Can blood loss during surgery predict recurrence and survival?

This study investigated if the amount of blood lost during surgery to remove metastatic tumors (cancer spread to distant organs of the body) on the liver from primary colorectal cancer (CRC) could be used as an indicator of long term survival and tumor recurrence (return of the cancer).

The liver is a common site for CRC to spread to. Left untreated, the prognosis of cancer once it has spread to the liver is generally poor. However, if the tumors on the liver are successfully removed, the 5 years survival (the percentage of patients who survive for at least 5 years after treatment) for these patients is approximately 58%. Nevertheless, surgery to remove tumors from the liver and be difficult and risky. The liver has a very rich blood supply and blood loss during surgery is a concern for surgeons. This study aimed to evaluate whether the volume of blood lost during surgery to remove liver metastases can indicate tumor recurrence and long term survival in CRC patients.

Information was collected for 139 patients who had surgery between January 2005 and December 2011 to remove liver tumors which had spread from primary CRC. The surgery in all of these patients was curative (the patient had no signs of cancer, either primary or metastatic, after the surgery). After an average of 3 years of follow up, researchers found that the volume of blood lost during surgery was significantly higher in patients with higher body mass index (overweight or obese patients), higher number of tumors on the liver and larger CRC tumors. The number of patients surviving 5 years after surgery was also associated with the amount of blood lost during surgery. A loss of less than 250 ml resulted in a 71% 5-year survival, which decreased to 33% when 250–500 ml of blood was lost and to 0% when more than 500 ml was lost. The rate of recurrence one year after surgery showed a similar trend. As the volume of blood loss increased during surgery the number of people experiencing a recurrence increased.

In summary, the volume of blood lost during surgery to remove liver metastasis from primary colorectal cancer is a good indicator of long term survival and cancer recurrence.

This study evaluated patients who were treated in the past (retrospective study), rather than following patients throughout their treatment and determining their outcomes. Retrospective studies are known to provide weaker statistical information.