Words to Know

laboratory test

A medical procedure that involves testing a sample of blood, urine or other substance from the body. Tests can help determine a diagnosis, plan treatment, check to see if treatment is working or monitor the disease over time.


Brand name, Tykerb. A medicine used with another anticancer agent to treat breast cancer that is HER2 positive and has advanced or metastasized (spread to other parts of the body) after treatment with other medicines. Lapatinib is also being studied in the treatment of other types of cancer. Also called GW572016, and lapatinib ditosylate.


A device that forms light into intense, narrow beams that may be used to cut or destroy tissue, such as cancer tissue. It may also be used to reduce lymphedema (swelling caused by a buildup of lymph fluid in tissue) after breast cancer surgery. Lasers are used in microsurgery, photodynamic therapy and many other procedures to diagnose and treat disease.

laser surgery

A surgical procedure that uses the cutting power of a laser beam to make bloodless cuts in tissue or to remove a surface lesion such as a tumor.

laser therapy

Treatment that uses intense, narrow beams of light to cut and destroy tissue, such as cancer tissue. Laser therapy may also be used to reduce lymphedema (swelling caused by a buildup of lymph fluid in tissue) after breast cancer surgery.c


A feeling of tiredness, weakness and lack of interest in daily activities.

late effects

Side effects of cancer treatment that appear months or years after treatment has ended. Late effects include physical and mental problems and second cancers.

late-stage cancer

A term used to describe cancer that is far along in its growth and has spread to the lymph nodes or other places in the body.


Describes a condition that is present but not active or causing symptoms.


A substance that promotes bowel movements.


Loop electrosurgical excision procedure. Also called loop excision. LEEP is a technique that uses electric current passed through a thin wire loop to remove abnormal tissue.

legal aid organization

A group or agency that gives legal help to people with low incomes. Health legal aid workers help people with issues related to getting good healthcare and getting insurance to cover certain individuals and conditions.


An area of abnormal tissue. A lesion may be benign (noncancerous) or malignant (cancerous).


A condition marked by drowsiness and an unusual lack of energy and mental alertness. It can be caused by many things, including illness, injury or medicines.


Brand name, Femara. A medicine used to treat advanced breast cancer in postmenopausal women. Letrozole causes a decrease in the amount of estrogen made by the body. It is a type of aromatase inhibitor.


A condition in which there is a lower-than-normal number of leukocytes (white blood cells) in the blood.

levels of evidence

A ranking system used to describe the strength of the results measured in a clinical trial or research study. The design of the study (such as a case report for an individual participant or a randomized double-blinded controlled clinical trial) and the endpoints measured (such as survival or quality of life) affect the strength of the evidence.


Also called escitalopram. A medicine used to treat depression and certain anxiety disorders. It belongs to the family of medicines called selective serotonin reuptake inhibitors (SSRIs).


Sexual desire or the mental energy or emotion related to sex.


A type of local anesthetic and antiarrhythmic. A substance used to relieve pain by blocking signals at the nerve endings in skin. It can also be given intravenously to stop heart arrhythmias.