Trip to the Oncologist - Cancer Cat Episode 2

SUMMARY:

·         Primary Complaint:  Nasal Adenocarcinoma (biopsy diagnosis)

·         Assessment:  Neelix’s assessment confirms the presence of a nasal adenocarcinoma. We discussed the biologic behavior as locally aggressive with a low potential for metastasis. We discussed staging with chemistry/CBC/UA, thoracic radiographs +/- abdominal ultrasound. Local therapy with radiation is the treatment of choice (Linear Accelerator or Cyber Knife) but systemic treatment options including chemotherapy (alternating doxorubicin and carboplatin has proven efficacy in a small number of dogs but has not been evaluated in cats), metronomic therapy, or Piroxicam alone are also reasonable. Additionally, symptomatic therapies can be instituted.

Plan: Chemistry/CBC is pending. Owner is considering staging tests and therapeutic options

History: Neelix presented for evaluation of recently diagnosed nasal adenocarcinoma. The owners noticed a swelling on the right side of Neelix’s nose in early October 2013. He was otherwise acting normally. The owners monitored it for a couple weeks thinking it might be an abscess or bite of some kind. There was no change in the mass and he was seen by a local veterinarian for the mass in mid-October. He seemed uncomfortable when his mouth was opened and swatted at the doctor and owner. A tooth root abscess was suspected and he was started on a 10 day course of azithromycin. There was no change in the mass on the antibiotics. (Evaluation 10-29-13). A Cryptococcus titer was negative and a biopsy was recommended. Neelix had an incisional biopsy on 11/8/13. Histopathology results were a nasal adenocarcinoma.

I am sorry now I even mentioned Neelix fighting me at the first vet, because I really think it was more about my making him wear his sweater and not bringing the carrying case than a pain issue.

Past Pertinent History: Had severe URI as kitten and has always had stertor since then.

I learned a new word. We always called his breathing Darth Vader.

Current Medications:  None

Physical Examination:  T= 97.5 F, P= 240 bpm, R= 32 bpm. Wt. = 4.64 kg (10.2 lbs.) Bright, alert, and responsive. Body condition score of a 5/9. Pink and moist mucous membranes with a normal capillary refill time. Stertor noted. Normal air flow from both nostrils. Mass effect (~1cm length) on right side of nose. No mass effect noted intraorally. Significant dental calculus with multiple resorptive lesions noted. Both eyes retro pulse normally. No murmur or arrhythmia ausculted. Lungs clear with referred upper airway noise. Unremarkable abdominal palpation. All peripheral lymph nodes within normal limits. Small (2-3mm) dermal mass left ventral abdomen. The remainder of Neelix’s examination was unremarkable (rectal, ophthalmic, musculoskeletal, and neurologic). 

Diagnostic Tests:

1. Review of medical record and biopsy:
1. Cryptococcus antigen titer 10/30/13: negative
2. Biopsy (incisional) of the right nasal cavity mass 11/13/13: Nasal adenocarcinoma with features that suggest possible adenoid cystic salivary carcinoma of the soft palate.

                                          i.    The specimen from the nasal cavity consists of a malignant neoplasm derived from the epithelial cells most likely respiratory mucosa, i.e. a nasal carcinoma

                                        ii.    The neoplastic cells vary from round to cuboidal have small amounts of eosinophilic cytoplasm and round to ovoid nuclei containing finely granular chromatin and a single small nucleolus.

                                       iii.    Neoplastic cells are present in varying sized nests and nodules surrounded by a thin fibrovascular stroma. In some of the nodules, neoplastic cells are forming small glandular or acinus-like structures.

                                       iv.    This neoplasm has some features that suggest a salivary gland origin, a finding that makes it possible that this could be a so-called adenocystic nasal carcinoma that arises from the salivary glandular tissue of the soft palate rather than the nasal mucosa.

                                         v.    The neoplasm extends into the margins of the specimen submitted

2. Chemistry 12/2/13: unremarkable
3. CBC 12/2/13: Eosinophils 2580, otherwise unremarkable
4. Diagnostics discussed for staging but declined at this time: 3 view thoracic radiographs and an abdominal ultrasound
1. The abdominal ultrasound is a low yield test with regards to metastatic disease and is recommended to look for concurrent disease that may affect treatment decisions.

Diagnosis:  Nasal Adenocarcinoma  

Treatment Administered: Convenia 37mg SQ for significant resorptive lesions in the mouth to protect against secondary bacterial infections and discussed oral Buprenex as the resorptive lesions are likely painful

Medications Recommended: none

Assessment/Tumor Biology: 

Recommendations are below in order of preference priority:

1.  Definitive radiation therapy

2.  Chemotherapy (alternating carboplatin/doxorubicin)

3.  Palliative radiation therapy 

4.   Metronomic therapy

5.   Piroxicam alone

Neelix was diagnosed with a nasal adenocarcinoma on biopsy samples. Feline adenocarcinomas are cancers that arise from epithelial/glandular cells. Tumors are locally invasive and extend into adjacent normal tissues. In addition to the local disease, feline adenocarcinomas have the potential to metastasize, although this is usually less of a problem and generally occurs late in the disease course; regional lymph nodes and the lungs are the most common place of disease spread. We recommended staging with thoracic radiographs prior to radiation therapy or chemotherapy. Prior to radiation it would be indicated to evaluate both local lymph nodes (submandibular) to better plan the radiation therapy in case the lymph nodes will need to be included in the radiation field. There is limited information in the literature regarding treatment of this tumor type in cats and more is known with regards to its treatment in dogs. The most information available is in regards to radiation therapy. 

