The elderly are routinely excluded from clinical trials for cancer treatments, even though 60% of all cancer cases occur among the senior population, according to new research.

Age does not influence cancer survival rates, according to the report, which was written by researchers at Hospital Vall d’Hebron in Spain. Still, little research has gone into finding new ways to treat elderly cancer victims, according to the report. Elderly participation in clinical trials does not exceed 25%, despite the prevalence of cancer in that population.

Treating elderly cancer patients is more difficult due to the increased likelihood of the patient having another debilitating health condition. Recent studies have found that nearly 90% of seniors have at least one chronic health condition. But this report shows that co-morbidity is also not a significant factor in survival rates, and researchers say more should be done to find new ways to aggressively treat older cancer patients.