Pentameric last-digit preference and stage border avoidance in pathology measurement

Area of Science:

• Oncology
• Medical Statistics
• Pathology

Background:

• Accurate tumor size determination is crucial for cancer staging and treatment planning.
• Tumor size measurement in clinical practice can be challenging, leading to rounded values.
• Previous observations suggest a tendency to report tumor sizes ending in 0 or 5.

Purpose of the Study:

• To investigate the frequency of terminal digit preference (0 or 5) in tumor size reporting.
• To analyze this phenomenon in national cancer registry data for breast and lung tumors.
• To understand the implications of measurement practices on cancer staging and treatment decisions.

Main Methods:

• Retrieved tumor size data from the Netherlands National Cancer Registry.
• Analyzed data specifically for patients with breast and lung cancer.
• Assessed the distribution of terminal digits in reported tumor sizes.

Main Results:

• A clear preference for terminal digits 0 or 5 (pentameric preference) was observed in lung cancer tumor size reporting.
• Breast cancer data showed avoidance of critical pentameric values at stage boundaries.
• These findings suggest distinct measurement and reporting strategies for different cancer types.

Conclusions:

• Pathologists employ practical approaches to tumor size measurement, including rounding.
• Rounding practices may differ between cancer types, with avoidance of critical values in breast cancer.
• These measurement strategies aim to simplify staging and facilitate treatment decisions.