Division of Surgical Oncology, University Hospitals, Cleveland, OH 44106, USA.
JAMA Dermatol. 2013 Jul;149(7):831-8. doi: 10.1001/jamadermatol.2013.409.
Merkel cell carcinoma (MCC) is a cutaneous neuroendocrine malignant neoplasm that can be highly aggressive and ultimately lethal. However, the cumulatively low incidence rate has made it difficult to accrue patients to prospective randomized trials.
To determine whether patients with MCC in the Surveillance, Epidemiology, and End Results (SEER) database who received radiation therapy after resection demonstrate improved survival.
The study population consisted of SEER patients with histologically confirmed MCC who underwent surgical resection between January 1, 1998, and December 30, 2006. Cox proprotional hazards regression models were used to determine factors associated with MCC-specific and overall survival. Propensity scoring with matched pairs was used to perform Kaplan-Meier survival analysis comparing patients who underwent surgery plus radiation therapy vs those who underwent surgery alone.
National database study of participants at least 20 years old with MCC, matched for age, sex, race/ethnicity, diagnosis period, tumor size, disease stage, surgery of the primary site, type of lymph node surgery, and geographic region. Exclusion criteria included survival of less than 4 months and metastatic disease.
Disease-specific survival and overall survival.
Factors that were independently associated with the use of radiation therapy included marital status, disease stage, and type of lymph node surgery. Factors associated with both MCC-specific and overall survival included age and disease stage. Propensity scoring and matched-pair analysis resulted in 269 matched pairs of patients and demonstrated that patients who received radiation therapy had improved overall survival (P = .03) but not MCC-specific survival (P = .26).
The improvement in overall survival among SEER patients who receive radiation therapy following surgical resection of MCC may be a result of selection bias or unmeasured factors and not radiation therapy.
默克尔细胞癌（MCC）是一种皮肤神经内分泌恶性肿瘤，具有高度侵袭性，最终可能致命。然而，累积发病率较低使得很难为前瞻性随机试验累积患者。
确定接受手术后接受放疗的监测、流行病学和最终结果（SEER）数据库中 MCC 患者的生存是否得到改善。
研究人群包括 1998 年 1 月 1 日至 2006 年 12 月 30 日期间接受手术切除的组织学证实 MCC 的 SEER 患者。使用 Cox 比例风险回归模型确定与 MCC 特异性和总生存率相关的因素。使用倾向性评分和匹配对进行 Kaplan-Meier 生存分析，比较接受手术加放疗与单独接受手术的患者。
至少 20 岁的 MCC 患者的全国性数据库研究，匹配年龄、性别、种族/民族、诊断期、肿瘤大小、疾病分期、原发部位手术、淋巴结手术类型和地理区域。排除标准包括生存时间少于 4 个月和转移性疾病。
疾病特异性生存率和总生存率。
与放疗使用独立相关的因素包括婚姻状况、疾病分期和淋巴结手术类型。与 MCC 特异性和总生存率相关的因素包括年龄和疾病分期。倾向性评分和匹配对分析产生了 269 对匹配患者，表明接受放疗的患者总生存率提高（P =.03），但 MCC 特异性生存率没有提高（P =.26）。
接受手术切除 MCC 后接受放疗的 SEER 患者总生存率的提高可能是选择偏倚或未测量因素的结果，而不是放疗的结果。
