Researchers have shown that testing for a specific collection of genes in early-stage non-small-cell lung cancer (NSCLC) tissue accurately predicts prognosis. The 15-gene signature appears to have promising potential to identify patients with NSCLC who may or may not benefit from adjuvant chemotherapy. The results reflect advances in developing more personalized approaches to the treatment of NSCLC.
Surgical resection is the standard of care for early-stage (stage I and II) NSCLC, and adjuvant chemotherapy is typically used for patients with stage II NSCLC and in only some cases of stage IB disease with a primary tumor larger than 4 cm. Researchers have sought an accurate prognostic marker to identify patients with good or poor prognosis to aid in decision-making about adjuvant treatment. Such a marker potentially could enable patients with a good prognosis to be spared the morbidity associated with adjuvant chemotherapy, while providing patients with a poor prognosis the potential benefit of improved survival with adjuvant chemotherapy. Such a marker has added greatly to similar decision-making in breast and colorectal cancers.
In the current study, which will be published in the January issue of the International Association for the Study of Lung Cancer's journal, the Journal of Thoracic Oncology (JTO), testing with the 15-gene signature classified 181 early-stage NSCLC specimens into high- and low-risk subgroups with significantly different overall 5-year survival. The signature predicted prognosis independent of stage or histology (adenocarcinoma, squamous cell carcinoma, or other). The results validate the findings of an earlier and smaller study of the signature.
"The results of this study provide additional evidence for developing the test into a clinical assay that can be further tested in prospective clinical trials," says Sandy Der, PhD, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada. "The signature may identify a subgroup of patients with stage I cancers who have a poor prognosis. Patients with stage I disease currently do not receive adjuvant chemotherapy, but potentially those who are at high risk for cancer recurrence may benefit from adjuvant chemotherapy. Proof of this will require a randomized clinical trial."
Dr. Der's coauthors include IASLC members Frances A. Shepherd MD, and Ming-Sound Tsao, MD.