Proteins in the body may be breast cancer signals

Identifying key proteins in the body that could signal the presence of cancer has tremendous potential to stop the disease at its earliest stages.

That’s the case with two proteins in the blood that could become important prognostic markers for long-term survival in breast cancer patients. The proteins identified by Hutchinson Center researchers are associated with chronic inflammation, which is known to contribute to cancer development and progression.

Dr. Cornelia Ulrich and colleagues measured the levels of C-reactive protein (CRP) and serum amyloid A (SAA) in 734 breast cancer patients at 31 months after diagnosis. They found that elevated levels of CRP and SAA are associated with reduced overall survival, regardless of patient age, tumor stage, race and body mass index. For example, women with breast cancer who had SAA blood levels in the top third were three times more likely to die from their disease within the following seven years compared to patients with levels in the bottom third. Similarly, women in the top third of CRP levels had twice the death rate.

"These associations are strong and they suggest that, in the long-term, elevated levels of inflammatory markers predict a woman’s chances of surviving after breast cancer," Ulrich said. "It also appears that there may be a threshold effect in that only women in the highest third of inflammation markers had increased mortality."

Cancer survivors with chronic inflammation may have an elevated risk of recurrence from the effects of inflammatory processes on cell growth or the presence of cancer cells that induce inflammation, according to Ulrich’s study.

"It is interesting that markers measured in the blood nearly three years after diagnosis predicted prognosis," Ulrich said. "We also found these associations to hold up after adjusting for a number of factors that associate with systemic inflammation, such as obesity. However, more research is needed to confirm these findings and to get more precise estimates of risk. We also need to learn more about the biologic mechanisms."