Risk Factors for Recurrence after Thymectomy
Sudharsan Madhavan1, Hannah Ng Jia Hui1, Chan Yiong Huak2, Aneez Dokev Basheer Ahmed3, Atasha Asmat3, Ministry of Health Holdings, Singapore1 National University of Singapore, Singapore2 Tan Tock Seng Hospital, Singapore3
OBJECTIVE: Surgical resection is the mainstay of treatment for thymomas and provides the best survival and opportunity for cure. Despite complete resection, some patients will have recurrent disease during the course of follow-up. The aim of this study was to review intermediate and long-term recurrence and identify risk factors.
METHODS: This is a retrospective review of patients who underwent surgical resection of thymoma with curative intent at a single institution between 2013 and 2017. Univariate analysis using Chi-square tests or T-tests were performed. Five-year recurrence was estimated using the Kaplan-Meier method. Log-rank tests were used to determine significance of factors against time to recurrence.
RESULTS: There were 51 patients with a mean age of 58 years. 60.8% were females, nearly half of the patients had myasthenia gravis and 9.8% had a previous history of cancer. Surgical approaches used were robotic-assisted (58.8%), sternotomy (33%) and hemiclamshell (5.9%). Masaoka-Koga stages were as follows: Stage I (11.8%), Stage II (60.8%), Stage III (21.6%), Stage IV (5.9%). The median follow-up duration was 24.5 months. During course of follow up, three patients had recurrence (5.9%). Univariate analysis and log-rank tests revealed male gender, thymic carcinoma (WHO Type C), Masoaka-Koga stage, TNM stage, adjacent organ involvement (phrenic nerve and great vessels), CD5 immunohistochemistry positivity and incompletion of adjuvant therapy were factors associated with shorter time to recurrence (p value<0.05).
CONCLUSIONS: In our patient population, greater attention needs to be given to the identified risk factors for recurrence of thymoma following surgical resection.