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Second cancers in patients with neuroendocrine tumors
Hui-Jen Tsai1, Chun-Chieh Wu2, Chia-Rung Tsai3
1National Institute of Cancer Research, National Health Research Institutes, Tainan, Taiwan ; Department of Internal Medicine, National Cheng Kung University Hospital, Tainan, Taiwan ; Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan ; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
Background:
Second cancers have been reported to occur in 10-20% of patients with neuroendocrine tumors (NETs). However, most published studies used data from a single institution or focused only on specific sites of NETs. In addition, most of these studies included second cancers diagnosed concurrently with NETs, making it difficult to assess the temporality and determine the exact incidence of second cancers. In this nationwide population-based study, we used data recorded by the Taiwan Cancer Registry (TCR) to analyze the incidence and distribution of second cancers after the diagnosis of NETs.
Methods:
NET cases diagnosed from January 1, 1996 to December 31, 2006 were identified from the TCR. The data on the occurrence of second cancers were ascertained up to December 31, 2008. Standardized incidence ratios (SIRs) of second cancers were calculated based on the cancer incidence rates of the general population. Cox-proportional hazards regression analysis was performed to estimate the hazard ratio (HR) and 95% confidence interval (CI) for the risk of second cancers associated with sex, age, and primary NET sites.
Results:
A total of 1,350 newly diagnosed NET cases were identified according to the selection criteria. Among the 1,350 NET patients, 49 (3.63%) developed a second cancer >3 months after the diagnosis of NET. The risk of second cancer following NETs was increased compared to the general population (SIR = 1.48, 95% CI: 1.09-1.96), especially among those diagnosed at age 70 or older (HR = 5.08, 95% CI = 1.69-15.22). There appeared to be no preference of second cancer type according to the primary sites of NETs.
Conclusions:
Our study showed that the risk of second cancer following NETs is increased, especially among those diagnosed at age 70 or older. Close monitoring for the occurrence of second cancers after the diagnosis of NETs is warranted.
Insights
Patients diagnosed with neuroendocrine tumors (NETs) have an increased risk of developing second cancers, particularly those aged 70 and older. Regular monitoring is recommended for early detection of subsequent malignancies.
Area of Science:
- Oncology
- Cancer Epidemiology
- Public Health
Background:
- Neuroendocrine tumors (NETs) are associated with a 10-20% incidence of second cancers.
- Previous studies often used single-institution data or focused on specific NET sites, limiting generalizability.
- Concurrent diagnoses in prior studies obscured the true incidence and temporal relationship of second cancers post-NET diagnosis.
Purpose of the Study:
- To analyze the incidence and distribution of second cancers occurring after a primary diagnosis of neuroendocrine tumors (NETs).
- To assess the risk of second cancers in NET patients compared to the general population.
- To identify demographic and clinical factors associated with second cancer development after NET diagnosis.
Main Methods:
- Utilized nationwide population-based data from the Taiwan Cancer Registry (TCR) for NET cases diagnosed between 1996 and 2006.
- Calculated standardized incidence ratios (SIRs) for second cancers against general population rates.
- Employed Cox-proportional hazards regression to determine hazard ratios (HR) for second cancer risk based on age, sex, and primary NET site.
Main Results:
- Identified 1,350 NET cases, with 49 (3.63%) developing a second cancer more than three months post-NET diagnosis.
- NET patients exhibited an elevated risk of second cancers (SIR = 1.48, 95% CI: 1.09-1.96).
- The risk was significantly higher for individuals diagnosed at age 70 or older (HR = 5.08, 95% CI: 1.69-15.22), with no clear preference for second cancer type based on primary NET site.
Conclusions:
- The risk of developing a second cancer following a neuroendocrine tumor (NET) diagnosis is significantly increased.
- Older patients, particularly those aged 70 and above at NET diagnosis, face a substantially higher risk.
- Close surveillance for secondary malignancies in NET survivors is crucial.
