Recent trends in the
treatment of cancer
Cancer is second only to heart disease as the leading cause of death in the
United States. More than 5,000 people are diagnosed with cancer each week in the UK.
There are four major types of cancer
treatment: surgery, radiotherapy,
chemotherapy, and immunotherapy. These therapies can be used either alone or in combination with each other. Many new treatments, including cancer vaccines and gene therapy, are being studied in clinical trials.
Methods for cancer treatment: Surgery is the oldest and most common form of cancer treatment. About 60% of cancer patients will undergo some sort of surgery, either by itself or in combination with other therapies.
ü Recent studies, including the EBMTR-sponsored 'CUP Trial' (conventional Chemotherapy, Unpurged autograft, Purged autograft), demonstrate that for patients under age 60 years with recurrent chemotherapy-sensitive disease, autologous stem cell transplantation (ASCT) provides a survival benefit over conventional therapy. Bone marrow transplantation and cryosurgery are other methods used.
ü Combined-modality treatment (CMT), including transurethral resection (TURBT), radiation therapy (RT) and systemic chemotherapy for bladder cancer is a reasonable treatment option for patients who are deemed medically unfit for cystectomy and for those seeking an alternative to radical cystectomy.
Chemotherapy uses powerful drugs to kill cancer cells, control their growth, or to relieve pain symptoms. Chemotherapy can be used in combination with other treatments such as surgery or radiation, to make sure all cancer cells have been eliminated. Hormone therapy for many cancers (e.g. prostrate cancer) is also in use.
ü Aromatase Inhibitors show promise for early breast cancer and are approved for the treatment of advanced metastatic breast cancer in postmenopausal women, whose disease has progressed during tamoxifen therapy.
Radiation uses large doses of high-energy beams or particles to destroy cancer cells in a specifically targeted area. Radiotherapy is most commonly used on localized solid tumors, and on cancers that affect the bloodstream, such as leukemia and lymphoma.
ü Brachytherapy, a new way to mix radionuclides for enhanced radiobiologic effects, and different fractionation schemes that have grown in clinical importance. Intensity-modulated radiotherapy has become a mainstay in head and neck cancer treatment.
ü Novel radiation techniques such as partial breast irradiation and shortened radiotherapy treatment courses are under development to make radiotherapy more acceptable to patients.
ü Targeted radiation therapy or radioimmunotherapy has been an important recent advance in the treatment of patients with B-cell non-Hodgkin's lymphoma (NHL). Yttrium 90-labeled ibritumomab tiuxetan (Zevalin) comprises the murine monoclonal antibody ibritumomab, the linker chelator tiuxetan, and the radiolabeled isotope yttrium 90.
Immunotherapy, also known as biologic therapy, stimulates the body's own defense systems to fight cancer. Immunotherapy, also known as biotherapy or biological response modifiers, works on white blood cells - the body's first line of defense against disease. Biological response modifiers are developed in a laboratory and then injected into the body.
There are five general types of biological response modifiers. They can be used alone or in combination with each other, or they can be used in addition to other cancer treatments.
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Interferons are a group of three proteins released by white blood cells in reaction to invading organisms, to improve the immune system's reaction to cancer.
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Interleukins are proteins that increase growth and activity in the body's immune cells.
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Monoclonal Antibodies are designed to attack specific areas on the surface of cells known as antigens. Antigens help the body identify cells that are foreign, like germs or caells, and stimulate an immune response.
Recent findings: Cetuximab, a monoclonal antibody against the epidermal growth factor receptor, and bevacizumab, a monoclonal antibody against vascular endothelial growth factor, have now been subject to rigorous assessment within several clinical studies, including a large randomized phase II study of cetuximab and a randomized phase III study of bevacizumab.
The most recent studies investigated monoclonal antibodies in the treatment of metastatic colorectal cancer. The additional therapy with the VEGF-antibody bevacizumab prolongs survival by more than 4 months compared to chemotherapy alone. The EGF-receptor antibody cetuximab is an effective therapy after progression with irinotecan.
Current research trends suggest a paradigm shift in emphasis from vaccines designed to elicit antibody responses to strategies such as dendritic cell vaccination that are designed to induce broader immunity, including ovarian tumor antigen-specific helper T-lymphocyte and cytotoxic T-lymphocyte responses.
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Vaccines help the body recognize cancer cells and trigger the immune system to destroy them. Cancer vaccines are used to either help the body reject cancer tumors or to keep them from recurring.
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Colony Stimulating Factors increase the division of bone marrow cells, which strengthens the immune system and allows patients to endure higher doses of chemotherapy drugs.
Gene therapy represents a new and innovative approach to the treatment of oral cancer especially in recurrent disease and adjuvant treatment. Gene therapy is defined as the introduction of genetic material in a patient's cells with resulting therapeutic benefit. It is a promising new biomedical discipline that could potentially lead to new treatments for hereditary diseases, cardiovascular and neurological disorders, cancer, diabetes and even infectious diseases. The introduction of genetic material into somatic cells requires gene delivery vectors. Since viruses have developed efficient means to introduce their own genetic material into cells they can be readily adapted as viral vectors for gene therapy. Gene Therapy identifies missing or defective genes that cause cancer or increase cancer risk, and replaces them with normal copies.