Changes

==Description==

==Description==

* No organism or chemical agent has been identified that will induce spontaneous intestinal adenocarcinoma.

* No organism or chemical agent has been identified that will induce spontaneous intestinal [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinoma]].

* The gross appearance of colorectal adenocarcinomas vary from pedunculated, particularly in the distal rectum, cobblestone, in particularly the middle rectum, and annular, also usually in the middle recutum, and may also have associations with tumour behaviour and prognosis.

* The gross appearance of colorectal [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinomas]]vary from pedunculated, particularly in the distal rectum, cobblestone, in particularly the middle rectum, and annular, also usually in the middle recutum, and may also have associations with tumour behaviour and prognosis.

* In cats, adenocarcinomas have been reported to have been found in the ileum and ileocaecal region. Another study reports the jejunum to be the most common site.

* In cats, [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinomas]] have been reported to have been found in the ileum and ileocaecal region. Another study reports the jejunum to be the most common site.

* Metastasis occurs via lymphatic and vascular routes. For small intestinal adenocarcinomas the most frequent sites of metastasis are the mesenteric lymph nodes. Other sites include the liver, kidneys, peritoneal cavity, omentum and lungs. Metastatic spread is commonly encountered at time of diagnosis.  

* Metastasis occurs via lymphatic and vascular routes. For small intestinal [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinomas]] the most frequent sites of metastasis are the mesenteric lymph nodes. Other sites include the liver, kidneys, peritoneal cavity, omentum and lungs. Metastatic spread is commonly encountered at time of diagnosis.  

* Large intestinal adenocarcinomas often metastasise to the deep inguinal lymph nodes. The liver is less frequently affected. These tumours also undergo aggressive local growth and local recurrence after resection frequently occurs.

* Large intestinal [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinomas]] often metastasise to the deep inguinal lymph nodes. The liver is less frequently affected. These tumours also undergo aggressive local growth and local recurrence after resection frequently occurs.

==Diagnosis==

==Diagnosis==

Is more sensitive than radiography in localising a mass and can assess involvement of surrounding structures. In addition, guided needle aspiration or biopsy may be taken at this time. Findings may include the following:

Is more sensitive than radiography in localising a mass and can assess involvement of surrounding structures. In addition, guided needle aspiration or biopsy may be taken at this time. Findings may include the following:

* Intestinal wall thickening with loss of wall layering - dogs with loss of layering are over 50 times more likely to have neoplastic disease rather than enteritis

* Intestinal wall thickening with loss of wall layering - dogs with loss of layering are over 50 times more likely to have neoplastic disease rather than enteritis

* In dogs, adenocarcinomas have been described as being usually hypoechoic and most dogs have reduced gut motility

* In dogs, [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinomas]] have been described as being usually hypoechoic and most dogs have reduced gut motility

* In cats, adenocarcinomas have been described as being of mixed echogenicity and are often asymmetric

* In cats, [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinomas]] have been described as being of mixed echogenicity and are often asymmetric

===Endoscopy and Laparoscopy===

===Endoscopy and Laparoscopy===

==Treatment==

==Treatment==

===Surgery===

===Surgery===

Surgical excision is advised as primary treatment for intestinal adenocarcinoma. Extraserosal invasion or adhesions may cause difficulties and care must be taken to ensure there is no iatrogenic damage to the biliary and pancreatic ducts for duodenal lesions. In the small intestine, wide local resection (4-8cm margins) can usually be achieved via enterectomy and anastomosis. Stapling and suturing by hand have been shown to be equally efficient for this procedure. If appropriate, regional lymph nodes should also be removed. Large margins may be more difficult to achieve for colorectal lesions due to access issues. Perioperative complications include peritonitis and sepsis.

Surgical excision is advised as primary treatment for intestinal [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinoma]]. Extraserosal invasion or adhesions may cause difficulties and care must be taken to ensure there is no iatrogenic damage to the biliary and pancreatic ducts for duodenal lesions. In the small intestine, wide local resection (4-8cm margins) can usually be achieved via enterectomy and anastomosis. Stapling and suturing by hand have been shown to be equally efficient for this procedure. If appropriate, regional lymph nodes should also be removed. Large margins may be more difficult to achieve for colorectal lesions due to access issues. Perioperative complications include peritonitis and sepsis.

