Department of Otolaryngology/Head and Neck Surgery, University of Florence, Florence, Italy.
Cancer. 2010 Mar 1;116(5):1291-7. doi: 10.1002/cncr.24854.
In the attempt to characterize the genetic bases of recurrent head and neck squamous cell carcinoma (HNSCC) after radiotherapy (RT), the authors compared the molecular profiles of primary tumors and recurrences.
TP53 gene status and instability at 10 microsatellite markers were determined in pre-RT lesions and corresponding local recurrences in a series of 16 HNSCCs.
Eight (50%) HNSCCs showed both TP53 and microsatellite instability (MSI) status concordance in pre- and postirradiation biopsies; 3 (18.7%) showed discordance of both TP53 and MSI status; and finally 5 (31.2%) had discordance at only 1 genetic test. Accordingly, the authors interpreted as true recurrence the 8 concordant cases, and as true second primary malignancies the 3 discordant ones. In the remaining 5 cases with partial DNA correspondence, the exact nature of the new lesion only partially related to the original cancer is a matter of discussion. Patients showing the same mutations among pre- and post-RT HNSCCs had a longer disease-free interval (DFI) and better survival than those showing discordant genetic features (log-rank test, P = .0045).
Post-RT recurrent HNSCCs are genetically heterogeneous. The genetic characterization of the recurrence, especially in those cases with a particularly short DFI showing partially discordant mutations, might have a useful clinical relevance in the restaging process.
为了研究放疗后复发性头颈部鳞状细胞癌（HNSCC）的遗传基础，作者比较了原发性肿瘤和复发性肿瘤的分子谱。
作者在 16 例 HNSCC 患者中，在放疗前病变和相应的局部复发中，比较了 TP53 基因状态和 10 个微卫星标记物的不稳定性。
8 例（50%）HNSCC 在放疗前和放疗后活检中 TP53 和微卫星不稳定性（MSI）状态一致；3 例（18.7%）TP53 和 MSI 状态均不一致；最后 5 例（31.2%）仅在 1 个基因检测中存在不一致。因此，作者将 8 例一致的病例解释为真正的复发，3 例不一致的病例解释为真正的第二原发恶性肿瘤。在其余 5 例 DNA 部分相符的病例中，新病变的性质与原发性肿瘤部分相关，这是一个需要讨论的问题。在 HNSCC 中，TP53 相同突变的患者无复发生存期（DFS）更长，生存率更高，而基因特征不一致的患者则较差（对数秩检验，P =.0045）。
放疗后复发性 HNSCC 具有遗传异质性。对复发性肿瘤进行遗传特征分析，特别是在 DFI 特别短且显示部分不一致突变的病例中，可能对重新分期过程具有有用的临床意义。
