Abstract 2650

Background:

Tumor associated macrophages (TAM) have at least two potential roles in promoting tumor growth: suppression of immune responses and potentiation of angiogenesis. In numerous cancer types, including lymphomas, high M2 type TAM content has been associated with worse prognosis. Rarely, high TAM content correlates with better survival. We have recently shown that CD68 positive TAMs in DLBCL contribute to unfavorable survival after high dose chemotherapy. Here we have extended our analyses on M2 type macrophages and questioned how combination of rituximab with chemotherapy influences TAM-associated clinical outcome.

Patients and Methods:

Expression of CD163 and CCL18, which are primarily expressed in M2 type macrophages, were identified immunohistochemically from samples of 101 de novo DLBCL patients treated with rituximab in combination with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone)-like regimen (immunochemotherapy). With a median follow-up of 65 months, (range 16–114 months), 5-year progression free survival (PFS) was 70% and overall survival (OS) 73%. 29 DLBCL patients previously treated with up front high dose chemotherapy served as a control group.

Results:

Correlation between CD163 and CCL18 positive TAMs was found (rs=0.427, p<0.001). In the Kaplan-Meier analyses the cutoff level of 67% was found to best discriminate between subgroups with different outcomes. Consistent with previous data, chemotherapy-treated patients with high CD163 or CCL18 positive TAM counts displayed a significantly inferior OS and PFS than the low group (Table). In contrast, after rituximab containing regimen, the patients with high CD163 and CCL18 positive TAM content tended to have favorable survival. Among the patients with low counts in both CD163 and CCL18 positive TAMs, PFS and OS were found to be significantly worse in comparison to others.

SurvivalMarkerImmunochemotherapy groupControl group
Low (%)High (%)P-valueLow (%)High (%)P-value
5-year OS CD163 70 80 0.235 75 33 0.019 
CCL18 69 84 0.151 74 33 0.037 
CD163+CCL18 65 85 0.035 100 38 0.003 
5-year PFS CD163 66 82 0.091 75 40 0.054 
CCL18 68 80 0.206 74 39 0.131 
CD163+CCL18 63 83 0.040 75 42 0.013 
SurvivalMarkerImmunochemotherapy groupControl group
Low (%)High (%)P-valueLow (%)High (%)P-value
5-year OS CD163 70 80 0.235 75 33 0.019 
CCL18 69 84 0.151 74 33 0.037 
CD163+CCL18 65 85 0.035 100 38 0.003 
5-year PFS CD163 66 82 0.091 75 40 0.054 
CCL18 68 80 0.206 74 39 0.131 
CD163+CCL18 63 83 0.040 75 42 0.013 
View Large
Conclusions:

In contrast to data on chemotherapy treated DLBCL or other lymphoma types, M2 type TAM content is associated with favorable prognosis in DLBCL patients after immunochemotherapy.

Disclosures:

No relevant conflicts of interest to declare.

Topics:
chemotherapy regimen, diffuse large b-cell lymphoma, macrophages, neoplasms, rituximab, lymphoma, cancer, cd68 antigen, human, cyclophosphamide, cyclophosphamide, doxorubicin, prednisone, and vincristine

Author notes

*

Asterisk with author names denotes non-ASH members.

© 2011 by The American Society of Hematology
2011
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