Acute phase response during radiotherapy.

PURPOSE: The acute phase response is characterized by changes in the plasma concentrations of a number of liver-synthesized proteins, one of which is C-reactive protein (CRP). The existence of these changes in the plasma profile underlies the change in erythrocyte sedimentation rate (ESR). Acute phase response itself is an illness and may result from immunologic reactions and inflammatory processes. This study is designed to determine whether the CRP level and ESR increase during radiotherapy and whether their rise correlates with acute and late radiation morbidity. METHODS AND MATERIALS: Between April 1997 and October 1998, 51 patients with the diagnosis of endometrium and cervical cancer were treated with surgery and postoperative radiotherapy. Median age at the time of radiotherapy was 52 (range, 26-73) years. Thirty patients received pelvic radiotherapy, and 21 patients were treated by pelvic-paraaortic irradiation. A total dose of 50.4 Gy to the pelvis and 45 Gy to the paraaortic field were delivered in conventional fraction. Erythrocyte sedimentation rates and CRP levels were studied before, during, and at the end of radiotherapy.
RESULTS: The mean ESR measurements before and after radiotherapy were 40 (8-100) and 52 (10-120), and mean CRP levels were 1.4 (0.12-9.8) and 2.7 (0.12-32.2), respectively. The statistical analysis yielded significant rise in ESR and CRP levels at the end of radiotherapy (p < 0.001). The increase was more prominent in patients who were irradiated through pelvic-paraaortic field than in patients with pelvic radiation (p = 0.005 and 0.028 respectively).
CONCLUSION: Acute phase response was present during radiotherapy. Radiotherapy should be considered as a cause of increase in CRP level and ESR especially in clinical conditions where acute phase response is important.