Dallas—The use of immunotherapy for cancer treatment is expanding, but the therapy might be unsuitable for the millions of Americans who have autoimmune diseases, warns a new study looking specifically at lung cancer patients.
The research letter published online by JAMA Oncology notes that clinical trials of immunotherapy have routinely excluded patients with autoimmune disease, a population estimated to be between 20 to 50 million people in the United States.
That is especially significant with lung cancer, according to a University of Texas Southwestern Medical Center–led study. Researchers estimate that between 14% and 25% of lung cancer patients reviewed in their study also had immune diseases—especially those who were female and older.
“Our team wanted to determine if this practice had a significant impact. The new immunotherapy treatments also convey the risk of unpredictable, possibly severe, and potentially irreversible autoimmune toxicities affecting a variety of organs,” explained first author Saad Khan, MD. “With combination immunotherapy regimens, rates of these adverse events may exceed 50%.”
Lung cancer patients aged 65 years or older were identified using Medicare data from 1991 to 2011 that was linked between 1992 and 2009 in the Surveillance, Epidemiology, and End Results (SEER) database. Diagnosis of autoimmune disease was determined using ICD-9 codes for seven systemic and 36 organ-specific diseases modified from a prior study.
Results indicate that, of 210,509 lung cancer patients older than age 65, 13.5% also had autoimmune disease, with rheumatoid arthritis, psoriasis, and polymyalgia rheumatica being most common.
Advanced age at diagnosis and smoking history are potential explanations for the relatively high rate of autoimmune diseases among lung cancer patients, Khan said.
“Since the use of cancer immunotherapy is growing, examining the effectiveness and toxicity of these promising treatments among patients with autoimmune diseases will be critical,” said co-author David Gerber, MD. “While prior research has suggested that administering immune therapy to patients with autoimmune disease may be feasible, doing so carries the risk of making their disease worse, and requires careful monitoring.”
Gerber added that, because patients with lung cancer tend to be older and more frequently have smoking histories, the findings cannot be generalized to other types of cancer.
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