CD8+ lymphocyte intratumoral infiltration as a stage-independent predictor of Merkel cell carcinoma survival: a population-based study

Am J Clin Pathol. 2014 Oct;142(4):452-8. doi: 10.1309/AJCPIKDZM39CRPNC.


Objectives: Intratumoral CD8+ lymphocytes (IT-CD8s) have shown promise as a prognostic indicator for Merkel cell carcinoma (MCC). We tested whether IT-CD8s predict survival among a population-based MCC cohort.

Methods: One hundred thirty-seven MCC cases that had not previously been analyzed for IT-CD8s were studied.

Results: Three-year MCC-specific survival rates were 56%, 72%, and 100% for patients with absent (n = 46), low (n = 85), and moderate or strong (n = 6) IT-CD8s, respectively. Increased IT-CD8s were associated with improved MCC-specific survival in a multivariate competing risk-regression analysis including stage, age, and sex (hazard ratio [HR] = 0.5; 95% confidence interval [CI] = 0.3-0.9). Although a similar trend was observed for overall survival, statistical significance was not reached (HR = 0.8; 95% CI = 0.6-1.0), likely because of the high rate of non-MCC deaths among older patients.

Conclusions: This study of prospectively captured MCC cases supports the concept that cellular immunity is important in MCC outcome and that CD8+ lymphocyte infiltration adds prognostic information to conventional staging.

Keywords: Merkel cell carcinoma; Survival; T cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • CD8-Positive T-Lymphocytes / immunology*
  • Carcinoma, Merkel Cell / immunology*
  • Carcinoma, Merkel Cell / mortality
  • Carcinoma, Merkel Cell / pathology*
  • Cohort Studies
  • Female
  • Humans
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Neoplasm Staging
  • Prognosis
  • Proportional Hazards Models
  • Prospective Studies
  • Skin Neoplasms / immunology
  • Skin Neoplasms / mortality*
  • Skin Neoplasms / pathology*
  • Survival Rate