Let me introduce you to some of my oncology patients

 Lexie, a 9 year old, female neutered, Labrador retriever   
She was presented to me with a generalised form of epitheliotropic lymphoma (skin and mucous membranes). Lexie suffered from a severe pruritus (itchiness) and secondary skin infections. Lexie was started on a drug called Lomustine, an anticancer drug that is given orally every three weeks. However, Lexie only achieved a partial and short-lived response. After a short period of time, the lomustine was swapped to a tyrosine kinase inhibitor (TKI), which managed to keep the disease stable.

Epitheliotropic lymphoma

is a relatively rare form of lymphoma in dogs and it originates from T lymphocytes.

It can manifest itself as a localised disease, affecting eyes, mucous membranes of the nose/ eyes, etc. The dogs can also be affected by the generalised form of the disease, where the cancer is widespread (skin, mucous membranes, etc). The treatment of choice in the generalised form is chemotherapy and the drug of choice is Lomustine. TKIs can also have a beneficial effect in some canine patients. Some dogs also benefit from glucocorticosteroid and wide spectrum antibiotic therapy.

Jess, a 10 year old, female neutered, Labradoodle
She was brought in to me for a consultation because of a severe drooling and moderately reduced appetite and mid lethargy. During investigations, a growth at the base of the tongue was found, biopsy of which was compatible with a squamous cell carcinoma (SCC). 

Jess underwent a laser removal of the tumour followed by an adjunctive carboplatin chemotherapy which resulted in a complete response. Unfortunately, after some time the mass started to grow back which was a cause of an increasing discomfort for Jess. Jess underwent a procedure called brachytherapy (a localised form of radiation therapy) which she completed without any complications and side effects and achieved a complete response.

Tumours of the base of the tongue

are very challenging to treat, mainly due to their location and oftentimes advanced stage of the disease at the time of presentation.

Due to their location, a complete excision is seldome achieved. Brachytherapy is a form of radiation therapy which allows a delivery of higher doses of radiation to more specific and tricky areas of the body without causing side effects from the nearby healthy tissue/ organs. During the brachytherapy treatment , radiation source is placed directly in the tumour which results in a delivery of a relatiely high dose of radiation within the tumour with concurrent very low dose ditribution to the nearby healthy tissue/ organs. In people, brachytherapy is often used in an adjuvant setting in the treatment of women with breast cancer. Jess’ case was probably the only case in the UK and Europe where brachytherapy was used as part of the multimodality approach.

 Bobby, a 12 year old
Domestic shorthair cat. He was presented to me following an earlier removal of a growth from the base of his tongue, histopathology of which was compatible with an incompletely excised SCC. 

Unfortunatelly, due to the tumour location, often an advanced stage of disease at the time of presentation and very aggressive local behaviour, this tumour type in cats is a a challlenge to treat and carries grave prognosis. All treatment options are palliative in nature. Very important component in the treatment plan in cats affected by this tumour is pain relief and feeding/ nutrition.

Ben, an 8 year old, male neutered, Border Collie
Ben was brought to me by his lovely owners because of a quickly progressing deformation of the head/ frontal area. Computed tomography (CT) revealed a large mass afftecting the frontal sinus histopathology of which was compatible with a frontal sinus SCC. 

Ben underwent a course of radiation therapy which initially shrunk the tumour mildly/ moderately. Unfortunately, soon after completion of the radiation protocol, Ben’s tumour started to grow back at which point the owners declined further treatment.

Primary frontal sinus carcinomas are very rare neoplasms in dogs. Due to their „difficult” location, the treatment is very challenging. Treatment options that can be offered in the management of these tumours, are: radiation therapy; chemotherapy; TKIs; surgery.

Tango, a 10 year old, male neutered Greyhound
Tango was presented to me during my weekend emergency shift. Tango had difficulty breathing due to his massively enlarged submandibular (and most likely cervial) lymph nodes. These enlarged lymph nodes pressed on the lymphatics and the trachea, the result of which was dyspnoea (difficulty breathing) and caval syndrome (swelling of the head and neck). During clinical examination, all of the peripheral lymph nodes were enlarged. A fine needle biopsy of some of the peripheral lymph nodes was performed for cytological and immunophenotypic (flow cytometry) examination, and the results were compatible with a B cell multicentric lymphoma. Tango was treated with chemotherapy (CHOP protocol) which he tolerated very well and achieved a complete remission.

Canine multicentric lymphoma can be either of B or T cell origin. The diagnostic methods that allow the differentiation between the two cell types, are: flow cytometry; immunocytochemistry; immunohistochemistry; PARR.

The treatment of choice in canine lymphoma is chemotherapy and most dogs will respond favourably and completely within a short period of time. The type of chemotherapy protocol chosen to treat the patient depends on whether it is a B or T cell lymphoma. The most commonly used and implemented chemotherapy protocols, are: CHOP, COP and LOP.

 Coffeebean, 4 years old, Domestic shorthair cat
Coffeebean was presented to me with a growth on his head, in between the eyes. The growth was hard to touch and fixed. The biopsy of the mass was performed and the results were compatible with a fibrosarcoma. Computed tomography of the head and thorax were performed and they reveleaed the mass to not be penetrating the skull and no signs of secondary tumour spread to the chest. 

Coffebean underwent a surgical excision of the mass however due to its location and the close proximity to the vital structures, there was no possibility for a margin of a normal, healthy tissue around the mass to be removed in surgery. In addition, Coffeebean was prescribed an adjuvant radiotherapy treatment in order to get rid of the remaining neoplastic cells. Coffeebean tolerated both the procedures very well with no side effects noted. Unfortunately, few months later the mass started to grow back. A repeat CT scan of Coffeebean’s head and thorax were performed and, yet again, the mass did not penetrate the skull bones and the lungs were free from the secondary cancer spread. Coffeebean underwent a second operation to remove the tumour and intraoperative brachytherapy. He tolerated these procedures very well with no side effects and remained in a complete response.

Fibrosarcomas are locally aggressive neoplasms which means they mainly cause problems in the area they arise from. Metastatic disease (secondary spread), mainly to the lungs, is possible but rare. The treatment of choice is surgical removal of the tumour with an adequate margin of a normal/ healthy tissue around the mass removed at the same time. However, sometimes it is not possible to obtain that margin and this is where adjuvant radiation therapy can be very useful. Location of the mass on the Coffeebean’s skull, especially in between the eyes, made it a very difficult place to irradiate. In addition, once a patient completed a prescribed radiation course, a repeat one within a short period of time could be associated with a significant toxicity to the patient. This is why intraoperative brachytherapy was advocated and used on Coffeebean, resulting in a successful management of this feline patient.