AT WSA 2016

CORONADO, CALIF. – Among advanced cancer patients with bowel obstruction, surgery was not an independent predictor of the ability to eat at discharge or survival within 90 days of consultation, results from a long-term retrospective study showed.

“I think this represents the complexity in treating these patients,” lead study author Brian D. Badgwell, MD, said at the annual meeting of the Western Surgical Association. “We need future studies to identify the optimal outcome measures.”

In a previous study, he and his associates found that bowel obstruction was the most common reason for palliative surgery consultation among oncology inpatients ( Support Care Cancer. 2009;17[6]:727-34 ). “It gets complex, because patients with a history of abdominal cancer surgery have benign causes [for bowel obstruction],” said Dr. Badgwell , a surgical oncologist at the University of Texas MD Anderson Cancer Center, Houston. “[Bowel obstruction from benign causes] in the literature ranges from 3% to 48%. Adding to this complexity is that the optimal outcome measure for bowel obstruction is not defined. It’s very easy to tell when things have gone bad in terms of morbidity and mortality, but we’re not as good at telling when things go right.”

For the current study, the researchers retrospectively reviewed the medical records of 490 patients who required surgical consultation for bowel obstruction at MD Anderson Cancer Center between January 2000 and May 2014. They set out to determine the incidence of obstruction due to intra-abdominal tumor and to identify variables associated with the ability to eat at hospital discharge and 90-day survival. They excluded patients without clinical or radiologic features of mechanical bowel obstruction. Clinical variables of interest included obstruction site, tumor vs. non-tumor cause, laboratory parameters, radiologic extent of malignancy, and the type of treatment performed (surgical, medical, or interventional, defined as interventional radiology or endoscopy). Overall survival was calculated from the date of first surgical evaluation for bowel obstruction to any cause mortality or last follow-up. Univariate and multivariate analyses were performed for ability to eat and a Cox proportional hazards model for 90-day survival.

Dr. Badgwell reported that the most common obstruction site in the 490 patients was the small bowel (64%), followed by large bowel (20%) and gastric outlet (16%). Obstruction etiology was identified as tumor-related in 68% of cases, followed by adhesion-related (20%) and unclear (12%). Nearly half of patients (46%) received chemotherapy within 6 weeks of their surgical consultation, but only 4% were neutropenic. More than half of patients (52%) had an albumin level of less than 3.5 g/dL, 52% had a hemoglobin of 10 g/dL or greater, 36% had lymphadenopathy, 35% had ascites, 34% had peritoneal disease, and 31% had a primary or recurrent tumor in place. In addition, 53% had an abdominal visceral malignancy, 9% had bone metastases, and 14% had lung metastases.

About half of patients (49%) received medical management as their treatment, followed by surgical and procedural treatment (32% and 17%, respectively). Fifteen percent were discharged to in-home hospice or to an inpatient hospice facility. More than two-thirds (68%) were able to eat at the time of discharge, and 43% died within 90 days of surgical consultation.

Multivariate analysis revealed that the following factors were negatively associated with eating at discharge: an intact/primary local recurrence (odds ratio, 0.46), carcinomatosis (OR, 0.34), and albumin level of less than 3.5 g/dL (OR, 0.55). At the same time, variables associated with death within 90 days of consultation included having an intact primary/local recurrence (hazard ratio, 1.75), carcinomatosis (HR, 1.98), and abdominal visceral metastasis (HR, 1.75). Finally, compared with procedural treatment, both medical management and surgical management were negatively associated with death within 90 days (HR of 0.51 and 0.44, respectively).

“There is a high rate of non-mechanical bowel dysfunction in patients undergoing surgical consultation for bowel obstruction,” Dr. Badgwell concluded. “It’s very difficult to categorize these cases preoperatively. They do require a selective approach. Variables associated with outcome measures support caution in patients with carcinomatosis, hypoalbuminemia, and multiple sites of disease on imaging.”

Dr. Badgwell reported having no financial disclosures.