Thoroughness of mediastinal staging in stage IIIA non-small cell lung cancer

Guidelines recommend that patients with clinical stage IIIA non-small cell lung cancer (NSCLC) undergo histologic confirmation of pathologic lymph nodes. Studies have suggested that invasive mediastinal staging is underutilized, although practice patterns have not been rigorously evaluated.

We used the Surveillance, Epidemiology, and End Results-Medicare database to identify patients with stage IIIA NSCLC diagnosed from 1998 through 2005. Invasive staging and use of positron emission tomography (PET) scanning were assessed using Medicare claims. Multivariable logistic regression was used to identify patient characteristics associated with use of invasive staging.

Of 7583 stage IIIA NSCLC patients, 1678 (22%) underwent invasive staging. Patients who received curative intent cancer treatment were more likely to undergo invasive staging than patients who did not receive cancer-specific therapy (30% versus 9.8%, adjusted odds ratio, 3.31; 95% confidence interval, 2.78-3.95). The oldest patients (age, 85-94 years) were less likely to receive invasive staging than the youngest (age, 67-69 years; 27.6% versus 11.9%; odds ratio, 0.46; 95% confidence interval, 0.34-0.61). Sex, marital status, income, and race were not associated with the use of the invasive staging. The use of invasive staging was stable throughout the study period, despite an increase in the use of PET scanning from less than 10% of patients before 2000 to almost 70% in 2005.

Nearly 80% of Medicare beneficiaries with stage IIIA NSCLC do not receive guideline adherent mediastinal staging; this failure cannot be entirely explained by patient factors or a reliance on PET imaging. Incentives to encourage use of invasive staging may improve care.