Researchers caution, though, that the association may be of uncertain validity because of residual confounding.
Cancer patients with COVID-19 who were treated with both hydroxychloroquine and azithromycin were three times more likely to die during the 30 days after they were diagnosed, according to findings presented at the American Society of Clinical Oncology’s annual meeting, which is being held virtually this weekend because of the pandemic.
But in a video press briefing about the findings, lead author Jeremy L. Warner, M.D., an associate professor at Vanderbilt University Medical Center, cautioned that the association is of “uncertain validity” and may stem from residual confounding. “For example,” he said, “patients receiving this combination were more likely to have severe disease or more likely to be hospitalized.”
The researchers also reported that neither drug was associated with an added mortality risk when they were taken alone.
After some statistical adjustments, the researchers found that patients with worsening cancer were five times more likely to have died within 30 days of their COVID-19 diagnosis than patients in remission or no evidence of disease.
The results reported by Warner and his colleagues were from a registry of cancer patients diagnosed with COVID-19 that was launched on March 15. As Warner explained, the registry was started because the relationship between cancer and COVID-19 is poorly understood. Still, there are reasons to believe that cancer patients might be more vulnerable to serious COVID-19-related illness and death cause of cancer patients tend to be older, have comorbidities, be immunosuppressed from the treatment or the disease itself, and have more frequent contact with the health care system than people without cancer.
Of the 928 people with cancer and COVID-19 included in study, 121, or 13%, died within 30 days of their COVID-19 diagnosis, according to findings that Warner presented in the video. The written abstract made available to the media had slightly different numbers: 1,108 cases and 106 deaths, or 10.4% of the total cases.
In their analysis of the cases and deaths, the researchers found that factors associated with a 30-day mortality risk were worsening, or progressing cancer, active cancer, older age, male sex, and being a former smoker.
Only tjree of the 121 deaths that Warner discussed in his video presentation were of people with no comorbidities. Of the 466 who were hospitalized, 106 died.