Non-invasive diagnostic tools to evaluate the severity of acute, radiation-induced proctitis are not readily available.
A group of researchers from Norway therefore examined the faecal excretion of eight markers of gut inflammation.
The investigators analyzed 5 proteins and 3 lipid derivates in sequential stool samples taken before and during radiation therapy.
In total, the research group examined stool samples from 15 patients with prostate cancer scheduled for radiation therapy.
The team measured pretreatment and in-treatment samples (2nd and 6th weeks) by enzyme-linked immunosorbent assay (ELISA) for calprotectin, lactoferrin, transferrin, leukotriene B4, prostaglandin E2, thromboxane B2 and TNFα, or by nephelometry for α1-antitrypsin.
|No changes in tumour necrosis factor α (TNFα), leukotriene B4, prostaglandin E2 and thromboxane B2 during treatment|
|Scandinavian Journal of Gastroenterology|
The researchers found that calprotectin and lactoferrin concentrations increased significantly during radiation treatment.
Transferrin was detected in only 9 out of 45 samples.
The team noted that there were no changes in tumour necrosis factor α (TNFα), leukotriene B4, prostaglandin E2 and thromboxane B2 during treatment, whilst α1-antitrypsin could not be detected in any sample.
Dr Larsen concluded, "This study indicates that faecal calprotectin and lactoferrin concentrations could be markers of acute, radiation-induced proctitis."
"Patient compliance and stability of the markers make this a promising method for clinical research."
Dr Larsen commented, "Eicosanoids could be measured in stool samples, but the concentrations did not increase with increasing radiation dose."