Genetic testing plays an integral part in diagnosing and treating lung cancer.
Doctors use this type of testing to look for certain mutations. A person with a specific mutation may benefit from a targeted treatment.
In this article, two experts in the field describe the use of genetic testing and its future in lung cancer treatment.
Genetic testing
Using genetic testing, doctors can identify changes in lung cells that may trigger and contribute to cancer growth, as the American Lung Association explains. A doctor may refer to these changes as “biomarkers” of the illness.
Identifying the biomarkers helps a doctor recommend the best approach to treatment. Certain therapies target specific genetic mutations to help prevent cancer growth and development.
These targeted therapies are less invasive than traditional cancer treatments because they do not destroy healthy cells — they stop only the cancer cells from growing and reproducing.
Dr. Jack Jacoub, an oncologist and the medical director of the MemorialCare Cancer Institute, at the Orange Coast Medical Center, in Fountain Valley, CA, reported that “Testing is mandatory on every patient” at his facility.
“Every cancer patient should have next-generation sequencing that maps out the person’s cancer cell genome,” he added.
Depending on the results of this sequencing, treatment may be swift and highly effective. Dr. Jacoub explained that “In the case of non-small cell lung cancer, you can give them a pill and within 4–6 weeks, their cancer has more or less gone away.”
Sandra Brown, MS, LCGC, the regional manager of genetics at Providence Southern California and the Leonard Cancer Institute, noted that “Most patients with a diagnosis of lung cancer will discuss the limits and benefits of tumor molecular profiling or somatic genetic testing with their medical oncologist.”
Dr. Jacoub reported that, for “the squamous cell group, it’s a little more controversial. But I would say everyone needs to be tested because [a genetic test] can catch some things [that a doctor] didn’t expect, and it can really be transformational,” in terms of the treatment.
Several biomarkers can help determine the most effective approach to treatment. However, not all doctors look for the same sequences.
Specific treatments are available for the following biomarkers of lung cancer:
- epidermal growth factor receptor (EGFR) mutation
- MET amplification or MET exon 14 skipping
- anaplastic lymphoma kinase (ALK) gene rearrangement
- PD-L1 level
- ROS1 rearrangement
- BRAF V600E mutation
- NTRK fusion
- RET rearrangements
“Each target has their own assigned therapeutic [drug] or multiple therapeutics,” Dr. Jacoub explained.
To be sure that they are receiving the most effective treatment, a person with lung cancer should receive comprehensive genetic testing as soon as possible.
Gene targeting therapies are typically oral medications. The table below shows which currently available medications match the most common genetic mutations in cases of lung cancer.
| EGFR mutations | ALK mutations | ROS1 mutations | BRAF mutations | RET mutations | MET mutations |
| afatinib (Gilotrif) | crizotinib (Xalkori) | crizotinib (Xalkori) | dabrafenib (Tafinlar) | selpercatinib (Retevmo) | capmatinib (Tabrecta) |
| osimertinib (Tagrisso) | ceritinib (Zykadia) | ceritinib (Zykadia) | trametinib (Mekinist) | pralsetinib (Gavreto) | tepotinib (Tepmetko) |
| erlotinib (Tarceva) | alectinib (Alecensa) | lorlatinib (Lorbrena) | |||
| dacomitinib (Vizimpro) | brigatinib (Alunbrig) | entrectinib (Rozlytrek) | |||
| gefitinib (Iressa) | lorlatinib (Lorbrena) |
“Each [treatment] has different side effects. But it doesn’t give you the nausea, vomiting, and hair loss of traditional chemotherapy,” Dr. Jacoub reported.
Targeted treatments can also greatly improve a person’s outlook. “These therapies have a prognosis of an average of 2–3 years,” which “substantially improves the average survival rate, which was 9–12 months and still is for lung cancer without these mutations,” he explained.
Researchers continually test new targeted treatments for lung cancer. As the Lung Cancer Foundation of America explains, researchers are investigating whether new drugs can treat lung cancers with other mutations.
Teams are looking into new treatments for mutations in the following genes:
- MET
- KRAS
- PD-L1
- HER2
- ROS1
- RET
- BRAF
- IGF1R
- ERBB2
- PIK3CA
For example, a current clinical trial is exploring the effectiveness of genetic testing and targeted therapies for a range of mutations. If, after receiving a drug under investigation, a participant experiences resistance or new growth in any tumor, they will undergo testing again and be offered a new treatment.
The
A person with lung cancer undergoes genetic testing so that their doctor can identify certain mutations in genes linked with cancer.
Then, the doctor may be able to recommend a treatment that targets the specific mutation but leaves healthy cells intact.
Ongoing research into targeted cancer therapies will continue to improve treatment options and outcomes for people with lung cancer.