(dailyRx)

New research from Trinity College Dublin published in April's Annals of Surgery points to a potentially significant advance in the treatment of patients undergoing major cancer surgery.

 

The study was carried out by the esophageal research group at Trinity College Dublin and St. James's Hospital. A randomized, controlled trial showed omega-3 fatty acids given as part of an oral nutritional supplement resulted in the preservation of muscle mass in patients undergoing surgery for esopahageal cancer, a procedure normally associated with significant weight loss and quality of life issues.

The trial was designed by John V. Reynolds, professor of surgery at Trinity College Dublin and  St. James's Hospital, and Dr. Aoife Ryan, Ph.D., a research dietitian at St. James's Hospital.

Omega-3 fats are essential fats found naturally in oily fish, with highest concentrations in salmon, herring, mackerel and sardines. Recently, food manufacturers have begun to add omega-3 fatty acids to foods such as yogurt, milk, juice, eggs and infant formula in light of a body of scientific evidence that suggests they reduce cardiovascular disease risk, blood pressure, clot formations and certain types of fat in the blood.

Previous studies had found that nutritional supplements containing one form of omega-3 fat, eicosapentaenoic acid (EPA), significantly reduced weight loss among inoperable cancer patients. The researchers hypothesized that a nutritional supplement rich in calories and a high dose of EPA would stem the debilitating weight loss seen in patients following esophageal surgery. The group chose to study patients undergoing surgery for esophageal cancer as this surgery is one of the most stressful and serious operations a patient can undergo.

Professor Reynolds said, "An increasing number of patients are treated with chemotherapy alone or in combination with radiation therapy before they undergo surgery. The surgery is a serious operation lasting several hours, and [it] can take weeks to recover from surgery and up to six months to recover pre-illness quality of life. Weight loss is extremely common both before and especially after this type of surgery, and any approach that can preserve weight, in particular muscle weight and strength, may represent a real advance."

In a double-blinded, randomized control trial, patients awaiting esophagectomy surgery were randomly assigned to treatment and control groups. While both groups received a 240 ml nutritional supplement twice daily starting five days before surgery,  patients in the treatment group received an enriched formula with omega-3 (2.2 g of EPA daily).  Immediately following surgery, the supplement was given through a feeding tube for 14 days while patients recovered in the hospital. Once patients could resume oral feeding, they continued drinking the supplement until 21 days post-surgery.

The esophageal research group at Trinity College Dublin and St.  James's Hospital found that patients given the standard feed suffered clinically severe weight loss post-surgery, losing an average of 4 pounds of muscle mass post-surgery, but the omega-3 group patients maintained all aspects of their body composition.

Commenting on the significance of the results, Dr. Ryan said, "The results were extraordinary in the sense that no previous nutritional formulation had revealed such an outcome, with supplemented patients maintaining all aspects of their body composition in the three weeks following surgery. Patients given the standard supplement without omega-3 lost a significant amount of weight comprising 100 percent muscle mass. In fact 68 percent of patients suffered 'clinically severe' weight loss post-surgery in the standard group (without omega-3) versus only 8 percent in the omega-3 group. The significant finding was that the patients did not lose just fat, as one would expect with weight loss, but instead they depleted their muscle stores significantly. Research has shown that a loss of 5 pounds of weight produces significant effects on quality of life and a patient's ability to mobilize and perform simple activities of daily living.  Losing 4 pounds of muscle is even more significant."

Professor Reynolds said, "Omega-3-enriched nutrition appears to prevent loss of muscle mass by reducing the amount of inflammatory markers in the blood: This means the metabolism is not as stressed as it usually is post-surgery.  We also saw that the omega-3 group was less likely to have a fever in the first week post-surgery, which points to the ability of omega-3 to suppress inflammation. Looking at their blood tests, omega-3-fed patients had much lower 'inflammatory compounds' circulating in their blood, which points to the ability of omega-3 to reduce inflammation."

Using specialized nutritional feeds with a highly purified form of EPA, the researchers were able to administer a dose of omega-3 that was much higher than that typically found in food. They noted that treatment with omega-3-enriched supplement is only slightly more expensive than traditional nutritional therapy, and previous studies have yielded significant cost-savings in the form of fewer complications following surgery using immuno-nutrition feeds similar to this. "Initial treatments like this may be cost effective for our cash-strapped health care system," said Dr. Ryan.