Objectives: Simultaneous second primary tumors (SSPT) are not uncommon in patients with oral cavity squamous cell carcinoma (OSCC) living in areas where the habit of betel quid chewing is widespread. We sought to identify the main prognostic factors in OSCC patients with SSPT and incorporate them into a risk stratification scheme.
Methods: A total of 1822 consecutive patients with primary OSCC treated between January 1996 and February 2014 were analyzed for the presence of SSPT. The 18-month and 5-year overall survival (OS) rates served as the main outcome measures.
Results: Of the 1822 patients, 77 (4%) were found to have SSPT (i.e, two malignancies identified within one month of each other). The 18-month and 5-year OS rates in patients without SSPT and with SSPT were 82% and 69%, and 72% and 53%, respectively (p = 0.0063). Patients with SSPT were further divided into patients with either esophageal cancer or hepatocellular carcinoma (eso-HCC subgroup, n = 8) and other tumors (NO eso-HCC subgroup, n = 69). After multivariate analysis, neck nodal extracapsular spread (ECS, n = 18) and the presence of eso-HCC were identified as independent adverse prognostic factors. The 18-month OS rates of SSPT patients with both eso-HCC and ECS (n = 5) vs. the remaining patients (n = 72) were 0% and 78%, respectively (p < 0.0001).
Conclusion: OSCC patients with neck nodal ECS and esophageal cancer or hepatocellular carcinoma as SSPT have a dismal short-term prognosis.