IKCC, German Cancer Society Issue Consensus Statement on RCC With Bone Mets

The International Kidney Cancer Coalition and the German Cancer Society’s interdisciplinary working group on renal tumors have issued a consensus statement with recommendations for the diagnosis and treatment of patients with renal cell carcinoma (RCC) and metastases to the bone.

According to the statement, bone is a major site of metastases in RCC. About one-third of patients diagnosed with metastatic RCC will already have disease that has spread to the bone. Moreover, another third will develop bone metastases later in the disease course.

The presence of bone metastases is generally associated with a poor prognosis, and the condition can be painful and functionally disabling for patients.

“Current data support a multimodal management strategy that includes wide resection of lesions, radiotherapy, systemic therapy, and other local treatment options, which can improve quality of life and survival,” wrote Viktor Grünwald, MD, PhD, of Hannover Medical School, Germany, and colleagues in Nature Reviews Urology. “Nevertheless, the optimal approach for metastatic bone disease in RCC has not yet been defined and practical recommendations are rare.”

To develop the current consensus statement, a multidisciplinary panel of experts was convened to review available literature and group experience with this patient population. The statement discusses available evidence, recommendations, and areas for future work regarding the diagnostic evaluation and treatment of these patients.

Focusing on treatment, the panel concluded that surgery can be a curative approach and should be performed prior to undergoing medical treatment.

“Wide resection with curative intent is the primary approach to solitary or oligometastatic bone metastases,” their statement said. “Even in patients with further metastatic disease, local wide resection might substantially and durably improve quality of life; however, mutilating surgery should be avoided.”

The panel also highlighted advances that have been made in the use of radiotherapy to treat bone metastases. Specifically, they recommended that radiotherapy be given as a single high-dose or as a hypo-fractionated stereotactic regimen.

“Considerable technological advances in radiotherapy such as stereotactic radiation therapy (SBRT) and stereotactic radiosurgery have enabled the delivery of high doses with an accuracy within millimeters, which broadens our perception of the use of radiotherapy beyond the scope of symptom control,” they wrote.

The panel did not recommend additive radiotherapy after resection of bone metastases resulting in negative margins or following conventionally fractionated radiotherapy.

However, they did recommend that medical drug treatment not be discontinued when radiotherapy is given.

“Among available targeted therapies, cabozantinib should be used preferentially in patients with multiple bone metastases,” the panel wrote.

In addition, they recommended that “early, immediate, and individual pain therapy should be offered to symptomatic patients.”

“Personalized therapy for patients with RCC and bone metastases remains an important topic and offers several clinical questions for future research,” the panel wrote. “The main goal is to incorporate patients’ needs into the management strategy for bone metastases from RCC.” Notably, the consensus includes a proposed algorithm for the clinical management of patients with RCC and bone metastasis, which the panel stated was developed “on the basis of the available evidence and expert opinion.”