Rapid Response Radiotherapy Program, Department of Radiation Oncology, Odette Cancer Centre, University of Toronto, Toronto, ON.
Curr Oncol. 2008 Oct;15(5):211-8. doi: 10.3747/co.v15i5.289.
Symptom clusters (scs) are a dynamic construct. They consist of at least 2 or 3 interrelated symptoms that may be a significant predictor of patient morbidity. In a previous study, we identified 2 scs in patients with bone metastases: An activity-related interference cluster, psychology-related interference cluster. These scs may be clinically important in the pain and symptom management of patients with metastatic bone pain. It is therefore important to validate the reported scs to determine if they hold true across similar patient populations.
From February to September 2007, our study accrued 52 patients with bone metastases [29 men (56%), 23 women (44%); median age: 68.5 years (range: 39-87 years)] who were referred for palliative radiotherapy (rt). Prostate (31%), breast (29%), and lung (19%) were the most common primary cancer sites. Treatment arms ranged from single to multiple fractions, with most patients receiving a single 8-Gy fraction (77%) or 20 Gy in 5 fractions (21%). The most prevalent sites for rt were spine (42%), hips (17%), and pelvis (14%). Worst pain at the site of rt and functional interference scores were assessed using the Brief Pain Inventory (BPI), a multidimensional pain instrument that uses 11-point numeric rating scales. Patients provided their symptom severity scores on the BPI at baseline and at 4, 8, and 12 weeks post rt. At all time points, a principal component analysis with varimax rotation was performed on 8 items (worst pain and 7 functional interference items) to determine relationships between symptoms before and after rt for bone pain.
Two scs were identified. Cluster 1 included worst pain and interference with general activity, normal work, and walking ability; cluster 2 consisted of interference with mood, sleep, enjoyment of life, and relations with others. Our statistical analysis produced varied results for the 2 clusters found in our previous investigation. These differences may be an indicator for the instability of scs or may be a result of the fewer number of patients accrued in the present validation study.
The scs in our two studies were not identical for patients receiving palliative rt for symptomatic bone metastases. Another sc validation study should be conducted with a larger sample before a conclusion is drawn about the existence of an unstable phenomenon in sc research.
症状群（SCs）是一个动态的概念。它们由至少 2 个或 3 个相互关联的症状组成，可能是患者发病率的重要预测因素。在之前的研究中，我们在患有骨转移的患者中确定了 2 个 SCs：与活动相关的干扰群、与心理相关的干扰群。这些 SCs 在转移性骨痛患者的疼痛和症状管理中可能具有重要的临床意义。因此，验证报告的 SCs 以确定它们是否在类似的患者群体中成立非常重要。
2007 年 2 月至 9 月，我们的研究纳入了 52 名患有骨转移的患者[29 名男性（56%），23 名女性（44%）；中位年龄：68.5 岁（范围：39-87 岁）]，他们因姑息性放疗（RT）而就诊。前列腺（31%）、乳房（29%）和肺（19%）是最常见的原发癌部位。治疗臂的范围从单次到多次分割，大多数患者接受单次 8 Gy 分割（77%）或 20 Gy 分 5 次（21%）。RT 最常见的部位是脊柱（42%）、臀部（17%）和骨盆（14%）。使用 Brief Pain Inventory（BPI）评估 RT 部位的最严重疼痛和功能干扰评分，BPI 是一种多维疼痛工具，使用 11 点数字评分量表。患者在基线和 RT 后 4、8 和 12 周时在 BPI 上提供他们的症状严重程度评分。在所有时间点，对 8 个项目（最严重疼痛和 7 个功能干扰项目）进行主成分分析和方差极大旋转，以确定 RT 前后骨痛症状之间的关系。
确定了 2 个 SCs。集群 1 包括最严重的疼痛和对一般活动、正常工作和行走能力的干扰；集群 2 由情绪、睡眠、生活乐趣和与他人的关系干扰组成。我们的统计分析对我们之前研究中发现的 2 个集群产生了不同的结果。这些差异可能是 SCs 不稳定的指标，也可能是本验证研究中纳入的患者数量较少的结果。
接受姑息性 RT 治疗有症状骨转移的患者的 2 个 SCs 并不相同。在得出 SC 研究中存在不稳定现象的结论之前，应该进行另一个 SC 验证研究，以获得更大的样本量。
