Yoshihide Okumura1,2, Takayuki Murase1, Kosuke Saida1,2, Kana Fujii1, Hisashi Takino1, Ayako Masaki1, Kei Ijichi3, Kazuo Shimozato2, Yuichiro Tada4, Ken-Ichi Nibu5, Hiroshi Inagaki1. 1. Department of Pathology and Molecular Diagnostics, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan. 2. Department of Maxillofacial Surgery, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan. 3. Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan. 4. Department of Head and Neck Oncology and Surgery, International University of Health and Welfare Mita Hospital, Tokyo, Japan. 5. Department of Otolaryngology - Head and Neck Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
Abstract
BACKGROUND: The National Comprehensive Cancer Network (NCCN) guidelines recommend considering postoperative radiotherapy (PORT) for completely resected T1/2N0M0 salivary mucoepidermoid carcinomas when they show tumor spillage, perineural invasion, or intermediate/high-grade histology. CRTC1/3-MAML2 fusions have been associated with a favorable clinical outcome. METHODS: Forty-seven T1/2N0M0 mucoepidermoid carcinoma cases positive for CRTC1/3-MAML2 fusions were completely resected and were not treated with PORT. RESULTS: Pathologically, none of the cases showed tumor spillage or perineural invasion. Cases with intermediate/high-grade histology numbered 9 (19%) to 26 (55%) with the currently used 3 different grading systems. During the follow-up (median 60 months), locoregional tumor recurrence occurred in 4 cases, which were treated with surgery alone. At the last follow-up (median 60 months; 7-160), all patients were alive with no evidence of disease. CONCLUSION: An excellent prognosis may be achieved without PORT in T1/2N0M0 mucoepidermoid carcinoma patients positive for CRTC1/3-MAML2 fusions when the tumors are completely resected without tumor spillage.
BACKGROUND: The National Comprehensive Cancer Network (NCCN) guidelines recommend considering postoperative radiotherapy (PORT) for completely resected T1/2N0M0 salivary mucoepidermoid carcinomas when they show tumor spillage, perineural invasion, or intermediate/high-grade histology. CRTC1/3-MAML2 fusions have been associated with a favorable clinical outcome. METHODS: Forty-seven T1/2N0M0 mucoepidermoid carcinoma cases positive for CRTC1/3-MAML2 fusions were completely resected and were not treated with PORT. RESULTS: Pathologically, none of the cases showed tumor spillage or perineural invasion. Cases with intermediate/high-grade histology numbered 9 (19%) to 26 (55%) with the currently used 3 different grading systems. During the follow-up (median 60 months), locoregional tumor recurrence occurred in 4 cases, which were treated with surgery alone. At the last follow-up (median 60 months; 7-160), all patients were alive with no evidence of disease. CONCLUSION: An excellent prognosis may be achieved without PORT in T1/2N0M0 mucoepidermoid carcinomapatients positive for CRTC1/3-MAML2 fusions when the tumors are completely resected without tumor spillage.
Authors: Stijn van Weert; Birgit I Lissenberg-Witte; Elisabeth Bloemena; C René Leemans Journal: Eur Arch Otorhinolaryngol Date: 2021-08-17 Impact factor: 3.236