Sticker sarcoma

from Wikipedia, the free encyclopedia

The sticker sarcoma ( English Canine transmissible venereal tumor , transmissible venereal tumor (TVT), sticker tumor or infectious sarcoma ) is an infectious tumor of the external genital organs of dogs . The disease occurs worldwide, but not endemic in Germany . In the tropical and subtropical regions (Africa, Mediterranean, South America) it is most common and occurs there mainly in stray dogs. The sticker sarcoma was discovered in 1876 by the Russian veterinarian M. A. Nowinski(1841-1914) who also found that this tumor can be transmitted from animal to animal. The tumor can be treated well with chemotherapy or radiation .

Pathogenesis

The transmission can take place on the one hand by mating, by direct contact or by licking the affected areas from animal to animal. While a virus was also assumed to be the cause of tumor formation for a time , it is now assumed that the transmission takes place via exfoliating tumor cells that implant themselves in the mucous membrane via the smallest epithelial defects.

The tumor has an immunogenic effect, i.e. it triggers an immune response . Whether it comes to spontaneous regression ( remission ) or, at the other extreme, metastasis , seems to depend heavily on the immune status of the animal concerned. The rate of metastasis is higher in younger animals.

In 2006, a working group from England proved the clonal origin of sticker sarcoma. Markers from histocompatibility antigens , microsatellite DNA and mitochondrial DNA were used. It was found that all of the tumors examined were genetically different from the host. It was also shown that tumors from 40 different dogs from all continents share a common clonal origin. The original tumor arose around 200 to 11,000 years ago - the numbers vary depending on the calculation method of the molecular clock and have a high standard deviation - in a Siberian wolf or a breed of dog and has since spread worldwide as a communicable tumor. Since its inception, sticker sarcoma has accumulated around 1.9 million mutations , and 646 genes have been deleted . About 500 years ago it spread in dog populations around the world.

Symptoms

This disease mainly affects the penis and prepuce in males and the vagina and labia in females . Reddish, nodular, rapidly bleeding tumors appear on the genital mucous membranes , also with purulent or bloody discharge from the genital organs. As the tumors grow, they take on a cauliflower-like shape and can grow to over 5 cm. Primary foci can also occur on other skin areas such as the oral or anal mucosa .

This tumor rarely metastasizes; the figures in the literature vary between 5 and 17%. Metastases can occur in the inguinal lymph nodes , perineum, and scrotum , especially if the tumor persists for more than a month. Organs more distant ( lungs , central nervous system , eye ) can very rarely be affected.

diagnosis

cytological findings

The diagnosis is made by a pathological examination of a biopsy . It is a round cell tumor of mesenchymal origin. The cells of the Sticker's sarcoma show signs of chromosomal anomaly . They have fewer chromosomes (57 to 62) than healthy cells (78).

therapy

In some cases, healing ( spontaneous remission ) occurs without treatment.

The tumor responds well to chemotherapy , and vincristine has been shown to be effective. It is given once a week for four to six weeks. The tumor also responds well to radiation . Recurrences can occur after surgical removal. Overall, however, the prognosis is good.

See also

Individual evidence

  1. ↑ C. Murgia, JK Pritchard, SY Kim, A. Fassati, RA Weiss: Clonal origin and evolution of a transmissible cancer. In: Cell (2006), Volume 126 (3), pp. 477-87. PMID 16901782 ; PMC 2593932 (free full text).
  2. ^ ID O'Neill: Concise review: transmissible animal tumors as models of the cancer stem-cell process. In: Stem Cells (2011), Volume 29 (12), pp. 1909-14. doi : 10.1002 / stem.751 . PMID 21956952 .
  3. ↑ a b c H. G. Parker, EA Ostrander: Hiding in Plain View - An Ancient Dog in the Modern World. In: Science. 343, 2014, pp. 376–378, doi : 10.1126 / science.1248812 .

Web links