61 | 6 key considerations when caring for GI neoplasia patients (featuring OncologyRVN)

PodcastGastroenterologyChronic Disease
Written By Laura Jones

Today is no normal day on the Medical Nursing Podcast - we’ve got a special guest helping me debunk (or should that be debulk?!) GI neoplasia.

 

That’s right - today we’re talking all things gastrointestinal tumours - which ones we see, how they affect our patients, how we diagnose them, and what treatment options we have. And, of course, most importantly, how we can support these patients as veterinary nurses and technicians.

If you want to learn exactly how to support these patients, then read on, because Inge Breathnach (RVN and oncology VTS, aka OncologyRVN) and I are here to help you do just that.

So, what gastrointestinal cancers do we see, and how do they affect our patients?

When it comes to gastrointestinal tumours, we have a whole list of tumour types we see in both dogs and cats, with a variety of locations in the alimentary tract. It’s quite extensive, and I’ll discuss mainly 3 types today, with a brief nod to benign tumours, too, because some of these we can cure with surgical resection.  

Let’s talk about adenocarcinoma (ACa)

Adenocarcinoma is an epithelial cell tumour. Epithelial cells line body cavities and organs and cover the internal and external surfaces of the body. 

ACa is the most common gastric malignant tumour in dogs, although it can also be found in the colon and rectum. Cats rarely develop a gastric form; they are far more likely to develop it in the small intestine.

In terms of dog breeds and ages, we usually see this in older dogs, with males slightly more represented than females. More commonly affected breeds are collies, staffies, Belgian shepherds, chows, and Norwegian Lundehunds. 

Intestinal tumours are overrepresented in Siamese cats, although realistically, I think most of what we see in practice is domestic shorthaired cats. 

ACa is most commonly found in the lesser curvature of the pylorus, but we can see it as a diffuse thickening of the stomach. Interestingly, humans have an intestinal form, which they suspect is a progression from gastritis to metaplasia to dysplasia, but dogs are more likely to have a diffuse form, which is caused by DNA mutation. 

In cats, there is some suggestion of a link between Helicobacter spp., although it’s hard to tell if it’s a causative agent or just normal gut flora that’s coincidental. In terms of prognosis, patients with an intestinal adenocarcinoma tend to have a better prognosis than those with a gastric one because it’s really difficult to surgically resect them when they are in the stomach, especially with the more diffuse forms. 

And then there’s lymphoma.

The second type of GI cancer I’m going to mention is lymphoma, which is a round cell tumour and is often called a ‘liquid’ tumour, meaning that it’s a cancer of blood and lymph. 

Lymphoma is the most common GI tumour we see in cats, and alimentary lymphoma is the most common form of lymphoma we see in cats in general. There is a link between lymphoma and FeLV/FIV in cats, although, in general, we see fewer cats with these viruses than we used to. 

It is multifactorial as to why lymphoma occurs anyway, though again, it’s usually older cats, and again, there is a bias towards domestic shorthair and Siamese cats. GI lymphoma in cats is either low-grade alimentary lymphoma (which is a bit more indolent and has a good prognosis), intermediate/high-grade alimentary lymphoma (which can range from poor to okay prognosis), or large granular lymphoma (which has a poor prognosis). 

Alimentary lymphoma is less common in dogs, accounting for around 5% of all canine lymphomas (the multicentric form being the most common). Most GI lymphomas in dogs are of T-cell origin, and boxers and Shar Peis are overrepresented. They tend to be relatively diffuse, and many have quite a poor prognosis unless they’re a rare localised tumour that can be removed. A more indolent small cell form has been reported that carries a more optimistic prognosis. 

What about connective tissue tumours?

Next, let’s talk about Leiomyosarcoma (and Leiomyoma, the benign version of this tumour), as well as gastrointestinal stromal tumours or GISTs. These are all mesenchymal tumours, which make up connective tissues. 

Leiomyosarcomas are more commonly found in the stomach and small intestines in the area of the cardia, while GISTs are more likely to be found in the large intestine. GISTs and Leiomyosarcomas are hard to differentiate, and studies vary on prognosis. 

Why is this? It’s suspected that historically, many cases reported as leiomyosarcomas were actually GISTs, which means that the rates of metastasis reported may well be skewed. Again, these occur in older dogs, and males are overrepresented. They’re rare in cats but, again, tend to be seen in older patients. 

