Macrophages expressing TREM-1 are involved in the progression of HPV16-related oropharyngeal squamous cell carcinoma.

INTRODUCTION

Many types of research have been performed to improve the diagnosis, therapy, and prognosis of oropharyngeal carcinomas (OP-SCCs). Since they arise in lymphoid-rich areas and intense lymphocytic infiltration has been related to a better prognosis, a TREM-1 putative function in tumour progression and survival has been hypothesized.

MATERIALS AND METHODS

Twenty-seven human papillomavirus (HPV) 16 OP-SCC specimens have been analyzed to relate TREM-1 expression with histiocytic and lymphocytic markers, HPV presence and patients' outcome.

RESULTS

No differences have been shown between intratumoral and stromal CD4 cells, while intratumoral CD8 lymphocytes are higher with respect to the tumour stroma (=.0005). CD68 cells are more than CD35 and TREM-1; their presence is related to CD35 and TREM-1 histiocytes (=.005 and .026, respectively). Intratumoral CD4 lymphocytes are higher in p16 cases (11/27) than in p16 (=.042); moreover, p16 positivity correlates to a better survival (=.034). CD4, CD8 and CD35 cells have no impact on survival, while CD68 expression heavily influences progression and bad outcome (=.037). TREM-1 positivity also leads to worst overall survival (=.001): peritumoral expression and death-cause relationship are always significant, particularly when the cause is OP-SCC (=.000).

CONCLUSION

While p16 shows to better stratify HPV16 patients' outcome, TREM-1 macrophages suggest their key importance in HPV-related OP-SCCs progression.KEY MESSAGESTREM-1 positivity correlates to the worst overall survival of HPV16-positive OPSCCs-affected patients.p16-positive HPV16 related OPSCCs patients have a better prognosis with respect to p16-negative ones.