(CNN) Researchers are learning more about the risks cancer patients face if they become sick with Covid-19, the disease caused by the novel coronavirus that has swept through the world.
Patients whose cancer was getting worse or spreading were more than five times more likely to die in the space of a month if they caught Covid-19, researchers said this week during the annual meeting of the American Society of Clinical Oncology.
Even if the patients' cancer wasn't spreading, coronavirus infection nearly doubled the risk of dying, the researchers found.
That early data, published in the medical journal The Lancet on Thursday, also showed that patients treated with the controversial coronavirus combination of hydroxychloroquine and azithromycin were nearly three times as likely to die within about a month. The researchers found no significant increase in risk for patients given either drug alone.
The researchers from across North America and Europe looked at data on 928 Covid-19 cases from between March and April.
About 20% of the patients were treated with the hydroxychloroquine and azithromycin combination and about 10% took hydroxychloroquine alone, Dr. Jeremy Warner, who worked on the research and is an associate professor of medicine and biomedical informatics at Vanderbilt University Medical Center, told reporters.
"One of the notable things is that only two of these patients got these drugs as part of a clinical trial. The rest of them were given the drugs off label -- since these drugs are generally available that's at the discretion of the treating provider, but it's still notable," Warner said. "Patients with all levels of severity of Covid-19 received these drugs, although certainly the patients that were hospitalized were more likely to receive these drugs."
The US Food and Drug Administration and National Institutes of Health both have warned against using the drugs outside of clinical trials. Currently, there is no approved treatment for Covid-19.
Overall, 121 patients total -- or 13% -- died during the study period and all deaths occurred within 30 days of being diagnosed with Covid-19, according to the data.
"While it's not surprising, it's informative that it looks like patients with cancer have twice the risk of dying than the general public," Warner told CNN on Thursday.
The new study comes with limitations, including that more research is needed to determine whether similar findings would emerge among a larger group of patients.
"Right now, we're working to quickly get information about why some patients with cancer become infected with the SARS-CoV-2 virus and identify the factors that affect disease severity and death," Warner said in a statement. "We're also interested in the effects of treatments that are being used to treat patients with cancer who have Covid-19."
Warner told CNN that more research also is needed to examine whether Covid-19 impacts patients with certain types of cancer differently, and how.
"I think the public perceives cancer as perhaps a catch-all, but there are at least 120 different types of cancer, some of which have essentially normal life expectancy with treatment," Warner said.
A separate study found that patients with lung cancer and other types of cancers in the chest had a 64% increased risk of dying from the coronavirus if they had been treated with chemotherapy recently -- within three months of a Covid-19 diagnosis.
Patients given corticosteroids to reduce inflammation were 1.5 times more likely to die. Other types of cancer treatment, such as immunotherapies and tyrosine kinase inhibitors, were not associated with a greater risk of death among the patients.
The study, conducted by an international team of researchers, included data on 400 thoracic cancer patients from around the world who had been diagnosed with Covid-19.
Patients with thoracic cancers -- lung cancers and others in the chest -- already are considered at high risk of severe illness or death from Covid-19 since they tend to be older and already have lung damage, among other risk factors. The data showed that 141 of the patients died. The majority, or 79%, died due to Covid-19 and 10% died due to their cancer.
The research should not deter patients from seeking care for their cancer due to fear of being exposed to the novel coronavirus in hospitals, said Dr. Toni Choueiri, of the Dana-Farber Cancer Institute and a professor of medicine at Harvard Medical School in Boston, who worked on the Lancet study.
Patients also should talk to their doctors about what may be best for them, Choueiri said.
"The biggest message here is that if you need treatment for your cancer that could be curative -- surgery, radiation, some sort of chemotherapy -- you really still should have it," Choueiri told CNN on Thursday.
"I really worry about the next two to three months when we're open, when we're more safe, and a patient is saying, 'Well my stage three kidney cancer that needs surgery or my acute leukemia that needs chemotherapy, I'm going to delay until next year,'" Choueiri said. "That's what we don't want to happen."
So far more than 100,000 people in the United States have died from Covid-19 during the coronavirus pandemic. The American Cancer Society predicts more than 600,000 people will die this year of cancer, said Dr. William Cance, the society's chief medical and scientific officer, who was not involved in the new research.
"Cancer is still moving at its pace. So we have to get people back in the research labs. We have to get our clinical trials back up and running, but in the context of this paper, we have to do it safely -- and when those patients undergoing therapy get Covid, it appears with these data that they have a much higher risk," Cance told CNN.
"But one of my greatest worries is the undiagnosed patient, the patients who need to be screened and they're not getting their screenings. In a lot of areas, colonoscopies have just stopped," he said.
"One bright spot is we are turning more to telehealth and lots of things can be done very well, if not better, through telehealth. This will force a change in how we take care of cancer patients."