Also called: Laser Treatment
Laser therapy is a relatively new way to treat cancer that uses high-intensity light to destroy cancer cells. Laser therapy has been commonly used to treat benign conditions, such as in corrective eye procedures. However, it is now being used in certain cancer treatments. In some patients, laser therapy has been shown to cure their cancer. More often, it is used to relieve symptoms such as bleeding and obstruction when other therapies cannot be used or fail to work.
Ordinary light is made up of many different wavelengths that spread in all directions. In contrast, laser light has one specific wavelength focused in a narrow beam of high-intensity light. Lasers can focus precisely on tiny areas, enabling them to accurately target small areas of human tissue. Laser therapy is most often used to treat superficial cancers, which include those on the surface of the body or the lining of internal organs. Laser therapy use is limited because the area treated must be visualized during treatment. The most common cancers treated with laser therapy include:
- Basal cell skin cancer
- Cervical cancer
- Penile cancer
- Vaginal cancer
- Vulvar cancer
- Non-small cell lung cancer
- Anus, colon or rectum
- Vocal cords
Currently, laser therapy is primarily used to relieve symptoms from the disease or its treatment (palliative therapy). Research continues to evaluate the effectiveness of laser therapy as means to cure various cancers.
About laser therapy
Laser therapy uses high-intensity light to destroy precancer or cancer cells. The term laser is an acronym for Light Amplification by Stimulated Emission of Radiation. Its use as a cancer treatment is relatively new and limited to certain cancers. Laser therapy can sometimes cure a patient’s cancer, but it is used more often to relieve symptoms such as bleeding and obstruction. It is more commonly used for conditions not related to cancer, such as in corrective eye procedures.
In some cases, laser therapy may be used to shrink or destroy tumors if other treatments fail to work. Laser therapy may also be used when standard therapies are not an option because of advanced age, malnutrition, or heart or pulmonary disease. In most cases, laser surgery is used on superficial cancers found on the surface of the body or the lining of internal organs. It is typically used in tandem with another form of treatment, such as chemotherapy, radiation therapy or surgery.
Lasers can be aimed precisely, allowing a physician to focus on tiny areas with great accuracy. There are several types of laser therapy used to treat cancer:
- Endoscopic laser therapy. Uses a flexible tube called an endoscope to direct the light beam.
- Photodynamic laser therapy (PDT). A photosensitizer chemical such as hematoporphyrin is injected into malignant (cancerous) tissues to make them more sensitive to light.
- Laser-induced interstitial thermotherapy (LITT). A method of laser therapy sometimes used to shrink tumors of the liver.
- Photocoagulation. Laser beams are aimed through the pupil or the side of the eyeball to help kill smaller tumors. This is not the standard form of treatment for eye cancers. They are usually treated by using radiation therapy or removing the eye.
Laser therapy may be performed to clear an obstruction or to maximize the effectiveness of other forms of cancer treatment. For instance, it may be used to keep a vital body tube open, such as the esophagus for swallowing, the trachea for breathing or the colon, rectum or anus for eliminating stool.
Laser therapy may also seal nerve endings and lymph vessels to reduce post-surgery pain and general swelling. In some cases, it may be used to keep tumor cells from spreading.
Different types of lasers can be used for different treatments, including:
- Carbon dioxide lasers and argon lasers. Cut the skin’s surface without penetrating deeper layers, allowing the removal of superficial cancers, such as skin cancer.
- Neodymium yttrium-aluminum-garnet lasers. Used to treat internal organs such as the uterus, esophagus, trachea and colon. This laser can also travel through optical fibers into specific areas of the body during LITT.
Conditions treated with laser therapy
Laser therapy is most commonly used as a palliative treatment, meaning it helps relieve symptoms rather than to cure a condition. In some patients, it may be used to complement surgery, chemotherapy or radiation therapy. Cancers that may be treated with laser therapy include:
- Tracheal and neck cancers. Laser therapy can be used to relieve symptoms caused by a tumor that is obstructing the windpipe (trachea). While laser therapy can remove the part of this tumor above the tissue surface, it will usually grow back, and additional treatments will likely be necessary in subsequent weeks. Laser therapy has been shown to help cure glottic cancers that have been irradiated previously.
- Colorectal and anal cancer. Laser therapy can be used to remove precancerous polyps in the colon, as well as offer potential cures for colorectal and anal cancers. However, surgery and radiation therapy remain the primary treatment for colorectal and anal cancer. Laser therapy is more often used to relieve symptoms. Laser treatments of these cancers are usually more effective if the tumor is growing inward into the bowel opening rather than growing outward into adjacent tissues.
- In colorectal cancers, one or two treatments can usually stop bleeding or reduce a tumor’s bulk. However, the tumor usually grows back and requires follow-up treatments every 4, 8 or 12 weeks.
In anal cancers, laser therapy may be used to address problems related to bleeding or tumor bulk. As with colorectal cancers, follow-up treatments may be necessary.
- Esophageal cancer. Two types of laser therapy have been evaluated for use in esophageal cancer: photodynamic therapy and laser ablation surgery. They are not widely available, but some physicians might recommend their use depending on the nature and extent of the cancer.