Radiation therapy

Given the behavior of nasal adenocarcinoma, local therapy, consisting of radiation therapy +/- surgery is the foundation of treatment. Prognostic variables associated with this tumor type in dogs are histologic subtype, advanced tumor stage, and presence of metastatic disease but these variables have not been reported on in cats. Surgery alone rarely improves survival times (1-4 months survival time) while definitive radiation therapy alone can result in median survival times of about 1 year.

A year? I know that is several years in cat time, but not much for the expense and pain considering Neelix's lack of a sense of time and my budget.

Unfortunately, radiation therapy is not offered at this locality at this time. Radiation therapy is about $5,500 and would require daily anesthesia Monday-Friday for about a month with a definitive protocol. A palliative protocol with the intent of stabilizing the tumor for 2-6 months would be about $2,500 and would be significantly fewer treatments and could be considered if the tumor seems to be causing Neelix discomfort. A CT scan would be recommended for radiation planning and costs around $1,500. Side effects of radiation include acute effects (skin irritation, oral irritation, ocular irritation, and oronasal fistula) and late effects which occur in roughly 5 percent of cats on average 5 years after radiation (bone necrosis, a new tumor developing, and cataracts). Acute side effects are more likely to occur with definitive radiation than palliative radiation but can be seen with either type or protocol. Cats typically tolerate radiation well and experience fewer side effects than dogs.The type of radiation protocol is dependent on the radiation oncologist in discussion with the owners.

Holy cow, this is not going to happen. Neelix and I are not roadtripping to torture-ville in Maryland or North Carolina, neighboring states where radiation is available. He would not understand the whys of that at all.

Chemotherapy

In one study of 8 dogs, chemotherapy alone (alternating doxorubicin and carboplatin) resulted in 50 percent of dogs having a complete response and an additional 25 percent having a partial response to therapy. Both of these agents have been used in cats with other types of carcinomas with varying effect (depending on tumor type). This specific protocol has not been evaluated in cats with nasal adenocarcinomas so expected response rates for cats are not available but it would be reasonable as an attempted therapy in Neelix. As discussed, monitoring responses in the dogs required repeated advanced imaging so we would recommend completing the protocol as long as he tolerates the chemotherapy well and he does not show signs of progression. Neelix is very nervous here in the hospital. It is possible that he may need sedation for chemotherapy in order for him to be still while it is being administered and minimize the risk of the agents getting outside of his vein which could damage the surrounding tissue. Side effects with chemotherapy include a 1:10 chance of vomiting and diarrhea and a 1:100 chance of life threatening side effects including severe WBC suppression that would put Neelix at risk of infection. Routine thoracic radiographs +/- abdominal ultrasound are recommended throughout therapy to assess response. Please be aware that Neelix will be shedding chemotherapy metabolites, which can be carcinogenic (cancer causing) in his urine, feces, and saliva for 48 hours after each dose of chemotherapy. Please wear gloves when handling his urine or feces and wash your hands well. Please do not allow pregnant women, women planning to become pregnant, immunocompromised people, or young children to handle his waste products.

Not only is Neelix very nervous here at the hospital, he would be a toxic waste dump for 48 hours after each treatment. 

Metronomic therapy

An alternative, less aggressive option to radiation and injectable chemotherapy, is metronomic therapy. Metronomic therapy involves the administration of one or more oral medications (Piroxicam, cytoxan, chlorambucil, Palladia, doxycycline) aimed at disrupting the blood supply to the tumor and thereby inhibiting tumor growth. Additionally, piroxicam (an NSAID) alone is likely of some benefit since nasal adenocarcinomas in dogs can overexpress COX-2 (81 percent of canine cases), although again this has not been evaluated in cats. However, NSAID’s can cause renal damage in cats so Neelix would need to be monitored really carefully to make sure we do not cause acute renal failure. The most common side effect from oral Cytoxan is sterile hemorrhagic cystitis (irritation to the bladder wall), which would make it uncomfortable for him to urinate. This side effect is extremely rare in cats since they have access to a litter box so they can urinate frequently. Chlorambucil is very well tolerated in cats but can cause bone marrow suppression with time. The palladia can cause damage to the kidneys as well but it is usually glomerular damage rather than tubular damage.  As discussed, there is no information available regarding the length of time that is the most beneficial with this therapy and the recommendation in humans is to continue until progressive disease is seen.  

I have been Google-searching these drugs and have yet to find anything exciting and encouraging. One cat, whose owner started a blog for her pretending to speak in her voice -- I find this really annoying story-telling, because cats are not humans and do not think that way -- was dead three months later despite the Palladia or Piroxicam. The blog just stops, and then there's one more entry three YEARS later explaining the cat died. I feel the Cytoxan is going to be too much, but I so much want the other drugs to keep the tumor small. The drugs themselves do not cost that much, but the office visits and blood work they insist you do every two weeks or monthly or whatever is what runs your bill up to the equivalent of a car payment every month.

I filled out all the paperwork for Fetch-a-Cure. If I got the maximum grant, that would buy us three months treatment, I think, but then I have to volunteer 10 hours a month for a year, which isn't a problem except being immersed in cancerland so intensely for so long. I cry in the shower so no one can see me.

Needed a nap in his favorite chair after exhausting visit to oncologist.