Division of Cancer Services, Princess Alexandra Hospital, University of Queensland, Brisbane, Queensland, Australia.
Int J Radiat Oncol Biol Phys. 2010 Jul 1;77(3):677-84. doi: 10.1016/j.ijrobp.2009.05.067. Epub 2009 Nov 10.
To assess the effect of radiotherapy (RT) dose and volume on relapse patterns in patients with Stage I-III Merkel cell carcinoma (MCC).
This was a retrospective analysis of 112 patients diagnosed with MCC between January 2000 and December 2005 and treated with curative-intent RT.
Of the 112 evaluable patients, 88% had RT to the site of primary disease for gross (11%) or subclinical (78%) disease. Eighty-nine percent of patients had RT to the regional lymph nodes; in most cases (71%) this was for subclinical disease in the adjuvant or elective setting, whereas 21 patients (19%) were treated with RT to gross nodal disease. With a median follow-up of 3.7 years, the 2-year and 5-year overall survival rates were 72% and 53%, respectively, and the 2-year locoregional control rate was 75%. The in-field relapse rate was 3% for primary disease, and relapse was significantly lower for patients receiving >or=50 Gy (hazard ratio [HR] = 0.22; 95% confidence interval [CI], 0.06-0.86). Surgical margins did not affect the local relapse rate. The in-field relapse rate was 11% for RT to the nodes, with dose being significant for nodal gross disease (HR = 0.24; 95% CI, 0.07-0.87). Patients who did not receive elective nodal RT had a much higher rate of nodal relapse compared with those who did (HR = 6.03; 95% CI, 1.34-27.10).
This study indicates a dose-response for subclinical and gross MCC. Doses of >or=50 Gy for subclinical disease and >or=55 Gy for gross disease should be considered. The draining nodal basin should be treated in all patients.
评估Ⅰ-Ⅲ期 Merkel 细胞癌（MCC）患者的放疗剂量和体积对复发模式的影响。
这是一项对 2000 年 1 月至 2005 年 12 月期间确诊为 MCC 并接受根治性放疗的 112 例患者进行的回顾性分析。
在 112 例可评估患者中，88%的患者因原发部位的明显（11%）或亚临床（78%）疾病接受了放疗。89%的患者接受了区域淋巴结放疗；在大多数情况下（71%），这是为了辅助或选择性治疗亚临床疾病，而 21 例（19%）患者接受了放疗治疗明显的淋巴结疾病。中位随访 3.7 年后，2 年和 5 年总生存率分别为 72%和 53%，2 年局部区域控制率为 75%。原发疾病的场内复发率为 3%，接受>50 Gy 放疗的患者复发率明显较低（危险比[HR] = 0.22；95%置信区间[CI]，0.06-0.86）。手术切缘不影响局部复发率。淋巴结放疗的场内复发率为 11%，对于淋巴结明显疾病，剂量有显著影响（HR = 0.24；95%CI，0.07-0.87）。未接受选择性淋巴结放疗的患者与接受选择性淋巴结放疗的患者相比，淋巴结复发率更高（HR = 6.03；95%CI，1.34-27.10）。
本研究表明亚临床和明显 MCC 存在剂量反应。对于亚临床疾病，应考虑>50 Gy 的剂量，对于明显疾病，应考虑>55 Gy 的剂量。所有患者都应治疗引流淋巴结区。
