The Cancer Patient and Nutrition

Nutrition is not often thought of as a critical issue in cancer management, but can be an important variable that effects quality of life and survival times. In patients with cancer, particularly metastatic disease, it is not a question of curing the patient, but a question of how can the quality of life for the patient be increased.

When cancer is diagnosed in a dog, there are one of three situations:

1. Neoplasia without nutritional complications
2. Neoplasia with anorexia
3. Neoplasia with cachexia

Most patients that are diagnosed to be having neoplasia have loss of weight but the dilemma is to determine whether the weight loss is due to anorexia, or cancer cachexia. A patient that presents with anorexia requires immediate attention including administration of enteral, or possibly partial or total parental nutrition. Often in advanced neoplastic diseases there is an element of intermittent anorexia associated with chemotherapeutic treatment of the disease itself.

In general, anorexia results in weight loss primarily of adipose tissue, while patients with cachexia will lose nearly equal amounts of skeletal muscle and fat mass.

The mechanisms of cancer cachexia are complex and biochemical and hormonal stimulation of weight loss and cachexia may also occur in these conditions as well and include:

• Starvation and malnutrition.

• Impaired oral intake.

• Stomatitis, taste aversions, zinc deficiency.

• Dehydration.

• Nausea.

• Constipation.

• Bowel obstruction.

• Pain.

• Impaired gastrointestinal absorption.

• Maldigestion.

• Exocrine pancreatic insufficiency.

• Diarrhea.

• Development of ascites, pleural effusion.

• Infections.

• Heart, lung, kidney failure, hyperthyroidism.

• Prolonged deconditioning.

• Growth hormone deficiency.

The Role of Nutrition in Cancer
The demise of the patient with neoplasia is not always due to the neoplasia itself, but to the overwhelming loss of body condition.

The two major nutritional goals that need to be equally addressed in a cancer patient are:

• Inhibiting tumor growth
• Preventing or managing cachexia

A well balanced diet is important to take care of both cachexia and tumour growth. When the protein concentration in the dog food increases, the quality of the food is often better meaning that a decrease in the overall nutritional balance of the food increases the incidence of neoplasia.