Hereditary form of RCC is best treated aggresively

June 1, 2005

San Antonio--A relatively new inherited syndrome known as hereditary leiomyomatosis and renal cell cancer (HLRCC) has a more aggressive clinical course than other hereditary renal cancer syndromes, and expectant management of even small HLRCC tumors is not recommended, according to a study presented at the AUA annual meeting here.

Those affected by HLRCC are at risk of developing cutaneous and uterine leiomyomas or fibroids, as well as an aggressive type of kidney cancer-a form suggestive of type II papillary renal carcinoma, according to senior author W. Marston Linehan, MD, chief of urologic surgery at the National Cancer Institute, Bethesda, MD.

"This type of inherited kidney cancer is very different than other types of inherited kidney cancer, such as Von Hippel-Lindau, hereditary papillary renal carcinoma, or Birt-Hogg-Dubé. In those types of kidney cancer, when patients present with small tumors-less than 3 cm-often the urologic surgeon will recommend conservative management of the cancer," Dr. Linehan said.

Most effective approach In the study, which Dr. Linehan and colleagues presented at the AUA annual meeting here, researchers report on 19 subjects with HLRCC-associated kidney cancer. Fifteen of those had radical nephrectomy, and four had partial nephrectomy.

"We looked at survival and wanted to gain insight into the most effective clinical management approach for these patients," Dr. Linehan said.

The researchers found that the median renal tumor size was 7.8 cm, with a range of 1.5 to 20 cm. On histologic evaluation, they found a variety of morphologic patterns, such as cysts, tubulopapillary formations, and pure papillary tumors suggestive of papillary type 2 and collecting duct RCC, with the hallmark presentation a large, prominent nucleus and nucleoli.

Nine of the 19 subjects (47%) presented with nodal or distant metastases. Three of 19 died of their disease, and four patients with localized disease developed metastases at the median 31.5-month follow-up.

"The aggressive management that we are suggesting based on this study's results is different than what doctors do normally with patients with hereditary types of kidney cancer," Dr. Linehan said. "Generally, when hereditary renal tumors are small (less than 3 cm), urologic surgeons manage those expectantly. With this hereditary cancer syndrome, it is clearly different. We do not recommend that type of management for these patients; rather we recommend surgical therapy early in the course of management of these patients."

Dr. Linehan noted that although these are aggressive cancers that can spread early, he and others have noted long-term survival in patients with HLRCC kidney cancer.

Consider genetic testing The gene that causes HLRCC is the Krebs cycle enzyme, fumarate hydratase (FH), and an FH germ line mutation analysis is available for families at risk for HLRCC.

"Accurate diagnosis of this hereditary cancer syndrome can improve management approaches and hopefully provide better long-term survival for patients affected with this hereditary cancer syndrome," Dr. Linehan said. "Intense efforts are under way to understand how alteration of the FH gene leads to kidney cancer."

HLRCC is a new hereditary cancer syndrome.

"We only saw our first family with this 10 years ago," he said. "Our experience with these families is that early surgical management is appropriate in this patient population."

According to Dr. Linehan, this study highlights the difference between HLRCC and other types of inherited kidney cancer and shows that small tumors of this type can spread early.

Dr. Linehan suggests that urologists consider genetic testing when patients present with early onset or bilateral kidney cancer to help determine if they are affected with HLRCC or other types of inherited kidney cancer.