In their article in this issue, Drs. Jatoi and Loprinzi review much of the data on weight loss and anorexia in cancer patients from the standpoint of the impact of nutrition and various pharmacologic agents on management, and they make some sound recommendations for therapy. The benefit of nutritional interventions in this area are often overhwhelmed by the patient’s complex disease course and, therefore, are difficult to demonstrate.
In their article in this issue, Drs. Jatoiand Loprinzi review much of the data on weight loss and anorexia in cancerpatients from the standpoint of the impact of nutrition and variouspharmacologic agents on management, and they make some sound recommendations fortherapy. The benefit of nutritional interventions in this area are oftenoverhwhelmed by the patient’s complex disease course and, therefore, aredifficult to demonstrate.
It is now clear that malnutrition occurs for many differentreasons, but that the metabolic abnormalities associated with cancer are largelydue to the host’s response to the tumor. In a sense, these abnormalities arean unavoidable component of the immune response, but many patients with cancerlose weight at the same rate as other malnourished patients with chronicdiseases.
Some cancer patients, especially breast and prostate cancerpatients, are not malnourished but obese. Therefore, it may be helpful toclassify the nutritional approach to cancer patients based on a more globalunderstanding of the role of nutrition in cancer prevention and treatmentrather than simply looking at weight loss therapy in isolation.
It has been estimated that in adults over age 50 years, one oftwo men and one of three women will be diagnosed with some form of cancer duringtheir lifetime. Many of these people will be successfully treated cancersurvivors who will be interested in preventing a recurrence of their disease.Weight loss in an obese cancer patient may be desirable. For example, areduction in body fat can lead to a reduction in circulating estradiol levels inpostmenopausal breast cancer patients. Moreover, the institution of a healthydiet rich in fruits and vegetables may, in turn, lead to significant weightloss.
Normal Starvation vs Cachexia
In true cancer cachexia as opposed to normal starvation, weightis lost disproportionately from protein stores. Calorie restriction of normalvolunteers leads to a 0.25-lb loss of lean mass per pound of weight lost.Disproportionately greater losses from muscle, due to the effects of cytokinesin patients with an active cancer that interferes with normal adaptation tostarvation, can lead to impaired immune function. However, in most studies theadaptive loss of muscle mass associated with simple starvation has not beenadequately separated from the disproportionate and rapid loss of muscle massthat increases the risk of infection. In many malnourished cancer patients,there is no evidence of malnutrition beyond that which results from the adaptiveresponse to reduced food intake, and rapidly progressive general weight loss ismuch less common than the disproportionate weight loss associated with cancer.
The End-Stage Patient
Twenty years ago, I routinely administered total parenteralnutrition to end-stage cancer patients. While this produced some salutaryeffects in selected patients, the risk-benefit considerations articulated in anumber of reviews and meta-analyses have convincingly argued against routine useof total parenteral nutrition in end-stage patients.
The Weak Patient Undergoing Therapy
Anorexia and weakness routinely develop in many patientsundergoing chemotherapy or radiation. Such patients should be encouraged to restadequately and avoid skipping meals. Nutritional supplements in liquid form areparticularly useful in this population.
As the result of depression, many cancer patients fail to eat atall and suffer undue amounts of fatigue. On the other hand, some patients equateweight loss with poor outcome and fight to gain weight during therapy to provethat they are prevailing over their cancer by eating high-fat desserts and redmeats. Some patients even become obese in the process, and this should not beencouraged. The period of therapy is usually brief when viewed in the context ofthe patient’s overall life span, and if the likelihood of response is high,then nutrition during therapy should take a backseat to quality-of-life issues.
The Patient Who Wants Nutritional ‘Therapy’
Many cancer patients obtain information on nutrition from books,friends, health food stores, and the Internet. It is important to advise thesepatients that nutrition is not a therapy for cancer, but rather it is a body ofinformation in the scientific literature that suggests that healthy nutritionincluding fruits, vegetables, cereals and grains, reduced dietary fat, and theachievement and maintenance of a healthy body weight may be beneficial in cancerprevention. Although the benefit of nutritional advice in reducing cancerrecurrence is far from certain, it can reduce the risk of other chronicdiseases. Some patients also enjoy an improvement in their quality of life frommaking nutritional and lifestyle changes.
As Drs. Jatoi and Loprinzi discuss, patients presenting withweight loss and anorexia should receive nutritional counseling and pharmacologictherapy as necessary. With increased attention to the nutrition of cancerpatients at all stages of treatment, medical oncologists can provide benefits by(1) enhancing the physician-patient relationship, (2) obviating needlessalternative therapies, (3) improving quality of life, and (4) preventing thedevelopment of malnutrition through early intervention. Future research ongene-nutrient interactions in cancer prevention and treatment will point the wayto new approaches.
1. Heber D, Blackburn GL, Go VLW (eds): Nutritional Oncology.San Diego, Academic Press, 2000.
2. Camoriano JK, Loprinzi CL, Ingle JN, et al: Weight change inwomen with adjuvant therapy or observed following mastectomy for node-positivebreast cancer. J Clin Oncol 8:1327-1334, 1990.
3. Owen OE: Obesity in Kinney JM, Jeejeebhoy KN, Hill GL, et al(eds): Nutritrion and Metabolism in Patient Care. Philadelphia, W. B. Saunders ,1988.