Anaplastic Thyroid Cancer: Recent Trend Toward Improved Survival

Abstract Background: Anaplastic thyroid carcinoma is a rare malignant tumor of the thyroid. In this study, we summarize the survival changes of Anaplastic thyroid carcinoma in recent years. Methods: Patients with Anaplastic thyroid carcinoma were selected from The Surveillance, Epidemiology, and End Results database (1973-2015). Survival rates were calculated and survival trends were compared among different stage, different years, under surgery and under radiotherapy or not.Results: A total of 1293 patients were enrolled in the study. The 5-year overall survival (OS) for Stage IVA, B and C were 26.6%, 11.7% and 2.5%, respectively. The 5-year cancer-specific survival (CSS) for the same respective stage were 43.5%, 22.3% and 4.9%. After year 1995, the CSS was further improvement (χ2=13.608, P=0.003 for log-rank test) and there was obvious improvement in survival for patients at stage IVB and stage IVC (stage IVB: χ2=12.987, P=0.005, stage IVC: χ2=21.992, P<0.001 for log-rank test). The surgery survival benefit was only observed in Stage IVB (OS: χ2=43.887, P<0.001, CSS: χ2=27.301, P<0.001 for log-rank test) and C (OS: χ2=16.399, P<0.001, CSS: χ2=12.521, P<0.001 for log-rank test). The radiotherapy OS benefit was observed in all different stage(stage IVA: χ2=7.346, P=0.007 for log-rank test, stage IVB: χ2=37.491, P<0.001 for log-rank test，stage IVC: χ2=23.208, P<0.001 for log-rank test) and the CSS benefit was observed in Stage IVB (χ2=18.717, P<0.001 for log-rank test) and C (χ2=12.615, P<0.001 for log-rank test). The median OS of patients with stage IV A receiving surgery, radiotherapy alone and the combination of the two is 4, 5 and 33 months (95% CI: 0.411-7.589, 0.000-10.500, 16.290-49.710, respectively). For Stage IVA patients, compared with the patients received surgery alone, the survival benefit was observed in patients who received surgery and radiotherapy combined (OS: χ2=6.454, P=0.011 for log-rank test). Conclusion: The 5-year cancer-specific survival for Anaplastic thyroid carcinoma was improved in recent years since 1990s. Patients with local metastasis or distant metastasis could benefit from surgery and radiotherapy. For Stage IVA patients, surgery or radiotherapy alone did not improve the cancer-specific survival. Combination of surgery and radiotherapy should get survival benefit.