CD8+ T cells infiltrated within cancer cell nests as a prognostic factor in human colorectal cancer.
The pathophysiological significance of tumor infiltrating lymphocytes remains controversial. To clarify their role, we performed clinicopathological analysis of CD8+ T cells in 131 cases of human colorectal cancer. CD8+ T cells were classified into three groups by their localization: (a) those infiltrated within cancer cell nests; (b) those distributed in the cancer stroma; and (c) those present along the invasive margin (tumor-host interface). Of these, CD8+ T cells within cancer cell nests were most significantly associated with a better survival of patients by both mono- and multivariate analyses. The impact on survival was similar to that of Dukes' staging. Granzyme B+ cytoplasmic granules were detected in lymphocytes within cancer cell nests, confirming their activated, cytotoxic phenotype. CD8 and Ki-67 double immunohistochemistry confirmed higher proliferative activity of CD8+ T cells within cancer cell nests. Our data suggested that human colorectal cancer tissue was infiltrated by various numbers of T cells that had cytotoxic phenotype, contributing to a better survival of patients. This infiltration of colorectal cancer cell nests by CD8+ T cells could be a novel prognostic factor.
Department of Pathology, Tohoku University School of Medicine, Sendai, Japan.
Y
Y
Naito
K
K
Saito
K
K
Shiiba
A
A
Ohuchi
K
K
Saigenji
H
H
Nagura
H
H
Ohtani
D000704:Analysis of Variance; D018414:CD8-Positive T-Lymphocytes / Q000145:classification* / Q000201:enzymology; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology*; D053804:Granzymes; D006801:Humans; D016246:Lymphocytes, Tumor-Infiltrating / Q000145:classification* / Q000201:enzymology; D009367:Neoplasm Staging; D011379:Prognosis; D012697:Serine Endopeptidases / Q000032:analysis
C509213:GZMB protein, human; D053804:Granzymes; D012697:Serine Endopeptidases