The best survival is obtained with a combinatorial approach: e.g. surgery and radiotherapy or radiotherapy combined with hyperthermia.
Surgery is the most common treatment for oral fibrosarcomas. Surgical resection of the tumour can cure the dog if there are no metastases present. Margins of at least 2 cm are necessary in case of fibrosarcomas.
The secondary effects depend on the quantity of tissue that needs to be removed. They can consist of wound dehiscence, nose bleeds, increased salivation, difficulties closing the mouth and picking up food with the mouth.
After elimination of (a piece of) the lower jaw, local relapse is reported to be 59% in dogs. On average, dogs survive during 11 months after surgery and 50% are still alive after 1 year.
After elimination of (a piece of) the upper jaw, local relapse is reported to be 40% in dogs and the average survival time is 12 months. When only surgery is performed, 50% of dogs is still alive after 1 year.
Cryosurgery is only advised for tumours less than 2 cm in diameter and attached to the bone or minimally invasive. For larger tumours, classic surgery is advised.
Radiotherapy can be used as sole treatment (with a curative or palliative purpose), or as supplementary treatment for incompletely resected tumours or tumours with a very aggressive local behaviour. In general, fibrosarcomas are considered to be tumours that are not very sensitive to radiotherapy and its use is advised in combination with other treatments.
The acute effects of radiotherapy are regularly seen and consist of local baldness, thinning of the skin accompanied by production of fluids, inflammation of oral mucous membranes, difficulties swallowing and changes to the eye (inflammation of the eyelid, the conjunctiva, the cornea or the internal eye). The degree in which these effects are seen depend on the intensity of the irradiation protocol and these symptoms are in general quickly resolved. Late complications are rare (less than 5% of cases), and consist of permanent local baldness, thickening of the skin, bone necrosis and formation of fistula between the nasal and oral cavity, development of a second tumour in the radiation field, desiccation of the eye/mouth, cataract, loss of function of the retina.
- When only radiotherapy is used as treatment, the mean survival time is 7 months.
- Radiotherapy can be combined with hyperthermia (a treatment during which a tumour is warmed up until 45°C which causes damage within the tumour, but minimal damage in the normal tissues). With this combination, 50% of dogs were still alive 1 year after treatment. However, these treatments have only been tested in a small number of dogs (max 17) and these results must be confirmed with a higher number of dogs.
- The best results have been seen with the combination surgery and radiotherapy: after these treatments, relapse has been reported to be limited to 32% of dogs and the mean survival time surpasses 2 years.
The combination of radiotherapy and surgery offers the best chances to locally control the tumour.
Hyperthermia on its own does not offer an advantage as opposed to cryosurgery and is mainly used as a supplementary treatment for radiotherapy.
There is insufficient proof that supplementary chemotherapy has an effect on the prevention of metastases.