Study identifies surgical means for improving kidney cancer survival

Each year in the United States, there are about 50,000 new cases of kidney cancer. In adults, the most common type of kidney cancer is renal cell carcinoma. The incidence of kidney cancer seems to be increasing, though it isn't clear why.

"Surgery remains critically important in the treatment plan for many patients. We are always looking for ways to improve patient care, including aggressive surgical management of the primary tumor and, in some cases, the metastases," says Bradley Leibovich, M.D., Mayo Clinic urological surgeon and lead author on the study.

In a Mayo Clinic study of 888 renal cell carcinoma patients, those patients who had complete removal of all tumors that spread survived an average of five years. By comparison, patients who did not have any metastatic tumors removed had only a one year cancer-specific survival rate. The results are encouraging because renal cell carcinoma is difficult to cure when it has spread to other organs. In about

30 percent of the patients, the cancer has already spread by the time the cancer is diagnosed, with the lung being the most common site for spread. Surgery for renal cell carcinoma which has not spread is often curative and is therefore a vital treatment option — particularly since this type of cancer does not respond well to chemotherapy or radiation, explains Dr. Leibovich.

Significance of the Mayo Research

"Mayo Clinic maintains a Renal Nephrectomy Registry that presents 30 years of renal cancer surgery outcome metrics," says Dr. Leibovich. "Our analysis shows that a significant proportion of patients with multiple renal cell carcinoma metastases will experience better outcomes if all metastases are removed."

The study compared survival of three groups of cancer patients, all of whom had their kidneys removed to treat the cancer originating in the kidney. The comparison groups were made up of patients treated at Mayo Clinic from 1976, as shown below:

1. Treatment type: No surgical removal of the metastatic tumor -- Patients in treatment category out of 888 total: 506 or 57% -- Median cancer-specific survival: 1.1 years
   
2. Treatment type: Incomplete surgical removal, in which some of the spreading ca was removed, but not all -- Patients in treatment category out of 888 total: 257 or 29 -- Median cancer-specific survival: 2.6 6ears
   
3. Treatment type: Complete removal to eradicate all visible tumor tissue -- Patients in treatment category out of 888 total: 125 or 14% -- Median cancer-specific survival: 4.8 years

The study also showed that survival varied with the location of metastases. For example, patients whose cancer spread only to the lung fared the best when they underwent a complete removal of the lung lesion, compared to patients who underwent complete removal of tumors from all other locations. For the lung group, the median cancer-specific survival rate (CSS) computed in terms of the cancer -- not other causes of death -- was more than 10 years. This compared to a median CSS rate of 3.6 years for the patients who underwent complete removal of tumors from all other locations.

Provided by Mayo Clinic (news : web)