Lawenda Brian D, Arnold Michelle G, Tokarz Valerie A, Silverstein Joshua R, Busse Paul M, McIntyre James F, Deschler Daniel G, Baldini Elizabeth H, Kachnic Lisa A
Department of Radiation Oncology, Naval Medical Center San Diego, San Diego, CA 92134-1014, USA.
Ear Nose Throat J. 2008 Nov;87(11):634-43.
Merkel cell carcinoma (MCC) is a rare and aggressive epidermal cancer. We conducted a retrospective study and literature review to investigate the impact that radiation therapy has on local, regional, and distant control as part of the oncologic management of MCC of the head and neck and to further elucidate the role of radiation therapy with regard to regional control for the clinically uninvolved neck. We reviewed all registered cases of head and neck MCC that had occurred at four institutions from January 1988 through December 2005. Treatment and outcomes data were collected on patients with American Joint Committee on Cancer stage I, II, and III tumors. Local, regional, and distant control rates were calculated by comparing variables with the Fisher exact test; Kaplan-Meier analysis was used to report actuarial control data. Stage I to III head and neck MCC was identified in 36 patients-22 men and 14 women, aged 43 to 97 years (mean: 71.6) at diagnosis. Patients with stage I and II tumors were combined into one group, and their data were compared with those of patients with stage III tumors. Twenty-six patients (72%) had clinical stage I/II disease and 10 patients (28%) had clinical stage III disease. Median follow-up was 41 months for the stage I/II group and 19 months for the stage III group. Based on examination at final follow-up visits, local recurrence was seen in 7 of the 36 patients (19%), for a local control rate of 81%. The 2-year actuarial local control rate for all stages of MCC was 83%; by treatment subgroup, the rates were 95% for those who had undergone radiation therapy to the primary site and 69% for those who had not-a statistically significant difference (p = 0.020). Based on information obtained at final follow-ups, 10 of the 36 patients (28%) experienced a regional recurrence, for a regional control rate of 72%. The 2-year actuarial regional control rate among all patients was 70%; by subgroup, rates were 82% for patients who had undergone regional node radiation therapy and 60% for those who had not-not a statistically significant difference (p = 0.225). Nine patients (25%) overall developed a distant metastasis, for a distant control rate of 75%. Salvage therapies included chemotherapy and/or radiation therapy to the metastatic site, but neither had any significant effect on survival. Regardless of treatment, the Kaplan-Meier survival curves leveled off at 30 months with 82% survival for the stage I/II group and at 19 months with 60% survival for the stage III group. We conclude that radiation therapy to the primary tumor site (either following resection or definitively) results in a local control rate of more than 90% in patients with head and neck MCC. We also found a trend toward improved regional control of the clinically negative neck with the addition of radiation therapy.
默克尔细胞癌（MCC）是一种罕见且侵袭性强的表皮癌。我们进行了一项回顾性研究并查阅了文献，以调查放射治疗对头颈部MCC肿瘤管理中局部、区域和远处控制的影响，并进一步阐明放射治疗在临床上未受累颈部区域控制方面的作用。我们回顾了1988年1月至2005年12月在四家机构发生的所有登记的头颈部MCC病例。收集了美国癌症联合委员会I期、II期和III期肿瘤患者的治疗及预后数据。通过Fisher精确检验比较变量来计算局部、区域和远处控制率；采用Kaplan-Meier分析报告精算控制数据。确诊时，36例患者被诊断为I至III期头颈部MCC，其中22例男性和14例女性，年龄43至97岁（平均71.6岁）。I期和II期肿瘤患者合并为一组，其数据与III期肿瘤患者的数据进行比较。26例患者（72%）为临床I/II期疾病，10例患者（28%）为临床III期疾病。I/II期组的中位随访时间为41个月，III期组为19个月。根据末次随访检查，36例患者中有7例（19%）出现局部复发，局部控制率为81%。MCC所有阶段的2年精算局部控制率为83%；按治疗亚组划分，原发部位接受放射治疗的患者为95%，未接受放射治疗的患者为69%，差异有统计学意义（p = 0.020）。根据末次随访获得的信息，36例患者中有10例（28%）出现区域复发，区域控制率为72%。所有患者的2年精算区域控制率为70%；按亚组划分，接受区域淋巴结放射治疗的患者为82%，未接受放射治疗的患者为60%，差异无统计学意义（p = 0.225）。总体有9例患者（25%）发生远处转移，远处控制率为75%。挽救性治疗包括对转移部位进行化疗和/或放射治疗，但两者对生存率均无显著影响。无论治疗情况如何，Kaplan-Meier生存曲线在30个月时趋于平稳，I/II期组生存率为82%，在19个月时III期组生存率为60%。我们得出结论，对头颈部MCC患者，对原发肿瘤部位进行放射治疗（无论是在切除后还是根治性治疗）可使局部控制率超过90%。我们还发现，增加放射治疗有改善临床上阴性颈部区域控制的趋势。
