Objective: To investigate the clinicopathologic features and prognostic factors in oral basaloid squamous cell carcinoma.
Methods: Retrospective analysis of oral basaloid squamous cell carcinomas patients who underwent tumor resection during the period from January 2002 to December 2020 in the authors' hospital, especially the clinicopathologic characteristics of 28 cases with confirmed diagnosis and follow-up data. Immunohistochemistry was performed to define the helpful markers for differentiation diagnosis. The factors influencing the prognosis were evaluated based on Kaplan-Meier method.
Results: The tongue and mouth floor (11 cases, 39.3%) were the most frequently involved sites, followed by gingiva (6 cases, 21.4%), buccal (5 cases, 17.9%), palate (4 cases, 14.3%), and oropharynx (2 cases, 7.1%). The majority of basaloid squamous cell carcinomas were in advanced stage, with 12 cases in stage Ⅱ and 16 cases in stages Ⅲ-Ⅳ. Twelve of 28 patients were identified to have cervical lymph node metastasis, which was confirmed by histopathological examination. The incidence rate of lymph node metastasis was 42.9% (12/28). Nine tumors recurred, with one metastasized to the lung. At the meantime, the 28 conventional squamous cell carcinomas were matched with the same stage, among which 13 cases were identified with cervical lymph node metastasis. The incidence rate of lymph node metastasis was 46.4% (13/28). Five cases recurred, with two cases that metastasized to the lung and one to the brain. The 5-year overall survival rates of the basaloid squamous cell carcinoma and conventional squamous cell carcinoma patients were 54.6% and 53.8%, respectively. Histopathologically, basaloid cells consisted of tumor islands without evident keratinization but frequently with comedo-like necrosis within the tumor islands. CK5/6 and P63 exhibited strongly positive in all the 28 cases, whereas neuroendocrine markers, CgA and Syn, were negative. Eight cases positively expressed P16; one case showed focal SOX10 positive but CK7 negative.
Conclusion: The majority of oral basaloid squamous cell carcinomas present in advanced stage with a high tendency to lymph node metastasis, but the overall survival rates are not significantly different from conventional squamous cell carcinomas matched with the same stage. The human papilloma virus (HPV), as HPV-positivity rate is high, correlates to good prognosis. In addition, CK7 & SOX10 immunohistochemistry could contribute to differential diagnosis for basaloid squamous cell carcinoma with solid adenoid cystic carcinoma.
目的: 回顾性分析基底样鳞状细胞癌临床病理特征及预后相关因素。
方法: 回顾性分析2002年1月至2020年12月在北京大学口腔医学院诊治并经病理确诊为基底样鳞状细胞癌患者的临床病理资料。选取诊断明确且组织学不伴有其他类型杂交瘤，并有明确手术治疗史及完善临床病理资料的基底样鳞状细胞癌28例，分析其临床病理特征，应用免疫组织化学染色筛选可用于鉴别诊断的特异性免疫标记，应用统计学方法进行生存分析，评估预后相关因素，同时随机选取28例临床分期相同的传统鳞状细胞癌患者作为对照组。
结果: 28例基底样鳞状细胞癌最常发生的部位是舌及口底，为11例(11/28，39.3%)，其余牙龈6例(6/28, 21.4%)、颊部5例(5/28, 17.9%)、腭部4例(4/28, 14.3%)、口咽部2例(2/28, 7.1%)。患者多为中晚期，12例为Ⅱ期，16例为Ⅲ~Ⅳ期。经组织病理学检查证实伴淋巴结转移者12例，占总病例数42.9%(12/28)，局部复发者9例，伴远处转移者1例(转移至肺)。28例传统鳞状细胞癌患者中经组织病理学检查证实伴淋巴结转移者13例，占总病例数46.4%(13/28)。局部复发者5例，伴远处转移者3例，其中2例转移至肺、1例转移至脑。临床分期相同的基底样鳞状细胞癌组和传统鳞状细胞癌组患者5年总生存率分别为54.6%、53.8%。基底样鳞状细胞癌组织学上表现为基底样细胞构成的实性癌巢，癌巢中心一般不形成角化，常可见粉刺样坏死结构。28例基底样鳞状细胞癌均呈现CK5/6、P63强阳性表达，而神经内分泌标志物CgA和Syn阴性表达，其中8例呈P16阳性表达，1例局灶阳性表达SOX10，但CK7阴性。
结论: 口腔基底样鳞状细胞癌中晚期患者多见，淋巴结转移率较高，但与相同临床分期的传统鳞状细胞癌总生存率差异无统计学意义；P16阳性患者与人乳头瘤病毒感染相关，预后较好；CK7与SOX10免疫组织化学可用于基底样鳞状细胞癌与实性型腺样囊性癌的鉴别诊断。
Keywords: Adenoid cystic carcinoma; Human papilloma virus; P16; Squamous cell carcinoma.