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 (p = .0005). CD68(+) cells are more than CD35(+) and TREM-1(+); their presence is related to CD35(±) and TREM-1(±) histiocytes (p = .005 and .026, respectively). Intratumoral CD4(+) lymphocytes are higher in p16(+) cases (11/27) than in p16(−) (p = .042); moreover, p16 positivity correlates to a better survival (p = .034). CD4(+), CD8(+) and CD35(+) cells have no impact on survival, while CD68 expression heavily influences progression and bad outcome (p = .037). TREM-1 positivity also leads to worst overall survival (p = .001): peritumoral expression and death-cause relationship are always significant, particularly when the cause is OP-SCC (p = .000). CONCLUSION: While p16 shows to better stratify HPV16(+) patients’ outcome, TREM-1(+) KEY MESSAGES: TREM-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.