[Analysis of factors affecting long-term survival in patients with anaplastic thyroid carcinoma and the efficacy of immunotherapy].

Objective: To explore the long-term survival outcomes of patients with anaplastic thyroid cancer (ATC) and analyze key factors influencing the prognosis. Methods: A retrospective analysis was conducted on the clinical and follow-up data of 77 ATC patients treated at the Sun Yat-sen University Cancer Center from March 2000 to July 2022, with tumor-specific survival as the primary endpoint. The Kaplan-Meier method was used to plot the survival curves, and univariate and multivariate Cox regression analyses were performed to identify the prognostic factors. Results: Among the 77 patients, 64 underwent surgical treatment, with 33 receiving surgery alone, 8 undergoing surgery combined with chemotherapy, 13 undergoing surgery with radiotherapy, 1 undergoing surgery with chemotherapy and radiotherapy, 2 receiving surgery combined with chemotherapy and targeted therapy, 3 receiving surgery with targeted therapy, and 4 receiving surgery with immunotherapy and targeted therapy. Among the 13 patients who did not undergo surgery, 2 received chemotherapy alone, 3 received targeted therapy alone, 1 received immunotherapy alone, 1 received chemoradiotherapy, 5 received chemotherapy combined with immunotherapy, and 1 received immunotherapy combined with targeted therapy. The median follow-up time was 8.4 months, with 58 patients (75.3%) died, and the median survival time was 6.63 months. Univariate Cox regression analysis showed that C-reactive protein, monocyte count, lymphocyte count, abnormal albumin levels, the maximum diameter of the primary tumor, BMI, and whether immunotherapy was administered were significantly associated with survival in ATC patients (all P＜0.05). Multivariate Cox regression analysis indicated that immunotherapy was an independent factor for survival in ATC patients (HR=0.18, 95% CI: 0.05-0.62, P=0.007). Among the 40 patients admitted after 2015, the 11 patients who received immunotherapy had a median survival time of 17.2 months, which was superior to the 29 patients who did not receive this treatment (median survival time 6.2 months, P=0.03). Conclusions: ATC patients receiving immunotherapy had a better prognosis and longer survival. Additionally, elevated C-reactive protein, abnormal albumin, monocyte count, lymphocyte count, and BMI might be associated with poorer prognosis in ATC. Tailoring treatment based on the individual characteristics of ATC patients may be beneficial for their long-term survival.