Effects of neoadjuvant chemotherapy on the contralateral non-tumor-bearing breast assessed by diffuse optical tomography

Background: The purpose of this study is to evaluate whether the changes in optically derived parameters acquired with a diffuse optical tomography breast imager system (DOTBIS) in the contralateral non-tumor-bearing breast in patients administered neoadjuvant chemotherapy (NAC) for breast cancer are associated with pathologic complete response (pCR). Methods: In this retrospective evaluation of 105 patients with stage II-III breast cancer, oxy-hemoglobin (ctO(2)Hb) from the contralateral non-tumor-bearing breast was collected and analyzed at different time points during NAC. The earliest monitoring imaging time point was after 2-3 weeks receiving taxane. Longitudinal data were analyzed using linear mixed-effects modeling to evaluate the contralateral breast ctO(2)Hb changes across chemotherapy when corrected for pCR status, age, and BMI. Results: Patients who achieved pCR to NAC had an overall decrease of 3.88 mu M for ctO(2)Hb (95% CI, 1.39 to 6.37 mu M), p = .004, after 2-3 weeks. On the other hand, non-pCR subjects had a non-significant mean reduction of 0.14 mu M (95% CI, - 1.30 to 1.58 mu M), p > .05. Mixed-effect model results indicated a statistically significant negative relationship of ctO(2)Hb levels with BMI and age. Conclusions: This study demonstrates that the contralateral normal breast tissue assessed by DOTBIS is modifiable after NAC, with changes associated with pCR after only 2-3 weeks of chemotherapy.

Automated summary

This study evaluated changes in optically derived parameters in the contralateral non-tumor-bearing breast of breast cancer patients undergoing neoadjuvant chemotherapy and found that these changes were associated with pathologic complete response after only 2-3 weeks of chemotherapy. Patients achieving pathologic complete response showed a significant decrease in ctO(2)Hb levels, while those who did not achieve it had non-significant changes. Additionally, there was a negative relationship between ctO(2)Hb levels and BMI and age.