The Role of Sex Hormones

Hormones such as estrogen, progesterone, and testosterone prepare the human body for reproduction and stimulate the development of sexual characteristics as an individual passes through puberty. In women, estrogen stimulates development of the breasts, ovaries, uterus, and the general shape of the body. The cells of the uterine lining are stimulated to grow and divide every month as part of the woman's menstrual cycle. If a pregnancy occurs, progesterone, along with estrogen, helps maintain the...

Prostate Cancer

Prostate cancer is the most common type of cancer in North American men. The number of men affected by prostate cancer is nearly equal to the number of women affected by breast cancer, but the mortality of prostate cancer is lower (see table on page 3). ANATOMY The prostate gland is part of the male reproductive system. It makes and stores portions of the seminal fluid, a fluid that is mixed with sperm to produce semen. The gland is about the size of a walnut and is located below the bladder...

Common Types Of Cancer

In 2003 more than 2 million new cancer cases were diagnosed in the United States alone, and in that same year, more than half a million Americans died of cancer. Cancer can strike anyone, but the risk increases with age, certain lifestyles, and the quality of the environment. Nearly 80 percent of all cancers are diagnosed in patients age 55 and older, and smokers are 20 times more likely to develop lung cancer than nonsmokers. Cancers can appear in any of our tissues and organs, but there are...

Leukemia

Each year, nearly 32,000 adults and more than 2,000 children in the United States learn that they have leukemia, a cancer of the blood cells. ANATOMY There are three different types of blood cells red blood cells (RBC or erythrocytes), white blood cells (WBC, or leukocytes), and platelets (thrombocytes). Red blood cells contain hemoglobin and use it to carry oxygen from the lungs to the tissues. White blood cells do not carry oxygen but are part of the body's immune system. White blood cells...

Skin Cancer

Production Sebum

This is the most common type of cancer in North America, with 1 million cases being diagnosed each year. The table on page 3 shows data only for melanoma. Nearly half of the North American population will develop some form of skin cancer by age 65. Although anyone can get skin cancer, the risk is greatest for people who have fair skin that freckles easily, often those with red or blond hair and blue or light-colored eyes. ANATOMY The skin protects us against heat, light, injury, and infection....

Chemotherapy

Certain drugs may be used to kill or inhibit the growth of cancer cells. The nature of a drug varies depending on the type of cancer, its location in the body, the effect it has on normal body functions, and the overall health of the patient. In general, cancer drugs damage DNA, block the synthesis of DNA and RNA, or damage the mitotic spindle. Cancer drugs can also interfere with normal physiology by blocking steroid hormone receptors that stimulate cancer cell growth. DRUGS THAT TARGET DNA...

Oncogenes and Protooncogenes

An oncogene is produced when its normal counterpart, the proto-oncogene, is altered in some way. Research in many laboratories over the past 20 years has shown that the conversion of proto-oncogenes to oncogenes a PO conversion occurs by essentially two methods a point mutation, occurring as described above for TSGs, and insertional mutagenesis. If the mutation occurs within the gene's promoter the genetic element that turns a gene on or off , the protein product will be the same before and...