Koul Rashmi, Dubey Arbind, Butler James, Cooke Andrew L, Abdoh Ahmed, Nason Richard
Department of Radiation Oncology, CancerCare Manitoba, Winnipeg, Manitoba, Canada.
Int J Radiat Oncol Biol Phys. 2007 Jul 1;68(3):714-8. doi: 10.1016/j.ijrobp.2007.01.009. Epub 2007 Mar 29.
To identify significant prognostic factors that can be used in clinical decision-making with regard to parotid cancer, which is characterized by a complex and diverse group of tumors with variable outcomes.
A historical cohort of 184 patients with parotid-gland malignancy, who had been registered in the Province of Manitoba from 1970 to 2003, was examined. Survival analysis was performed using Kaplan-Meier curves and a log-rank test for comparing subgroups. The independent effect of factors that predicted survival at the bivariate level was determined using a Cox proportional hazard model.
The mean age at presentation was 62 years. The mean follow-up was 64 months. Absolute and disease-specific survival at 5 years was 41.70% and 57.94%, respectively. Survival for Stages I-IV at 5 years was 85.35%, 76.9%, 56.1%, and 8.4%, respectively (p < 0.0001). Factors with an independent effect on survival (p < 0.05) included age, tumor size, local invasion (Stages T4 vs. T1), and distant metastasis at presentation, tumor differentiation, and treatment. Adjuvant radiotherapy vs. surgery alone reduced the risk of death from disease at 5 years by 50% (hazard ratio [HR], 0.5; 95% confidence interval, 0.228-0.995; p = 0.0486).
Despite the variety of malignant parotid tumors, easily identifiable prognostic indicators such as advanced age, tumor size, local invasion, and tumor differentiation have a significant impact on outcome. Patients with adverse prognostic factors benefit from adjuvant radiotherapy. The threshold for the use of adjuvant radiotherapy in managing parotid malignancy should be low.
腮腺癌是一组复杂多样、预后各异的肿瘤，本研究旨在确定可用于腮腺癌临床决策的重要预后因素。
对1970年至2003年在曼尼托巴省登记的184例腮腺恶性肿瘤患者的历史队列进行了研究。采用Kaplan-Meier曲线和对数秩检验进行生存分析以比较亚组。使用Cox比例风险模型确定在双变量水平上预测生存的因素的独立作用。
就诊时的平均年龄为62岁。平均随访时间为64个月。5年时的绝对生存率和疾病特异性生存率分别为41.70%和57.94%。I-IV期患者5年生存率分别为85.35%、76.9%、56.1%和8.4%（p<0.0001）。对生存有独立影响（p<0.05）的因素包括年龄、肿瘤大小、局部侵犯（T4期与T1期）、就诊时的远处转移、肿瘤分化程度和治疗方式。辅助放疗与单纯手术相比，可使5年时疾病死亡风险降低50%（风险比[HR]，0.5；95%置信区间，0.228-0.995；p=0.0486）。
尽管腮腺恶性肿瘤种类繁多，但年龄较大、肿瘤大小、局部侵犯和肿瘤分化程度等易于识别的预后指标对预后有显著影响。具有不良预后因素的患者可从辅助放疗中获益。在腮腺恶性肿瘤管理中使用辅助放疗的阈值应较低。
