Presence of bone marrow micro-metastases in stage I-III colon cancer patients is associated with worse disease-free and overall survival

Cancer Med. 2017 May;6(5):918-927. doi: 10.1002/cam4.1056. Epub 2017 Apr 12.


The prognostic significance of bone marrow micro-metastases (BMM) in colon cancer patients remains unclear. We conducted a prospective cohort study with long-term follow-up to evaluate the relevance of BMM as a prognostic factor for disease free (DFS) and overall survival (OS) in stage I-III colon cancer patients. In this prospective multicenter cohort study 144 stage I-III colon cancer patients underwent bone marrow aspiration from both iliac crests prior to open oncologic resection. The bone marrow aspirates were stained with the pancytokeratin antibody A45-B/B3 and analyzed for the presence of epithelial tumor cells. DFS and OS were analyzed using a Cox proportional hazard model and robust standard errors to account for clustering in the multicenter setting. Median overall follow-up was 6.2 years with no losses to follow-up, and 7.3 years in patients who survived. BMM were found in 55 (38%) patients. In total, 30 (21%) patients had disease recurrence and 56 (39%) patients died. After adjusting for known prognostic factors, BMM positive patients had a significantly worse DFS (hazard ratio [HR] 1.33; 95% confidence interval [95% CI]: 1.02-1.73; P = 0.037) and OS (HR 1.30; 95% CI: 1.09-1.55; P = 0.003) compared to BMM negative patients. Bone marrow micro-metastases occur in over one third of stage I-III colon cancer patients and are a significant, independent negative prognostic factor for DFS and OS. Future trials should evaluate whether node-negative colon cancer patients with BMM benefit from adjuvant chemotherapy.

Keywords: Bone marrow; colon cancer; micro-metastases; prognosis.

Publication types

  • Clinical Trial
  • Multicenter Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Bone Marrow Neoplasms / diagnosis
  • Bone Marrow Neoplasms / mortality*
  • Bone Marrow Neoplasms / secondary*
  • Colonic Neoplasms / mortality*
  • Colonic Neoplasms / pathology*
  • Disease-Free Survival
  • Female
  • Humans
  • Male
  • Neoplasm Micrometastasis
  • Neoplasm Recurrence, Local / epidemiology
  • Neoplasm Recurrence, Local / mortality
  • Neoplasm Staging
  • Prognosis
  • Prospective Studies
  • Survival Analysis