcinogenesis driven by p53 reduction and Tsc1 loss. Targeting mTOR, an unexpected vulnerability in p53 (haplo)deficiency HCC, can be exploited therapeutically to treat Abcc4-positive patients with HCC.

LAY SUMMARY

Tsc1 loss facilitates the p53 (haplo)insufficiency-mediated activation of the PTEN/Akt/mTOR axis, leading to the elevated expression of Abcc4 to drive HCC tumorigenesis and metastasis in mice. Inhibition of mTOR protects against p53 haploinsufficiency and Tsc1 loss-triggered tumour-promoting activity, providing a new approach for treating an aggressive subtype of HCC exhibiting high Abcc4 expression.

PI3K Inhibitors and Adverse Events: Optimizing Patient Care for the Treatment of Advanced Breast Cancer

BACKGROUND

Excessive activation of the PI3K pathway has been associated with malignant transformation and resistance to treatment in various cancer types. Various PI3K inhibitors have been evaluated in phase 3 clinical trials; however, most have been associated with modest clinical improvement and poor tolerability. The safety profile of PI3K inhibitors poses new challenges in treatment monitoring and management of common adverse events (AEs).

OBJECTIVES

The purpose of this article is to provide an overview of AEs associated with PI3K inhibitors, with a focus on alpelisib, as well as guidance on the prevention and management of AEs.

METHODS

The literature and results from phase 3 trials evaluating the efficacy and safety of endocrine therapy plus PI3K inhibitors in patients with advanced breast cancer were reviewed.

FINDINGS

AEs associated with PI3K inhibitors include hyperglycemia, diarrhea, nausea, rash, and decreased appetite. Prevention strategies are recommended to avoid the development or decrease the severity of these AEs. Patient education and multidisciplinary care are necessary for the optimal care of these patients.

Significant cases of central cusps, enamel pits, and oral fibromas in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder in which benign nodular tumors form in the cerebral cortex, cerebellum, and throughout the body causing various symptoms. In this study, we summarized the incidence of dental findings in patients with TSC at our hospital and its association with diseases in various organs. Patients diagnosed with TSC at our hospital between January 2013 and September 2017, and who were examined in the dental and oral surgery department were included in this study. The presence of intraoral manifestations (central cusps, enamel pits, oral fibromas) was examined by means of visual inspection, intraoral photography, and X-ray photography. In addition, the relationship with associated diseases (neurological, cutaneous, cardiac, renal, and pulmonary) according to organ and disease severity was examined. The mean age (± SD) of the 42 TSC patients (19 men and 23 women) was 27.8 ± 14.6 years, of which 24 patients (11 men and 13 women) presented with oral manifestations. Of these patients, seven had central cusps, 10 had enamel pits, and 17 had oral fibromas. The group with central cusps had significantly higher neurological issues in the relationship between intraoral manifestations and associated disease based on the involved organ. The prevalence of central cusps in TSC was 16.7%, which is significantly higher than the 2.6% reported in healthy Japanese subjects. The central cusp is a diagnostic factor alongside the presence of enamel pits and oral fibromas, which can aid in the early diagnosis of TSC by dentists.

Oral manifestations of allograft recipients immediately before and after kidney transplantation

Objective: To identify the oral lesions of individuals with kidney disease immediately before and shortly after kidney transplantation, taking into account the immunosuppressive regimen, antiviral prophylaxis and type of transplantation.Methods: A prospective observational cohort study was carried from January 2017 to January 2018. Eighty individuals aged 18 years or older who were admitted for kidney transplantation were eligible to participate. Clinical data regarding medical history, immunosuppressive therapy, antiviral prophylaxis, laboratorial data and oral examination were performed by the same trained researcher, in three different moments: 24 hours before transplantation (1st time point), 15-20 days (2nd time point) and 45-60 days (3rd time point) after transplantation.Results: In the first, second and third time points, it was found that 3.7% (3/80), 23.7% (18/76) and 25.7% (19/74) of the participants showed oral soft tissue lesions. Ulcers and candidiasis were the most frequent oral lesions, and they were associated with the use of everolimus (p = .005) and azathioprine (p = .034), respectively. Less patients reported xerostomia after transplantation than before (p < .001).Conclusions: Oral lesions are common in the short term after renal transplantation and are particularly related to both toxicities of immunosuppressive drugs and immunosuppression.

