Patients with kidney cancer that has spread to the lungs may develop a separate lung cancer that is easily overlooked, according to a study.
The danger is that lung cancer can be more aggressive than kidney cancer, so the risk to the patient can increase if the lung cancer goes undetected.
The study dealt with primary non-small cell lung cancer (NSCLC) in patients with metastatic renal cell carcinoma (RCC).
The findings, titled “Renal Cell Carcinoma With Pulmonary Metastasis and Metachronous Non-Small Cell Lung Cancer,” were published in Clinical Genitourinary Cancer.
“Kidney cancer spreads primarily to the lungs making the detection of a primary lung cancer difficult. Lung cancer is typically more aggressive than kidney cancer. Undetected, lung cancer may spread and eventually kill the patient,” Dr. James Brugarolas, director of the Kidney Cancer Program at the University of Texas Southwestern Medical Center, said in a press release. He is also an associate professor of internal medicine at the center.
Brugarolas and his team decided to assess how frequently a patient with kidney cancer developed NSCLC. They examined 151 metastatic kidney cancer patients treated at the Simmons Comprehensive Cancer Center between January 2006 and October 2013.
Doctors used the appearance of lung cancer lesions in medical imaging to distinguish between progression of metastatic kidney cancer and a new primary lung cancer.
Three of the 85 patients with kidney cancer metastasis in the lungs had a primary NSCLC — or 3.5 percent.
Mel Moffitt, an Army veteran who served in Vietnam, is among those fighting both kidney cancer and lung cancer. He was diagnosed with kidney cancer in 2008. It spread to his lungs and lymph nodes in 2012. Then, in 2015, he was diagnosed with lung cancer.
“It was like we turned around, and the cancer said, ‘By the way, I’m over here, too,'” said his wife of 47 years, Kennon Moffitt.
“I will keep fighting,” Mel Moffitt said. He has already been through targeted drug therapy and radiotherapy. He is now receiving immunotherapy and chemotherapy.
Because UT Southwestern is a tertiary care referral center, the researchers said the incidence of second lung cancers in kidney cancer patients could go as high as 6 percent.
“Our report raises an important flag for medical oncologists and radiologists to be on the lookout for a hidden lung cancer,” said Brugarolas.