Cancer Chemotherapy

Cancer Chemotherapy
Cancer chemotherapy involves the use of drugs to destroy cancer cells. Although an ideal chemotherapy drug would destroy cancer cells without harming normal cells, only a few of such drugs exist. Instead, in chemotherapy, drugs are designed to inflict greater damage on cancer cells than on normal cells. Nonetheless, all chemotherapy drugs affect normal cells and can cause side effects.
Not all cancers respond to chemotherapy. The type of cancer determines which drugs are used, in what combination and at what dose. Chemotherapy may be used as a sole treatment or a combination with radiation therapy or surgery.
Another approach is to use a variety of molecularly targeted drugs that capable entering cancerous (malignant) cells and interrupt the important pathways of information flow in cancerous cell. These molecules render the cells to become defective and then die. Imatinib is the first drug that alters the energy sites in the malignant cell and is highly effective in chronic myelocytic leukemias and certain tumors of the digestive tract. Other drugs target cell surface receptors in non-small cell lung cancer and colon cancer, but are not yet available for general use.
Dose intensity chemotherapy is a new technique but a risky approach in which special high doses of drugs are used. This therapy is used for a few types of cancer including some types of myeloma, lymphoma and leukimia that have recurred even though the person had a good response when first treated with drugs. This tumors have already demonstrated sensitivity to the drug, so the strategy is to increase the drug dose to kill more cancer cells and prolong patient survival time.
However dose intensity chemotherapy can cause life threatening injury to the bone marrow. Therefore dose intensity chemotherapy is commonly combined with bone marrow rescue technique. Where the bone marrow cells are collected before the chemotherapy is administrate and returned back to the person once the chemotherapy treatment is done. In some cases , stem cells can be isolated from a blood sample and used instead of bone marrow to restore the bone marrow.

Cancer Radiation Therapy

Cancer Radiation Therapy
Radiation is a beam of intense energy focused on a certain area or organ of the body. It can be generated by a radioactive substance such as cobalt or with an atomic particle (linear) accelerator. In other stategies, a radioactive substance may be injected into a vein to travel to the cancer. For example, radioactive iodine which is used in treatment of thyroid cancer, or radioactive implants which may be placed directly into the cancer. A linear accelerator directs the radiation to the tumor, while normal tissue is shielded as much as possible. To reduce exposure of normal tissue to the beam, multiple beam paths are used.
Radiation preferentially kills cells that divide rapidly. Cancer cells divide more often than normal cells and therefore are more likely than most cells to be killed by radiation. Nonetheless, cancer cells differ in how easily they are killed by radiation. Some are very resistant and thus cannot be effectively treated with radiation therapy. Unfortunately , radiation can damage normal tissues adjacent to the tumor, especially tissues in which cells normally divide rapidly, such as skin, the bone marrow, hair follicles and the lining of the mouth, esophagus and intestines. Radiation can also damage the ovaries and testes. Doctor tries to accurately target the radiation therapy to protect normal cells.
Radiation therapy is divided into series of doses over a prolonged period of time. This method increases the lethal effects of the radiation therapy on the tumor cells, while decreasing the toxic effects of the radiation on normal cells. The latter effect occurs because normal cells have the capacity to repair themselves quickly after being exposed to radiation.
Radiation therapy plays a key role in curing many cancers, including Hodgkin's disease, early stage non-Hodgkin's lymphoma, squamous cell cancer of the head and neck, seminoma (a testicular cancer), prostate cancer, early stage non-small cell lung cancer and medulloblastoma ( a brain or spinal cord tumor). For early stage cancers of the larynxand prostate, the rate of cure is essentially the same with radiation therapy as with surgery.
Radiation therapy can reduce symptoms when cure is not possible, as in multiple myeloma and advanced lung, esophageal, head and neck cancers. By temporarily shrinking the tumors, radiation therapy can be given as palliative therapy to relieve symptoms caused by spread of cancer to bone or brain.
New techniques of intense and highly focused radiaton therapy such as proton radiation can effectively treat certain tumors in areas where damage to normal tissue is a worry. Such as in the eyes, brain or spinal cord. Radioactive seed implants is a small pellets of a radioactive substances are often used to treat prostate cancer. These seed implants provide intense radiation to the cancer and little to surrounding tissues.

Cancer Surgery

Cancer Surgery:
Cancer surgery is one of the oldest forms of cancer treatment and often is the most effective. Surgery is usually the sole or primary means of treating tumors that have not spread beyond their own original site of growth. Which mean surgery treatment cannot be use for metastatic cancer. However surgery cannot be used for all early stages cancer. Some tumors occur in inaccessible sites. In the other instances, removing the tumor might require removing a necessary function or organ. In some instances, surgery must be combined with other treatments like chemotherapy or radiotherapy to prevent regrowth of the same tumors. In some cases, surgery is intended to remove part of the cancer in a process which doctors call debulking. Debulking may reduce symptoms and improve the likelihood that radiation therapy or chemotherapy will be effective.

Cancer Prevention

Cancer Prevention:
Reducing risk of cancer may be possible through dietary and other lifestyle changes. How risk can be reduced depends on the specific cancer. For example in lifestyle changes is stop smoking and avoid exposure to tobacco smoke can greatly reduce the risk of lung, kidney, bladder, head, neck cancer. Avoiding the use of smokeless tobacco (snuff,chew) decrease the risk of cancer of the mouth and tongue. Avoiding sun exposure especially during the middle of the day can reduce the risk of skin cancer. Covering exposed skin with sun blocking lotion with high sun protection factor (SPF) againts ultraviolet light also helps reduce the risk of skin cancer. Other lifestyles changes reduce the risk of several types of cancer. A reduced intake of fat in the diet appears to decrease the risk of breast and colon cancer. Use of aspirin and other non-steroidal anti-inflammatory drugs (NSAID) reduces the risk of colon cancer.

Cancer Screening

Cancer Screening Recommendations :
Screening tests serve to detect the possibility that a cancer is present before symptoms occur.

Skin Cancer :

• Physical Examination : part of general check-up
  
• Whole body photography : not routinely needed
  

Lung Cancer :

• Chest X-Ray : not routinely needed
• Sputum Cytology : not routinely needed
• Low-dose spiral computed tomography : not routinely needed

Rectal and Colon Cancer :

• Stool examination for occult blood : every year after age of 50
  
• Rectal examination : every year after age of 50
  
• Sigmoidoscopic or colonoscopic examination : every 3 to 5 year after age of 50

Prostate Cancer :

• Rectal examination : every year after age of 50
• Blood test for prostate specific antigen : every year after age of 50
  

Testicular Cancer :

• Testicle self examination : monthly after age of 14
  

Cervical, Uterine and Ovarian Cancer :

• Pelvic examination : Every 1 to 3 years between age of 18 to 40
  

Cervical Cancer :

• Papanicolaou (Pap) test : every year between age of 18 to 65
  

Breast Cancer :

• Breast self-examination : monthly after age of 18
  
• Breast physical examination : every 3 years between age of 18 and 40
  
• Mammography : yearly after age of 35