Early tumor shrinkage and depth of response in patients with metastatic esophageal cancer treated with 2-weekly docetaxel combined with cisplatin plus fluorouracil: an exploratory analysis of the JCOG0807

BACKGROUND

We herein investigated the association between early tumor shrinkage (ETS) and depth of response (DpR) and clinical outcomes in patients with metastatic esophageal cancer treated with 2-weekly docetaxel combined with cisplatin plus fluorouracil (bDCF) using data from the JCOG0807, a phase I/II trial of bDCF as first-line chemotherapy for metastatic esophageal cancer.

METHODS

ETS was defined as a percent decrease in the sum of the target lesions' longest diameter after 8 weeks, whereas DpR was defined as a percentage of the maximal tumor shrinkage during the treatment course. Multivariable analyses were conducted to identify significant prognostic variables in progression-free survival (PFS) and overall survival (OS): one for ETS and covariates, and another for DpR and covariates.

RESULTS

Among 53 patients, 35 patients with ETS ≥ 20% (66.0%) had longer PFS (7.5 vs. 3.4 months, hazard ratio [HR]: 0.26, 95% confidence interval [95% CI] 0.14-0.49), OS (13.8 vs. 6.1 months, HR 0.20, 95% CI 0.11-0.39), and PPS (6.4 vs. 2.8 months, HR 0.38, 95% CI 0.20-0.72) than those with ETS < 20%. In addition, 37 patients with DpR ≥ 30% (69.8%) had longer PFS (7.5 vs. 2.9 months, HR 0.17, 95% CI 0.08-0.34), OS (13.8 vs. 6.0 months, HR 0.14, 95% CI 0.07-0.27), and PPS (6.8 vs. 2.8 months, HR 0.30, 95% CI 0.15-0.58) than those with DpR < 30%. Multivariable analyses revealed that each ETS and DpR was an independent factor of longer PFS and OS.

CONCLUSIONS

ETS and DpR might be associated with clinical outcomes in patients with metastatic esophageal cancer treated with bDCF.