CASE REPORT article
Front. Oncol.
Sec. Head and Neck Cancer
This article is part of the Research TopicAdvancements in Personalized Medicine for Head and Neck Cancer: Molecular-based Approaches to Treatment and CareView all 22 articles
Development of a Second Primary Tumor During Maintenance Immunotherapy in Metastatic Gingival Squamous Cell Carcinoma: A Case Report
Provisionally accepted
- 1Loudi Central Hospital, Loudi, China
- 2The Second Xiangya Hospital of Central South University Department of Oncology, Changsha, China
- 3The Second Xiangya Hospital of Central South University Department of Geriatrics, Changsha, China
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Multiple primary tumors are defined as two or more distinct malignancies occurring simultaneously or metachronously in the same patient. This report describes a patient with extensively metastatic gingival squamous cell carcinoma who achieved radiologic complete remission (CR) through combined immunotherapy,chemotherapy, and local radiotherapy. The patient continued immunotherapy maintenance for 38 months. Two years after CR, a second primary tumor emerged. The second tumor was surgically resected, followed by postoperative maintenance therapy with oral Tegafur-Gimeracil-Oteracil (S-1) capsules. As of the last follow-up on January 14, 2025, nearly two years after the second surgery, the patient showed no local recurrence or distant metastasis. This case suggests that while immunotherapy provided excellent overall tumor control, it failed to prevent the occurrence of the second primary tumor. Whether prolonged immunotherapy (38 months vs. the standard 24 months) positively impacts patient prognosis requires further exploration. This case highlights that even after achieving CR with immunotherapy, vigilance for the development of second primary tumors during maintenance therapy is crucial.
Keywords: case report, Gingival squamous cell carcinoma (GSCC), Head and neck squamous cell carcinoma (HNSCC), Immunotherapy, second primary tumors (SPTs)
Received: 16 Nov 2025; Accepted: 16 Feb 2026.
Copyright: © 2026 Liu, Sun, Chen, He, Ouyang and Liu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Min Ouyang
Ping Liu
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.