Tumour T-lymphocyte subset infiltration and tumour recurrence following curative resection for colorectal cancer A.A. Ali a , D.C. McMillan a, *, I.I. Matalka b , A.M. McNicol b , C.S. McArdle a a University Departments of Surgery, Royal Infirmary, Glasgow, Scotland G31 2ER, UK b University Department of Pathology, Royal Infirmary, Glasgow, Scotland G31 2ER, UK Accepted for publication 19 November 2003 KEYWORDS Colorectal cancer; CD4þ; CD8þ T-lymphocytes; Recurrence Summary Aim. The relationship of tumour T-lymphocytic subset infiltration and recurrence in patients undergoing potentially curative resection for colorectal cancer has not been clearly defined. Methods. Tumour sections from patients who had undergone potentially curative resection for colorectal cancer were stained and counted for CD4þ and CD8þ T-lymphocytes. Results. Twenty-three patients developed recurrence during the follow-up period. Patients were grouped according to whether or not they developed recurrence. The groups were similar in age, sex, site of tumour, Dukes stage and the numbers of patients receiving adjuvant therapy. The total percentage volume of labelled CD4þ T-lymphocytes in the tumour was significantly lower in the patients who recurred ðp , 0:05Þ: Conclusions. The results of the present pilot study suggest that a reduction in tumour T-lymphocyte infiltration, in particular CD4þ T-lymphocyte infiltration, is associated with recurrence in patients following potentially curative resection for colorectal cancer. Q 2004 Elsevier Ltd. All rights reserved. Introduction Local and systemic inflammatory responses are regulated through the production of proteins, such as cytokines, by immunologically active cells. In cancer, this mechanism may be disturbed, and this dysregulation contributes to the poorer outcome in the cancer patient. 1 Mononuclear cell infiltrates, are commonly seen surrounding and/or infiltrating primary tumours. They are associated with a favourable prognosis in colorectal cancer. 2–4 There may be a link between the magnitude of lymphocytic infiltration, in or around tumour, the stage of disease and survival. 4–6 Nielsen and coworkers 6 examined lymphocytic infiltration in almost 600 patients who underwent resection for colorectal cancer and found that the presence of a marked lymphocytic infiltration was associated with better survival, independent of Dukes stage. This infiltrate is composed predominantly of T helper (CD4þ ) and cytotoxic (CD8þ ) subsets. 7 The presence of these lymphocyte subsets within tumours may reflect the aggressiveness of the EJSO (2004) 30, 292–295 www.ejso.com 0748-7983/$ - see front matter Q 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.ejso.2003.11.018 *Corresponding author. Tel.: þ 44-141-211-5435; fax: þ 44- 141-552-3229. E-mail address: d.c.mcmillan@clinmed.gla.ac.uk