Evaluation of second-line treatment options in metastatic esophageal squamous cell carcinoma

Aims: Esophageal cancer is the seventh most common cause of death worldwide and the survival rate of patients with metastatic esophageal cancer is very low. Although current guidelines recommend immunotherapy as a second-line treatment for esophageal squamous cell carcinoma (SCC), a significant proportion of patients have difficulty accessing this treatment. Therefore, conventional chemotherapy is used as second-line treatment. In this study, we aimed to compare the efficacy and tolerability of irinotecan- and taxane-containing chemotherapy regimens as second-line treatments for patients with disease progression after first-line cytotoxic chemotherapy. Methods: This study included 43 patients with metastatic esophageal SCC at the time of diagnosis or relapse during follow-up. The patients were divided into two groups: irinotecan-based chemotherapy regimens (n=21) and taxane-based chemotherapy regimens (n=22). Demographic characteristics, treatment regimens, treatment responses, grade 3-4 toxicities, overall survival (OS), and progression-free survival (PFS) were documented and analyzed using appropriate statistical methods. Results: Of the 43 patients who received second-line treatment, 25 (58.1%) were male and 18 (41.9%) were female. The mean age was 55.86±11.6 years. At the time of diagnosis, 72.1% of the patients had metastatic disease. The median OS was 5 months (95% CI, 2.5 to 7.4) for the irinotecan-based regimen and 10 months (95% CI, 2.6 to 17.3) for the taxane-based regimen (p=0.122). The median PFS was 4 months (95% CI, 2.9 to 5.0) in the irinotecan-based regimen group and 7 months (95% CI, 4.8 to 9.1) in the taxane-based regimen group (p= 0.80). There were no significant differences in OS and PFS between the two groups. Grade 3-4 neutropenia (p=0.046) and grade 3-4 neuropathy (p=0.034) were higher in the group receiving taxane-based regimens, while grade 3-4 mucositis (p=0.027) was higher in the group receiving irinotecan-based regimens. There were no statistically significant differences in other side effects (p>0.05). Conclusion: We found no statistically significant difference in the median PFS and median OS between the two chemotherapy groups used as second-line treatment for metastatic esophageal SCC. Grade 3-4 neutropenia and grade 3-4 neuropathy were higher in the group receiving taxane-based regimens, while grade 3-4 mucositis was higher in the group receiving irinotecan-based regimens. Although our study has limitations, such as its retrospective and single-center nature, it is one of the few studies performed in this patient group in recent years and is important because it reflects our clinical practice.