Blood tests used in some patients to detect potential risks for breast cancer may not accurately determine levels of concerning hormones, new research suggests.

Scientists at Georgetown University tested actual breast tissue from three different areas in women, and noted the levels of several hormones linked to increased cancer risk.

They found that hormone measurements in the breast did not match those found in blood tests, and noted that blood tests could not determine which breast was at risk.

"If we want to know what is occurring in the breast, then we have to go to the tissue itself," said lead author Adana Llanos. "Measuring blood would be more convenient, but our study shows that, alas, this may not be accurate."

Although biopsies may be a more accurate way of finding breast cancer, several methods may reduce the risk before tests are needed.

Calcitrol, one component of vitamin D, was found by UMDNJ researchers to inhibit the growth of breast cancer tumors and improved diagnoses.

Reducing one’s weight to a healthy level may also provide beneficial, according to a research review by the American Cancer Society that linked obesity and insulin resistance to an increased risk for breast cancer.