chapter 23 nutrition, cancer, and hiv infection

Nutrition, Cancer, and HIV Infection

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Cancer

• Growth of malignant tissue• Second most common cause of death in

the United States• Different types of cancers vary based on:

– Characteristics– Locations in the body– Disease course– Required treatments



Cancer (cont’d.)

Type of cancer Origination (tissues or cells)

Adenocarcinomas glandular tissues

Carcinomas epithelial tissues

Leukemias white blood cell precursors

Lymphomas lymphoid tissue

Melanomas pigmented skin cells

Myelomas plasma cells in the bone marrow

Sarcomas connective tissues



Cancer (cont’d.)

• How cancer develops: carcinogenesis– Often proceeds slowly– Continues for several decades– Genetic mutations alter gene expression in a

single cell• Alterations promote cellular growth, interfere with

growth restraint, or prevent cellular death• Affected cells unable to halt cell division; produce

daughter cells with the same genetic defects



Cancer (cont’d.)

• How cancer develops– Tumors: abnormal mass of cells

• Disrupts surrounding tissue function• Metastasize: spread to other body regions

– Various reasons for cancer development• Inherited genetic defects• Metabolic processes• Interactions between genes and environment• Carcinogens



Cancer Development



Cancer Development (cont’d.)



Cancer: Nutrition and Cancer Risk

• How cancer develops– Environmental factors can increase cancer

risk (Table 23-1)• Nutrition and cancer risk

– Nutrition can influence cancer risk (Table 23-2)

– Food components, energy balance, and growth rate involved



Cancer: Nutrition and Cancer Risk (cont’d.)

• Nutrition and increased cancer risk– Obesity is a risk factor for a number of

different cancers– Alcohol correlates strongly with cancers of the

head/neck, liver, colon, rectum, and breast• Head/neck cancer risk increased with smoking

– Food preparation can produce carcinogens• Frying or boiling meat, poultry, and fish• Grilling meat and fish




• Nutrition and decreased cancer risk– Fruits and vegetables may reduce risk of

some cancers• Nutrients and phytochemicals with antioxidant

activity• Other phytochemical activities in the body• Folate plays roles in DNA synthesis and repair• Dietary fiber may protect against colon and rectal

cancers




• Nutrition and decreased cancer risk: guidelines for risk reduction– Achieve and maintain a healthy body weight– Be physically active as part of everyday life– Choose a healthy diet that emphasizes plant

sources• Limit consumption of energy-dense foods and

sugary drinks




• Nutrition and decreased cancer risk: guidelines for risk reduction– Limit consumption of foods that may increase

cancer risk• Red meat, processed meats, salty or moldy foods

– Limit consumption of alcoholic beverages– Aim to meet nutritional needs through the diet– Avoid using tobacco in any form



Cancer (cont’d.)

• Consequences of cancer– Complications due to tumor’s impingement on

surrounding tissues– Symptoms

• Nonspecific: anorexia, fatigue, unexplained weight loss, fever, night sweats, skin lesions, hyperpigmented skin

• Some cancers asymptomatic in early stages



Cancer: Consequences of Cancer (cont’d.)

• Anorexia and reduced food intake– Mental stress– Chronic nausea and early satiety– Fatigue– Pain– Gastrointestinal obstructions– Effects of cancer therapies




• Metabolic changes– Cytokines induce an inflammatory and

catabolic state– Increased protein turnover rate, but reduced

muscle protein synthesis– Muscle is used for glucose production– Triglyceride breakdown elevates serum lipids




• Cancer cachexia– A wasting syndrome characterized by

anorexia, muscle wasting, weight loss, and fatigue

– What factors play a key role in the muscle wasting associated with cancer?



Cancer: Treatments for Cancer

• Treatments for cancer– Highest likelihood of effective treatment with

early detection and intervention– Surgery

• May remove tumors, determine the extent of cancer, and protect nearby tissues

– Chemotherapy• Drugs that inhibit tumor growth, shrink tumors

before surgery, prevent/suppress metastasis



Cancer: Treatments for Cancer (cont’d.)

• Radiation therapy– Bombard cancer cells with X-rays, gamma

rays, or various atomic particles– What are the advantages of radiation therapy

over surgery and chemotherapy? – What are the nutrition-related side effects of

chemotherapy and radiation therapy? (Table 23-5)




• Hematopoietic stem cell transplantation– Replaces blood-forming stem cells destroyed

by high-dose chemotherapy or radiation therapy

• Biological therapies– Immunotherapy: biological molecules that

stimulate immune responses against cancer cells




• Medications to combat anorexia and wasting– Megestrol acetate and dronabinol stimulate

appetite– Antiemetic drugs control nausea

• Alternative therapies– Complementary and alternative medicine

(CAM): e.g., multivitamin and herbal supplements



Cancer: Nutrition Therapy

• Nutrition therapy for cancer– What are the goals of nutrition therapy for

cancer patients?– Protein and energy

• Protein requirements: 1.0 to 1.6 g/kg/day• Weight loss is a problem for many cancer patients• Breast cancer patients often gain weight and body

fatness• Box 23-6 discusses high-kcal, high-protein meals



Cancer: Nutrition Therapy for Cancer (cont’d.)

