| Cancer is a word that strikes fear into the heart of most pet owners, immediately conjuring up thoughts of the worst kind of terminal diseases. However with modern advances in both medical and surgical treatments are now revolutionising the way vets can deal with cancer in pets, and many cancers are now considered treatable. Whereas dogs and cats diagnosed with diseases such as lymphoma or skin cancer might have expected to survive just a few months a decade or two ago, now many of these patients can enjoy a good quality of life for many months or even years. What is cancer? The word cancer is used to describe an incredibly wide range of diseases affecting all parts of the body. The one thing these diseases have in common is that they involve the growth and proliferation of abnormal cells. Sometimes these cells form solid masses, which are then usually referred to as tumours, but in other cases they can be more diffuse such as in cancers of the blood or bones. The words ‘cancer’, ‘tumour’ and ‘neoplasia’ are all interchangeable and used to refer to the same type of diseases. What is the difference between benign and malignant cancers? Benign cancers are those that have little potential to spread or cause life-threatening complications. Examples of benign cancers include some types of mammary tumours which never spread to the rest of the body and soft patty lumps called lipomas which are technically cancerous but not generally dangerous. Malignant cancers on the other hand are much more serious. These forms of cancer are likely to spread and cause serious complications and include diseases such as malignant mammary tumours, most forms of blood cancer, bone cancer and many forms of skin cancer. How do cancers spread? Cancers spread in several ways including local invasion of tissues and metastasis. Metastasis is the technical term for the spread of a cancer throughout the body, usually by means of the blood stream. This is how cancers can spread from the initial location, such as a mammary gland, to completely different parts of the body such as the lungs. How are cancers treated? There are many different treatments available for cancer nowadays but in general they can be grouped into 3 categories – surgical, medical and radiological. Surgical treatment is often the treatment of choice for lumps such as skin tumours, where complete removal can often cure the disease and prevent recurrence. Medical treatments usually involve drugs that target rapidly dividing cells and some of these can be toxic to the rest of the body and lead to side effects, so the benefits of medical treatments always need to be weighed against the potential adverse effects. The same is very much true for radiological treatments where radiation is used to attack cancer cells as this is a technique which can also lead to unwanted side effects. |
