For early stage limited kidney cancer and locally progressive kidney cancer, surgical resection is usually preferred and often results in good treatment. But for advanced metastatic kidney cancer, does it still make sense to use surgical treatment because the tumor has spread to organs other than the kidney?
Surgery is primarily used as an adjuvant treatment for metastatic kidney cancer
The 2014 edition of the guidelines for the diagnosis and treatment of renal cell carcinoma states that metastatic kidney cancer should now be treated with a combination of treatments, with surgery used primarily as an adjuvant treatment that can lead to longer-term survival for a small number of patients.
Surgical treatment of metastatic kidney cancer is divided into two main conditions:
- One is resection surgery for the primary renal lesion, aimed at reducing the tumor load, i.e., tumor reduction surgery;
- The other is surgical treatment for metastases, which is mainly used to relieve symptoms caused by metastases.
Here we focus on subtractive nephrectomy for the primary site.
Which patients are eligible for surgical treatment?
Guidelines recommend that subtractive surgery should be preferred for patients with metastatic kidney cancer in good physical status with few risk factors because of the potential survival benefit.
The assessment of physical status is well understood and is perceived by the patient themselves, such as whether they can take care of themselves, whether their activities are limited, whether they are frequently bedridden, and so on. What are the risk factors? This requires a number of tests to clarify, specifically lactate dehydrogenase, hemoglobin, blood calcium, time since disease diagnosis, physical status score (Karnofsky score), and number of metastatic organs (Table 1).
Table 1. Risk factor scores affecting the prognosis of metastatic kidney cancer
| Influencing factors | Exception Criteria |
| Lactate dehydrogenase | > 1.5 times the upper limit of normal |
| Female <11.5g/L, Male <13g/L | |
| Blood calcium | >> 10mg/dL |
| Karnofsk score | ≤ 80 points |
| Number of organs transferred | ≥ 2 |
| Note: Low risk: 0; intermediate risk: 1 to 2 risk factors; high risk: ≥ 3 risk factors. | |
The more of the above risk factors a patient meets, the higher the risk level and the greater the risk of surgical treatment; conversely, for patients with fewer risk factors, physicians may recommend tumor reduction surgery.
How long can surgery prolong survival?
In two randomized controlled studies in the United States and Europe, the median survival time for patients with metastatic kidney cancer treated with subtractive nephrectomy combined with IFN-α was 13.6 months compared with 7.8 months in the IFN-α alone group, with the combination extending patient survival by an average of 5.8 months and reducing the risk of death by 31%.
Another large retrospective study evaluating the value of subtractive nephrectomy in the era of targeted therapy found that subtractive nephrectomy prolonged the median overall survival of patients with metastatic kidney cancer by 11.1 months (a full doubling) compared with patients who did not undergo surgery. Thus, even in the era of targeted therapy, surgery remains one of the effective treatments.
In addition, for patients with renal tumors causing severe hematuria and pain, palliative nephrectomy and renal artery dissection can be chosen to relieve symptoms and improve quality of survival. However, surgery itself carries certain risks, with a mortality rate of 2% to 11% for metastatic kidney cancer, so patients should be carefully evaluated before surgery to weigh the pros and cons.
Metastatic surgery may also provide a survival benefit
Patients with kidney cancer are often afraid of metastases, believing that once they metastasize, they lose hope for survival, but this is not the case. A retrospective study showed that patients with complete resection of metastases had a 5-year survival rate of 44%, compared with 14% with incomplete resection.
Most metastases from kidney cancer occur in the lungs, and there are reports of 5-year survival rates of up to 60% after surgery in patients with pulmonary metastases. Resection of metastases from the liver and pancreas also prolongs overall survival, and complete resection of liver metastases has a better survival advantage than partial resection of liver metastases.
For patients with concomitant metastases from kidney cancer, physicians will perform metastasectomy with kidney surgery at the same time or in stages, depending on the patient’s medical condition.
Summary
In conclusion, for patients with advanced metastatic kidney cancer, although current targeted agents are effective in controlling progression and improving patient survival, surgery still has important therapeutic value as an adjunct. However, there are still challenges in screening those patients who are most likely to benefit from surgical treatment.