- What is adoptive T-cell transfer therapy?
Adoptive cell transfer is an experimental anticancer therapy that attempts to enhance the natural cancer-fighting ability of a patient’s T cells. In one form of this therapy, researchers first harvest cytotoxic T cells that have invaded a patient’s tumor. They then identify the cells with the greatest antitumor activity and grow large populations of those cells in a laboratory. The patients are then treated to deplete their immune cells, and the laboratory-grown T cells are infused into the patients.
In another, more recently developed form of this therapy, which is also a kind of gene therapy, researchers isolate T cells from a small sample of the patient’s blood. They genetically modify the cells by inserting the gene for a receptor that recognizes an antigen specific to the patient’s cancer cells and grow large numbers of these modified cells in culture. The genetically modified cells are then infused into patients whose immune cells have been depleted. The receptor expressed by the modified T cells allows these cells to attach to antigens on the surface of the tumor cells, which activates the T cells to attack and kill the tumor cells.
Adoptive T-cell transfer was first studied for the treatment of metastatic melanoma because melanomas often cause a substantial immune response, with many tumor-invading cytotoxic T cells. Adoptive cell transfer with genetically modified T cells is also being investigated as a treatment for other solid tumors, as well as for hematologic cancers (24-29).
- What are the side effects of biological therapies?
The side effects associated with various biological therapies can differ by treatment type. However, pain, swelling, soreness, redness, itchiness, and rash at the site of infusion or injectionare fairly common with these treatments.
Less common but more serious side effects tend to be more specific to one or a few types of biological therapy. For example, therapies intended to prompt an immune response against cancer can cause an array of flu-like symptoms, including fever, chills, weakness, dizziness,nausea or vomiting, muscle or joint aches, fatigue, headache, occasional breathing difficulties, and lowered or heightened blood pressure. Biological therapies that provoke an immune system response also pose a risk of severe or even fatal hypersensitivity (allergic) reactions.
Potential serious side effects of specific biological therapies are as follows:
MAbs
o Flu-like symptoms
o Severe allergic reaction
o Lowered blood counts
o Changes in blood chemistry
o Organ damage (usually to heart, lungs, kidneys, liver or brain)
Cytokines (interferons, interleukins, hematopoietic growth factors)
o Flu-like symptoms
o Severe allergic reaction
o Lowered blood counts
o Changes in blood chemistry
o Organ damage (usually to heart, lungs, kidneys, liver or brain)
Treatment vaccines
o Flu-like symptoms
o Severe allergic reaction
BCG
o Flu-like symptoms
o Severe allergic reaction
o Pain or burning sensation during urination
o Increased urgency or frequency of urination
o Blood in the urine
Oncolytic viruses
o Flu-like symptoms
o Tumor lysis syndrome: severe, sometimes life-threatening alterations in blood chemistry following the release of materials formerly contained within cancer cells into the bloodstream
Gene therapy
o Flu-like symptoms
o Secondary cancer: techniques that insert DNA into a host cell chromosome can cause cancer to develop if the insertion inhibits expression of a tumor suppressor gene or activates an oncogene; researchers are working to minimize this possibility
o Overexpression of the introduced gene may harm healthy tissues
o Virus vector transmission to other individuals or into the environment
- How can people obtain information about clinical trials of biological therapies for cancer?
Both FDA-approved and experimental biological therapies for specific types of cancer are being studied in clinical trials. The names of the biological therapy types listed below are links to descriptions of ongoing clinical trials that are testing those types of biological therapies in cancer patients. These trial descriptions can also be accessed by searching NCI’s list of cancer clinical trials on the NCI website. NCI’s list of cancer clinical trials includes all NCI-funded clinical trials as well as studies conducted by investigators at hospitals and medical centers throughout the United States and around the world.
Lasers in Cancer Treatment
1. What is laser light?
The term “laser” stands for light amplification by stimulated emission of radiation. Ordinary light, such as that from a light bulb, has many wavelengths and spreads in all directions. Laser light, on the other hand, has a specific wavelength. It is focused in a narrow beam and creates a very high-intensity light. This powerful beam of light may be used to cut through steel or to shape diamonds. Because lasers can focus very accurately on tiny areas, they can also be used for very precise surgical work or for cutting through tissue (in place of a scalpel).
