Head and neck cancer relapse after chemoradiotherapy correlates with CD163+ macrophages in primary tumour and CD11b+ myeloid cells in recurrences

Abstract

Background: We investigated the prognostic role of tumour-associated macrophages (TAMs) in patients with head and neck squamous cell carcinoma (HNSCC) treated with definitive chemoradiotherapy (CRT).

Methods: The expression of CD68+, CD163+ and CD11b+ cells was assessed using immunohistochemistry in n=106 pre-treatment tumour biopsy samples and was correlated with clinicopathological characteristics, including T-stage, N-stage, grading, tumour localisation, age and sex as well as local failure-free survival (LFFS), distant metastases-free survival (DMFS), progression-free (PFS), and overall survival (OS). Finally, TAMs expression and vessel density (CD31) were examined in n=12 available early local recurrence samples and compared with their matched primary tumours . The diagnostic images and radiotherapy plans of these 12 patients were also analysed. All local recurrences occurred in the high radiation dose region (⩾70 Gy).

Results: With a median follow-up of 40 months, OS at 2 years was 60.5%. High CD163 expression in primary tumours was associated with decreased OS (P=0.010), PFS (P=0.033), LFFS (P=0.036) and DMFS (P=0.038) in multivariate analysis. CD163 demonstrated a strong prognostic value only in human papillomavirus (p16(INK4))-negative patients. Early local recurrence specimens demonstrated a significantly increased infiltration of CD11b+ myeloid cells (P=0.0097) but decreased CD31-positive vessel density (P=0.0004) compared with their matched primary samples.

Conclusions: Altogether, baseline CD163 expression predicts for an unfavourable clinical outcome in HNSCC after definitive CRT. Early local recurrences showed increased infiltration by CD11b+ cells. These data provide important insight on the role of TAMs in mediating response to CRT in patients with HNSCC.

Figure 1

Prognostic significance of the TAMs markers (A) CD68 and (B) CD163 with regard to overall survival (OS), progression-free survival (PFS), locoregional failure-free survival (LFFS) and distant metastases-free survival (DMFS) in patients with head and neck cancer following definitive chemoradiotherapy.

Figure 2

Examples of tumour samples with low and high stromal (A) CD68 and (B) CD163 expression. Areas of interest are depicted as dotted lines (tumor) or arrows (stroma), respectively. Magnification, × 10.

Figure 3

Analysis of CD68, CD163 and CD11b cell number in samples from n=12 primary tumours and their matched local recurrence. (A) We did not observe a difference in CD68+ or CD163+ cell influx in the recurrent samples compared with primary tumours . In contrast, there was a significant increase (P=0.0097) in CD11b+ cell infiltration in recurrent tumours compared with their matched primary tumour samples. (B) Cell number in each of the 12 patients (No.1–12) is shown as indicated. Columns/points, median; bars, s.d. (C) Example of CD11b+ expression in primary tumour (left) and its matched recurrence sample (right). Magnification, × 10.