Spontaneous intestinal adenocarcinoma in geriatric macaques (Macaca sp.)
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Published on: July 6, 2017
C R Valverde1, R P Tarara, S M Griffey
1California Regional Primate Research Center, University of California, Davis 95616, USA.
Background And Purpose:
Intestinal adenocarcinoma appears to be the most common malignant neoplasm in macaques, and is a substantial cause of morbidity and mortality in the elderly.
Methods:
A retrospective review of 32 cases was done.
Results:
Thirty-two cases were reviewed. Clinical examination had revealed severe weight loss, anorexia, and palpable abdominal mass. Microcytic hypochromic anemia, intermittent fecal occult blood positive test results, hypoproteinemia, and hypoalbuminemia were the predominant clinical laboratory findings. Carcinoembryogenic antigen serologic testing and single-strand conformational polymorphism analysis were performed in selected cases. The most common sites of the intestinal adenocarcinoma were ileocecal junction, colon, ileum, jejunum, and cecum. Metastases were evident in 34% of the cases and involved peripheral nodes, liver, lungs, pancreas, and adrenal gland. Overall survival of 12 macaques that underwent surgical excision was 83% at 6 months, 58% at 1 year, 50% at 1.5 years, 33% at 2 years, and 8% at 4 years. The overall mean survival rate (MSR) was > 483 postoperative days.
Conclusion:
Intestinal adenocarcinomas should be amenable to surgical resection. Early detection of localized, non-invasive neoplasms will increase surgical cure rate. Survivability could be potentially improved by use of adjuvant therapies.
Insights
Intestinal adenocarcinoma is a common macaque neoplasm causing significant mortality. Surgical resection offers a potential cure, with early detection improving outcomes and adjuvant therapies possibly enhancing survival rates.
Area of Science:
- Veterinary Pathology
- Primate Oncology
- Surgical Oncology
Background:
- Intestinal adenocarcinoma is the most frequent malignant neoplasm in macaques.
- This condition is a significant cause of morbidity and mortality, particularly in older animals.
Purpose of the Study:
- To review cases of intestinal adenocarcinoma in macaques.
- To analyze clinical findings, diagnostic methods, and survival rates associated with this neoplasm.
Main Methods:
- Retrospective review of 32 macaque cases diagnosed with intestinal adenocarcinoma.
- Analysis of clinical signs, laboratory findings, diagnostic test results, and surgical outcomes.
Main Results:
- Common clinical signs included weight loss, anorexia, and palpable abdominal masses.
- Laboratory findings revealed anemia, positive fecal occult blood tests, hypoproteinemia, and hypoalbuminemia.
- The ileocecal junction, colon, ileum, jejunum, and cecum were most frequently affected; 34% of cases had metastases.
- Survival rates for surgically treated macaques were 83% at 6 months, decreasing to 8% at 4 years, with a mean survival rate of over 483 days.
Conclusions:
- Intestinal adenocarcinomas in macaques are amenable to surgical resection.
- Early detection of localized, non-invasive tumors is crucial for increasing surgical cure rates.
- Adjuvant therapies may potentially improve long-term survivability.
