Hi, all,
I'm the person who posted to the list back in March regarding my kuvasz
having developed an perianal tumor (fibrosarcoma). Although I've been
told that my girl has a poor prognosis, she is so far doing quite well
after surgery--no return of the tumor yet; no signs of spread.
I wanted to pass on some helpful information that I received from her
breeder regarding chemotherapy treatment for fibrosarcoma. This info.
came from a website ([EMAIL PROTECTED]). In the course of my
research on fibrosarcoma (best treatment), I received conflicting advice
from vets regarding whether or not chemo would be helpful for
fibrosarcoma, so I was particularly grateful for this information. It
was both specific and clear.
Basically, the article specified which kinds of canine cancers respond
to chemo. Note that there is no mention of fibrosarcoma. The article
was titled "Tumours Sensitive to Cytotoxic Chemotherapy" (produced by
2000 Veterinary Radiology Ltd.; last modified May 25, 2001).
Use chemo as primary treatment for:
1. LYMPHOID TUMORS: With lymphoid tumors (multi-centric lymphoma of
B-cell origina, chronic lymphocytic leukaemia, myeloma) using chemo as
the primary therapy can be quite effective as these kinds of tumors
respond to chemo. 75+ percent "achieve complete remission" with
"median survival times of 12+ months." If your dog has this kind of
tumor, there will be many chemo protocols to choose from, so you should
ask for referral to an oncologist.
2. TRANSMISSIBLE VENEREAL TUMOR: This is rare (at least in UK). It is
commonly cured outright be chemo.
Use chemo as adjuvant treatment for the following tumors that spread
(metastasize) for:
1. OSTEOSARCOMA (dogs). Chemo can be used following amputation or "limb
salvage" of the primary tumor.
2. HAMANGIOSARCOMA (dogs) after splenectomy.
3. MAMMARY CARCINOMA (cats) after mastectomy.
4. TONSILLAR CARCINOMA (dogs) along with sugery and radiotherapy for the
primary tumor.
Also use chemo of "bulky primary or secondary disease."
The article states that dogs with advanced malignant disease OF THE
FOLLOWING KINDS OF CANCER can be helped with "judicial use of cytotoxic
drugs to palliate clinical signs, even though cures will be rare in
these cases":
1. ANAL SAC CARCINOMA (dogs)
2. PERIANAL ADENOCARCINOMA (dogs)
3. MAST CELL TUMOR POORLY DIFFERENTIATED (dogs)
4. TRANSITIONAL CELL CARCINOMA (dogs)
The info. in this article as well as that in all other articles that I
read on the topic seemed to say that chemo is NOT effective for this
kind of cancer. Fibrosarcoma is usually a slow growing tumor but can
spread if it is large, the cells are poorly differentiated, and the
tumor has been incompletely removed.
Also available at the same website was an article titled "Tumours and
Other Conditions Sensitive to Radiation Therapy," produced by Veterinary
Radiology Ltd. (last modified May 25, 2001).
This article provided the following info.:
These tumors (and other conditions) are sensitive to radiation therapy
(note: total excision remains the treatment of choice for the majority
of solid non-lymphoma tumors but radiation therapy has an important
role):
1. MOUTH TUMORS
--Results are excellent for basal cell tumor (acanthomatous
epulis)
--Results are excellent for ameloblastoma
--Results are good for squamous cell carcinoma
--Results for fibrosarcoma are fair to good
--Results for malignant melanoma are good
2. SKIN TUMORS
Use radiation therapy for a solitary tumor when surgical excision is
likely to be incomplete, especially for the following spindle cell
tumors (50 percent reduction of recurrence rate; FIBROSARCOMA,
haemangiopericytoma, etc.); good results for mast cell tumors (well and
intermediate differentiation); fair to good results for sebaceous
adenocarcinoma; fair to good resutls for sweat gland adenocarcinoma.
Radiation therapy can be used for limb tumors (like osteosarcoma of the
long bones) but amputation is best treatment. Radiotherapy in this case
is to give palliation.
Radiation therapy can give palliation for nasal adenocarcinoma but
recurrence is common.
For solitary carcinoma (not involving the lymph nodes) and other round
cell tumors, radiation therapy alone can be curative.
Radiotherapy can produced "marked reduction and long term control" for
thyroid carcinoma, which can be a serious surgical problem.
Brain tumors can also respond dramatically (remission signs for more
than 12 months).
Again: most articles/experts recommend radiation therapy as adjunct
therapy for a fibrosarcoma that is a skin tumor if the tumor is large
and is likely to spread and the surgery has not gotten all of it
(according to path report). In one case after multiple surgeries and
radiation, a dog (berner) seemed to be cured for fibrosarcoma, only to
develop MH 6 months later--and the owner wondered if the radiation
therapy contributed to the development of the MH. Radiation therapy runs
$5000. Chemo about $1000. Surgery may be $400--$2000.
Some of the following info. is from the website for the Flat-Coated
Retriever Society of America): SURGERY is the mainstay of treatment of
fibrosarcoma (best done by a board-certified surgeon who is used to
doing this kind of surgery, according to one of my vets) and may be the
only treatment that is necessary if the tumor is completely removed.
Young dogs with oral fibrosarcomas have a higher potential for
metastasis. Fibrosarcoma can sometimes be locally controlled for long
periods of time by removing the mass each time it recurs.
Although chemo has not been shown to be effective, it could certainly be
tried, but keep in mind the use of doxorubicin is seriously limited by
the development in the heart of acute and chronic toxic effects, so if
your dog has a weak heart it should be avoided.
Hope this info. helps someone!
Christy Kabler
