Background: The reason for the thermal abnormality associated with some breast cancers is unclear. We previously reported that a thermographic abnormality is associated with tumor size and lymph node involvement. Despite this association, we were unable to demonstrate an independent association between an abnormal thermogram and survival.
Methods: To expand our previous findings, we assessed patients undergoing liquid crystal (contact) thermography (LCT) to identify a basis for the thermal abnormality and its relationship to survival. We assessed 420 women with invasive ductal carcinoma (IDC) followed for a mean of 6.2 years. In a consecutive series of 181 patients from the overall group, vascularity was assessed using a Doppler ultrasound (US) and microvessel density (MVD) by immunohistochemical staining with Factor VIII-related antigen. The tumor proliferation rate was measured immunohistochemically using Ki-67 monoclonal antibody.
Results: An abnormal thermogram was found in 18.6% of patients with IDC. A significant association was demonstrated between an abnormal LCT and age, stage, lymph nodal status, size, grade, and estrogen receptor status. We found no association between a LCT abnormality and MVD or proliferation rate. There was a significant relationship with US-demonstrated vascularity. In multivariate analysis, we found that LCT abnormality was not an independent prognostic variable for either overall or disease free survival.
Conclusions: An abnormal thermogram is associated with large tumor size, high grade, and lymph node positivity but not proliferation rate or MVD. It also may be associated with relatively large regional vessels that can be identified by US. However, thermography is not an independent prognostic indicator.