NEW YORK (Reuters Health) – The 2009 influenza A(H1N1) pandemic caused severe illness and mortality in cancer patients with solid tumors, investigators report in Cancer online February 22.
“Early initiation of antiviral therapy is crucial in this patient population to decrease morbidity and probably mortality,” advise Dr. Roy F. Chemaly, with the University of Texas M. D. Anderson Cancer Center in Houston, and colleagues.
They note that data on the effect of H1N1 infection in patients with solid malignancies have been nonexistent. They therefore retrospectively reviewed the records of such cancer patients during the 2009 influenza pandemic at three major cancer centers — M. D. Anderson, the Mexican National Cancer Institute in the Mexico Federal District, and the King Hussein Cancer Center in Amman, Jordan.
The team identified 115 cases of H1N1 infection in this population, 58 of whom required hospitalization with lengths of stay ranging from 1 to 33 days. Pneumonia developed in 27 patients (23%), with those who were older or more severely immunocompromised at particular risk. Eleven patients died from H1N1 infection, for a case fatality rate of 9.5%.
Most patients received a neuraminidase inhibitor, usually oseltamivir, and further analysis showed that administration within 48 hours of symptom onset reduced the risk of pneumonia (p<0.001) with a trend toward reduced mortality (p=0.06), Dr. Chemaly and colleagues report.
“In summary, during a pandemic, influenza A infection may present as a severe disease in patients with solid tumors, as it does in other immunocompromised patients,” they conclude, adding: “A delay in the initiation of antiviral therapy is associated with a greater risk of developing of pneumonia.”