Cancer registry problems in classifying invasive bladder cancer

Area of Science:

• Urologic oncology
• Cancer epidemiology
• Pathologic diagnosis

Background:

• The Surveillance, Epidemiology, and End Results (SEER) Program is a key resource for cancer statistics in the United States.
• Accurate classification of cancer invasiveness is critical for prognosis and treatment planning.
• Previous classifications of bladder cancer invasiveness may require re-evaluation.

Purpose of the Study:

• To compare the accuracy of bladder cancer invasiveness classification between a pathology slide review and the Iowa SEER Program data.
• To assess the impact of classification discrepancies on survival analysis.

Main Methods:

• A retrospective review of 364 bladder cancer cases identified through the Iowa SEER Program in 1983.
• Pathologic tissue slides were re-examined to classify cancer invasiveness.
• Survival data was analyzed using hazard ratios to compare classification methods.

Main Results:

• The slide review classified 26.6% of cases as invasive, contrasting with the Iowa SEER Program's 79.4% classification.
• A significantly higher hazard ratio for invasive bladder cancer was observed using slide review findings (4.54) compared to SEER data (1.70).
• These findings indicate a substantial underestimation of non-invasive bladder cancers in the original SEER classification.

Conclusions:

• Pathologic slide review offers a more accurate assessment of bladder cancer invasiveness compared to the traditional SEER Program coding.
• Discrepancies in classification can significantly impact survival analyses and epidemiological findings.
• Revisiting diagnostic methodologies within cancer registries is crucial for improving data accuracy.