===Adjuvant Chemotherapy===

===Adjuvant Chemotherapy===

Doxirubicin has been shown to significantly improve survival times for cats with colonic adenocarcinoma with median durations of 56 and 280 days for those not receving and those receiving chemotherapy respectively. No other evidence exists to confirm the benefits of adjuvant chemotherapy in dogs or cats. Piroxicam, a non-steroidal anti-inflammatory drug may have beneficial effects for rectal malignancy.

Doxirubicin has been shown to significantly improve survival times for cats with colonic [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinoma]] with median durations of 56 and 280 days for those not receving and those receiving chemotherapy respectively. No other evidence exists to confirm the benefits of adjuvant chemotherapy in dogs or cats. Piroxicam, a non-steroidal anti-inflammatory drug may have beneficial effects for rectal lesions.

===Radiotherapy===

===Radiotherapy===

Rarely reported due to concerns of intolerance of surrounding tissues leading to for example perforations and adhesions. In addition it cannot be relied upon that the same target will be irradiated each day due to intestinal mobility. There has been a report of single high-dose irradiation being used for anorectal adenocarcinomas which had been surgically exposed and no long-term side effects were observed.

Rarely reported due to concerns of intolerance of surrounding tissues leading to for example perforations and adhesions. In addition it cannot be relied upon that the same target will be irradiated each day due to intestinal mobility. There has been a report of single high-dose irradiation being used for anorectal [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinomas]] which had been surgically exposed and no long-term side effects were observed.

==Prognosis==

==Prognosis==

If no metastasis has occurred long term survival may be achieved following wide excision of a well differentiated small intestinal tumour. The rate of metastasis of adenocarcinoma to the local lymph nodes for both dogs and cats is approximately 50%. Without surgical intervention, the mean survival of dogs with small intestinal adenocarcinoma is 12 days and reports varying from 114 days to 7-10 months for those who receive surgical treatment. In one study males with small intestinal adenocarcinoma had a significantly better prognosis than females with the same disease though the sample size was small. Intensity of treatment is prognostic for colorectal tumours with palliative care carrying a poorer prognosis than local excision. Local excision of colorectal adenocarcinoma has a median survival time of 22 months while the use of stool softeners alone has a median survival time of 15 months.  

If no metastasis has occurred long term survival may be achieved following wide excision of a well differentiated small intestinal tumour. The rate of metastasis of [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinoma]] to the local lymph nodes for both dogs and cats is approximately 50%. Without surgical intervention, the mean survival of dogs with small intestinal [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinoma]] is 12 days and reports varying from 114 days to 7-10 months for those who receive surgical treatment. In one study males with small intestinal [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinoma]] had a significantly better prognosis than females with the same disease though the sample size was small. Intensity of treatment is prognostic for colorectal tumours with palliative care carrying a poorer prognosis than local excision. Local excision of colorectal [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinoma]] has a median survival time of 22 months while the use of stool softeners alone has a median survival time of 15 months.  

There is significant perioperative risk associated with cats with small intestine adenocarcinoma with a high mortality rate within the first two weeks following surgery. However, after these two weeks long term control may be achieved. For cats with large intestinal adenocarcinoma survival time after surgery alone has been reported as approximately 4.5 months.

There is significant perioperative risk associated with cats with small intestine [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinoma]] with a high mortality rate within the first two weeks following surgery. However, after these two weeks long term control may be achieved. For cats with large intestinal [[Intestine Proliferative - Pathology #Adenocarcinoma|adenocarcinoma]] survival time after surgery alone has been reported as approximately 4.5 months.

==References==

==References==

* Liptak J. M, Withrow S.J, (2007), Cancer of the Gastrointestinal Tract, in Withrow and MacEwen's Small Animal Clinical Oncology, fourth edition, Eds Withrow S.J, Vail D.M, Missouri, Saunders Elsevier, pp 491-501

* Liptak J. M, Withrow S.J, (2007), Cancer of the Gastrointestinal Tract, in Withrow and MacEwen's Small Animal Clinical Oncology, fourth edition, Eds Withrow S.J, Vail D.M, Missouri, Saunders Elsevier, pp 491-501

* White, R. A. S, (2003), Tumours of the intestines, in BSAVA Manual of Canine and Feline Oncology, second edition, Eds Dobson J. M, Lascelles B. D. X, Gloucester, British Small Animal Veterinary Association, pp 229-233

* White, R. A. S, (2003), Tumours of the intestines, in BSAVA Manual of Canine and Feline Oncology, second edition, Eds Dobson J. M, Lascelles B. D. X, Gloucester, British Small Animal Veterinary Association, pp 229-233