Only 0.19% of cholecystectomy patients had incidental gallbladder cancer, and incidence was just 0.03% in patients who lacked risk factors for the malignancy, according to investigators. The report was published in Annals of Surgery.
The results were lower than historical reports, probably because cholecystectomy has been increasingly performed in younger patients, said Dr. Susan Pitt of Washington University, St. Louis, and her associates.
The investigators reported that significant risk factors for incidental gall bladder cancer (iGBC) included open (vs. laparoscopic) cholecystectomy, older age, Asian or African-American race, female sex, and an elevated alkaline phosphatase (ALP) level (Ann. Surg. 2014 Feb. 6 [doi:10.1097/SLA.0000000000000485]).
The retrospective cohort study included 91,260 patients aged 16 years and older who underwent laparoscopic (n = 80,924 [88.7%]) or open (n = 10,336 [11.3%]) cholecystectomy from 2005 to 2009. Patients were identified through the American College of Surgeons-National Surgical Quality Improvement Program Participant Use File.
Only 0.05% of laparoscopic patients had iGBC, vs. 0.60% of laparoscopic converted to open cholecystectomy patients (P less than .001) and 1.13% of open cholecystectomy patients (P less than .001), the researchers said. Multivariable predictors for iGBC included open vs. laparoscopic approach (odds ratio, 12.0; 95% confidence interval, 8.5-16.7); age 65 years or older (OR, 5.3; 95% CI, 3.7-7.4); Asian (OR, 2.2; 95% CI, 1.1-4.4) or African-American race (OR, 1.7; 95% CI, 1.1-2.6); alkaline phosphatase level 120 units/L or greater (OR, 1.7; 95% CI, 1.3-2.3); and female sex (OR, 1.6; 95% CI, 1.1-2.2).
"Even in the presence of all these risk factors, the incidence of iGBC is only 1.4%, although it is nearly 50-fold higher than a patient without any risk factors," Dr. Pitt and her associates wrote. Identifying patients at risk of iGBC before surgery "might allow a surgeon to be prepared to perform an adequate R0 resection at the initial procedure or refer the patient to a center with expertise in liver surgery, especially in the presence of a gallbladder polyp or mass on imaging," they added.
Within 30 days of surgery, patients with iGBC had significantly higher rates of death, serious morbidity, overall morbidity, surgical site infection, and organ space surgical site infection (P less than .001 for all outcomes), the researchers reported.
The study database lacked information on symptoms, preoperative diagnoses, or diagnostic studies specific to gallbladder disease, Dr. Pitt and her coworkers noted. The large sample size increased the possibility of type I error because small differences might reach statistical significance even if they lacked clinical importance, they added.
The authors received no funding for the study. One of the investigators, Dr. Bruce Hall, is a paid consultant for the American College of Surgeons.