Successful targeted therapy in treatment of non-resectable refractory squamous cell cancer of nasal cavity with mutation in PTCH1 gene

Cancer of the nasal mucosa is a malignant tumor originating from the mucous epithelium of the nasal cavity or paranasal sinuses. Nasal and paranasal sinus cancer accounts for 1.4 % of all malignancies and 3–5 % of head and neck tumors. males are twice as likely to be affected as females, particularly those aged 55 years and older (nearly 80 % of cases). The five-year survival rate is 8 2 % in patients with stage I disease and 43 % in patients with stage Iv disease. Despite the advances in the diagnosis of nasal cancer, over 80 % of new patients are diagnosed with stage III–Iv disease because of nonspecific symptoms in early (I and II) stages. Traditional treatment methods (including surgery, radiation therapy and chemotherapy) often allow us to achieve complete recovery in patients with this disorder. However, in most patients with locally advanced cancer, this approach has a limited effectiveness and is often associated with severe side effects. Considering frequent progression of nasal squamous cell carcinomas on standard regimens, it is necessary to search for new treatment targets to improve outcomes. Extensive molecular testing using multigenic panels based on next-generation sequencing can be helpful in this case. The most common mutations in nasal cancers occur in five genes: TP53 (up to 80 % of cases), EGFR (up to 77 % of cases), IDH2 (approximately 55 % of cases), PIK3CA (14 % of cases), and CDKN2A (9 % of cases). we report a case of successful treatment of a patient with locally advanced, non-resectable, drug-resistant nasal squamous cell carcinoma with a rare driver mutation.