Prognostic significance of baseline positron emission tomography and importance of clinical complete response in patients with esophageal or gastroesophageal junction cancer treated with definitive chemoradiotherapy

BACKGROUND: Metabolic imaging is of interest in esophageal cancer; however, the usefulness of initial standardized uptake value (SUV) in positron emission tomography (PET) is unknown in patients with esophageal or gastroesophageal carcinoma treated with definitive chemoradiotherapy. The authors hypothesized that initial SUV would correlate with patient outcome. METHODS: The authors retrospectively analyzed esophageal or gastroesophageal carcinoma patients who had baseline PET and endoscopic ultrasonography in addition to other routine staging. All patients received definitive chemoradiotherapy. Multiple statistical methods were used. RESULTS: The authors analyzed 209 consecutive esophageal or gastroesophageal carcinoma patients treated with definitive chemoradiation for outcome; of these, 180 had baseline PET for additional analyses. The median overall survival (OS) for all patients was 20.7 months (95% confidence interval, 18.8-26.3). Patients with clinical complete response (CR) lived longer than those with less than clinical CR (P <.0001). The median initial SUV was 12.7 (range, 0-51). Higher initial SUV was associated with longer tumors (P =.0001), higher T-stage status (P <.0001), positive N-stage status (P =.0001), higher overall stage (P <.0001), lack of clinical CR (P =.0002), and squamous cell histology (P <.0001). In the univariate analysis, initial SUV was associated with OS (Cox model, P =.016; log-rank test, P =.002). In the multivariate analysis, initial SUV dichotomized by the median value (P =.024) and tumor grade (P =.016) proved to be independent OS prognosticators. Median initial SUV for clinical CR patients was 10.2, compared with 15.3 for less than clinical CR patients (P =.0058). CONCLUSIONS: The data indicate that a higher initial SUV is associated with poorer OS in patients with esophageal or gastroesophageal carcinoma receiving definitive chemoradiation. Upon validation, baseline PET may become a useful stratification factor in randomized trials and for individualizing therapy.