Cytology is an accurate, safe, cost-effective, and guideline-recommended method for the diagnosis of small cell lung carcinoma (SCLC), but little is known about whether its use varies by treatment facility and patient characteristics.
Methods of diagnosis (cytology vs histology) for 86,830 patients with SCLC from 1314 facilities that contributed data to a nationwide registry and associations of diagnostic methods with patient and facility characteristics were studied in bivariate and multivariate analyses.
The percentages of SCLC cases diagnosed by cytology in community cancer programs, comprehensive community cancer programs, academic cancer programs, and National Cancer Institute-designated cancer centers were 13.2%, 15.4%, 23.3%, and 31.3%, respectively (P < .0001). The corresponding prevalence ratios (and 95% confidence intervals [CIs]) of cytologic diagnosis using multivariate marginal logistic regression models and National Cancer Institute-designated cancer centers as the referent category were 0.45 (95% CI, 0.36-0.57), 0.52 (95% CI, 0.42-0.64), and 0.78 95% CI, (0.62-0.96), respectively. In contrast, the use of cytology varied little by patient demographic and clinical factors.
The substantial variation among different types of cancer centers in their use of cytology for the diagnosis of SCLC suggests a need for additional research to study reasons for these differences as well as quality-improvement interventions to encourage adherence to guidelines for SCLC diagnosis. Cancer (Cancer Cytopathol) 2016;124:44-52. © 2015 American Cancer Society.