Denver Health researchers have proved something long suspected at hospitals: Blood transfusions can make cancer spread faster.
Cancerous tumors grew four times as fast in mice that received blood transfusions compared with mice that received a manufactured substitute for red blood cells, according to the study.
“We proved the wives’ tale true,” said Dr. Carlton Barnett, director of surgical oncology at Denver Health Medical Center.
The mice used in the research had pancreatic cancer, one of the most aggressive types. But Barnett said the findings could affect treatment for all kinds of cancer.
Even though doctors have suspected for years that blood transfusions aren’t ideal for cancer patients, as many as 80 percent of people who have surgery to treat pancreatic cancer receive blood transfusions, according to researchers.
Doctors have known since the 1970s that receiving a blood transfusion can weaken a person’s immunity. Donated blood can be stored for up to 42 days before it’s pumped into someone’s body, and as it sits, cells break down, Barnett said.
It’s unclear exactly why donated blood makes tumors grow faster, but researchers suspect it has to do with a weakening of the immune system after a transfusion.
The research gives a boost to polymerized hemoglobin, a blood substitute marketed under the name PolyHeme.
PolyHeme, developed by a lab in Evanston, Ill., is a solution of chemically modified human blood that is compatible with all blood types and has a shelf life of about one year.
“Our hope is this will turn out to be safer, and then we could give this instead of blood,” Barnett said.
Further research is necessary before recommending a switch to PolyHeme, he said.
Barnett is continuing to investigate why certain blood types and blood donated by men also seem to make tumors grow faster.
The research was funded by a grant from the American Cancer Society.
Jennifer Brown: 303-954-1593 or jenbrown@denverpost.com
