The histologic grading of cancer

Area of Science:

• Oncology
• Cancer Research
• Pathology

Background:

• Histologic tumor grade offers prognostic insights beyond disease stage.
• Poorly differentiated tumors typically exhibit more aggressive behavior than well-differentiated ones.

Purpose of the Study:

• To investigate the frequency of tumor grading and its relationship to patient outcomes.
• To analyze grading data across 15 anatomic cancer sites using Surveillance, Epidemiology, and End Results (SEER) Program data.

Main Methods:

• Analysis of 793,649 cancer cases from the SEER Program.
• Examination of grading frequency trends from 1973 to 1987.
• Correlation of tumor grade with survival rates across different stages and histologic types.

Main Results:

• Tumor grading frequency increased between 1973 and 1987, varying by site and type.
• Survival rates decreased as tumor grade advanced.
• Histologic grade identified distinct prognostic subgroups within each disease stage, refining staging accuracy.

Conclusions:

• Histologic grade is a potent prognostic indicator, particularly for urinary bladder, endometrial, and prostate cancers.
• Despite observer variation, histologic grade consistently predicts outcomes and enhances prognostic information from staging.
• Grading is crucial for identifying high- and low-risk subgroups, aiding clinical decision-making.