Clinical and prognostic features of multiple primary cancers with oral squamous cell carcinoma.

OBJECTIVE

To characterize the epidemiological, clinical, and prognostic features of multiple primary cancers (MPC) following oral squamous cell carcinoma (OSCC).

DESIGN

Data from the Surveillance, Epidemiology, and End Results Program database were analyzed to determine the standardized incidence ratio (SIR) of multiple subsequent sites, difference in clinical and prognostic features between MPC and single primary OSCC.

RESULTS

The sites with the highest SIRs were the oral cavity (SIR = 69.48), other oral cavity and pharynx (SIR=55.46), pharynx (SIR=39.21), tonsils (SIR=33.52), trachea (SIR=33.24), esophagus (SIR=18.00), and larynx (SIR=13.12). The 5- and 10-year survival rates for single primary OSCC were 57.9% (95% CI: 56.7-59.2%) and 47.1% (95% CI: 45.7-48.6%), respectively, while those for MPC were 66.9% (95% CI: 64.6-69.4%) and 42.2% (95% CI: 39.5-45.2%), respectively. The mean age of MPC patients was significantly higher than that of single primary OSCC patients. MPC are more common in the gums and other sites of the oral cavity, and more likely to be detected in early TNM stage and pathological grade. Age, site, T-stage, and N-stage were significantly associated with prognosis of MPC.

CONCLUSIONS

Significant differences in clinical and prognostic features were found between MPC and single primary OSCC. Considering MPC has a poor long-term prognosis, it is necessary to identify MPC and single primary OSCC early.