(P053) Esophageal Cancer Pathologic Complete Response Rate After Neoadjuvant Chemoradiation: Is There a Difference Between Academic Centers vs Community Centers

Wendy Gao, MD, Gurleen Dhami, MD, Brant K. Oelschlager, MD, Veena Shankaran, MD, Shilpen Patel, MD, Smith Apisarnthanarax, MD, Jing Zeng, MD; University of Washington

INTRODUCTION: Trimodality treatment, consisting of preoperative chemoradiation followed by surgical resection, has been established as the standard of care for locally advanced esophageal cancer. Rates of pathologic complete response (pCR) range from 29% to 40% in phase III trials. We reviewed our institution’s pCR rate and assessed whether there is a difference for patients treated at our academic institution vs in the community.

METHODS: Consecutive patients with esophageal cancer who underwent esophagectomies at our institutionafter chemoradiation from January 2012 to October 2014 were included in this retrospective analysis. Patient characteristics, staging, histology, and pathologic response data were collected. Chi-square and t-tests were used to compare patient groups. 

RESULTS: A total of 51 patients were found to have undergone resection after chemoradiation for esophageal cancer between January 2012 to October 2014; 28 patients (55%) were treated at our academic center, and 23 (45%) were treated in the community. Patients treated in the community were older (median age: 65 vs 61 yr; P = .047). Staging distribution was similar for the two patient groups: community stage: II = 34%, IIIA = 43%, and IIIB = 23%; academic center stage: II = 39%, IIIA = 53%, and IIIB = 7%. Most patients had adenocarcinoma (88.2%) vs 9.8% squamous cell and 2% adenosquamous. Location of the tumors was distal esophagus in 47 patients (92.1%) and midesophagus in 4 (7.9%). Median radiation dose was 50.4 Gy (range: 37.8–50.4 Gy) for all patients. All patients treated at our center received carboplatin and paclitaxel (carbo/taxol) vs 10% of patients in the community receiving regimens other than carbo/taxol (one docetaxel, cisplatin, and 5-fluorouracil [5-FU] [DCF]; one 5-FU/oxaliplatin; and one alternating carbo/taxol with 5-FU/oxaliplatin).

Pathologic complete tumor response occurred in 21.5% of patients. By histology, the pCR rate was 50% for squamous cell (2/4 patients), and 19% for adenocarcinoma (9/47 patients). For the primary tumor, there was downstaging in 41.2% of tumors, no change in 35.3%, and upstaging in 2%. Pathologic complete nodal response occurred in 41.2%, downstaging occurred in 3.9%, there was no change in 35.3%, and upstaging occurred in 19.6% of patients. There was no statistically significant difference in pCR rate between patients who received neoadjuvant chemoradiation at University of Washington Medical Center (21%) vs at an outside institution (17%) (P = 1.0).

CONCLUSIONS: Pathologic outcomes after neoadjuvant chemoradiation for esophageal cancer were similar between patients treated at an academic center and community setting, although patients treated in the community tended to be older than patients treated at our academic center. These results will need to be validated with a larger dataset. The pCR rate after neoadjuvant chemoradiation at our institution was 21%, consistent with published data.

Proceedings of the 97th Annual Meeting of the American Radium Society- americanradiumsociety.org