Background: The incidence and survival of oral squamous cell carcinoma (OSCC) patients have increased in recent years. Understanding their long-term survival aspects is essential for optimal treatment and follow-up planning. Almost one in five cancers diagnosed occurs nowadays in individuals with a previous diagnosis of cancer.
Methods: Patients diagnosed with primary OSCC during 1953-2015 were retrieved from the Finnish Cancer Registry. Both standardized incidence ratios (SIR) and excess absolute risk (EAR) per 1000 person-years at risk (PYR) of second primary cancer (SPC) were calculated relative to the general population.
Results: Among 6602 first primary OSCC patients there were 640 (10%) SPCs. The SIR for SPCs was 1.85 (95% CI: 1.71-1.99, P < .001) corresponding to an EAR of 8.78 (95% CI: 7.29-10.26).
Conclusions: Health care professionals should be aware of the second primary cancer risk after management of primary OSCC and patients need to be counseled about this phenomenon.
Keywords: head and neck cancer; oral cancer; second primary cancer; second primary malignancy; second primary tumor.
© 2020 Wiley Periodicals, Inc.