Patients who develop infectious complications after undergoing curative surgery for colorectal cancer face a significantly increased risk of death, results from a large retrospective study showed.
“The association of postoperative complications with long-term survival after major surgery has been suggested by several studies in mixed populations and is to some degree expected and intuitive,” authors led by Dr. Avo Artinyan, of the surgery department at Baylor College of Medicine, Houston, wrote online Sept. 1 in Annals of Surgery. “It has been difficult, however, to determine a specific cause-effect relationship, particularly because this association is noted even in patients who suffer late mortality, that is, those who presumably recover from postoperative complications.”
In an effort to investigate the effect of postoperative complications on long-term survival after colorectal cancer resection, the researchers evaluated the records of 12,075 patients from the Veterans Affairs Surgical Quality Improvement Program and the Central Cancer Registry databases who underwent resection for nonmetastatic colorectal cancer from 1999 to 2009 (Ann. Surg. 2014 Sept. 1 [doi: 10.1097/SLA.0000000000000854]). They categorized patients by presence of any complication within 30 days and by type of complication (infectious vs. noninfectious); excluded patients who died within 90 days of the procedure; and performed univariate and multivariate analyses adjusted for patient, disease, and treatment factors.
The average age of the cohort was 69 years, 98% were men, more than two-thirds (69%) had an American Society of Anesthesiologists (ASA) classification score of 3, and 61% had stage 1 or 2 disease. Dr. Artinyan and his associates found that the overall morbidity and infectious complication rates were 27.8% and 22.5%, respectively.
Compared with patients who had no postoperative complications, those who did were older and had lower postoperative serum albumin, worse functional status, and higher ASA scores (P less than .001). Multivariate analysis revealed that the presence of any complication was associated with a 24% increased hazard of death (hazard ratio, 1.24; P less that .001). When the analysis was limited to the type of complication, patients with infectious complications (in particular, surgical site infections) had an increased hazard of death (HR, 1.31), predominately those with severe infections (HR, 1.41).
“To our knowledge, this is the largest single study to examine the association of postoperative complications with long-term survival for CRC,” the authors wrote. “Similar to other groups, we have demonstrated that postoperative complications occur in a significant proportion of patients after CRC resection and that most patients with postoperative morbidity have at least one infectious complication.”
They acknowledged certain limitations of the study, including its retrospective design and the potential for selection bias. “Additional limitations include the absence of margin data – which may have a considerable impact on both the risk of organ-space infections and disease recurrence – and the inability to calculate cancer-specific survival and other cancer-specific outcomes,” they wrote.
“Overall all-cause survival, however, is still a commonly used and useful outcome measure, and we have attempted to mitigate the effect of early non–cancer-related mortality with the exclusion of early deaths.”
The authors reported having no financial disclosures.
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