Endoscopic laser therapy also can be used to clear the opening of the esophagus when it is blocked by tumor tissue. This can help patients to better swallow their own saliva and food. During the procedure, the endoscope is passed through the mouth and down the esophagus to the tumor site. Three or more sessions may be needed to create an opening. The sessions are usually scheduled 48 hours apart.
Tumors typically return fairly quickly, and therapy usually needs to be repeated every two to eight weeks. Laser therapy that opens the esophagus is an alternative to a prosthetic tube. Although a tube is normally successful, the procedure poses a risk of complications and even death.
- Lung cancer. Laser therapy can be used to ease symptoms of some lung tumors that can grow enough to block airways and cause difficulty breathing. The laser therapy can reduce the airway blockages although it cannot completely remove the tumor.
- Bladder cancer. Patients who are physically unable to tolerate major surgery may find their symptoms relieved via laser therapy. Tumors in the bladder can grow and block the flow of urine into and out of the bladder. It also is not unusual for these tumors to bleed. Laser treatments can shrink these tumors and eliminate complications for long periods of time.
- Penile cancer. Although rare in the United States, laser therapy has been successfully used in penile cancers, often in conjunction with partial or total removal of the penis. As with other forms of laser therapy, recurrence is more likely following laser therapy, but follow-up procedures are often successful at controlling the local return of cancerous cells.
In some cases, laser therapy may used to cure some cancers, such as the following:
- Eye cancer. Laser therapy can be used to treat smaller tumors of the eye, a process known as photocoagulation. The precise nature of the laser can be useful in treating melanomas of the optic nerve while causing less nerve damage than radiation therapy. Photocoagulation usually has to be repeated two or three times, with about a month between treatments.
- Cervical cancer. Laser therapy can be used to burn off abnormal cells or to remove a small sample of tissue for analysis. Laser surgery is only used to treat preinvasive cervical cancer, not invasive cancer.
- Vulvar cancer. Laser therapy can be used to treat cancer of the vulva by burning off the layer of skin containing abnormal cells. It is used as a treatment for preinvasive cancer, not invasive cancer.
- Skin cancer. Laser therapy has recently been used to treat squamous cell carcinoma in situ, which involves only the epidermis (outer protective layer of the skin). It can also be used to treat superficial basal cell carcinomas, which are located near the surface of the skin.
Before and during the procedure
Patients who are scheduled to undergo laser surgery should follow the preparatory instructions given by their oncologist or surgeon. As with any form of surgery, this may include dietary restrictions and changes with certain medications for several hours or days prior to the procedure.
In some cases, a local anesthetic will be used during laser surgery. In others, the patient will be placed under general anesthesia and will be asleep during the procedure. The procedure itself will be performed differently depending on the type of laser therapy:
- Endoscopic laser therapy. The healthcare professional uses an endoscope to find the tumor, and then aims the light beam directly onto the tissue. Once the laser is focused on the tissue, the operator sends a stream of high energy into the laser that produces intense heat. At 140 degrees Fahrenheit (60 degrees Celsius), the heat causes protein to coagulate. At 212 degrees Fahrenheit (100 degrees Celsius), the heat vaporizes tissue. Tissue usually burns off in a few seconds. A bit of smoke is produced, as well as a small hole or ulcer where the tissue existed.
- Photodynamic laser therapy. Patients are injected with a drug known as a photosensitizer. This agent is absorbed by cells throughout the body over a 2- to-72 hour period. Cancer cells absorb much of the agent, which is then exposed to a specific wavelength of light. This light produces a form of oxygen that kills nearby cells. Specific wavelengths activate each photosensitizer and determine how deeply the light penetrates the body.
Photosensitizers can also damage blood vessels in the tumor. Damage or destruction of blood vessels helps prevent cancer from receiving essential nutrients for growth. Photosensitizers can also trigger the immune system to attack and destroy the tumor cells.
- Laser-induced interstitial thermotherapy (LITT). This technique is related to hyperthermia, a type of heat therapy used to cure cancer. LITT involves inserting an optical fiber into the tumor. Laser light at the tip of the fiber then heats up the tumor cells and damages or destroys them. LITT is sometimes used to shrink tumors of the liver.
- Photocoagulation. Laser beams are aimed through the pupil or the side of the eyeball onto tumors. During the photocoagulation procedure, an ophthalmologist sits in front of the patient and directs the laser with a foot pedal. The powerful laser beam targets spots in the eye that must be treated. The patient will see a brief flash of light with the laser beam application. This process will be repeated several times until all of the areas are treated.
- Low-power laser therapy (LPLT). A type of laser therapy that uses low-level beams to target various points in the body. LPLT is used primarily for the temporary relief of body pain (e.g. low back pain). Recent research has found that LPLT may be effective in treating oral mucositis, painful inflammation and ulceration of the lining of the mouth, throat and tongue, which is a common side effect among patients receiving high-dose cancer therapy and stem cell transplantation. The laser beams are delivered by a fiber-optic instrument in to the mouth to treat the lips, tongue, palate and floor of the mouth. The use of LPLT in cancer treatment is available only in clinical trials.
