Risk factors for patients with multiple synchronous primary cancers involving oral and oropharyngeal subsites.

Objective: To evaluate risk factors and prognosis for multiple synchronous primary cancers (MSPCs) associated with head and neck squamous cell carcinoma.

Study Design: The retrospective study included 1623 patients.

Results: The most common MSPC site involved was the head and neck region. The presence of multiple oral dysplastic lesions (P < .001) was the sole risk factor for the occurrence of MSPCs. A multivariate survival analysis showed that the pathologic grade (P = .003) was an independent predictive factor for the 5-year disease-specific survival of patients with MSPCs. A Kaplan-Meier analysis showed that the 5-year disease-specific survival of patients who developed MSPCs was worse than that of patients who did not develop MSPCs (P = .020).

Conclusions: MSPCs are a significant negative prognostic factor for patients with head and neck squamous cell carcinoma. However, a worse prognosis is predicted for patients with MSPCs with several features: a higher pathologic grade, a more aggressive growth pattern, male gender plus a tobacco or alcohol habit, and no multiple oral dysplastic lesions.