• Managing symptoms and complications– Dietary considerations for specific cancers

(Table 23-6)– Tips for improving food intakes (Box 23-7)– Responses to strategies vary, so adjustments

may be necessary• Food safety concerns

– What are low-microbial (neutropenic) diets?



Cancer: Nutrition Therapy for Cancer (cont’d.)

• Enteral and parenteral nutrition support– Indications:

• Complications that interfere with food intake• Long-term or permanent GI impairment

– Enteral strongly preferred over parenteral nutrition to preserve GI function and avoid infection



HIV Infection

• Acquired immune deficiency syndrome (AIDS)– Develops from human immunodeficiency virus

(HIV) infection• Prevention of HIV infection

– Spread by direct contact with contaminated body fluids

– At-risk individuals should undergo testing



HIV Infection (cont’d.)

• Consequences of HIV infection– Destroys immune cells with protein called

CD4 on their surfaces• Most affected are helper T cells (CD4+ T cells)• Infected cells produce additional copies of the virus

– Left untreated, HIV increases susceptibility to opportunistic infections

– AIDS: advanced stages of HIV infection• What diseases and complications are included in

AIDS-defining illnesses?



HIV Infection: Consequences of HIV Infection (cont’d.)

• Weight loss and wasting– Anorexia and inadequate food intake– Nutrient malabsorption– Altered metabolism– Diet-drug interactions




• Reduced food intake– Oral infections: candidiasis, herpes simplex

virus– Cancer: Kaposi’s sarcoma– Medications– Respiratory disorders: pneumonia,

tuberculosis– Emotional distress, pain, and fatigue




• GI tract complications– Attributed to opportunistic infections,

medications, or the HIV infection itself– Advanced stages of HIV: AIDS enteropathy

• Lipodystrophy– Abnormalities in body fat and fat metabolism– Buffalo hump, lipomas– Altered blood lipid levels




• Neurological complications– Clinical features: mild to severe dementia,

muscle weakness and gait disturbances, and pain, numbness, tingling in legs and feet

• Other complications– Anemia, skin disorders, kidney diseases, eye

disorders, and coronary heart disease




• Treatments for HIV infection– Help to slow its progression, reduce

complications, and alleviate pain– Standard drug treatment: combination of at

least three antiretroviral drugs (Table 23-9)– In addition to antiviral drugs, why may adjunct

drug therapies be necessary?– Box 23-10 lists nutrition-related drug effects



HIV Infection: Treatments for HIV Infection (cont’d.)

• Control of anorexia and wasting– Anabolic hormones, appetite stimulants, and

regular physical activity• Reverse unintentional weight loss and increase

muscle mass

• Control of lipodystrophy– Aerobic activity and resistance training may

help to reduce abdominal fat



HIV Infection: Treatments for HIV Infection (cont’d.)

• Control of lipodystrophy– Medications to treat abnormal blood lipid

levels and insulin resistance• Alternative therapies

– Monitoring patients’ use of dietary supplements is essential

• Reduces likelihood of adverse effects or diet-drug interactions




• Nutrition therapy for HIV infection– Initial assessment: evaluation of body weight

and body composition– Follow-up measurements may indicate

adjustments to dietary recommendations and drug therapies

– Weight management• For overweight or obese patients, moderate weight

loss may be recommended



HIV Infection: Nutrition Therapy for HIV Infection (cont’d.)

• Weight management– With weight loss and wasting, a high-kcalorie,

high-protein diet may be beneficial• Nutrient-dense snacks, bars, oral supplements

• Metabolic complications– Insulin resistance – Elevated triglyceride and LDL cholesterol

levels




• Metabolic complications– Achieve or maintain a desirable weight– Replace saturated fats with unsaturated fats– Increase fiber– Limit intakes of trans fats, cholesterol, added

sugars, and alcohol– Regular physical activity




• Vitamins and minerals– Supplements are often recommended– Why is it important that supplement doses be

close to DRI recommendations?• Symptom management (Box 23-7)

– Food consumption may be difficult– Electrolyte balance affected by vomiting and

diarrhea




• Food safety concerns– High susceptibility to foodborne illness– Need detailed safe handling and preparation

instructions– Water safety considerations

• Cryptosporidiosis




• Enteral and parenteral nutrition support– Aggressive nutrition support may be needed

in later stages of illness– Parenteral nutrition is reserved for patients

unable to tolerate enteral nutrition– Careful measures to avoid bacterial

contamination of nutrient formulas and feeding equipment



Nutrition in Practice:Ethical Issues in Nutrition Care

• Ethical principles surrounding the decision to withhold or withdraw nutrition support

• Life-sustaining treatments• Legal decisions about nutrition support for

incapacitated patients– Nancy Cruzan case– Terri Schiavo case



Nutrition in Practice:Ethical Issues in Nutrition Care (cont’d.)

• Legal documents used to declare preferences about medical treatments– Advance health care directive (living will)– Durable power of attorney (health care proxy)

• Appoints a health care agent to make decisions– Do-not-resuscitate (DNR) order


chapter 23 nutrition, cancer, and hiv infection

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