Postoperative Serum Levels of Interleukin-6 are Affected by Age in Patients with Colorectal Cancer

SummaryBackgroundSerum interleukin-6 (IL-6) levels are elevated in patients receiving major surgery. Little is known about the correlation between age and post-operative IL-6 levels in colorectal cancer (CRC) patients.MethodsThirty-six CRC patients underwent bowel resection, and their serum samples were taken preoperatively and at 2, 24, and 48 h after surgery for cytokine quantification by ELISA. C-reactive protein (CRP) was quantified preoperatively, as well as 48 h and seven days after surgery. Demographic data, blood tests, and the stage of cancer were compared statistically with cytokine and CRP levels.ResultsPostoperative median IL-6 levels were elevated 2 h after surgery and declined to near preoperative levels 48 h after surgery. Older age was correlated significantly with increased magnitude of change in IL-6 at 2, 24, and 48 h after surgery, but was not correlated with the preoperative IL-6 levels. The increment of CRP (Δ CRP) at 7 days after surgery was positively correlated with age. Older patients (≥63 years) showed significantly higher increments of IL-6 from 2 to 48 h postoperatively than did younger patients (<63 years). The Δ CRP at 48 h after surgery was significantly greater in the older group.ConclusionOur study demonstrates a significant correlation between age and postoperative increments of IL-6 in CRC patients. Advanced age was positively associated with a higher increment of postoperative IL-6 and CRP levels. Additional studies are warranted to further explore the biological role of IL-6 in older patients who have higher levels of IL-6 after surgery.