A retrospective, multicenter, observational research study led by investigators at Sylvester Comprehensive Cancer Center and the Division of Pulmonary, Critical Care, Sleep and Allergy at the University of Miami Miller School of Medicine has found that patients with underlying malignancy who develop sarcoidosis and sarcoid-like reactions have a lower risk of stage 4 metastatic disease and better survival outcomes compared with patients who do not develop granulomatous reactions.
Granulomas — masses or nodules of chronically inflamed tissue that are the body's attempt to wall off or isolate organisms and other foreign particles that are difficult for the immune system to eradicate or dispose of — are the classic sign of sarcoidosis. The disease can occur in any part of the body, but it is most commonly found in the lungs and lymph nodes.
“Multiple studies have demonstrated an increased risk of cancer following sarcoidosis,” said Mehdi Mirsaeidi, M.D., a Sylvester member and associate professor of medicine, who was the lead investigator and corresponding author of the study published today in the European Respiratory Journal Open Research. “Less, however, is known about the development of sarcoidosis after the onset of malignancy. To date, only a few studies have analyzed the occurrence of sarcoidosis after cancer diagnosis, and most are case reports. Whether the presence of sarcoid-like granulomas affects survival if developed after cancer onset is difficult to assess, as different studies have reported conflicting results.”
To help resolve the conflicts in those prior studies, Dr. Mirsaeidi and colleagues studied 1,809 subjects at University of Miami Hospital, the Miami Veterans Affairs Medical Center and Chiba University in Chiba, Japan. Any patient with a pathology finding of sarcoid-like granuloma during or after cancer was included in the study.
Patients with skin, breast, and prostate cancers and lymphoma were more likely to develop sarcoid-like granulomas than were patients with other types of cancers. Most important, the study found a decreased incidence of stage 4 cancer in patients with sarcoid-like granulomas compared with controls, leading to a significant survival advantage at 2, 4, 6 and 10 years.
“Our findings may suggest a protective role for sarcoid-like granulomas with regard to metastasis in cancer patients,” Dr. Mirsaeidi said. “This effect may be due to cancer cells being prevented from evading activated immune cells when there is a high tendency to develop granulomas. Further investigation may lead to new therapeutic agents for cancer immunotherapy.”