Stomatitis And Everolimus: A Review Of Current Literature On 8,201 Patients

Background

Oral toxicities, such as mucositis and stomatitis, are some of the most significant and unavoidable side effects associated with anticancer therapies. In past decades, research has focused on newer targeted agents with the aim of decreasing the rates of side effects on healthy cells. Unfortunately, even targeted anticancer therapies show significant rates of toxicity on healthy tissue. mTOR inhibitors display some adverse events, such as hyperglycemia, hyperlipidemia, hypophosphatemia, hematologic toxicities, and mucocutaneous eruption, but the most important are still stomatitis and skin rash, which are often dose-limiting side effects.

Aim

This review was performed to answer the question “What is the incidence of stomatitis in patients treated with everolimus?”

Methods

We conducted a systematic search on the PubMed and Medline online databases using a combination of MESH terms and free text: “everolimus” (MESH) AND “side effects” OR “toxicities” OR “adverse events”. Only studies fulfilling the following inclusion criteria were considered eligible for inclusion in this study: performed on human subjects, reporting on the use of everolimus (even if in combination with other drugs or ionizing radiation), written in the English language, and reporting the incidence of side effects.

Results

The analysis of literature revealed that the overall incidence of stomatitis after treatment with everolimus was 42.6% (3,493) and that of stomatitis grade G1/2 84.02% (2,935), while G3/4 was 15.97% (558).

Conclusion

Results of the analysis showed that the incidence of stomatitis of grade 1 or 2 is higher than grade 3 or 4. However, it must be taken into account that it is not possible to say if side effects are entirely due to everolimus therapy or combinations with other drugs.

Tuberous sclerosis complex: new insights into clinical and therapeutic approach

Tuberous sclerosis complex (TSC) is a complex disease with many different clinical manifestations. Despite the common opinion that TSC is a rare condition, with a mean incidence of 1/6000 live births and a prevalence of 1/20,000, it is increasingly evident that in reality this is not true. Its clinical sequelae span a range of multiple organ systems, in particular the central nervous system, kidneys, skin and lungs. The management of TSC patients is heavily burdensome in terms of time and healthcare costs both for the families and for the healthcare system. Management options include conservative approaches, surgery, pharmacotherapy with mammalian target of rapamycin inhibitors and recently proposed options such as therapy with anti-EGFR antibody and ultrasound-guided percutaneous microwaves. So far, however, no systematically accepted strategy has been found that is both clinically and economically efficient. Thus, decisions are tailored to patients' characteristics, resource availability and clinical and technical expertise of each single center. This paper reviews the pathophysiology and the clinical (diagnostic-therapeutic) management of TSC.

Oral stomatitis and mTOR inhibitors: A review of current evidence in 20,915 patients

BACKGROUND

Traditional treatment of malignancies with chemotherapeutic agents is often affected by the damage inflicted on non-cancerous cells. Toxicities of the oral cavity, such as mucositis and stomatitis, are some of the most significant and unavoidable toxicities associated with anti-cancer therapies. For such reason, in the last decades, newer targeted agents have been developed aiming to decrease the rates of side effects on healthy cells. Unfortunately, targeted anti-cancer therapies also showed significant rate of toxicity on healthy tissues. mTOR inhibitors showed some adverse events, such as hyperglycemia, hyperlipidemia, hypophosphatemia, hematologic toxicities, and mucocutaneous eruption, but the most important are still stomatitis and skin rash, often reported as dose-limiting side effects.

