Multimodal treatment of radiation-induced esophageal cancer: Results of a case-matched comparative study from a single center

Purpose: Radiation-induced esophageal cancer (RIEC) is a rare but severe late consequence of radiotherapy. The literature regarding this topic is predominately limited in describing the risk of this disease. Tumor behavior, treatment strategies, and prognosis of this cancer remain poorly defined. Patients and methods: We collected data of patients who were referred to our unit between 2000 and 2020 for RIEC. After tumor board discussion, upfront surgery or neoadjuvant therapy and surgery were indicated as the main treatment. Preoperative characteristics, long-term and short-term postoperative outcomes of RIEC patients were compared with a 1:1 clustering-matched cohort of patients affected by primary esophageal cancer (PEC). Results: At pre-matching, 54 RIEC and 936 PEC patients were enrolled. The median time between primary irradiation and diagnosis of RIEC was 13.5 years, and the median primary radiation dose was 60 Gy. Compared to the unmatched cohort of PECs, RIEC patients were more frequently female (p = 0.0007), had earlier detection of disease (p = 0.03) and presented more frequently with upper esophageal cancers (p < 0.0001). Neoadjuvant treatment was used less frequently in RIEC patients (p < 0.0001). After matching, the 51 RIEC and 50 PEC patients showed comparable results in terms of exposure to neoadjuvant treatment, surgical radicality and survival outcomes. RIEC patients had more severe postoperative complications (p = 0.04) and a higher proportion of pulmonary complications (p = 0.04). Conclusions: Curative treatments are feasible for RIEC. Neoadjuvant chemotherapy or chemoradiation can be used in this subgroup, treatment response and long-term outcomes are comparable to those of PEC. The risk of postoperative complications is probably related to the detrimental effect of primary irradiation on lung function.