Patients with head, neck cancers at excess risk for second primary malignant neoplasms
Patients with head and neck squamous cell carcinoma appeared at increased risk for second primary malignant neoplasms, according to a population-based retrospective cohort study.
This association appeared more pronounced among those with non-HPV-related cancers.
“There are an estimated 430,000 HNSCC survivors in the United States, and the number
is expected to continue to rise,” Eric Adjei Boakye, PhD, MA, statistical consultant at Saint Louis University Center for Outcomes Research, and colleagues wrote. “The incidence of second primary malignant neoplasm in HNSCC patients is about 3% to 7% per year, with an estimated 20-year cumulative risk of 36%. Approximately one-third of HNSCC deaths are attributable to second primary malignant neoplasms.”
Second primary malignant neoplasms cause the death of three times as many patients with HNSCC than those who die of metastatic disease.
Researchers used the SEER registry to assess 109,512 adults (mean age, 61.9 years; 76.1% men) diagnosed with HNSCC between from 2000 and 2014 for incidence of second primary malignant neoplasms.
Median follow-up was 31 months.
Among the study population, 12.3% of patients with HNSCC developed a second primary malignant neoplasm. The mean time between first HNSCC and second primary malignant neoplasm was 3.9 years.
The overall standardized incidence ratio (SIR) for second primary malignant neoplasms was 2.18 (95% CI, 2.14-2.22), which corresponds to 160 excess cases of secondary malignancies per 10,000 person-years at risk.
SEER did not include information about patient-specific HPV status; therefore, the researchers used anatomical sites well established for HPV-associated tumors to assess differences in rates of second primary malignant neoplasms.
Researchers observed different risks between these groups. Those with HPV-associated cancers had a lower risk for second primary malignant neoplasms (SIR = 1.98; excess absolute risk [EAR] = 114 excess cases per 10,000 person-years at risk) than patients with non-HPV-associated cancers (SIR = 2.28; EAR = 188 excess cases per 10,000 person-years at risk).
The limitations of the study included the lack of information on HPV status and risk factors like tobacco and alcohol use, as well as use of a 2-month delay to define second primary malignant neoplasm.
“These findings could be useful for clinicians in the diagnosis and prevention of subsequent cancers in these patients,” the researchers wrote. “Efforts made by public health policy makers and oncology care professionals should be sustained to develop effective smoking cessation interventions. Future studies should evaluate if there are differences in risks of second primary malignant neoplasm among patients with HNSCC in earlier years vs later years owing to shifting risk profiles among patients with HNSCC.” – by Cassie Homer
Disclosures: The researchers report no relevant financial disclosures.