COPENHAGEN, Denmark — The addition of neoadjuvant chemoradiotherapy to surgery extended OS in patients with locally advanced esophageal squamous cell carcinoma, according to phase 3 study results presented at the European Society for Medical Oncology Congress.
“Surgery is the main treatment of esophageal squamous cell carcinoma, but the prognosis of patients with locally advanced disease is unsatisfactory,” Hong Yang, MD, associate professor in the department of thoracic surgery at Sun Yet-sen University Cancer Center in Guangzhou, China, said during his presentation. “Based on previous studies, preoperative chemoradiotherapy followed by surgery seems to hopefully improve the survival of these patients. Nevertheless, the results of different studies were inconsistent.”
Yang and colleagues evaluated whether neoadjuvant chemoradiotherapy prolonged OS in 451 patients aged 18 to 70 years with stage IIB to stage III squamous cell carcinoma of the thoracic esophagus from eight cooperative cancer centers.
Two hundred twenty-seven patients underwent surgery alone. The other 224 patients first received two cycles of 25 mg/m2 vinorelbine (day 1, 8, 22 and 29) and 75 mg/m2 cisplatin (day 1 and 22) concurrently with 40 Gy radiotherapy delivered in 20 daily fractions of 2 Gy each for 4 weeks.
Three- and 5-year OS served as the study’s primary endpoints. Secondary endpoints included DFS, safety, rate of R0 resection and rate of pathologic complete response after induction chemoradiotherapy.
Median follow-up for surviving patients was 30.6 months.
A total of 184 patients in the chemoradiotherapy arm proceeded to surgery 4 to 6 weeks after completion of neoadjuvant therapy.
More patients who received chemoradiotherapy achieved R0 resection (98.4% vs. 91.2%; P = .002) and pathologic complete response (43.2% vs. 0%).
“This suggested that neoadjuvant chemoradiotherapy would significantly increase the R0 resection rate, which a positive prognostic factor,” Yang said. “Pathologic complete response is another positive independent prognostic factor. It has been reported that the 5-year OS can be higher than 60%, so can this transfer into a survival benefit?”
At 3 years, OS was 69.6% in the chemoradiotherapy arm and 62.4% in the surgery-alone arm (HR = 0.71; 95% CI, 0.52-0.98).
Common adverse events associated with chemoradiotherapy included low hemoglobin (grade 3, 3.6%; grade 4, 0.4%), leukopenia (grade 3, 31.8%; grade 4, 17%), neutropenia (grade 3, 23.3%; grade 4, 22.4%), thrombocytopenia (grade 3, 4.5%; grade 4, 2.7%) and hepatic dysfunction (grade 1, 10.3%). There was no significant difference in the incidence or surgery-related complications, with the exception of arrhythmia in the chemoradiotherapy arm (13% vs. 4%; P = .001).
“Neoadjuvant chemoradiotherapy followed by surgery can increase the R0 resection rate, downstage the patient significantly and achieve a [higher] pathologic complete response rate, with satisfactory safety and toxicity,” Yang said. “It can significantly prolong OS compared with surgery alone.” – by Alexandra Todak
Yang H, et al. Abstract 611O. Presented at: European Society for Medical Oncology Congress; Oct. 7-11, 2016; Copenhagen, Denmark.
Disclosure: The researchers report no relevant financial disclosures.