Clinician Theme 1: Perceptions about the order of staged resections

All clinicians expressed concern at the lack of evidence base to guide the order of staged resections in patients who were currently asymptomatic or not requiring emergency bowel intervention. Clinicians, particularly colorectal surgeons, were concerned that leaving the bowel primary in situ risks

subsequently developing a bowel emergency such as obstruction or perforation. This was also the point of view from an oncologist, that once the bowel primary was resected, it eliminates the risk of bowel perforation or obstruction (particularly more so if the patient is symptomatic from the bowel tumour).

Part of the concerns if you were to leave in situ to perform a liver resection, you would potentially put the patient at risk of developing emergency bowel

presentations. (colorectal surgeon)

My preference is to take the bowel out first. That's the offending neoplasm, that's the metastatic seeding source and I'd like to take control of that, and it’s the one that's going to cause more acute emergency presentations. (colorectal surgeon) I know it doesn’t, but my gut feeling is that I want to primary out first. Every week at MDT when we discuss this, I have a huge problem going liver-first, or going chemotherapy, then liver then bowel, because to me, if the primary is still there, it’s

still sending out all the seedlings and I’ve just got an issue with that. (colorectal surgeon)

And so it’s often more straightforward when the patient has had the bowel tumour resected before you start the chemo because you’re just worrying about the liver. So I know that’s slightly anecdotal, but I guess that’s one of the things when a patient is quite symptomatic, you might as well just get on and do the bowel. (oncologist)

The indications for a liver-first resection are also limited, with one clear indication being the

‘therapeutic window’ between long course chemoradiotherapy and the bowel resection. Progression of the liver metastatic disease did not appear to be a deciding factor from a colorectal point of view.

I’ve always been under the impression that the role for liver-first is quite limited... The first indication is if you have synchronous disease where the primary is in the rectum and needs some sort of radiotherapy… - short or long – and then perform the liver resection while you wait to do the bowel surgery.... The other option is when you have unresectable liver disease - borderline unresectable disease - at presentation. You give neoadjuvant chemotherapy. The lesions in the liver shrink, and shrink to a level where they become resectable…. In that case, a reverse approach is advisable to clear the liver while its resectable, so to avoid losing control of the disease. (HPB Surgeon)

if you’re looking at somebody who is needing long course, then in many ways that defines quite a bit of the pathway, and you’re trying to fit your other interventions around it. (Oncologist)

Yes, the liver can progress, but typically, if the liver does progress, it would have progressed anyway... that's what we've seen. (colorectal surgeon)

There was also a belief amongst both HPB and colorectal surgeons that the bowel primary is the source of metastatic disease, and that leaving the bowel primary in situ risked further seeding of tumour through the portal venous system to distant organs and thus developing more extensive metastatic disease. From a radiologist’s point of view, this belief seems less important so long as the disease is resectable, although they can appreciate the patient’s point of view and the psychological impact.

We want to neutralise the primary tumour before it spreads further, and also to give time for the disease to declare itself. So, I can’t think of a scenario where I would perform a reverse approach in a patient who is chemo-naïve. (HPB Surgeon)

I always think doing the bowel first seems sensible because you’ve removed the source of the metastases. I can also understand why people say do the liver first because if that gets out of control, it becomes more difficult and less likely to be resectable and therefore curative. (colorectal surgeon)

Effectively, I see disease and I want to get rid of all of it as soon as possible. In terms of the radiology side of things, I don't think it really matters. I get the theory that this is the tumour and it’s going to spread if it’s still in there, but it’s going to resection because of the fact that there's something that's resectable… I suppose if its borderline, I would go for the bowel resection anyway, because like I said, it’s a psychological thing for the patient as well. (radiologist)

Clinicians also felt that patients would prefer the first surgery to remove the bowel primary, which they perceive as the ongoing source of the metastatic disease. For bowel-first and synchronous surgical strategies, clinicians feel it’s an easier discussion to have with their patients regarding surgery. A liver- first strategy is more difficult to discuss as there is a perception (from both the clinician and the patient) that the source of the problem is not being treated.

It’s really difficult, because they’re going to say ‘it’s already spread, and if you leave it in, isn’t it going to spread even further?’ That’s really difficult to answer.

(colorectal surgeon)

I think it depends on how you explain it to them. If you explain the rationale behind the decision, most patients are agreeable to it. I think its easiest to explain to someone that they’re having a synchronous resection, because from their point of view, everything is being dealt with in one go. (colorectal surgeon)