HER2 screening recommended for lung adenocarcinoma patients
medwireNews: Researchers highlight the importance of testing for HER2 mutations in patients with non-small-cell lung cancer (NSCLC), adding to evidence that supports the use of HER2-targeted drugs in this population.
The largest case series to date, published in the Journal of Clinical Oncology, reports on the outcomes of 65 (1.7%) patients who tested positive for a HER2 in-frame insertion in exon 20, out of 3800 European NSCLC patients. Only one patient had a second known mutation (KRAS).
Patients with the HER2 mutation were aged a median of 60 years and, as found in earlier studies, tended to be female (69.0%) never smokers (52.3%) with adenocarcinomas (100%).
"Nevertheless, we identified some men and heavy smokers (up to 60 packs-year) suggesting that HER2 testing could be guided by tumor subtype (adenocarcinoma), but should not be restricted to clinically defined subgroups," caution Julien Mazières (Centre Hospitalier Universitaire de Toulouse, France) and co-authors.
Half of the patients had stage IV disease at diagnosis, and 16 of these patients were treated with HER2-targeted drugs, in addition to conventional chemotherapy. Of these, three received two and one received four different agents. Seventeen patients did not receive HER2-targeted drugs owing to a lack of availability of the drugs or clinical trials.
Progression-free survival was a median of 5.1 months in patients given HER2-targeted agents and median survival was 22.9 months. Four patients experienced progression, seven had stable disease, and 11 patients achieved a partial response, giving an overall response rate of 50% and a disease control rate of 82%.
The disease control rate was 96% for the 15 patients given trastuzumab-based treatment plus chemotherapy, and 100% for the four patients given afatinib alone, but no control was achieved by either of the two patients given lapatinib alone or the one patient given masatinib.
"The relative efficacy of these molecules clearly deserves prospective evaluation in larger international clinical trials," Mazièrs et al therefore conclude.
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By Lynda Williams, Senior medwireNews Reporter