Cytology is an accurate, safe, cost-effective, and guideline-recommended method for pancreatic cancer diagnosis, particularly for unresectable disease. However, to the authors' knowledge, the frequency and determinants of its use have not been described to date. The current study examined patterns of cytological diagnosis among patients with unresectable pancreatic cancer by treatment facility type and by patient characteristics.
The prevalence of definitive cytological diagnosis (cytology only, without confirmatory histology) versus histological diagnosis (with or without accompanying cytology) was examined in National Cancer Data Base records of 13,657 patients diagnosed with unresectable (American Joint Committee on Cancer stages III and IV) pancreatic cancer in 2011 and 2012 who did not undergo surgical treatment (mode of diagnosis could not be ascertained for surgical patients). Associations between definitive cytological diagnosis and patient and facility characteristics were assessed using multivariable marginal logistic regression models and expressed as odds ratios (OR) and 95% confidence intervals (95% CIs).
Overall, 26.8% of unresectable pancreatic cancer cases were definitively diagnosed with cytology. The prevalence of cytological diagnosis ranged from 16.5% in community cancer programs and 22.6% in comprehensive community cancer programs to 31.3% in academic/teaching/research cancer programs and 43.2% in National Cancer Institute-designated cancer programs (P<.001). Compared with patients diagnosed in National Cancer Institute-designated cancer programs, those from community cancer programs (OR, 0.29; 95% CI, 0.20-0.42), comprehensive community cancer programs (OR, 0.42; 95% CI, 0.31-0.59), and academic/teaching/research cancer programs (OR, 0.60; 95% CI, 0.43-0.84) had lower odds of being diagnosed with cytology.
Greater than 25% of unresectable pancreatic cancers were diagnosed definitively with cytology, with wide variation in its use by facility type, suggesting opportunities for quality improvement interventions that increase the use of cytology. Cancer Cytopathol 2016;124:791-800. © 2016 American Cancer Society.