A new study used computer models to compare the effectiveness of personalized treatment and surgery for kidney cancer in patients at risk of worsening kidney disease.
Kidney cancer is the third most common cancer of the urinary tract. It is among the 10 most common cancers in men and women. It usually affects people over the age of 64 years and is rarely seen in people younger than 45 years. While the incidence of kidney cancer is slowly rising, the mortality rate of kidney cancer is slowly declining.
Interestingly, most small kidney tumors are a result of incidental finding. The availability of sophisticated radiological imaging has helped in an increased rate of the incidental finding of small kidney tumors that are usually less than 4cm, benign, and of a low stage with a low progression potential.
The incidental findings of kidney cancer are becoming clinically important issues that health practitioners have to deal with. Therefore, a better understanding of the treatment and management of kidney cancer is needed.
Incidence of kidney cancer
The highest incidence of small kidney tumors that are usually asymptomatic, occurs in elderly patients with multiple diseased conditions. The small tumors of the kidney account for about 40-60% of renal cell carcinoma cases. The incidence of renal cell carcinoma has been increasing in all age groups, with highest increase observed in patients with localized kidney tumors.
Treatment options for kidney cancer patients
Currently, the standard treatment for kidney cancer is surgery that removes the affected kidney (radical nephrectomy) or the tumor affected area of the kidney (partial nephrectomy). Partial nephrectomy is also called nephron-sparing or kidney-sparing surgery. There are also some non-surgical treatment options that destroy small tumors either by freezing the cancer cells (cryoablation) or by heating the cancer cells (radiofrequency ablation).
For some high-risk patients who cannot be operated surgically, active surveillance is used to delay or avoid the need for interventional treatment. Active surveillance is a method of care for the elderly and patients with other health conditions who have tumors of small size with a low malignant and metastatic potential. During active surveillance, the patients are tested regularly and intervention is recommended if the tests show any signs of disease progression.
Each of these procedures have their advantages for different kidney cancer patients. Many physicians face the issue of choosing between being aggressive or conservative in the treatment and management of kidney cancer patients given the fact that many of these small kidney tumors are benign and usually grow slowly. In many cases, biopsy of the renal tissue is performed to confirm the benign nature of the tumor.
It is important to assess the potential of personalized treatments based on factors such as different risks associated with kidney tumor, presence of one or more additional diseases, and type of treatment for a particular patient.
Do specialists have the right tools to choose between various treatments?
The researchers suggest that active surveillance has a high potential for kidney cancer treatment but it may be currently underutilized. There is a lack of guidelines and tools to support decision-making for the specialists. A better way of weighing the risks associated with different treatment options is needed so that more patients can be considered for non-surgical ways of treatment and management of kidney cancer.
In new research published in Radiology, scientists at New York University used a computer-based program to explore the impact of different treatments of kidney cancer in patients with normal kidney function and those with chronic kidney disease. The researchers constructed a computer-simulated population of kidney cancer patients with varying degrees of chronic kidney disease severity, the presence of additional disease conditions, and kidney tumors with variable malignant potential and complexity. The computer simulations were used to compare the effectiveness of personalized treatment for small kidney tumors, less than 4cm, with the routinely used partial nephrectomy procedure for treatment.
Partial nephrectomy versus personalized treatment
The analysis of one million simulations revealed that partial nephrectomy as the treatment option in kidney cancer patients of all ages with normal renal function resulted in longest life expectancy. However, personalized treatment strategies such as active surveillance extended the life expectancy in patients with chronic kidney disease compared with routine surgical procedures.
The researchers also found that MRI could prove to be a helpful tool in predicting a slow-growing type of kidney cancer known as papillary renal carcinoma, that may help physicians choose active surveillance to improve long-term health benefits for these patients.
The model suggests that if tumor subtype information of the kidney cancer is taken into consideration in the decision-making process, the effectiveness of biopsy to discriminate between malignant and benign cancers can be improved.
Computer model may help identify the right treatment for the right patients
It is important to note the advantages of using computer models in clinical research. The computer simulation models provide an understanding of diseases when information from clinical trials cannot be obtained either because of limited reach to the patients, a limited set of patient population or high expenses. These models could also help the researchers steer the direction in which clinical research is most needed.
The computer model used in this study provides guidance on the risks and benefits of active surveillance for the management of kidney cancer patients. The researchers suggest that using this model may help physicians identify the right treatment for the right patients. The authors also highlight that this study may help patients, as well as providers, get more information on the most viable treatment options based on the patient condition and type of cancer.
Personalized treatment may extend life expectancy for some kidney cancer patients
The results of the analysis revealed that personalized treatment such as active surveillance can possibly increase life expectancy for patients with small renal tumors and chronic kidney disease. For patients with normal kidney function, partial nephrectomy remains the treatment of choice. The model also revealed that MRI could prove to be a useful non-invasive tool to help differentiate patients based on their cancer risk and therefore may help increase life expectancy.
The researchers commented that although this model does not prescribe one specific treatment of kidney cancer, it does provide a set of estimates to help patients and providers find information on the most viable treatment option.
Written by Preeti Paul, MS Biochemistry
Reference: Stella K. Kang et al., Personalized Treatment for Small Renal Tumors: Decision Analysis of Competing Causes of mortality. Radiology 2019;00:1-12 https://doi.org/10.1148/radiol.2018181114