Changes of breast cancer staging when AJCC prognostic staging manual is used: a retrospective analysis of a Chinese cohort.

Background: This study aimed to investigate staging changes for Chinese breast cancer patients assessed by the 7 (anatomic) and 8 (prognostic) editions of the AJCC staging manual, and to explore the predictive factors for these changes.

Methods: Data of patients who received curative surgery for stage I-III breast cancer at Ningbo Medical Center Lihuili Eastern Hospital were retrospectively reviewed. The assessment of staging was according to the criteria of the 7 and 8 editions of the AJCC staging manual. Univariate and multivariate logistic regression analyses were performed to analyze the associations between staging changes and clinicopathological characteristics.

Results: Staging changes were found in 59.37% of patients and were more likely to be seen in stage IIIA (96.10%) and IIA (85.94%), then IIB (70.33%), IB (68.75%), followed by IA (36.17%) and IIIC (30.08%). In univariate analysis, staging changes were associated with tumor location, clinical tumor size, clinical axillary lymph node status and Ki67 index. However, multivariate analysis found that staging changes were significantly associated with tumor size >2 cm (odds ratio [OR] = 3.263, 95% confidence interval [95% CI], 2.638-4.036), lymph node involvement (OR = 2.261, 95% CI, 1.830-2.794) and high Ki-67 index (OR = 1.661, 95% CI 1.343-2.054).

Conclusions: Our study demonstrated that there were marked staging changes when 2 different editions of the AJCC staging manual were used. Since prognostic biomarkers are available in routine clinical practice, the more recent staging manual should be followed to select better systemic therapy and give better outcomes for Chinese breast cancer patients.