Background: This study aimed to explore whether metabolic responses to positron emission tomography/computed tomography (PET/CT) collected before, during, or after the treatment can predict the long-term survival rate of patients with esophageal cancer.
Main body: We searched for the following indices in articles listed in English and Chinese literature databases: the maximum standard uptake value (SUVmax), mean standard uptake value (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). If their values exceeded the thresholds, we defined them as responders; if they did not, we defined them as non-responders. We then performed a meta-analysis by extracting the hazard ratio (HR) and 95% confidence interval (95% CI) from each report to predict whether the status of responder or non-responder had an impact on prognosis.
We identified 34 articles with a combined sample size of 2794 patients. HRs and 95% CIs were measured as follows: SUVmax = 1.15 (0.98-1.35), MTV = 3.45 (0.78-15.25), TLG = 1.04 (1.02-1.07), and SUVmean = 1.85 (1.33-2.57) (before treatment); ΔSUVmax = 1.22 (1.06-1.39), Δ MTV = 1.07 (0.54-2.15), and ΔTLG = 1.09 (0.59-2.02) (during treatment); and SUVmax = 1.13 (1.05-1.22) and TLG = 1.05 (1.02-1.09) (after treatment). The results showed that the overall survival of the patients with low SUV (MTV, TLG) values was significantly higher than that of the patients with high SUV (MTV, TLG) values.
Conclusions: This meta-analysis shows that the prognoses of patients with PET metabolic responses are significantly better than those of non-responders. Our findings may help inform the clinical treatment and prediction of the prognoses of patients with esophageal cancer.