The Prognostic Significance of Ki67 Before and After Neoadjuvant Chemotherapy in Breast Cancer

Breast Cancer Res Treat. 2009 Jul;116(1):53-68. doi: 10.1007/s10549-008-0081-7. Epub 2008 Jul 1.

Abstract

Purpose: To compare the prognostic significance of proliferation, as assessed by Ki67 expression, in breast cancer before and after neoadjuvant chemotherapy.

Methods: A retrospective search of a prospectively maintained clinical database was performed to identify patients treated with neoadjuvant chemotherapy at the Royal Marsden Hospital. The expression of Ki67 was assessed using immunohistochemistry in pre-therapy core-needle biopsy and post-therapy surgical excision specimens. The following factors were considered pre- and post-chemotherapy for their relationship with relapse-free and overall survival: age, menstrual status, T and N stage, pre-therapy operability, Ki67, ER, PgR, HER2, grade, histological subtype, vascular invasion, clinical response, chemotherapy regimen, type of surgery performed, adjuvant therapy, pathological tumour size and nodal involvement.

Results: In a matched cohort of 103 patients, on multivariate analysis of relapse-free survival, post-therapy Ki67 was the only significant independent prognostic factor. On multivariate analysis for overall survival, both pre- and excision Ki67 were significant independent predictors but the latter showed a stronger prognostic impact. The highest and lowest tertiles of excision Ki67 had different prognosis for both 5-year relapse-free (27% vs. 77%) and overall (39% and 93%) survival. In a cohort of 284 patients with only excision samples, post-therapy Ki67 was a significant independent prognostic factor on multivariate analysis.

Conclusion: Post-chemotherapy Ki67 is a strong predictor of outcome for patients not achieving a pathological complete response.

MeSH terms

  • Adult
  • Aged
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
  • Biomarkers, Tumor / analysis*
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / mortality
  • Breast Neoplasms / pathology
  • Combined Modality Therapy
  • Female
  • Humans
  • Immunohistochemistry
  • Kaplan-Meier Estimate
  • Ki-67 Antigen / biosynthesis*
  • Middle Aged
  • Neoadjuvant Therapy*
  • Neoplasm Staging
  • Prognosis
  • Radiotherapy, Adjuvant
  • Retrospective Studies

Substances

  • Biomarkers, Tumor
  • Ki-67 Antigen