Determining the clinical significance of monoclonal gammopathy of undetermined si

描述（由申请人提供）：多发性骨髓瘤（MM）之前均伴有意义不明的单克隆丙种球蛋白病（MGUS）。虽然MGUS的生物学意义已经确定，但其临床意义尚未确定。MGUS通常在具有提示MM和相关恶性肿瘤的体征或症状的患者的检查期间偶然发现。MGUS的患病率很高（50岁和70岁以上人群中分别有3%和5%），但转化为MM和相关恶性肿瘤的风险非常低（考虑到竞争性死亡原因后，每年为0.4%）。然而，专家建议对MGUS患者进行无限期的年度随访，进行体格检查和实验室检查，即使目前没有可用的治疗方法可以预防恶性转化，也没有证据表明这种随访有助于改善临床结果。事实上，由于癌症预期，随访可能对患者造成心理困扰，可能对医疗保健系统造成巨大的经济负担（2008年有360万人患有MGUS），并且可能减少癌症护理的获得（美国临床肿瘤学会预测到2020年将缺少4000名血液学家-肿瘤学家）。因此，必须确定MGUS的临床意义。为了实现这一目标，并利用监测流行病学和最终结果（SEER）计划和相关的医疗保险数据，我们的研究有2个具体目标。在目标1中，我们将确定初治MM和相关恶性肿瘤患者与既往诊断为MGUS的患者之间的总体和疾病特异性生存期是否存在差异。在目标2中，我们将比较这两组之间主要癌症并发症（高钙血症、骨折和透析依赖性肾病）的发生率。在目标3中，我们将确定各种MGUS随访策略对临床结局的影响。我们将使用监测流行病学和最终结果（SEER）计划和相关的医疗保险数据。

DESCRIPTION (provided by applicant): Multiple myeloma (MM) is uniformly preceded by monoclonal gammopathy of undetermined significance (MGUS). While the biological significance of MGUS has been established, its clinical significance has yet to be determined. MGUS is generally discovered incidentally during the work-up of patients with signs or symptoms suggestive of MM and related malignancies. The prevalence of MGUS is high (3% and 5% of people age over 50 and 70 years, respectively), but the risk of transformation to MM and related malignancies is very low (0.4% per year after taking into account competing causes of death). Yet experts recommend indefinite annual follow- up of MGUS patients with physical examinations and laboratory tests, even though no currently available treatment can prevent malignant transformation and no evidence exists to suggest that such follow-up contributes to better clinical outcomes. In fact, follow-up may cause psychological distress to patients due to cancer anticipation, may represent an enormous economic burden on the health care system (3.6 million people in 2008 harboring MGUS), and may decrease access to cancer care (shortfall of 4000 hematologist- oncologists by 2020 projected by the American Society of Clinical Oncology). Therefore, the clinical significance of MGUS must be determined. Toward that goal, and utilizing the Surveillance Epidemiology and End Results (SEER) program and the linked Medicare data, our study has 2 specific aims. In Aim 1, we will determine whether there is a difference in overall and disease-specific survival between patients with MM and related malignancies who presented de novo and those who had a preceding diagnosis of MGUS. In Aim 2, we will compare the rates of major cancer complications (hypercalcemia, bone fracture, and dialysis- dependent kidney disease) between these 2 groups. In Aim 3, we will determine the impact of various MGUS follow-up strategies on clinical outcome. We will use the Surveillance Epidemiology and End Results (SEER) program and the linked Medicare data.