[Results of surgical treatment of skull-base primary malignant tumors with intracranial invasion].

Objective: Analysis of factors affecting life expectancy at patients with primary malignant tumors of anterior and middle parts of the skull base with intracranial invasion.

Material And Methods: 139 patients (47 women and 92 men) with primary malignant tumors of the anterior and middle parts of the skull base with intracranial invasion (stage T4 according to TNM classification or stage C according to Kadish classification for estesioneuroblast ) were treated at the NMRCN Burdenko for the period from 2004 till 2018. The study was conducted by the method of total sampling. The observations are divided into 2 groups: primarily operated (group I) and repeatedly operated (group II).

Results: The average age in both groups was 50 years. In most (64.7%) cases, the tumor affected the medial sections of the base of anterior and middle cranial fossae, and in 35.3% of cases it was localized laterally. All tumors were classified to T4 stage according to TNM classification or (9 olfactory neuroblastomas) to stage C according to Kadish classification.

Discussion: The impact on life expectancy was largely provided by postoperative radiation therapy, the repeated nature of operation, and the presence of brain infiltration. In the total cohort of patients 5-year OS, 5-year RVS, 5-year-old IDF and 5-year LC were 50.7, 35, 54.2 and 36.4%, respectively. In group I, the medians OS and IDF were equal and amounted to 138.3 months. The median RVS was 43.8 months. 5-year OS equal to 63.6%, 5-year RVS - 40.8%, 5-year-IDF - 64.8%, 5-year LC was up to 65.7%. The survival rate in the analyzed cohort for 1, 2, 3 years was 81.4, 71.8 and 67.8%, respectively. In group II, the treatment results for the group of repeatedly treated patients were significantly worse. There were no cases of 5-year survival. The 1-, 2-, and 3-year survival rates were 59.3, 50.8 and 31.8%, respectively. The median OS was 27.1 months, IDF was 27.1 months, RVS was 18.2 months, and LC was 9.1 months.

Conclusion: The results and analysis of literature justify the feasibility of surgical treatment of patients with malignant tumors of craniofacial localization at T4 stage. The purpose of surgical intervention should be: elimination of the immediate threat to the patient's life due to edema and dislocation of the brain; the maximum possible removal of tumor tissue (cytoreduction); if possible, the elimination of the most significant symptoms for the patient (pain, nasal breathing disorders, cosmetic defect). If there are special reserves, it is obligatory to include radiation and chemotherapy in the treatment process.