Accuracy of PET-CT in predicting survival in patients with esophageal cancer.

Background: Positron emission tomography (PET) is an integral part of tumor staging for patients with esophageal cancer. Recent studies suggest a role for PET scan in predicting survival in these patients, but this relationship is unclear in the setting of neoadjuvant therapy. We examined pretreatment maximum standard uptake value (SUV(max)) of the primary tumor in patients treated with and without neoadjuvant therapy.

Methods: All patients undergoing esophagectomy with a preoperative PET scan over a nine-year period (2001-2010) were identified from a prospectively maintained database. Positron emission tomography data were obtained from computers housing the original PET scans. Overall survival was correlated with SUV(max) of the primary tumor.

Results: A total of 191 patients were identified, and 103 patients met inclusion criteria. Eighty-two had an adenocarcinoma (80%), and 21 (20%) had a squamous cell carcinoma. Fifty-seven (55%) patients received neoadjuvant therapy. In the surgery alone group, a SUV(max) of > 5.0 in the primary tumor was associated with poor prognosis [Hazard Ratio (HR) 0.32; p = 0.007], but this factor did not retain its significance on multivariate analysis (HR 0.65; p = 0.43). Pretreatment SUV(max) in patients who underwent neoadjuvant therapy was not significant in predicting overall survival (p = 0.10).

Conclusions: This study does not support the use of SUV(max) on pretreatment PET scans as a prognostic tool for patients with esophageal cancer, especially in those who have received neoadjuvant therapy. Lymph node status is a more accurate predictor of outcome, and efforts to improve pretreatment staging should focus on this factor.