Eco-Pap: The Ecological Modification of the Papanicolaou Stain for Sustainable Cervical Cancer Diagnosis

Acta Cytol. 2019;63(1):35-43. doi: 10.1159/000493113. Epub 2018 Oct 23.

Abstract

Objectives: To validate the ecological modification of the Papanicolaou stain (Eco-Pap) for the diagnosis of cervical cancer.

Study design: A prospective study was performed at the Mother and Child "San Bartolomé" Hospital, Lima, Peru. Reagent handling strategies were divided into three phases: we used (1) Harris progressive hematoxylin (for nuclear staining), (2) a polychromatic solution (a mix of EA-36/Orange G-6 to suppress the use of several alcohol baths), and (3) direct mounting (with Entellan® solution). The cellular details were analyzed by the staining quality index, an external quality control, and the Bethesda System 2014.

Results: We evaluated 72,901 cervical smears stained with the Eco-Pap. The validation of the Eco-Pap against the conventional Pap stain was optimal (κ = 0.89; 95% CI: 0.87-0.92), showing a sensibility and specificity of 88.3% (95% CI: 85.1-90.0) and 98.7% (95% CI: 98-99.2), respectively. The Eco-Pap dramatically reduced the environmental pollution caused by 72 L of xylene, hydrochloric acid, and ammonia (6 L each) and mercury oxide.

Conclusion: The Eco-Pap is an innovative and efficient staining method reducing the use of toxic reagents with carcinogenic potential during cervical cancer screening by exfoliative cytology.

Keywords: Cervical cancer screening; Cervical cytology; Eco-Pap; Hydrochloric acid; Papanicolaou test; Polycyclic aromatic hydrocarbons.

Publication types

  • Comparative Study
  • Validation Study

MeSH terms

  • Ammonia / adverse effects
  • Azo Compounds / chemistry
  • Coloring Agents / chemistry
  • Cross-Sectional Studies
  • Environmental Pollutants / adverse effects*
  • Environmental Pollution / adverse effects
  • Environmental Pollution / prevention & control*
  • Female
  • Hematoxylin / chemistry
  • Humans
  • Hydrochloric Acid / adverse effects
  • Medical Waste Disposal*
  • Mercury Compounds / adverse effects
  • Oxides / adverse effects
  • Papanicolaou Test / adverse effects
  • Papanicolaou Test / methods*
  • Peru
  • Predictive Value of Tests
  • Prospective Studies
  • Reproducibility of Results
  • Staining and Labeling / methods*
  • Uterine Cervical Neoplasms / pathology*
  • Vaginal Smears*
  • Xylenes / adverse effects

Substances

  • Azo Compounds
  • Coloring Agents
  • Environmental Pollutants
  • Medical Waste Disposal
  • Mercury Compounds
  • Oxides
  • Xylenes
  • Ammonia
  • mercuric oxide
  • Hydrochloric Acid
  • Hematoxylin