Dechaphunkul Arunee, Thongwatchara Phatcharaporn, Thongsuksai Paramee, Dechaphunkul Tanadech, Geater Sarayut Lucien
Holistic Center for Cancer Study and Care (HOCC-PSU), Medical Oncology Unit, Department of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand.
Department of Pathology, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand.
J Pathol Transl Med. 2022 May;56(3):126-133. doi: 10.4132/jptm.2022.01.04. Epub 2022 Feb 28.
Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) mutations have been reported in many cancers, including head and neck squamous cell carcinoma (HNSCC). The frequency of these mutations varies among tumor locations and might be relevant to treatment outcomes among HNSCC. In this study, we examined the frequency of PIK3CA mutations in the different subsites of HNSCC.
Ninety-six fresh biopsy specimens were investigated for mutations in PIK3CA exons 4, 9, and 20 using allele-specific real-time polymerase chain reaction. Patient characteristics and survival were analyzed and compared between specimens with or without PIK3CA mutations.
The study included primary tumors originating from the oral cavity (n=63), hypopharynx (n=23), and oropharynx (n=10). We identified mutations in 10.4% of patients (10 of 96 specimens). The overall mutational frequency was 17.4% (4/23) and 9.5% (6/63) in the hypopharynx and oral cavity, respectively. No patients with oropharyngeal carcinoma had mutations. Among the 10 mutant specimens, five were missense mutations (exon 9 [E545K] in two samples and exon 20 [H1047R] in three samples) and five were silent mutations in exon 20 (T1025T). Mutations were not found in exon 4. Among 84 patients with available clinical data, we found no significant differences in clinical characteristics and survival based on the presence or absence of PIK3CA mutations.
The results indicate that PIK3CA mutations are involved in HNSCC carcinogenesis, and the hypopharynx should be considered a primary site of interest for future studies, particularly in Southeast Asian populations.
磷脂酰肌醇-4,5-二磷酸3-激酶催化亚基α（PIK3CA）突变已在包括头颈部鳞状细胞癌（HNSCC）在内的多种癌症中被报道。这些突变的频率在不同肿瘤部位有所不同，并且可能与HNSCC的治疗结果相关。在本研究中，我们检测了HNSCC不同亚部位中PIK3CA突变的频率。
使用等位基因特异性实时聚合酶链反应检测96份新鲜活检标本中PIK3CA外显子4、9和20的突变情况。分析并比较有或无PIK3CA突变标本的患者特征和生存率。
该研究包括起源于口腔（n = 63）、下咽（n = 23）和口咽（n = 10）的原发性肿瘤。我们在10.4%的患者（96份标本中的10份）中发现了突变。下咽和口腔的总体突变频率分别为17.4%（4/23）和9.5%（6/63）。口咽癌患者均未发生突变。在10份突变标本中，5份为错义突变（2份样本中外显子9 [E545K]，3份样本中外显子20 [H1047R]），5份为外显子20的沉默突变（T1025T）。外显子4未发现突变。在84例有可用临床数据的患者中，我们发现基于PIK3CA突变的存在与否，临床特征和生存率无显著差异。
结果表明PIK3CA突变参与HNSCC的致癌过程，下咽应被视为未来研究的主要关注部位，尤其是在东南亚人群中。
