Tumor-associated CD3- and CD8-positive immune cells in colorectal cancer: The additional prognostic value of CD8+-to-CD3+ ratio remains debatable

Abstract

<p>Background<br></p><p>A large number of infiltrating CD3- and CD8-positive inflammatory cells indicates an improved survival in colorectal cancer (CRC), similar to many other cancers.<br></p><p>Objective<br></p><p>We investigated the prognostic value of different combinations of CD3- and CD8-positive immune cells in CRC patients.<br></p><p>Methods<br></p><p>The densities of CD3- and CD8-positive cells in intratumoral and stromal tissues were evaluated from 539 patients, for which we calculated a CD3 tumor–stroma index, a CD8 tumor–stroma index, and a CD3–CD8 tumor–stroma index.<br></p><p>Results<br></p><p>High CD3 and CD8 tumor–stroma indices associated with stage I to II disease (<i>p</i> < 0.001 for both). The CD3 tumor–stroma index associated with a colonic tumor location (<i>p</i> = 0.006), while the CD8 tumor–stroma index associated with right-sided tumors (<i>p</i> < 0.001) and histological grade 3 tumors (<i>p</i> = 0.032). High intratumoral and stromal densities for CD3- and CD8-positive immune cells, the CD3 tumor–stroma index, the CD8 tumor–stroma index, and the CD3–CD8 tumor–stroma index all indicated a better DSS.<br></p><p>Conclusions<br></p><p>The CD3 tumor–stroma index carries a strong prognostic value in CRC, and none of the CD3 and CD8 combinations we analyzed proved superior.<br></p>