A prognostic assay helps identify patients with high-risk T1a node-negative non-small-cell lung cancer, which may inform post-surgical treatment, according to a research letter published Oct. 23 in Journal of the American Medical Association.  

Although National Comprehensive Cancer Network clinical practice guidelines recommend physicians consider adjuvant chemotherapy in high-risk stage I tumors, guidelines to assist in the identification of these tumors are lacking, according to Johannes R. Kratz, MD, of University of California, San Francisco, and colleagues.

Kratz and colleagues devised a study to analyze the performance of the molecular prognostic assay in small, node-negative tumors. The cohort included 269 patients with node-negative disease.

The researchers studied a molecular assay that measures the expression of 14 genes and assigns patients to low-, intermediate- and high-risk groups.

The assay categorized 92 patients as high risk, 79 patients as intermediate risk and 98 patients as low risk.

Patients in the low-risk group had greater overall survival at five years, with 83 percent of patients in this group surviving five years, compared with 69.1 percent in the intermediate-risk group and 52.3 in the high-risk group.

The researchers observed similar trends among patients with tumors 1.0 cm or smaller.

Kratz et al noted that adjuvant chemotherapy is increasingly effective as the risk of metastasis and mortality of T1a tumors increases. However, conventional staging leaves a gap as trials that evaluated this mechanism have failed to demonstrate benefits in stage Ia disease.

The researchers concluded, “The identification of high-risk patients may further maximize the benefit of T1a node-negative tumors through low-dose computed tomography screening.”