Increased expression of EGFR-positive myeloid cells associated with tumor progression and reduced survival in bowel cancer.
Scientists have uncovered a potential reason why some patients with bowel cancer respond to anti-epidermal growth factor receptors (EGFR) antibodies and other patients do not.
In a study published in Gastroenterology, investigators discovered that EGFR is found in both the tumor cells of patients with bowel cancer and in the immune cells that surround the tumor.
“In a mouse model, we were able to show that EGFR-positive myeloid cells stimulate tumor growth,” said lead investigator Maria Sibilia. “By switching of the EGFR in these immune cells, growth was as good as stopped.”
The presence of EGFR-positive myeloid cells in these tumors produced a poorer prognosis for survival. Also, EGFR causes increased production of interleukin-6 (IL6) in the myeloid cells. Previously, the presence of EGFR in the cells surrounding the tumor were not given much consideration because it was assumed that its expression only played a role in the tumor cells themselves.
This finding could explain why EGFR therapy aimed at the tumor is less efficacious or unsuccessful in some patients.
“It could be that EGFR does not actually work in the tumor itself but that it is primarily the EGFR-positive myeloid cells that act as the power plant for the tumor,” Sibilia said.
The authors noted that more research needs to be done to confirm their findings.
“This is a further step towards precision medicine, that is to say personalized medicine,” Sibilia concluded.
EGFR plays a role in the development and progression of bowel cancer, as well as many other types of cancers. Colon cancer is one of the most common types of cancer in western industrialized countries, and is the second most common form of cancer in women and third in men.