Objective To observe the effectiveness and safety of pirfenidone in the prevention and treatment of radiation-induced lung injury in esophageal cancer.

Methods We retrospectively analyzed the data of 103 patients with esophageal cancer, of whom 53 in the combined group were treated with simultaneous chemoradiotherapy combined with pirfenidone and 50 in the control group were treated with simultaneous chemoradiotherapy only. The patients were followed up for three years to observe the treatment effects, adverse effects, and survival, as well as the incidence of radiation-induced lung injury, lung function, and changes in lung injury cytokine levels within one year after radiotherapy.

Results Treatment efficiency in the combined group was higher than that in the control group (86.8% vs. 70.0%, P<0.05). The two- and three-year survival rates in the combined group were 84.9% and 71.7%, respectively, which were higher than those (68.0% and 52.0%) in the control group (P<0.05). The one-, two-, and three-year disease-free survival rates in the combined group were 86.8%, 67.9%, and 47.2%, respectively, which were higher than those (62.0%, 46.0%, and 28.0%) in the control group (P<0.05). The incidence rates of radiation pneumonitis at three months, pulmonary fibrosis at six months, and one year after radiotherapy in the combined group were 22.6%, 13.2%, and 14.0%, respectively, which were lower than those (42.0%, 30.0%, and 31.8%) in the control group at the same time (P<0.05). At the end of radiotherapy and at three months, six months and one year after radiotherapy, the combined group showed higher levels of lung function indicators but lower levels of lung injury-related cytokines than the control group (P<0.05). The incidence of rash in the combined group was 18.9%, which was higher than that (2.0%) in the control group (P<0.05). However, no statistically significant difference in the incidence and severity of other adverse reactions was found between the two groups (P>0.05).

Conclusion Pirfenidone not only effectively reduces radiation-induced lung injury and improves lung function in esophageal cancer patients undergoing simultaneous chemoradiotherapy, but also helps improve tumor control rates and patient survival with a good safety profile.