S1316: Surgery Can Help Bowel Obstruction Symptoms

The study has generated much-needed evidence aiming to guide clinicians in managing bowel obstructions in patients with cancer who are terminally ill.

Malignant bowel obstruction (MBO) is a common complication faced by patients with GI and GU tumors, and it can cause significant suffering in terms of nausea, vomiting, bloating, and pain. MBO can be approached surgically or non-surgically, but thus far, there has been no accepted algorithm for making this decision with many patients.

S1316 has generated some of the evidence to inform this choice. The trial enrolled 221 patients with an abdominal or intra-peritoneal primary cancer, who presented with MBO. To be eligible, patients had to be considered candidates for surgery.

The trial deployed an interesting hybrid design incorporating both a randomized pathway and a patient-choice pathway. All enrolled patients were given the opportunity to be randomized to surgical vs. non-surgical treatment. Those who chose not to be randomized (about three-fourths of patients) were registered to the patient-choice pathway and with their doctor decided for themselves whether to undergo surgery.

The primary outcome measured was the number of days a patient was alive and out of the hospital – appropriately termed “good days” – during the three months following trial registration.

The S1316 team found the number of good days did not vary significantly between patients who underwent surgery for their obstruction and those who did not. Patients’ ability to eat, and 90-day survival rates, were also similar across arms.

What did vary between those two groups, though, was the patients’ experience of symptoms. On average, at week 4, those who had had surgery reported better symptom severity scores for vomiting, constipation, nausea, and pain. And among patients who were hospitalized for MBO, those who had surgery reported fewer MBO symptoms once they left the hospital.

The takeaway message from the trial is that for patients with advanced cancer who develop an MBO, those who are good candidates for surgery are likely to experience better symptom management and quality of life if they go ahead with that surgery. Being able to advise patients of this in a palliative care setting, drawing on evidence from a randomized prospective trial, is a real advance in our ability to care for these patients. We’re indebted to the large team of professionals who made this trial happen and most of all to the patients who participated in the study.

We’re particularly indebted to S1316 study chair Dr. Robert Krouse, who is also a co-chair of our palliative and end-of-life care committee. He championed the idea of this study over quite a lengthy period. You can learn the details, as related by Dr. Krouse himself, in this recording from the spring 2021 group meeting.

S1316 is the largest prospective study ever done comparing surgical to nonsurgical approaches in treating MBO, and it’s the first to include a randomized pathway comparing these approaches. The results give clinicians a stronger base of evidence to build on in discussing MBO treatment options with their patients.

The study team is far from finished in terms of learning from the wealth of data collected, which includes data on diet and on various quality-of-life measures. Stay tuned for future lessons. For now, I recommend you read the paper and our press release on it.
 

Registration for SWOG’s fall 2023 group meeting is slated to open next Tuesday, August 8th. Check the website that day for a link, or watch your email. I’ll have more to say about our group meeting in next week’s Front Line.

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Trial of the Week

S2212: Shorter Anthracycline-Free Chemo Immunotherapy Adapted to Pathological Response in Early Triple Negative Breast Cancer (SCARLET), A Randomized Phase III Study

Activated just two weeks ago, S2212 is a classic example of a trial that could only be done as a “public powered” study. Whereas phase III randomized trials typically start with a standard treatment control arm and then add an investigational agent or two, S2212 starts with a standard treatment arm and removes an agent or two (in this case, two).

The trial compares a standard four-chemo-drugs-plus-immunotherapy neoadjuvant regimen for triple negative breast cancer to that same regimen minus doxorubicin and cyclophosphamide.

The primary objective is to look for non-inferior breast cancer event-free survival in the investigational arm. The trial also includes an extended set of patient-reported outcome (PRO) objectives looking at whether removing the anthracyclines from the neoadjuvant regimen leads to better patient quality of life, primarily using measures of patient fatigue and physical function.

The study is chaired by Dr. Priyanka Sharma, of the University of Kansas Medical Center, with international co-chair Dr. Zahi Mitri, of the British Columbia Cancer Agency.

Fifty sites have already activated this de-escalation trial in its first two weeks. Who wants to be #51!

Learn more at the SWOG S2212 page or the CTSU S2212 page.