High expression of macrophage colony-stimulating factor-1 receptor in peritumoral liver tissue is associated with poor outcome in hepatocellular carcinoma after curative resection

Abstract

Background: Macrophage colony-stimulating factor 1 receptor (CSF-1R) expression in hepatocellular carcinoma (HCC) and its prognostic values are unclear. This study evaluated the prognostic values of the intratumoral and peritumoral expression of CSF-1R in HCC patients after curative resection.

Methods: Tissue microarrays containing material from cohort 1 (105 patients) and cohort 2 (32 patients) were constructed. Immunohistochemistry was performed and prognostic values of these and other clinicopathological data were evaluated. The CSF-1R mRNA level was assessed by quantitative real-time polymerase chain reaction in cohort 3 (52 patients).

Results: Both the CSF-1R density and its mRNA level were significantly higher in peritumoral liver tissue than in the corresponding tumor tissue. CSF-1R was distributed in a gradient in the long-distance peritumoral tissue microarray, with its density decreasing as the distance from the tumor margin increased. High peritumoral CSF-1R was significantly associated with more intrahepatic metastases and poorer survival. Peritumoral CSF-1R was an independent prognostic factor for both overall survival and time to recurrence and affected the incidence of early recurrence. However, intratumoral CSF-1R did not correlate with any clinicopathological feature. Peritumoral CSF-1R was also associated with both overall survival and time to recurrence in a subgroup with small HCCs (< or =5 cm).

Conclusions: Peritumoral CSF-1R is associated with intrahepatic metastasis, tumor recurrence, and patient survival after hepatectomy, highlighting the critical role of the peritumoral liver milieu in HCC progression. CSF-1R may become a potential therapeutic target for postoperative adjuvant treatment.

Figure 1.

Patterns of CSF-1R expression and distribution. Representative strong (case 20, (A), (B)) and mild (case 60, (C), (D)) immunostaining of colony-stimulating factor 1 receptor (CSF-1R) in peritumoral (A, C) and intratumoral (B, D) tissue microarray (TMA) chips (200×). (E–H): Immunostaining of intratumoral (E) and peritumoral (F–H) CSF-1R in a long-distance peritumoral TMA chip. (I): CSF-1R expression differed in tumor and peritumoral liver tissue and presented a gradient distribution pattern in the latter. *p < .05, one-way analysis of variance, compared with proximal peritumoral CSF-1R density. (J): Quantitative real-time polymerase chain reaction analyses of CSF-1R and hypoxia-inducing factor 1α gene expression in intratumoral and peritumoral specimens. *p < .05, paired-samples t-test between the two intratumoral or peritumoral subgroups.

Figure 2.

Immunofluorescence double staining of CD68 and colony-stimulating factor 1 receptor (CSF-1R) in eight hepatocellular carcinoma samples. CD68 staining used Cy3 ((A), red), CSF-1R staining used Cy5 ((B), green), and nucleus staining used 4′,6-diamidine-2′-phenylindole dihydrochloride ((C), blue) as substrates. (D) was merged from (A), (B), and (C).

Figure 3.

Cumulative overall survival (OS) and time to recurrence (TTR) curves of patients (cohort 1) with low or high macrophage colony-stimulating factor-1 receptor (CSF-1R) density. Low peritumoral CSF-1R density was associated with a longer OS time and TTR (A, C), whereas intratumoral CSF-1R density was associated with neither the OS time nor the TTR (B, D). (E, F): Receiver operating characteristic curve: All the other adopted factors predicted death and 1-year recurrence precisely (p < .05 for all), whereas microvascular invasion could not predict death (p = .143).