Cancer is a term used to describe the uncontrolled growth of cells in the body. Some types of cancer can spread to other parts of the body, but there are also rare cases where cancerous cells themselves can spread between individuals.

These types of cancer are known as contagious cancers or transmissible cancers. Here we discuss some of the known types of contagious cancers and how they can spread.

Devil Facial Tumor Disease (DFTD)

DFTD is a contagious cancer that affects Tasmanian devils, a species of marsupial found only in the Australian island state of Tasmania.

The cancerous cells are transmitted between individuals through biting and cause facial tumors that ultimately prove fatal. DFTD was first discovered in 1996 and has had a devastating impact on Tasmanian devil populations. In some areas, up to 90% of the population has been wiped out by the disease.

Due to the highly contagious nature of DFTD, conservation efforts are focused on isolating individuals that are not infected to prevent the disease from spreading further.

Canine Transmissible Venereal Tumor (CTVT)

CTVT is a contagious cancer that affects dogs. The disease is spread through sexual contact and causes tumors on the genitals of both male and female dogs.

Unlike other types of cancer, CTVT cells do not contain the usual genetic mutations that a tumor cell might acquire, indicating that the cancer may have originated from a single case many thousands of years ago. CTVT is usually self-limiting and will often regress without treatment, although chemotherapy is sometimes used to accelerate the regression.

Tasmanian Devil Facial Tumour 2 (DFT2)

DFT2 is another contagious cancer that affects Tasmanian devils. Like DFTD, the disease is spread through biting and causes facial tumors that can be fatal.

Unlike DFTD, however, DFT2 has not yet reached epidemic proportions and is found in a smaller geographic area than its predecessor.

Related Article The 6 most infectious types of cancer

Soft-shell Clam Leukemia

Soft-shell clam leukemia is a contagious cancer that is found in bivalve mollusks such as soft-shell clams and mussels.

The disease is caused by the transmission of cancerous cells from one individual to another, either through the water or through contact with infected tissue. Infected clams develop tumors on their external and internal tissues, which can interfere with their feeding and other vital processes.

Although the disease has been documented in several species of bivalve mollusks, it is not clear how common it is or what factors make some individuals more susceptible to infection than others.

Bivalve Transmissible Neoplasia

Bivalve transmissible neoplasia is a term used to describe a range of contagious cancers that affect bivalve mollusks.

The diseases are transmitted through contact with infected tissue or through the water, and can cause a range of symptoms depending on the species affected. In some cases, the diseases can be highly virulent and lead to the death of infected animals. In other cases, the diseases may cause only mild symptoms or go undetected altogether.

Researchers are actively working to understand the causes of bivalve transmissible neoplasia and to develop strategies for controlling the diseases in affected populations.

Conclusion

Contagious cancers are a rare but fascinating type of cancer that can spread from one individual to another.

Tasmanian devils, dogs, and various species of bivalve mollusks are known to be susceptible to these types of cancers, although the exact mechanisms by which the diseases are transmitted can vary.

Although the impact of contagious cancers on populations can be devastating, knowledge of these diseases is helping researchers to understand the underlying causes of cancer and to develop strategies for prevention and treatment in both animal and human populations.