Abstract
AB012. Extent of thymectomy in anti-acetylcholine receptor antibody-positive thymoma
Yasufumi Uematsu, Kazuhisa Tanaka, Ryo Karita, Hiroki Imabayashi, Daiki Shimizu, Takahiro Ochi, Takahiro Yamanaka, Jotaro Yusa, Yuki Sata, Takahide Toyoda, Terunaga Inage, Hajime Tamura, Masako Chiyo, Yukiko Matsui, Hidemi Suzuki
Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
Correspondence to: Yasufumi Uematsu, MD, Department of General Thoracic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba 260-8670, Japan. Email: yasufumi.uematsu.76@gmail.com.
Background: Treatment guidelines recommend complete tumor resection and extended thymectomy for myasthenia gravis (MG)-associated thymoma patients. However, the extent of thymectomy for thymoma patients positive only for anti-acetylcholine receptor antibody (anti-AchR antibody) without MG complications remains uncertain. We investigated the effectiveness of extended thymectomy compared with thymomectomy in patients with thymoma who were positive for anti-AchR antibodies alone and had no MG complications.
Methods: We retrospectively reviewed 178 resected thymoma cases from January 2006 to December 2018 at our institution cases positive for preoperative anti-AchR antibodies were analyzed for surgical outcomes and MG incidence.
Results: Seventy-seven cases met the inclusion criteria, with a mean age 55.6 years (range, 20–81 years), an almost equal gender distribution (39 males and 38 females). Sixty cases were MG-positive (MG+) and 17 were MG-negative (MG−). Mean anti-AchR antibody was 38.12 nmol/L (range, 0.4–310 nmol/L). The average tumor diameter was 4.5 cm, predominantly histologically classified as Type A (1 case), AB (20 cases), B1 (12 cases), B2 (36 cases), and B3 (8 cases). The pathological staging revealed stage I in 73 cases and stage III in 4 cases. Sixty-nine patients underwent extended thymectomy, while 8 patients underwent partial thymectomy. Among the latter, 5 were MG-negative, with a mean age of 69.1 years (range, 54–81 years). One MG (−) patient developed MG postoperatively, with an anti-AchR antibody level of 3.0 nmol/L, subsequently undergoing extended thymectomy. The 5-year recurrence-free survival rates were 100% and 87.5% for extended thymectomy and thymomectomy, respectively (P<0.001), with no statistically significant difference observed. Recurrence occurred in 4 cases: 3 with pleural dissemination and 1 with local recurrence. No local recurrence was noted among patients undergoing partial thymectomy. All 4 deaths were attributed to non-thymoma-related causes.
Conclusions: Thymomectomy appears to be a viable surgical approach for anti-AchR antibody-positive MG-negative thymoma cases, as it did not lead to postoperative MG development and showed comparable recurrence rates to extended thymectomy.
Keywords: Thymoma; partial-thymectomy; extended-thymectomy; anti-acetylcholine receptor antibody (anti-AchR antibody); myasthenia-gravis
Acknowledgments
Funding: None.
Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://med.amegroups.com/article/view/10.21037/med-24-ab012/coif). The authors have no conflicts of interest to declare.
Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). The study was approved by Chiba University Hospital Clinical Research Ethics Review Committee (No. 2652) and individual consent for this retrospective analysis was waived.
Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.
doi: 10.21037/med-24-ab012
Cite this abstract as: Uematsu Y, Tanaka K, Karita R, Imabayashi H, Shimizu D, Ochi T, Yamanaka T, Yusa J, Sata Y, Toyoda T, Inage T, Tamura H, Chiyo M, Matsui Y, Suzuki H. AB012. Extent of thymectomy in anti-acetylcholine receptor antibody-positive thymoma. Mediastinum 2024;8:AB012.