And then there are our benign tumours.

Finally, for some relief from the badness, we have the benign tumours: gastric adenomas, polyps, and the aforementioned leiomyomas. 

These can do really well if they’re surgically resectable. We like diagnosing these over the other tumours because we can do much more for patients with them!   

Okay. Thanks to Inge, we know what tumours we’re dealing with. But what clinical signs do these patients present with?

The clinical signs we see in our GI neoplasia patients depend on several factors: the tumour’s location, the extent of its growth, whether it has metastasised, and whether any paraneoplastic syndromes (such as hypoglycaemia or hypercalcaemia) are present.

That being said, the most common clinical signs associated with GI neoplasia include:

  • Vomiting

  • Anorexia

  • Weight loss

  • Diarrhoea

  • Lethargy

Haematemesis and/or melena may be present in patients with gastrointestinal haemorrhage or ulceration due to their tumour, commonly seen in patients with leiomyomas or leiomyosarcomas.

Tumours in the colon or rectum are likely to cause haematochezia and tenesmus, whereas tumours in the small intestine are most commonly associated with anorexia, weight loss and diarrhoea.

What complications can we see in GI neoplasia patients, and how do they present?

Patients with discrete intestinal masses commonly present with intestinal obstruction, similar to those with a foreign body. Signs include abdominal pain, weight loss, intractable vomiting, dehydration and potential signs of aspiration.

Gastrointestinal perforation is always a risk to be aware of in patients with GI neoplasia. If this occurs, the patient will present with an acute abdomen, often with signs including hypotension, bradycardia, vasodilation, abdominal pain, and abdominal effusion (which could be septic due to the contamination from intestinal content leaking into the abdominal cavity). These patients require rapid stabilisation and surgical correction to repair the perforation and remove the abnormal tissue (where possible).

And what about paraneoplastic syndromes? What other signs do we see?

Several paraneoplastic changes have been reported in patients with gastrointestinal neoplasia. These include hypoglycaemia, alopecia, erythrocytosis (increased RBC count), hypercalcaemia and even nephrogenic diabetes insipidus. The most common of these is hypoglycaemia, which has been reported in over 50% of dogs with intestinal smooth muscle tumours.

Clinical signs in a hypoglycaemic patient are usually neurological since the central nervous system is the body’s largest user of glucose. Things like mentation changes, ataxia, and even seizures are possible. This hypoglycaemia is usually episodic because emergency hormones like adrenaline and cortisol will kick in and rapidly correct glucose levels.

Ok, so those are the common signs we see - but what about when we examine these patients?

Clinical examination often doesn’t reveal any specific changes indicating GI neoplasia, and many findings are similar to those of our other gastrointestinal patients. Signs of dehydration (tacky mucous membranes, sunken eyes), abdominal discomfort (in some cases), reduced body weight, and a poor body condition score are often noted, though not always. 

Patients with generalised intestinal neoplasia (e.g. small cell lymphoma) do not have a distinct mass that you can detect on palpation, though the intestine may feel thickened and abnormal. Other tumours, such as large cell lymphoma, will cause a distinct intestinal mass that may be more obvious on abdominal palpation.

Other signs noted include abdominal effusion in the case of intestinal perforation or where patients have disseminated cancer or spread to the peritoneum lining the abdominal wall.

It’s also important to note that rectal examination is essential in patients presenting with haematochezia or tenesmus who may have a palpable rectal mass. A thorough exam generally requires anaesthetic or sedation, especially as these patients are often uncomfortable and will require sedation for diagnostic imaging anyway.

And how do we diagnose them?

Like many other medical patients, our diagnostic approach starts with biochemistry and haematology, followed by diagnostic imaging.

As veterinary nurses and technicians, we are heavily involved in this process, performing blood tests, supporting patients with ultrasounds, and assisting with sampling and other diagnostic procedures. This means we must know which procedures are indicated and what results we might see.

Let’s start with bloodwork.

Though we don’t see specific changes associated with GI neoplasia on our patient’s blood results, we can see a lot of abnormalities, including:

  • Hypoglycaemia or hypercalcaemia due to paraneoplastic causes

  • Anaemia due to gastrointestinal haemorrhage

  • Hypoalbuminaemia due to gastrointestinal haemorrhage or protein-losing enteropathy

  • Hypochloraemia due to vomiting

  • Hypokalaemia due to anorexia

  • Azotaemia due to gastrointestinal haemorrhage

  • Metabolic acidosis or alkalosis due to diarrhoea or vomiting

And then we have imaging

Like most of our GI patients, x-rays don’t provide the detail we need to investigate and diagnose GI neoplasia. Instead, we prefer ultrasound, CT or both when diagnosing these patients.

