Breast cancer tumor response to neoadjuvant chemotherapy (NAC) measured
Diffuse optical spectroscopic tomographic imaging (DOST) might be useful to predict which patients will best respond to chemotherapy used to shrink breast cancer tumors before surgery, according to a new study. These findings could eliminate delays in effective early treatment for tumors unlikely to respond to neoadjuvant chemotherapy (NAC).
Breast cancer is the most common nonskin cancer in women worldwide, and the second leading cause of cancer deaths in women in the United States. A common treatment strategy is to shrink those breast cancer tumors larger than 3 centimeters with a 6- to 8-month course of NAC prior to surgery. Clinical studies have shown that patients who respond to NAC have longer disease-free survival rates, but only 20% to 30% of patients who receive NAC fit this profile.
"Our work represents the first clinical evidence that tumor total hemoglobin (estimated from DOST images) is different in the women with locally advanced breast cancer who respond to neoadjuvant chemotherapy," said lead author Shudong Jiang, PhD, associate professor of Engineering at the Thayer School of Engineering at Dartmouth College in Hanover, New Hampshire. "We were able to predict breast tumor response to NAC based on image data acquired before the initiation of therapy."
DOST imaging is used to measure tumor tissue for hemoglobin and oxygen saturation levels, which are key indicators of the presence the tiny blood vessels cancer tumors need to grow. This study suggests that biomarkers obtained through DOST imaging could help physicians determine the best treatment strategy for patients. The study was published in Clinical Cancer Research (2014; doi:10.1158/1078-0432.CCR-14-1415).
"The implication of this information is that certain tumors are predisposed to responding to neoadjuvant chemotherapy, and that this predisposition could be known prior to choosing the therapy," said Jiang. "The study also could dramatically accelerate future randomized clinical trials on optimal NAC regimes. By using a validated imaging surrogate as an outcome measure, we could potentially reduce the number of patients required, and the length of time they need to be followed."
Jiang said the next step will be to develop a portable and compact system to more accurately measure changes in the breast prior to and/or during neoadjuvant chemotherapy. This system could be integrated into the workflow of clinical oncology practice to maximize patient participation, and determine whether additional prognostic information could be obtained that would influence patient management.