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Lasers in Cancer Treatment: Questions and Answers 

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. Lasers are most commonly used to treat superficial 

cancers (cancers on the surface of the body or the lining of internal organs) such as basal 

Key Points

• Laser light is a light of such high intensity and narrow beam that it can be used to 

do precise surgery to remove cancer or precancerous growths or to relieve 

symptoms of cancer. It is used most often to treat cancers on the surface of the 

body or the lining of internal organs (see Questions 1 and 2). 

• Laser therapy is often given through a thin tube called an endoscope. An 

endoscope can be inserted in openings in the body to treat cancer or precancerous 

growths inside the trachea (windpipe), esophagus, stomach, or colon (see Questions 

2 and 3). 

• Laser therapy causes less bleeding and damage to normal tissue than standard 

surgical tools, and there is a lower risk of infection (see Question 5). 

• However, laser therapy is extremely expensive and the effects of the surgery may 

not be permanent, so the surgery may have to be repeated (see Question 6). 
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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 as surgery, 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 National Cancer Institute (NCI) 

fact sheet Hyperthermia in Cancer Treatment: Questions and Answers, which can be 

found at http://www.cancer.gov/cancertopics/factsheet/Therapy/hyperthermia on the 

Internet.) 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 the liver. 

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 for approximately 6 weeks, 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: Questions and Answers, which can be found at 

http://www.cancer.gov/cancertopics/factsheet/Therapy/photodynamic on the Internet.) 

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 
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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 an outpatient 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. Also, 

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 

and prostate, among others. To learn more about clinical trials, call the NCI’s Cancer 

Information Service at the telephone number listed below or visit the clinical trials page 

of the NCI’s Web site at http://www.cancer.gov/clinicaltrials on the Internet. 

# # # 

Related Resources

Publications (available at http://www.cancer.gov/publications) 

• National Cancer Institute Fact Sheet 2.11, Clinical Trials: Questions and Answers

• National Cancer Institute Fact Sheet 6.7, Cancer: Questions and Answers

• National Cancer Institute Fact Sheet 7.3, Hyperthermia in Cancer Treatment: 

Questions and Answers

• National Cancer Institute Fact Sheet 7.7, Photodynamic Therapy for Cancer: 

Questions and Answers

• What You Need To Know AboutTM Cancer
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National Cancer Institute (NCI) Resources

Cancer Information Service (toll-free)

 Telephone: 1–800–4–CANCER (1–800–422–6237) 

 TTY: 1–800–332–8615 

Online 

NCI’s Web site: http://www.cancer.gov 

LiveHelp, NCI’s live online assistance: 

https://cissecure.nci.nih.gov/livehelp/welcome.asp

 

This fact sheet was reviewed on 8/10/04