Ultrasound commonly reveals focal or diffuse thickening throughout the GI tract, with abnormalities in the layers of the intestinal wall. Distinct masses may be obvious, and enlarged lymph nodes, hepatomegaly or splenomegaly may also be seen.

We don’t always see these abnormalities, though. In one study looking at gastric tumours in dogs and cats, we saw only 50% of cases on ultrasound but 95% with endoscopy. So, a normal ultrasound doesn’t equal a normal patient!

Of course, we’re not just interested in the GI tract. Many tumours metastasise to the lungs or other abdominal organs, and thoracic imaging, in addition to abdominal ultrasound, is vital.

Speaking of endoscopy, let’s chat about sampling.

Imaging is only a small piece of the puzzle—we’ll need to sample the GI tract to identify the tumour present and begin appropriate treatment.

There are a few ways to do this, and which route we choose depends on the individual patient and the size and location of their disease.

Our options include FNAs, endoscopic biopsies or surgical biopsies.


Fine needle aspiration (FNA) 

FNAs are useful for distinct masses, enlarged lymph nodes, or thickened areas of the GI wall, but they are more likely to produce non-diagnostic results.

Endoscopic biopsies 

These can be useful in patients with gastric, small intestinal and colonic neoplasia. The jejunum (middle portion of the small intestine) cannot be reliably reached endoscopically, so abnormalities there need to be accessed surgically. In addition, changes in the deeper layers of the intestinal wall may be missed on endoscopic biopsies, as they are partial-thickness.

Surgical biopsies

Surgical biopsies involve the complete removal of a portion of the abnormal tissue. This may be an incisional biopsy, where a small (2-5mm) tissue segment is removed, or an excisional biopsy, where a discrete intestinal mass is completely removed. Some patients will not be candidates for surgical biopsies due to the risk of impaired healing and surgical site breakdown (e.g., patients with very low albumin levels)—where possible, endoscopic biopsies are preferred.

Once your samples are collected, they are submitted for cytology (FNAs) or histology (biopsies) and any additional tests are performed as required.

What other tests do we perform?

Histology and cytology can be used to determine the grade (severity) of the tumour, which gives us an idea of its aggressiveness and helps us determine an appropriate treatment protocol.

However, additional tests may be required to identify the tumour subtype or specific characteristics of that tumour—for example, whether a lymphoma is B-cell or T-cell in origin.

We’ll use all of this information - the tumour type, grade, subtype (if applicable) and the presence of metastasis or paraneoplastic syndrome - to guide our treatment and nursing care.

Ok, so you’ve diagnosed your patient with gastrointestinal neoplasia. What do you do next?

Well, it depends.

Again, treatment will depend massively on the diagnosis and the presence of metastasis, which is why we are staging these patients with additional imaging. 

ACa is often located late, and therefore, it has usually metastasised by the time we’ve diagnosed it. About 70-80% have locoregional metastasis, which might be to the local lymph nodes, or the tumour might have exfoliated (shed) tumour cells directly into the abdomen. 

This means our abdominal organs might be affected, like the spleen, liver, and pancreas, so we want to make sure we are biopsying anything that looks concerning. 

Lung metastasis is less common but also possible, so lung metastases should definitely be imaged. Our smooth muscle tumours will metastasise to similar places as the ACas, but slower. If you haven’t already, it’s worth staging these patients fully, with advanced imaging and abdominal ultrasound, sampling anything abnormal, including any regional lymph nodes, even if they look normal.  

Let’s talk surgery.

Except for lymphoma, if we have a solitary lesion with no metastasis, surgery is usually going to be our mainstay. 

For something benign like our leiomyoma, we might be able to just do a marginal curative surgery. However, we might need a more extensive surgery with larger margins for a more aggressive tumour. 

Gastric tumours are more challenging to remove surgically, and intestinal tumours are a bit easier where we can perform resection and anastomosis. 

There are some risks with surgery, things like sepsis or peritonitis, and it’s important to remember that if we have diffuse tumours, that tissue isn’t going to heal if we perform surgery. 

