Cancer

The term cancer refers to many different diseases. They all have in common uncontrolled cell proliferation (growth and division). Cancers are usually named for the organ or cell type that is originally involved. After beginning at one site, cancer may metastasize (spread) to other organs. The cancer is still named by its place or origin.

Types of Cancer

X-Ray of patient with tumor cancer in right lung

Lung tumor

Data are for USA

• Most common cancers in men:

1. Prostate
2. Lung
3. Colorectal

• Deadliest cancers in men:

1. Lung
2. Prostate
3. Colon
4. Pancreatic
5. Leukemia
6. Liver
7. Stomach

• Most common cancers in women

1. Breast
2. Lung
3. Colorectal

• Deadliest cancers in women

1. Lung
2. Breast
3. Colorectal
4. Pancreatic
5. Uterus
6. Stomach

Prevention and Screening

Preventative strategies are continuously being revised. Please see references below for up to date information.

• Breast cancer: In women without a family history of breast cancer, mammograms should be done yearly. Clinical breast exam by a medical professional should also be done yearly. Women who have had abortions are significantly more likely to contract breast cancer.
• Lung cancer: There are no currently accepted preventative guidelines
• Prostate cancer: evidence is inconclusive, but most doctors recommend yearly PSA blood test and digital rectal exam
• Colon cancer: in people without a family history of colon cancer, most sources recommend a colonoscopy at age 50, with further studies based on the results. Fecal occult blood testing should also be conducted yearly.
• Cervical cancer: yearly Pap smears should be done on all women who have been sexually active and have not had a hysterectomy. Over age 65, women in monogamous relationships and recent normal Pap smears probably do not need to be screened as frequently.
• Testicular cancer: the evidence is unclear, however most physicians recommend routine testicular exams in young men.
• Skin cancer: keep skin protected from sunlight by use of clothing and sunscreen, and watch you skin for new moles, or changes in existing moles.

Treatment of cancer

chemotherapy

Chemotherapy is the use of drugs that kill tumor cells. Conventionally, the drugs that are used are those that target cells which are rapidly undergoing mitosis; this approach is effective but is limited by side effects, which occur because these drugs have an adverse effect on normal tissues that contain rapidly-dividing cells. Research is under way to find drugs with a wider therapeutic margin. One approach is to study specific molecular markers that may be used to identify cancer cells, and to develop drugs that preferentially kill cells that exhibit those markers.

radiation therapy

Radiation therapy involves the use of precisely-targeted radiation to destroy cancer cells. Because radiation damages DNA and thus has the ability both to treat and to cause cancer, this method of treatment must be administered by physicians highly-skilled in physics.

surgery

The goal of cancer surgery is to physically remove the abnormal cells. This becomes more difficult after the cancer spreads. Often, chemotherapy is used either before or after surgery to kill cancer cells that have metastasized.

immunotherapy

The immune system contains a number of cell types, such as NK cells and killer T cells that have the capability to destroy other cells that have become infected with viruses or have become cancerous. Immunotherapy utilizes these natural defenses against tumor cells.

References

• http://www.cdc.gov
• American Cancer Society: Cancer statistics for 2007
• American Cancer Society: What is chemotherapy?
• American Cancer Society: How does chemotherapy Work?
• American Cancer Society: What's new in chemotherapy research?
• Agency for Healthcare Research and Quality: Guide to Clinical Preventive Services
• Mayo Clinic: Chemotherapy: Drug treatment uses chemicals to kill cancer cells
• Myth: Cancer cannot be prevented