From the Guidelines
Upper tract urothelial carcinoma (UTUC) can metastasize to bone, with a reported incidence of 19.6% in patients presenting with stage IV disease. UTUC primarily spreads to regional lymph nodes, liver, and lungs before affecting the bones. When bone metastasis does occur, it typically affects the spine, pelvis, and ribs, causing symptoms like bone pain, pathological fractures, and hypercalcemia. Bone metastases from UTUC are associated with poor prognosis and reduced survival rates. The mechanism involves cancer cells detaching from the primary tumor, entering the bloodstream or lymphatic system, and eventually settling in bone tissue where they disrupt normal bone remodeling processes.
According to the most recent study by Barker et al 1, the presence of enlarged lymph nodes can be suggestive of metastases, and distant metastases can also be evaluated for at the same time as local disease staging on CTU. The study found that the most common metastatic sites for UTUC are lungs, liver, bones, and lymph nodes.
Key points to consider in the management of UTUC include:
- Regular imaging studies like bone scans or PET-CT to monitor for bone metastases in patients with advanced UTUC
- Treatment options for bone metastases include systemic therapies (chemotherapy, immunotherapy), radiation therapy, bone-targeted agents like bisphosphonates or denosumab, and surgical interventions for pathological fractures or spinal cord compression
- The importance of accurate staging and diagnosis, with CTU being the most accurate and preferred modality for diagnosis and staging of UTUC, as reported by the European Association of Urology guidelines 1
- The need for careful evaluation of patients with UTUC for distant metastases, including bone metastases, to ensure timely and effective treatment.
In terms of morbidity, mortality, and quality of life, it is essential to prioritize early detection and treatment of bone metastases in patients with UTUC, as delayed diagnosis and treatment can lead to significant morbidity and mortality. As reported by Barker et al 1, the overall accuracy of multidetector CTU in the diagnosis of low and advanced T stage tumors was 80.8%, highlighting the importance of accurate imaging in the management of UTUC.
From the Research
Upper Tract Urothelial Carcinoma Metastasis
- Upper tract urothelial carcinoma (UTUC) can metastasize to various sites, including bone 2, 3, 4
- The frequency of bone metastasis in UTUC patients is reported to be around 19.6% 4
- UTUC patients with bone metastasis often have a poor prognosis, with a 1-year overall survival rate of 23.8% 2
- Simultaneous lung and liver metastases are common in UTUC patients with bone metastasis, occurring in 33.4% and 31.1% of cases, respectively 2
- Surgery and chemotherapy are considered optimal management strategies for UTUC patients with bone metastasis 2
Metastatic Sites and Prognosis
- The most common metastatic sites for UTUC are lung, distant lymph nodes, bone, liver, and adrenal gland 4
- The presence of distant metastases, including bone metastasis, is a significant prognostic factor for overall survival in UTUC patients 5, 3, 4
- Multivariate analyses have identified factors such as initially diagnosed stage IV disease, number of metastatic organs, response to chemotherapy, and cycles of chemotherapy as independent prognosticators for overall survival in metastatic UTUC patients 4
Treatment and Chemosensitivity
- Platinum-based chemotherapy has been the cornerstone of treatment for locally advanced and metastatic UTUC 6
- However, UTUC is thought to have low chemosensitivity, with an overall response rate of only 28.7% to first-line chemotherapy 4
- Recent advances in the genomic and immune landscape of UTUC have led to the development of precision-based therapeutic approaches, including immune checkpoint inhibitors and targeted therapies 6