Lapatinib as first-line treatment for muscle-invasive urothelial carcinoma in dogs.

Epidermal growth factor receptors 1 and 2 (EGFR and HER2) are frequently overexpressed in various malignancies. Lapatinib is a dual tyrosine kinase inhibitor that inhibits both EGFR and HER2. Although a phase III trial failed to show the survival benefits of lapatinib treatment after first-line chemotherapy in patients with EGFR/HER2-positive metastatic urothelial carcinoma, the efficacy of lapatinib for untreated urothelial carcinoma is not well defined. Here, we describe the therapeutic efficacy of lapatinib as a first-line treatment in a canine model of muscle-invasive urothelial carcinoma. In this non-randomized clinical trial, we compared 44 dogs with naturally occurring urothelial carcinoma who received lapatinib and piroxicam, with 42 age-, sex-, and tumor stage-matched dogs that received piroxicam alone. Compared to the dogs treated with piroxicam alone, those administered the lapatinib/piroxicam treatment had a greater reduction in the size of the primary tumor and improved survival. Exploratory analyses showed that HER2 overexpression was associated with response and survival in dogs treated with lapatinib. Our study suggests that lapatinib showed encouraging durable response rates, survival, and tolerability, supporting its therapeutic use for untreated advanced urothelial carcinoma in dogs. The use of lapatinib as a first-line treatment may be investigated further in human patients with urothelial carcinoma.

Efficacy of chemotherapy and palliative hypofractionated radiotherapy for cats with nasal lymphoma.

Nasal lymphoma (NL) is the most common nasal tumor in cats, and radiotherapy, chemotherapy, or a combination of these treatments have been described as the treatment for this disease. However, the previous studies included various machines and protocols of radiotherapy. Therefore, we aimed to retrospectively compare the prognosis among cases treated with palliative hypofractionated radiotherapy, chemotherapy, and a combination of them with united machine and protocol of radiotherapy. When compared overall survival and progression free survival, there was no significant difference among these three groups. The data of this study suggested that similar efficacy could be achieved by palliative hypofractionated radiotherapy, chemotherapy, or a combination of them.

Foxp3+ Regulatory T Cells Associated With CCL17/CCR4 Expression in Carcinomas of Dogs.

Regulatory T cells (Tregs) can be targeted in cancer immunotherapy. A previous study has shown that the chemokine CCL17 and the receptor CCR4 play a role in Treg recruitment in canine urothelial carcinoma. Here, we describe the association of tumor-infiltrating Tregs with CCL17/CCR4 expression in dogs with other carcinomas. In this study, we investigated 23 dogs with mammary carcinoma, 14 dogs with oral squamous cell carcinoma, 16 dogs with pulmonary adenocarcinoma, and 8 healthy control dogs. Immunohistochemistry showed that Foxp3+ Tregs and CCR4+ cells were increased in the tumor tissues of mammary carcinoma, squamous cell carcinoma, and pulmonary adenocarcinoma, when compared with the healthy tissues. The number of CCR4+ cells was associated with that of Foxp3+ Tregs. Double immunofluorescence labeling confirmed that most tumor-infiltrating Foxp3+ Tregs expressed CCR4. In vitro, canine carcinoma cell lines expressed CCL17 mRNA. Quantitative RT-PCR (reverse transcriptase-polymerase chain reaction) showed that CCL17 mRNA expression in canine carcinomas was increased approximately 10- to 25-fold relative to that of healthy tissues. These results suggest that the CCL17/CCR4 axis may drive Treg recruitment in a variety of canine carcinomas. CCR4 blockade may be a potential therapeutic option for tumor eradication through Treg depletion.

Successful rituximab treatment of granulomatosis with polyangiitis with cranial neuropathies.

BACKGROUND: In granulomatosis with polyangiitis (GPA), peripheral nerve involvement is common but central nervous system (CNS) involvement is extremely rare and treatment strategy has not been established. We report a case of intravenous cyclophosphamide (IVCY)-resistant GPA with associated cranial neuropathies that was successfully treated with rituximab (RTX). CASE PRESENTATION: A 37-year-old man with intractable sinusitis had several months of headache, hoarseness, and dysphagia; a month of right-sided deafness and nasal bleeding; and a week of dysarthria, steppage gait, and numbness in the right L5 distribution. A magnetic resonance imaging (MRI) examination of the head showed an infiltrative lesion in the right skull base encasing the carotid sheath. Computed tomography (CT) scan of the chest revealed a 23 mm nodule in the left upper lobe. Histology was inconclusive. Therefore, the patient was diagnosed as GPA. He was treated with glucocorticoids (GC) and IVCY. Three months later, he was readmitted for recurrence of headache and new left-sided hearing loss. He was treated with GC and RTX, and a 1-year remission followed. The molecular mechanism of RTX is not fully understood. In this case, RTX was more effective at rapidly and strongly suppressing B cells than CY. Since the B cell count was proportional to the patient's clinical manifestations, B cells might represent a suitable target for the treatment of GPA with cranial neuropathies. CONCLUSIONS: GPA with cranial neuropathies might be useful with RTX as induction therapy.