2. What is laser therapy, and how is it used in cancer treatment?
Laser therapy uses high-intensity light to treat cancer and other illnesses. Lasers can be used to shrink or destroy tumors or precancerous growths. Lasers are most commonly used to treat superficial cancers (cancers on the surface of the body or the lining of internal organs) such asbasal cell skin cancer and the very early stages of some cancers, such as cervical, penile,vaginal, vulvar, and non-small cell lung cancer.
Lasers also may be used to relieve certain symptoms of cancer, such as bleeding or obstruction. For example, lasers can be used to shrink or destroy a tumor that is blocking a patient’s trachea(windpipe) or esophagus. Lasers also can be used to remove colon polyps or tumors that are blocking the colon or stomach.
Laser therapy can be used alone, but most often it is combined with other treatments, such assurgery, chemotherapy, or radiation therapy. In addition, lasers can seal nerve endings to reduce pain after surgery and seal lymph vessels to reduce swelling and limit the spread of tumor cells.
3. How is laser therapy given to the patient?
Laser therapy is often given through a flexible endoscope (a thin, lighted tube used to look at tissues inside the body). The endoscope is fitted with optical fibers (thin fibers that transmit light). It is inserted through an opening in the body, such as the mouth, nose, anus, or vagina. Laser light is then precisely aimed to cut or destroy a tumor.
Laser-induced interstitial thermotherapy (LITT), or interstitial laser photocoagulation, also uses lasers to treat some cancers. LITT is similar to a cancer treatment called hyperthermia, which uses heat to shrink tumors by damaging or killing cancer cells. (More information about hyperthermia is available in the NCI fact sheet Hyperthermia in Cancer Treatment.) During LITT, an optical fiber is inserted into a tumor. Laser light at the tip of the fiber raises the temperature of the tumor cells and damages or destroys them. LITT is sometimes used to shrink tumors in theliver.
Photodynamic therapy (PDT) is another type of cancer treatment that uses lasers. In PDT, a certain drug, called a photosensitizer or photosensitizing agent, is injected into a patient and absorbed by cells all over the patient’s body. After a couple of days, the agent is found mostly in cancer cells. Laser light is then used to activate the agent and destroy cancer cells. Because the photosensitizer makes the skin and eyes sensitive to light afterwards, patients are advised to avoid direct sunlight and bright indoor light during that time. (More information about PDT is available in the NCI fact sheet Photodynamic Therapy for Cancer.)
4. What types of lasers are used in cancer treatment?
Three types of lasers are used to treat cancer: carbon dioxide (CO2) lasers, argon lasers, and neodymium:yttrium-aluminum-garnet (Nd:YAG) lasers. Each of these can shrink or destroy tumors and can be used with endoscopes.
CO2 and argon lasers can cut the skin’s surface without going into deeper layers. Thus, they can be used to remove superficial cancers, such as skin cancer. In contrast, the Nd:YAG laser is more commonly applied through an endoscope to treat internal organs, such as the uterus, esophagus, and colon.
Nd:YAG laser light can also travel through optical fibers into specific areas of the body during LITT. Argon lasers are often used to activate the drugs used in PDT.
5. What are the advantages of laser therapy?
Lasers are more precise than standard surgical tools (scalpels), so they do less damage to normal tissues. As a result, patients usually have less pain, bleeding, swelling, and scarring. With laser therapy, operations are usually shorter. In fact, laser therapy can often be done on anoutpatient basis. It takes less time for patients to heal after laser surgery, and they are less likely to get infections. Patients should consult with their health care provider about whether laser therapy is appropriate for them.
6. What are the disadvantages of laser therapy?
Laser therapy also has several limitations. Surgeons must have specialized training before they can do laser therapy, and strict safety precautions must be followed. Laser therapy is expensive and requires bulky equipment. In addition, the effects of laser therapy may not last long, so doctors may have to repeat the treatment for a patient to get the full benefit.
7. What does the future hold for laser therapy?
In clinical trials (research studies), doctors are using lasers to treat cancers of the brain andprostate, among others. To learn more about clinical trials, call NCI’s Cancer Information Service at 1–800–4–CANCER or visit the clinical trials page of NCI’s Web site.
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