Comparative analysis of the long-term surgical treatment results of noninvasive thymus gland tumors

The study compared the long-term results of thymectomy from traditional “open” thoracic/sternotomic and endovideosurgical access in 98 patients with thymus tumors. All patients were divided into two groups depending on the thymectomies performed from various surgical approaches. The control group consisted of 34 patients in whom surgical interventions were performed via the traditional “open” access, and the main group consisted of 29 patients in whom surgical interventions were performed via the endovideosurgical access. Both groups were comparable by sex, age, concomitant pathology, presence, and severity of clinical signs of myasthenia gravis, tumor size, morphological structure, and progression stage according to the classifications by Masaoka-Koga (1997) and TNM-8 2017. According to the frequency of tumor recurrence and regression of myasthenic disorders within 3 years after surgery, no significant differences were found between the groups (2 (5.9%) and 0, p = 0.27;

9 (69.2%) and 10 (71.4%), p = 0.52, respectively). Moreover, no significantly significant differences were found in the long-term survival (so-called Kaplan–Meier survival function) between the two groups. The annual, 3-, 5- and 10-year survival rates in the control group were 100%, 90.3% ± 2%, 87% ± 4%, and 87% ± 4%, and in the video-assisted thymectomy group, the survival rates were 100%, 100%, 100%, and 92.3% ± 3%, respectively (p = 0.71). In general, the long-term results of endovideosurgical thymectomy with small tumors and the absence of invasion into neighboring anatomical structures do not differ from those of traditional “open” surgical interventions in terms of the main oncological indicators, namely, long-term survival and frequency of tumor recurrence. The obtained results are consistent with world literature data, according to which the most significant prognostic factor of long-term survival is the stage of tumor progression by TNM. The average 5-year survival rates following radical thymectomy were 90%, 90%, 60%, and 25%, respectively, for TNM stages I, II, III, and IV.