Transcript Lecture One

Cancer:
a number of diseases that arise
due to genetic alterations in cells
that lead to unchecked growth
(tumorigenesis).
Dietary and immune factors are
thought to influence risk of cancer.
Tumors can be MALIGNANT (spread aggressively
to other parts of the body) or BENIGN (nongrowing tumors that do not threaten life).
Cancer Terminology
Cancers are classified by their tissue of origin.
Examples:
Carcinomas: originate in epithelial tissues.
Adenomas: originate in glandular tissues.
Sarcomas: originate in soft tissues (e.g., muscle, bone,
or connective tissues)
Melanomas: originate from pigmented cells in the skin.
Lymphomas: originate from lymph tissues.
Leukemias: arise from white blood cells.
Gliomas:
arise from cells in the nervous system.
Genetic Alterations That Lead to Colorectal Cancer
Effect of Dietary Constituents?
Figure 1: A theoretical framework ued to describe the
process of carcinogenesis.
NORMAL CELL
INITIATED CELL
CLONAL GROWTH
Initiation
Promotion
Progression
Inflammation
Rapid Cell Growth/ Tumor Growth
Inhibition of
Dissemination
Apoptosis
Mutations
in Tumor
Suppressor/
Oncogenes
Metastasis
Source: L.W. Wattenberg. Cancer Research (1993) 53:5890.
Nutritional Consequences of Cancer
Dependent upon:
1.
Stage of Cancer (e.g., Duke’s)
2.
Location of Cancer
3.
Treatment Modality (e.g., radiation,
chemotherapy, surgery, etc.)
Cancer patients MAY or MAY NOT be hypermetabolic.
Cancer Cachexia:
Loss of Appetite
PEM associated with
cancer.
weight loss
Depletion of lean body mass
Depletion of serum proteins
Cancer Cachexia is caused by altered metabolism
due to cytokines produced BY THE TUMOR.
These cytokines cause anorexia and
help to shunt fuel to the tumor.
Causes of Inadequate Nutrient Intake
1.
Early satiety and nausea.
2.
Fatigue.
3.
Pain.
4.
Psychological stress.
5.
GI Obstructions.
Causes of Nutrient Losses in Cancer
•
Malabsorption
•
Diarrhea
•
Vomiting
•
Inadequate Digestion
Where Does Diet Fit in Cancer Treatment?
Primary Cancer Treatments?
Radiation, Chemotherapy, Surgery
These treatments pose significant threats to health and
nutritional status.
New Therapies-- Monoclonal antibodies against the Her/Neu
receptor (Herceptin)
AntiAngiogenesis therapies: neomycin,
angiostatin, endostatin
Immunotherapy
Adequate nutrition is supportive therapy only.
Diet cannot cure cancer but adequate nutritional
status can help patients survive difficult treatments.
You’ll hear many accounts of dietary success in
cancer treatment. Some are likely to be true.
Cancer Treatment Centers of America uses diet
as adjunctive therapy for all types of cancer.
Rationale behind Treatment Strategies:
Radiation:
Interferes with cell’s ability to divide.
Since many cancer cell-types grow faster than
normal cells, this treatment SHOULD preferentially
kill cancer cells.
Fastest growing tissues are the ones hit hardest by
radiation treatment:
GI epithelium, bone marrow, hair, skin
Primary Side Effects of Radiation Treatment
Fatigue, Anorexia, Nausea, Vomiting, Diarrhea
Mouth Ulcers
Lack of Saliva Production
Damage to teeth and mandible
Chewing/
Swallowing
Difficult
Radiation Enteritis= malabsorption, blood loss
fluid/electrolyte imbalances