Many studies over the past

Many studies over the past 20 years have shown the potential of urinary markers in the detection of the presence of bone metastases [3–11], the use of urinary markers for its prognostic value in bone disease [2,4,12–20], as well as directing therapy for bone metastases patients [2,6,12–18,21–25]. The purpose of this review is to summarize relevant studies reporting the potential and advances in using urinary markers in the management of bone metastases.
Methods
Results We identified a total of 34 articles, with 23 original studies, that detailed the use of urinary markers as a diagnostic tool, prognostic tool, or in directing therapy for patients with bone metastases. The results of the 23 original studies are summarized in Table 1. The criterion for inclusion was strictly for studies that examined urinary markers; as such, there are many more studies in the literature not included that examines other bone markers exclusively. Studies that included both urinary markers and other bone markers were not omitted.
Conclusion
Conflicts of interest
Acknowledgments We thank the generous support of Bratty Family Fund, Michael and Karyn Goldstein Cancer Research Fund, Pulenzas Cancer Research Fund, Joseph and Silvana Melara Cancer Research Fund, and Ofelia Cancer Research Fund.
Introduction Bone is one of the most common sites of metastasis in advanced cancer, present in approximately 50–75% of patients [1]. Bone metastases are especially prevalent in patients with prostate, breast, or lung primaries [2–4] and are of great concern to both physicians and patients as they can result in complications such as pathologic fractures, hypercalcemia, and spinal cord nicotinic receptors [2,5–7]. One of the most common symptoms of bone metastases is pain, occurring in an estimated 70% of patients [8]. Often, patients initially present with multiple bone metastases and often, multiple sites of pain. Pain may be localized or diffuse, and may worsen upon weight bearing [9]. As a consequence of bone pain, patients often have increased difficulty with activities of daily living and decreased quality of life (QOL) [8]. Radiation therapy (RT) is considered to be the standard treatment for cancer patients with symptomatic bone metastases [3,7,10,11]. Various studies have shown that approximately 60–70% of patients experience at least some degree of pain relief following RT, regardless of radiotherapy regime [5,7]. Moreover, about 25% of patients experience complete pain relief, otherwise known as a complete response [2,7]. Although pain relief is a proven benefit of radiation therapy, this is not necessarily indicative of improved QOL. QOL is a multidimensional model that attempts to capture the physical, social, and psychological well-being of the patient [12]. Many components influence QOL, including physical symptoms of the disease, side effects of treatment, social and family support. Treatment in the advanced cancer population is palliative rather than curative in intent, meaning that the goal is managing symptoms as opposed to prolonging life [7,13]. With this goal in mind, it is important for health care providers to consider treatment in terms of not only managing symptoms, but also stabilizing or improving other factors that affect QOL. As QOL is a subjective concept, it can be difficult to capture in an accurate and meaningful fashion [12]. Currently, various tools are employed to assess pain and QOL in advanced cancer patients and in those specifically with bone metastases. The European Organisation for Research and Treatment of Cancer (EORTC) has developed one of the most commonly used measurements for this purpose: the QLQ-C30 [13]. Associated with this measurement is the QLQ-C15-PAL, a reduced version of the parent QLQ-C30 designed to capture QOL outcomes in a brief internationally recognized and validated tool. The EORTC QLQ-BM22 is a sub-module of the QLQ-C30 and is an internationally recognized and validated scale used to measure QOL in bone metastases patients [7,12].