Targeted Therapies for Lung Cancer

Woman in bathrobe taking medication in bathroom
Targeted therapy for lung cancer. Astronaut Images/Caiaimage/Getty Images

New medical treatments called targeted therapies are becoming available for lung cancer. Unlike traditional chemotherapy, these treatments target proteins on cancer cells or target normal cells that have been hijacked by the tumor in its attempts to grow. For that reason, they tend to have fewer side effects that many of the medications used for cancer. Currently, these are used primarily for stage 3 and 4 lung cancer that has not responded to other treatments.

Two of the more common targeted therapies include:
 

Tarceva (erlotinib)

The surface of lung cancer cells are covered with a protein called epidermal growth factor receptor (EGFR), which helps the cells divide. Tarceva works by not allowing EGFR to tell cancer cells to grow. While potentially effective in many kinds of patients, it has been shown to be more likely to work for those who have never smoked or in younger women. Given as a daily pill, the most common side effects are a skin rash similar to acne, and diarrhea. Though the skin rash can be a cosmetic nuisance, those who develop a rash with erlotinib are more likely to be responding to therapy.

Xylori (crizotinib)

Between 3 and 5% of people with non-small cell lung cancer have a mutation known as an ALK-EML4 gene rearrangement.  For people with this mutation, the medication crizotinib has been found to increase progression-free survival.

 As with erlotinib, crizotinib often has fewer side effects than traditional chemotherapy and can be taken as an oral medication.  Likewise, this mutation if more likely to be found in people who have never smoked.  While crizotinib prolongs progression-free survival, resistance invariably develops in time.

 Thankfully new medications have been found in clinical trials that may work when resistance to crizotinib develops, and it is hoped that in time, ALK-positive lung cancer may be treated as a chronic disease, such as diabetes.

Learn more about ALK positive lung cancer in this article

As of 2014, crizotinib has also been approved for people with ROS1 mutations.  Like those with ALK mutations, crizotinib increases progression-free survival.

Other medications are currently being evaluated in clinical trials for people who have become resistant to medications for EGFR mutations and ALK mutations, and other "target mutations" are being studied.

Genetic Testing (Molecular Profiling) For Lung Cancer

It's now felt that everyone with advanced lung adenocarcinoma (and some people with squamous cell lung cancer, especially those who have never smoked) should be tested for gene mutations, and the potential that their tumors will respond to the newer targeted medications.  Despite this, many people who may be positive for these mutations and consequently candidates for these medications, do not receive the benefit of testing.

Learn more about molecular profiling for lung cancer in this article

Sources:

American Cancer Society. Targeted Therapies. 08/13/15. http://www.cancer.org/cancer/colonandrectumcancer/detailedguide/colorectal-cancer-treating-targeted-therapy

National Cancer Institute. Non-Small Cell Lung Cancer (PDQ). Treatment Option Overview. Updated 05/12/15. http://www.cancer.gov/cancertopics/pdq/treatment/non-small-cell-lung/Patient/page4

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