Abstract P3-12-20: The impact of everolimus on radiation-induced pulmonary fibrosis in wistar albino rats: Results of an experimental study

Abstract

Objectives:

This study was performed to evaluate the effects of everolimus on pulmonary fibrosis, given concurrently or sequential with irradiation in rats.

Materials and Methods:

Forty female Wistar albino rats were randomized into five groups. The first group (Group 1: sham) was observed with identical conditions of the animals in other groups. The second group (Group 2) had only everolimus application. The third group (Group 3) had thoracic irradiation first and they had everolimus injection 22 hours after radiotherapy. The fourth group (Group 4) had irradiation to whole thoracic region in 2 hours of following everolimus administration. The last group (Group 5) had irradiation to whole thoracic region. As an end point the percentage of lung with fibrosis for each rat was quantified with image analysis of histological sections of the lung. Groups were compared using the linear regression method, Fisher's exact and chi-square tests were used to assess the association between treatment groups.

Results:

There was a statistically significant difference in the distribution of fibrosis scores among all groups (p=0.0022). Linear regression analyses revealed that all treatment groups showed an increased risk of lung fibrosis compared to control group. Group 2 (p=0.0020), group 3 (p<0.0001), group 4 (p<0.0001), and group 5 (p=0.0002). Chi-square test demonstrated that there was no statistically significant difference between the sequentially and concurrent treatment groups.

Conclusion:

This experimental study showed that of everolimus by itself may lead pulmonary fibrosis and addition to radiotherapy either sequentially or concomitantly increased the severity of the lung damage in rats.

Keywords: Radiotherapy, everolimus, rats, pulmonary fibrosis.

Citation Format: Eren MF, Ay Eren A, Yücel B, Elagöz S, Özgüven Y, Altun A, Kiliçkap S, Matsuno R, Bese N. The impact of everolimus on radiation-induced pulmonary fibrosis in wistar albino rats: Results of an experimental study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-12-20.