18F-FDG-PET/CT in patients with breast cancer and rising Ca 15-3 with negative conventional imaging: a multicentre...

Breast cancer is the second cause of death in women in Europe and North America. The mortality of this disease can be reduced with effective therapy and regular follow up to detect early recurrence. Tumor markers are sensitive in detecting recurrent or residual disease but imaging is required to customize the therapeutic option. Rising tumor markers and negative conventional imaging (US, X-mammography, CT and MR) poses a management problem. Our aim is to assess the role of 18F-FDG-PET/CT in the management of post-therapy patients with rising markers but negative conventional imaging.

In the period from January 2008 to September 2009, 89 female patients with breast cancer who developed post-therapy rising markers (serum Ca 15-3 levels=64.8±16.3 U/mL) but negative clinical examination and conventional imaging were investigated with 18F-FDG-PET/CT.

Tumor deposits were detected in 40/89 patients in chest wall, internal mammary nodes, lungs, liver and skeleton. The mean SUVmax value calculated in these lesions was 6.6±1.7 (range 3.1-12.8). In 23/40 patients solitary small lesion were amenable to radical therapy. In 7 out of these 23 patients a complete disease remission lasting more than 1 year was observed.

18F-FDG-PET/CT may have a potential role in asymptomatic patients with rising markers and negative conventional imaging. Our findings agree with other studies in promoting regular investigations such as tumor markers and 18F-FDG-PET/CT rather than awaiting the developments of physical symptoms as suggested by current guidelines since the timely detection of early recurrence may have a major impact on therapy and survival.