A role for the substance P/NK-1 receptor complex in cell proliferation in oral squamous cell carcinoma.

Objective: To investigate the presence and distribution of substance P (SP) and neurokinin 1 receptor (NK-1R) in oral squamous cell carcinoma (OSCC) and their relationship with proliferation.

Patients And Methods: Ninety OSCCs from 73 patients were immunohistochemically analyzed using monoclonal antibodies against SP, NK-1R and Ki-67 in a case and control study.

Results: Seventy-one percent (n=49) of cases expressed SP on tumour cell membrane, 81.3% (n=69) in cytoplasm, 39.4% (n=28) in nucleus, 81.6% (n=71) in infiltrating lymphocytes, and 58.1% (n=43) in peritumoural or intratumoural blood vessels; 14% (n=12) of cases expressed NK-1R on tumour cell membrane, 50% (n=43) in cytoplasm, 48.3% (n=42) in infiltrating lymphocytes and 22.5% (n=18) in tumour blood vessels. All cases expressed Ki-67, which was expressed in >25% of tumour cells in 79.8% of cases (n=63). Direct significant associations were observed in SP expression between different tissue levels (p<0.01), between SP and NK-1R tumour cell membrane expression (p<0.01), and between joint SP and NK-1R expression in tumour cell cytoplasm and a higher expression of Ki-67 (p<0.05).

Conclusion: The ubiquitous presence of SP strongly suggests a role for SP/NK-1R complex in tumour development and progression and possibly for NK-1R antagonists, such as L-773060, in the management of patients with oral cancer.