Definition

 Cancer disorder of cell growth and regulation and control division of abnormal cells

     condition in which cells proliferated in an irregular or uncontrolled way

Epidemiology

•  major cause of mortality in United State

• Second to CVD 

• mostly cases seen in older individual

• Two third of all cases were in those over age 65 

• Lungs and bronchus is the number of 1 Killer in both men and women'

• 2nd killer prostate cancer in male and breast cancer in female.

• 3rd colorectal cancer

• African American men have a 90% higher cancer incidence rate and 37% higher

•  cancer mortality rate than white men.

• African American women have 6% lower incidence rate than white females have a 17% higher mortality rate.

Etiology

 Carcinogenesis is a multi-step process in which normal cell are transformed into cancer cells.

       Due to exposure to

• Chemical 
• physical agent 
• radiation
•  infectious microorganism 
• genetic and nutritional factors

 Though only small percentage of cancel are actually considered hereditary all cancers in   involved genetics to a certain degree.

    Mechanism of defect in gene

     Due to;

1. Exposure to viral ,bacterial agents ,chemicals
2. Nutritional component of (antioxidants ,soy protein fat , alcohol phytochemicals)

 Unbalance diet (1/3 third of 500000 Cancer deaths are due to diet and activity)

   Physical in activit;

• Cigarette smoking cause lungs cancer 
• UV rays cause skin cancer
• Red meat consumption (increase cancer risk specially for colorectal, bladder, prostate breast , gastric ,oral and pancreatic cancers)

Biomarkers

• Biomarkers are distinctive biological or biologically derived indicators( such as a Biochemical metabolite  in the body) that may be used;

•  Used to identify nutrient exposure
•  Help to improve precision of epidemiologic study
• Uses as a measure of internal (does to indicate the nutrient available to issues after absorption and metabolism)
• Measure of dietary change

• Fruit and vegetables give cancer preventive effect against mouth ,pharynx, esophagus, stomach colon, rectum, larynx, lung, ovary (vegetable only), bladder (fruit only ),and kidney

• Whole grains, fiber, vitamin D, and physical activity shows inverse relation with cancer risk.

• Intake of total fat/ certain type of fat (e.g. saturated fat )and alcohol, obesity  (as measured by a high body mass index (BMI ))and certain food preparation methods such as smoking ,salting ,and pickling foods, and high temperature cooking of meats shows direct relation with cancer severity.

• BMI >40 death rate 52% in manner and 62% in women

• Cancer of esophagus, colon, rectum, liver, gallbladder, pancreas and kidney most likely occur in individuals BMI >40

• Overweight and obesity accounts for 14% death in men and 20% in women

• Individuals having metabolic syndrome are more likely to have cancer specially prostate collateral and breast cancer.

Pathophysiology:

        Basic principal of cell growth;

• All cells reproduce during the embryonic phase, but only some cells continue to reproduce after the first few months following birth.

• Cells that reproduce (liver ,bone marrow skin, and gastrointestinal tract)

• Copy their DNA exactly
• Split into two new daughter cells
• This type of cells to constantly regenerate.

• Cells that reproduced do so at an in Nate rate (rate at which they are genetically programmed to reproduce)

• This rate may be decrease or increase depended on genetic factors.

Cell type

• 
  
• Cell are classified as
• Cycling cells 
• non dividing cells 
• resting cells

     Cycling cells divide continuously; the epithelial cells that line the gastro-intestinal tract         are an examples.

     Non dividing cells divide before they different (specialize), and then they do not divide       again.

     Resting cells remain dormant initially, but certain condition can stimulate their                     replication and growth.

    In general, the cells of the bone marrow and the gastrointestinal tract have the fastest rate       of replication.

Control of division

 Genetic control for cellular division and growth include two basic sets of genes              called;

• Oncogenes and tumor suppressor genes
• Oncogenes stimulate growth
• Suppressor genes, suppress cellular growth

 Cellular growth is also controlled by a counting system based on telomeres.

• Telomeres are end pieces of chromosomes that become shorter after each cell division .when the  telomere shortens to a specific length, the cell will stop dividing.

•  Normal cellular reproduction is controlled by a combination of factors:

• genetic controls,
•  Harmons ,
• growth substances secreted by distant .cells
• local growth factors .
• chemical caused from neighboring cells.

Cancer cell growth

• Unlike a normal cell, whose growth is closely regulated a cancer cell reproduces at an uncontrolled rate.

• The cancer cell becomes autonomous from the normal growth signals and genetics control, and may even secrete its own growth factor.

• In a cancer cell, and enzyme is secreted that destroys the telomere,

• The process of cell differentiation may, change and a specific cell type may take on other traits.

• The physical characteristics of the cancer cell are altered.

• The nucleus and cytoplasm may be largid
• The mitosis rate is usually higher
• There may be derangements in the chromosomes sequence.
• The change form normal cell tour cancer cell theoretically 

       Involves several steps;

• Initiation 
• promotion 
• progression

• It is difficult in some  situations to distinguish between initiation  and promotion, but in general initiation occurs as a result of exposure to an initiating agent, such as tobacco.

• An agent predisposes the cell to genetic mutation.

• Factor that promote the cells movement through the carcinogenic change includes some hormones such as estrogen aur testosterone.

• These promoter required and activation of the carcinogen  as well as a failure of natural immunity and cellular repair mechanism. 

• Tumor growth rate is depend on characteristics of the host such as sex ,age ,overall health ,nutritional status and immune function.

• Cancer cells may grow locally at the original primary site of cell transformation or spread to distant sites.

• This distant spread is called metastasis

• Specific cancer type have typing routes for metastasis that include the lymphatic system, circulatory system or nearby body cavities.

• For example breast cancer typically metastasizes to brain and lungs tissues through both the circulatory and lymphatic systems.

•   What is the simple definition of cancer?

•   How does cancer effect the body?

Nutritional manifestation of cancer

Cancer nutrition intervention