Tumor infiltrating B-cells are increased in prostate cancer tissue

J Transl Med. 2014 Jan 30;12:30. doi: 10.1186/1479-5876-12-30.

Abstract

Background: The presence of increased B-cell tumor infiltrating lymphocytes (TILs) was seen in mouse prostate cancer (PCa) but has not been fully documented in human PCa. We, therefore, investigated the density of infiltrating B cells within human PCa utilizing a quantitative computational method.

Methods: Archived radical prostatectomy specimens from 53 patients with known clinical outcome and D'Amico risk category were obtained and immunohistochemically (IHC) stained for the B cell marker, CD20. Slides were reviewed by a genitourinary pathologist who manually delineated the tumoral regions of PCa. Slides were digitally scanned and a computer algorithm quantified the area of CD20 stained B-cells as a measure of B cell density within the outlined regions of prostate cancer (intra-tumoral region), versus extra-tumoral prostate tissue. Correlations were analyzed between B-cell density and demographic and clinical variables, including D'Amico risk groups and disease recurrence.

Results: For the entire cohort, the mean intra-tumoral B cell density was higher (3.22 SE = 0.29) than in the extra-tumoral region of each prostatectomy section (2.24, SE = 0.19) (paired t test; P < 0.001). When analyzed according to D'Amico risk group, the intra-tumoral B cell infiltration in low risk (0.0377 vs. 0.0246; p = 0.151) and intermediate risk (0.0260 vs. 0.0214; p = 0.579) patient prostatectomy specimens did not show significantly more B-cells within the PCa tumor. However, patient specimens from the high-risk group (0.0301 vs. 0.0197; p < 0.001) and from those who eventually had PCa recurrence or progression (0.0343 vs. 0.0246; p = 0.019) did show significantly more intra-tumoral CD20+ B-cell staining. Extent of B-cell infiltration in the prostatectomy specimens did not correlate with any other clinical parameters.

Conclusions: Our study shows that higher B-cell infiltration was present within the intra-tumoral PCa regions compared to the extra-tumoral benign prostate tissue regions in prostatectomy sections. For this study we developed a new method to measure B-cells using computer-assisted digitized image analysis. Accurate, consistent quantitation of B-cells in prostatectomy specimens is essential for future clinical trials evaluating the effect of B cell ablating antibodies. The interaction of B-cells and PCa may serve as the basis for new therapeutic targets.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD20 / metabolism
  • B-Lymphocytes / immunology*
  • B-Lymphocytes / pathology*
  • Cell Count
  • Demography
  • Humans
  • Image Processing, Computer-Assisted
  • Immunohistochemistry
  • Lymphocytes, Tumor-Infiltrating / immunology*
  • Lymphocytes, Tumor-Infiltrating / pathology*
  • Male
  • Mice
  • Middle Aged
  • Prostatectomy
  • Prostatic Neoplasms / immunology*
  • Prostatic Neoplasms / pathology*
  • Prostatic Neoplasms / surgery
  • Treatment Outcome

Substances

  • Antigens, CD20