If we have to perform rectal surgery, we also have a risk of faecal incontinence, stricture, wound dehiscence and infection, which is where really good nursing care is going to make all the difference. 

So, for many of these malignant cases, surgery is risky, and there is a high mortality rate, but most seem to achieve better survival times if they make it through surgery than if it isn’t attempted at all. 

However, sometimes surgery can also be palliative. Just by resecting what we can, we can reduce bleeding, remove ulceration, or relieve obstruction and give our patients significant relief from vomiting. We can also resolve paraneoplastic hypoglycemia with surgery.  

What about managing lymphoma?

Solitary tumours are rare in dogs, though, when present, they can be surgically excised. Otherwise, we are looking at chemotherapy. 

For rare small cell T cell Lymphoma cases, we would treat them with prednisolone and chlorambucil, which can yield good results. Most GI lymphomas, however, are treated with a CHOP-based protocol, but they don’t tend to have a great prognosis. 

Again, in cats, if there is a large discrete lesion, obstruction, or perforation, we may perform surgery and then follow up with chemotherapy. 

For intermediate/high or large granular lymphoma, this is usually a COP or CHOP-based protocol, with a middling to poor prognosis. 

For low-grade lymphoma, we can get good survival times with chlorambucil and prednisolone; some of these cats do really well. 

And managing our other tumours medically? How will we do that?

Regarding adjuvant chemotherapy for other tumours, we don’t have much evidence that it’s massively useful using most drugs. 

Sometimes, we use doxorubicin or carboplatin as injectable agents. 

We use tyrosine kinase inhibitors for some of these tumours that express T-kit proteins – so treatments like toceranib (Palladia) and we often use COX-2 inhibitors (as intestinal carcinomas express COX-2). 

It’s essential to be careful, though, as if we have gastric ulceration or diarrhoea, we probably don’t want to use NSAID COX 2 inhibitors.  

Finally, radiotherapy tends not to be used in these cases, as we have a lot of organs at risk from treatment, and we could well make our patient very unwell. 

Ok, so that’s treatment taken care of. But what do we need to think about when nursing these patients?

The nursing care we provide these patients depends on whether they’re an inpatient or an outpatient.

What about when they’re in the hospital?

Our GI neoplasia inpatients have nursing considerations similar to those of our other GI diseases - they’ll have the same clinical signs, and so much of our management is the same. Areas to focus on include:

  • Providing nutritional support

  • Fluid therapy administration and monitoring

  • Managing eliminations, particularly defecation

  • Bathing and skin and coat care, especially around the perineal area, hindlimbs and tail

  • Monitoring, particularly for complications such as anaemia or sepsis

  • Providing sufficient vascular access (whilst leaving ‘clean’ veins for injectable chemotherapy where needed)

  • Managing nausea and vomiting

  • Assessing pain and providing analgesia

But our care doesn’t stop when these patients are discharged—there’s a lot more we can do to support them as they return for chemotherapy and reassessment.

So what can we do to help these patients long-term?

There is a lot to think about when nursing cancer patients long-term. Our role as nurses and technicians is really to advocate for those patients and maximise their overall wellbeing, including:

  • Providing patient-centred care

  • Supporting caregivers with ongoing pain assessment and management

  • Nutritional support

  • Providing supportive management of vomiting, diarrhoea and nausea

  • Providing environmental enrichment and support

  • Educating caregivers about chemotherapy health and safety and anticipated side effects

  • Providing QOL support and education, particularly when the disease has progressed

  • Providing end-of-life support where needed

  • Providing general support to clients and caregivers.

So there you have it! An overview of the most common gastrointestinal cancers we see, how they affect our patients, and how we can use that information to provide tailored treatment and nursing care—while using a load of our nursing skills!

Plus, the six keys to giving that great care: consider the patient’s disease process and clinical signs, stabilise and support emergency patients, assist with diagnostics, treat and support them in the hospital, continue that contextualised care at home, and remember their quality of life above all.

Thanks so much for joining us for another podcast episode! Huge thank you to Inge for coming to chat with us all about oncology-specific considerations for these patients, and a huge thank you to you for learning with us both. 

Did you enjoy this episode? If so, I’d love to hear what you think. Take a screenshot of it and tag me on Instagram (@vetinternalmedicinenursing) so I can give you a shout-out and share it with a colleague who’d find it helpful!

References and Further Reading

Laura Jones
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