Long-Term Follow-Up on Systemic Bevacizumab Treatment in Recurrent Respiratory Papillomatosis.

OBJECTIVES/HYPOTHESIS: Recurrent respiratory papillomatosis (RRP) is a primarily benign disease affecting the entire respiratory tract. Treatment is challenging and usually involves surgical interventions and adjuvant medications. Previously, promising results on systemic administration of bevacizumab have been reported. However, experience on long-term systemic use in patients with RRP is not yet available. Here, we present our long-term follow-up on RRP patients undergoing systemic bevacizumab treatment. STUDY DESIGN: Case series. METHODS: To describe experience on long-term systemic bevacizumab administration, we performed the underlying investigation. Clinical, radiological, and bronchoscopy data were collected. RESULTS: To date, a total of n = 5 patients has been treated with systemic bevacizumab at Muenster University Hospital. With a median follow-up since first systemic bevacizumab administration of 95.5 months long-term follow-up is illustrated. Following bevacizumab treatment partial remission or very good partial remission were achieved in all patients. After papilloma recurrence/progression due to bevacizumab discontinuation, further response was documented in all patients in whom bevacizumab was started again. In one patient, bevacizumab was discontinued due to loss of efficacy. Lung cancer developed in one patient with pulmonary papillomatosis prior to bevacizumab administration whereas three patients suffered from malignant transformation during bevacizumab treatment. Systemic bevacizumab led to long-term reduction in surgical interventions in all patients. Except from mild proteinuria and hypertension in two patients therapy was well tolerated. CONCLUSIONS: Systemic bevacizumab represents a promising long-term treatment option for aggressive forms of papillomatosis. Rate of malignant transformation under bevacizumab treatment, optimal treatment schedule, and influence on survival should be further evaluated in clinical trials. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1926-E1933, 2021.

Progressive Multifocal Leukoencephalopathy after Ibrutinib Therapy for Chronic Lymphocytic Leukemia.

Progressive multifocal leukoencephalopathy (PML) is a devastating neurological disease observed nearly exclusively in immunocompromised patients. Recently, the introduction of monoclonal antibodies significantly inhibiting the immune system such as rituximab has led to an increase in PML cases. Although rituximab-based immunochemotherapy remains the standard of treatment for chronic lymphocytic leukemia (CLL), the importance of Bruton's tyrosine kinase inhibitors such as ibrutinib is steadily increasing. However, long-term experiences regarding possible side effects of these new substances are rare. Here, we report the development of eventually fatal PML possibly associated with ibrutinib therapy for CLL after multiple prior treatment lines, including rituximab. To the best of our knowledge, this is the first study to report such findings. Since the last course of rituximab was applied over 3 years ago, it is conceivable that the strong B cell inhibition by ibrutinib led to PML. With increased awareness of this potential side effect, further clinical studies are certainly warranted to evaluate this possible association.

Prostate specific membrane antigen (PSMA) expression in non-small cell lung cancer.

OBJECTIVES: PSMA (prostate-specific membrane antigen) is overexpressed in prostate cancer cells and is reported to be a promising target for antibody-based radioligand therapy in patients with metastasized prostate cancer. Since PSMA expression is not restricted to prostate cancer, the underlying study investigates PSMA expression in non-small cell lung cancer (NSCLC). MATERIAL AND METHODS: Immunohistochemistry was used to identify PSMA expression in n = 275 samples of NSCLC tissue specimens. By means of CD34 co-expression, the level of PSMA expression in tumor associated neovasculature was investigated. The impact of PSMA expression on clinicopathologic parameters and prognosis was evaluated. RESULTS: PSMA tumor cell expression in NSCLC is as low as 6% and was predominantly found in squamous cell carcinoma (p = 0.002). Neovascular PSMA expression was found in 49% of NSCLC. High neovascular PSMA expression was associated with higher tumor grading (G3/G4) (p < 0.001). Neither for PSMA tumor cell expression, nor for PSMA neovascular cell expression prognostic effects were found for the investigated NSCLC cases. CONCLUSION: Here, we report on the expression of PSMA in NSCLC tissue samples. Against the background of a potential treatment with radiolabeled PSMA ligands, our data might serve for the future identification of patients who could benefit from this therapeutic option.