Sept. 13 (UPI) -- While antibiotics fight off infections, they can lower survival rates for patients receiving immunotherapy for cancer, a new study says.
Patients who took antibiotics before starting immunotherapy survived, on average, for two months following treatment, according to research published Thursday in JAMA Oncology. That's compared to those who take antibiotics during immunotherapy, who live an average of nearly 15 months after treatment.
"Cancer immunotherapy can be successful in around 20 percent of patients, but it's very difficult to predict who is going to respond," David Pinato, a researcher at Imperial College London and study corresponding author, said in a news release."We have shown that with prior antibiotic exposure, patients' response to immunotherapy and survival crashes."
The researchers looked at nearly 200 cancer patients in Britain receiving checkpoint inhibitor immunotherapy, a normal treatment pathway for cancer patients. The patients were diagnosed with either non-small cell lung cancer, head and neck cancer, carcinoma, melanoma and other cancers.
"It raises questions of whether we need a higher threshold for antibiotic prescribing in cancer patients due to receive immunotherapy," Pinato said.
In all, 26 patients took antibiotics up to 30 days prior to beginning immunotherapy, while 68 took them during treatment.
The lowered survival rate existed for cancer patients no matter the antibiotic they received. Those included beta-lactams, quinolones, macrolides, sulphonamides, tetracyclines, aminoglycosides and nitroimidazole.
The researchers acknowledge other illnesses may have contributed to the deaths of some patients. But they remain confident antibiotics played a major factor in their shortened survival rates.
"It is important that patients who need antibiotics to treat bacterial infections receive the drugs they need," Pinato said. "But these findings urge for more care in the decision-making process for some patients.