PATIENTS AND METHODS

A search of the literature was performed by authors on the PubMed online database using the following key words: "sirolimus" OR "everolimus" OR "temsirolimus" OR "deforolimus" OR "ridaforolimus" combined with the Boolean operator AND with the terms: "stomatitis" OR "mucositis" OR "oral pain." Titles and abstracts of 382 potentially relevant studies were screened; of these, 114 studies were excluded because they did not report the inclusion criteria. In the second round, 268 studies were read full-text, but only 135 reported the inclusion criteria and were included for data extraction. Of the included studies, 95 referred to everolimus use, 16 to ridaforolimus, and 26 to temsirolimus (two studies referred to both everolimus and temsirolimus).

RESULTS

The incidence rate of stomatitis according to the agent used was 25.07% (3,959/15,787) for everolimus, 27.02% (724/2,679) for temsirolimus, and 54.76% (598/1,092) for ridaforolimus. All the three agents analyzed showed high rates of low-grade stomatitis (G1-G2), while the onset of severe stomatitis (G3-G4) was rare.

CONCLUSIONS

Analysis of the reports with patients treated with everolimus, temsirolimus, and ridaforolimus showed a clear prevalence of stomatitis grade 1 or 2. These data differ from that of patients treated with conventional chemotherapy in which mucositis is predominantly of grade 3 or 4.

Breast cancer patients have increased risk of developing mTOR inhibitor-associated stomatitis

A total of 115 patients who used everolimus were evaluated. The mean age was 57 (±13.3) years old, and 87 patients were women (75.6%). mTOR inhibitor-associated stomatitis (mIAS) was observed in 36 patients (31.3%). The lesions ranged from 0.5 cm to 1.5 cm, and the tongue was the main site affected. In addition, 21 patients (58.3%) required a dose reduction of everolimus due to mIAS. Patients who had breast cancer presented 2.29-fold higher risk for developing mIAS when compared to patients with kidney or neuroendocrine tumors. This study emphasizes the high prevalence of mIAS in patients using everolimus, in particular, in patients with breast cancer.

Everolimus-associated stomatitis in a patient who had renal transplant

Everolimus is used as an immunosuppressant in renal allograft transplant rejection and in metastatic breast cancer treatment. One side effect of everolimus is stomatitis, referred to as mammalian target of rapamycin inhibitor-associated stomatitis. This side effect can affect treatment course and contribute to discontinuation of therapy or dose reduction, previously reported in the treatment of metastatic breast cancer. Here, we present a case of everolimus-associated stomatitis with a novel management method with intralesional triamcinolone that allows for continuous course of everolimus.

Oral mucosal injury caused by mammalian target of rapamycin inhibitors: emerging perspectives on pathobiology and impact on clinical practice

In recent years oral mucosal injury has been increasingly recognized as an important toxicity associated with mammalian target of rapamycin (mTOR) inhibitors, including in patients with breast cancer who are receiving everolimus. This review addresses the state-of-the-science regarding mTOR inhibitor-associated stomatitis (mIAS), and delineates its clinical characteristics and management. Given the clinically impactful pain associated with mIAS, this review also specifically highlights new research focusing on the study of the molecular basis of pain. The incidence of mIAS varies widely (2-78%). As reported across multiple mTOR inhibitor clinical trials, grade 3/4 toxicity occurs in up to 9% of patients. Managing mTOR-associated oral lesions with topical oral, intralesional, and/or systemic steroids can be beneficial, in contrast to the lack of evidence supporting steroid treatment of oral mucositis caused by high-dose chemotherapy or radiation. However, steroid management is not uniformly efficacious in all patients receiving mTOR inhibitors. Furthermore, technology does not presently exist to permit clinicians to predict a priori which of their patients will develop these lesions. There thus remains a strategic need to define the pathobiology of mIAS, the molecular basis of pain, and risk prediction relative to development of the clinical lesion. This knowledge could lead to novel future interventions designed to more effectively prevent mIAS and improve pain management if clinically significant mIAS lesions develop.