From the Guidelines
Renal cell carcinoma (RCC) metastases to the kidney are typically defined as small renal masses (SRM) when they are ≤ 4 cm in diameter, as stated in the American Society of Clinical Oncology clinical practice guideline 1.
Definition of Small Renal Masses
The definition of SRM is based on the size of the tumor, which is usually consistent with stage T1a renal cell carcinoma (RCC) 1.
- SRMs are incidentally image-detected, contrast-enhancing renal tumors
- They are usually consistent with stage T1a renal cell carcinoma (RCC)
- SRMs may be unusual malignant tumor types, such as lymphoma, sarcoma, or a metastasis to the kidney
Size of Metastases
The size of RCC metastases varies considerably depending on the stage of disease, time since primary tumor development, and the specific organ involved.
- Common metastatic sites include lungs, bones, liver, brain, and adrenal glands
- Lung metastases often being multiple and ranging from a few millimeters to several centimeters
- Bone metastases tend to be larger, sometimes exceeding 5 cm
- Brain metastases are typically 1-3 cm at diagnosis
Treatment Planning
The size of metastases is important for treatment planning, as smaller lesions (<3-4 cm) may be amenable to localized treatments like surgical resection, stereotactic radiotherapy, or ablative procedures, while larger or more numerous metastases often require systemic therapy with targeted agents, immunotherapy, or combination approaches 2.
- Localized treatments are preferred for smaller lesions
- Systemic therapy is often required for larger or more numerous metastases
- The growth rate of RCC metastases varies, with some exhibiting indolent behavior and others growing rapidly, reflecting the heterogeneous nature of this cancer
From the Research
Size of RCC of the Kidney Metastasis
- The size of RCC of the kidney metastasis is not explicitly stated in the provided studies 3, 4, 5, 6, 7.
- However, the studies discuss the treatment and management of metastatic renal cell carcinoma (RCC), including the use of pazopanib and sunitinib as first-line therapy 3, 5, 6.
- The studies also mention the importance of diagnostic tests, such as CT and MRI imaging, in detecting RCC and monitoring its progression 4.
- Additionally, the studies highlight the significance of factors such as tumor histology, patient performance status, and presence of metastasis in determining treatment outcomes and survival rates 4, 6.
Treatment Outcomes and Survival Rates
- The studies report varying treatment outcomes and survival rates for patients with metastatic RCC, depending on the treatment regimen and patient characteristics 3, 5, 6.
- For example, a study found that pazopanib was noninferior to sunitinib in terms of progression-free survival, with a hazard ratio of 1.05 (95% CI, 0.90 to 1.22) 3.
- Another study reported a median progression-free survival time of 7.4 months for patients treated with pazopanib after sunitinib failure 5.
- A retrospective analysis of real-life data found that sunitinib and pazopanib produced similar overall survival and progression-free survival rates in first-line treatment of metastatic RCC 6.