Targeted Therapy Effective in HER2-Positive Lung Cancer

Some therapies targeted against the HER2 mutation provide prolonged responses and stabilization of cancer among patients with HER2-positive non-small lung cancer (NSCLC), according to an article recently published in the Journal of Clinical Oncology.

Lung cancer remains the leading cause of cancer-related deaths in the world. Non-small cell lung cancer (NSCLC) is the most common type of lung cancer in the United States, comprising approximately three-quarters of all lung cancers.

Mutations within the human epidermal receptor (HER)-2 pathway occur in only approximately 2%-6% of all NSCLC cases. Because of its rarity, not many studies have focused on individualized treatment for these patients. However, a significant portion of breast cancer is positive for mutations in the HER2 pathway (HER2-positive), so therapies targeted directly against the HER2 pathway have been developed for treatment of this disease are already FDA approved for clinical use.

Researchers from Europe recently evaluated data including agents targeted against the HER2 mutation in patients with NSCLC. The researchers evaluated 3,800 patients, 65 (1.7%) of whom had a HER2 mutation. Of these 65 patients;

Over half of the patients had never smoked.
69% of the patients were women.
Median age was 60 years.
Half of the patients had stage IV (cancer spread from lung to distant sites in the body) upon diagnosis.
All cancers were adenocarcinoma (specific type of cell within the lung).
Patients who received an agent targeted against the HER2 pathway were treated with either trastuzumab, afatinib, lapatinib, masitinib. Some received chemotherapy and/or bevacizumab as well.

Disease control was achieved in 93% of patients treated with trastuzumab and 100% of patients treated with afatinib.
No patients treated with lapatinib or masitinib responded to therapy.
Median survival was 89.6 months for patients with stage I-III cancer and nearly 23 months for those with stage IV cancer.
The researchers concluded that “This study, the largest to date dedicated to HER2-mutated NSCLC, reinforces the importance of screening for HER2 mutations in lung adenocarcinomas and suggests the potential efficacy of HER2-targeted drugs in this population.”

Reference: Mazieres J, Peters S, Lepage B, et al. Lung Cancer That Harbors a HER2 Mutation: Epidemiologic Characteristics and Therapeutic Perspectives. Journal of Clinical Oncology. Published online before print. April 22, 2013, doi:10.1200/JCO.2012.45.6095.