Objective: To define the clinical factors that influence local recurrence and survival in patients with lower gingival squamous cell carcinoma (LGSCC) and determine whether bone invasion is an independent prognostic factor for them.
Methods: A total of 104 patients with LGSCC hospitalized in Peking University Stomatology Hospital from June 2013 to December 2015 were enrolled in this retrospective study.All the patients were followed-up for more than 3 years.The degree of bone invasion was assessed using preoperative imaging data (CT and panoramic radiograph).The degree of bone invasion was divi-ded into four categories: no bone invasion, invasion of cortical bone, invasion of bone marrow cavity, and invasion of the mandibular canal.According to the central position of tumor, it was divided into two types: anterior mandibular invasion (anterior region of the mental foramen) and posterior mandibular invasion (posterior region of the mental foramen).
Results: of different invasion depth groups were compared using Mann-Whitney U test.P value < 0.05 was considered to be statistically significant.Kaplan-Meier survival analysis method was used to draw survival curve, and COX regression was used to explore the risk ratio (HR) and 95% confidence interval (CI) of prognostic factors of LGSCC.
Results: The follow-up results showed that the 1-, 3-, and 5-year survival rates of LGSCC in this group were 91%, 84%, 82%, respectively.32.7%(34/104) of patients had cervical lymph node metastasis.The cervical lymph node metastasis rate of the anterior segment of the mandible was 12.5%(2/16), and 36.4%(32/88) for the posterior segment of the mandible (P < 0.05).Univariate and multivariate COX analysis showed that the N stage and local recurrence were the prognostic factors of LGSCC patients (P < 0.05).
Conclusion: As the degree of mandibular invasion increases, the prognosis of patients with mandibular gum cancer becomes worse.N stage and local recurrence are prognostic risk factors for LGSCC.The incidence of cervical lymph node metastasis for LGSCC is related to the primary tumor location.It is concluded that tumors located at the posterior of the mandible might be more prone to cervical lymph node metastasis than the anterior of the mandible.Thus various levels of cervical lymph node dissection strategies should be adopted for different sites of LGSCC.
目的: 分析影响下颌牙龈鳞状细胞癌(lower gingival squamous cell carcinoma, LGSCC)局部复发和生存的因素, 以及不同骨侵犯深度是否是LGSCC的独立预后因素。
方法: 回顾性分析2013年6月至2015年12月于北京大学口腔医院住院治疗的初诊为LGSCC的患者104例, 所有患者随访3年以上。通过术前影像资料(螺旋CT和曲面体层片)评判骨侵犯程度, 分为未侵犯、侵犯骨皮质、侵犯骨髓腔及侵犯下颌管。按照肿瘤中心位置分为下颌骨前段(颏孔前区)和下颌骨后段(颏孔后区)侵犯两类。不同侵犯深度组间比较采用Mann-Whitney U秩和检验, P < 0.05为差异有统计学意义。应用Kaplan-Meier生存分析法绘制生存曲线, 运用COX回归探讨LGSCC预后影响因素的风险比及其95%可信区间(CI)。
结果: 随访结果显示, 104例LGSCC患者术后1年、3年和5年生存率分别为91%、84%, 82%。本组有34例(32.7%)发生颈部淋巴结转移, 下颌骨前段和后段颈部淋巴结转移率分别为12.5%(2/16)和36.4%(32/88)。单因素和多因素COX分析显示, N分期和局部复发是影响预后的独立因素(P < 0.05)。
结论: 下颌骨侵犯程度越严重, 下颌牙龈癌患者预后越差; N分期和局部复发是下颌牙龈癌的预后风险因素。颈部淋巴结转移与肿瘤原发部位相关, 原发部位位于下颌骨后段的LGSCC可在疾病早期发生颈部淋巴结转移, 应采取更积极的颈部淋巴结清扫策略。
Keywords: Gingival neoplasms; Mandible; Neoplasm invasiveness; Prognosis; Squamous cell carcinoma.