After the laser therapy procedure
Post-operative recovery time and long-term prognosis vary significantly depending on the condition being treated by laser surgery. Patients should consult with their physician prior to the procedure about these topics. In most cases, laser therapy is performed on an outpatient basis but in some cases it may require hospitalization. Patients who will be going home after outpatient surgery may want to arrange for transportation.
The skin and eyes of patients who have photodynamic laser therapy will be sensitive to light for about six weeks. Patients should avoid direct sunlight and bright indoor lights during this period of time. Sunglasses may help protect the eyes during this time.
Laser therapy is not as effective in removing tumors as conventional surgery because this treatment only removes the top portion of the tumor. Treatment does not impact the portion of the tumor that lies beneath the tissue surface. In addition, the benefits of laser therapy are more likely to be short-term than those of conventional therapy. In many cases, the patient will need one or more follow-up procedures to continue to treat the tumor if it grows back.
In most cases, laser therapy is used in combination with other forms of cancer treatment, including:
- Surgery. Used for the complete or partial removal of a tumor.
- Chemotherapy. Uses one or more drugs to target dividing cancer cells to prevent them from reproducing and spreading throughout the body.
- Radiation therapy. Uses an energy called ionizing radiation to kill cancer cells and shrink tumors. Radiation targets dividing cancer cells and disrupts or destroys their genetic material, preventing the cells from continuing to grow and spread throughout the body. Researchers are working to develop certain laser-driven radiation beams that can provide more precise treatment for cancer. Scientists hope these beams will be more accurate, reducing the damage to surrounding healthy tissues.
- Biological therapy. Repairs, stimulates or enhances the immune system so that it can better recognize and destroy cancer cells. Some forms of biological therapy directly attack cancer cells. This therapy is also used to alleviate side effects associated with cancer treatments such as chemotherapy.
- Hormone therapy. Treatment that alters the hormones in the body to prevent the growth and spread of certain cancers. Patients who undergo this treatment sometimes take medications that reduce the levels of certain hormones, such as estrogen and testosterone. In other cases, patients may take drugs that prevent cancer from attaching to hormones that help the disease thrive.
- Bone marrow transplants. Replace bone marrow damaged by cancer or cancer treatments with healthy marrow obtained from a donor. Bone marrow contains stem cells that produce red blood cells, white blood cells and platelets necessary for life.
Potential benefits and risks
Because lasers are more precise than traditional surgical scalpels, they can cause less damage to normal tissues. As a result, patients typically experience less pain, bleeding, swelling and scarring than they would with traditional surgery. Some forms of laser surgery can be performed on an outpatient basis without an incision. Patients usually heal more quickly and are less likely to get infections.
Laser therapy comes with fewer risks than traditional surgery, but the corrective results often are temporary. Physicians may have to repeat the procedure, sometimes multiple times during the course of treatment. In addition, the procedures may be costly and requires a surgeon who has specialized training in laser therapy. Some forms of laser therapy also can have physical side effects. For example, photocoagulation can cause a degree of vision loss. Other side effects that have been associated with laser surgery include:
- Changes in skin color
Ongoing research in laser therapy
There are a number of clinical trials that are studying the potential benefits of laser therapy in the prevention and treatment of cancers, including:
- Head and neck cancers. Photodynamic laser therapy is being evaluated for the treatment of precancerous and early-stage esophageal cancer. Endoscopic laser treatments are also being studied for the treatment of certain laryngeal cancers and nasopharyngeal cancers.
- Brain tumors. Various forms of laser therapy are being evaluated in clinical trials for brain tumors in children and adults. These treatments include photodynamic therapy, interstitial laser therapy and magnetic resonance imaging (MRI) guided laser therapy.
- Eye cancers. Clinical trials are examining the use of laser therapy in conjunction with various chemotherapy drugs for the treatment of retinoblastoma.
- Prostate cancer. Photodynamic laser therapy is being studied for the treatment of prostate cancer. In addition, laser therapy combine with chemotherapy is being examined for use in patients with recurrent prostate cancer.
- Skin cancers. Although laser therapy is regularly used in skin cancer treatment, new regimens are being studied. Photodynamic therapy is being evaluated in clinical trials for several specific skin cancers, including basal cell carcinoma, squamous cell carcinoma, T-cell lymphoma and actinic keratosis.
Questions for your doctor about laser therapy
Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their condition. Patients may wish to ask their doctors the following questions about laser therapy:
- Am I a candidate for laser therapy?
- What type of laser therapy do you recommend>
- Is the laser therapy a treatment for cancer or just the symptoms?
- What are the benefits of this therapy as treatment for my cancer?
- What are the risks in using laser therapy for my condition?
- Will the laser therapy be performed as an outpatient procedure?
- What can I expect in terms of recovery from laser treatments?
- Am I likely to need more than one laser treatment? If so, how many and on what schedule?
- How effective is laser therapy for my type of cancer?
- If I have laser therapy, will I need other treatments? If so, which ones?
- How will you know if the laser therapy has been successful?
- Is laser therapy for my cancer considered experimental?
- How can I find a physician who specializes in laser therapy for my cancer?
- How can I become enrolled in an appropriate clinical trial?