Low-Dose Radiation Yields Lower Rates of Pathologic Response in Esophageal Cancer Patients.

Area of Science:

• Oncology
• Radiation Oncology
• Surgical Oncology

Background:

• Neoadjuvant chemoradiation (nCRT) followed by surgery is standard for locally advanced esophageal or gastroesophageal junction (E/GEJ) cancer.
• The optimal radiation dose for nCRT in E/GEJ cancer remains under investigation.

Purpose of the Study:

• To evaluate the effect of varying preoperative radiation doses (41.4 Gy, 45 Gy, 50.4 Gy) on pathologic response and survival outcomes.
• To compare outcomes between different radiation doses in patients with E/GEJ cancer, analyzing adenocarcinoma (AC) and squamous cell carcinoma (SCC) separately.

Main Methods:

• Retrospective analysis of 326 consecutive E/GEJ cancer patients treated with curative intent between 2009 and 2016.
• Patients were stratified into three groups based on preoperative radiotherapy dose: 41.4 Gy, 45 Gy, or 50.4 Gy.
• Outcomes assessed included pathologic complete response (pCR), postoperative morbidity, overall survival (OS), and disease-free survival (DFS).

Main Results:

• A higher radiation dose of 50.4 Gy was independently associated with an increased likelihood of pCR (OR 2.78).
• pCR rates were 15% (41.4 Gy), 30% (45 Gy), and 34% (50.4 Gy) (p=0.047).
• In adenocarcinoma patients, pCR rates varied significantly by dose (6.2% vs 29.2% vs 22.7%, p=0.035), but no differences in OS or DFS were observed across dose groups.

Conclusions:

• A preoperative radiation dose of 41.4 Gy was associated with lower pCR rates in adenocarcinoma patients.
• Radiation dose did not significantly influence postoperative complications, long-term survival, or recurrence rates.
• The findings suggest that higher radiation doses may enhance pathologic response, but their impact on overall survival warrants further investigation.