The predictive role of plasma TGF-beta1 during radiation therapy for radiation-induced lung toxicity deserves further study in patients with non-small cell lung cancer.
BACKGROUND
This study aimed to further investigate the role of circulating TGF-beta1 during radiation therapy (RT) in predicting radiation-induced lung toxicity (RILT).


METHODS
Patients with stages I-III non-small cell lung cancer treated with RT based therapy were included in this study. Platelet poor plasma was obtained pre-RT, at 2 and 4 weeks during-RT, and at the end of RT. TGF-beta1 was measured using an enzyme-linked immunosorbent assay. The primary endpoint for RILT was >or=grade 2 radiation pneumonitis or fibrosis.


RESULTS
Twenty-six patients with a minimum follow-up of 12 months were included. Six patients (23.1%) experienced >or=grade 2 RILT. There was no significant difference in absolute TGF-beta1 levels pre-RT, at 2 and 4 weeks during-RT, or at the end of RT between patients with and without RILT. The TGF-beta1 ratios (over the pre-RT levels) for patients with and without RILT at 2, 4 weeks during-, and the end of RT were 2.8+/-2.2 and 1.0+/-0.6 (P=0.123), 2.3+/-1.3 and 0.8+/-0.5 (P=0.001), 1.5+/-0.9 and 0.8+/-0.5 (P=0.098), respectively. Using 2.0 as a cut-off, the TGF-beta1 ratio at 4 weeks during-RT predicted RILT with a sensitivity and specificity of 66.7% and 95.0%, respectively.


CONCLUSIONS
Elevation of plasma TGF-beta1 level 4 weeks during-RT is significantly predictive of RILT. The role of plasma TGF-beta1 in predicting RILT deserves further study.
Zhao
Lujun
L
Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI 48109, USA.
Sheldon
Kerby
K
Chen
Ming
M
Yin
Moli S
MS
Hayman
James A
JA
Kalemkerian
Gregory P
GP
Arenberg
Doug
D
Lyons
Susan E
SE
Curtis
Jeffrey L
JL
Davis
Mary
M
Cease
Kemp B
KB
Brenner
Dean
D
Anscher
Mitchell S
MS
Lawrence
Theodore S
TS
Kong
Feng Ming
FM
D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood; D002289:Carcinoma, Non-Small-Cell Lung / Q000097:blood / Q000473:pathology / Q000532:radiotherapy*; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D011832:Radiation Injuries / Q000097:blood*; D053773:Transforming Growth Factor beta1 / Q000097:blood*
D014408:Biomarkers, Tumor; D053773:Transforming Growth Factor beta1