The incidence and risk of second primary cancers in patients with nasopharyngeal carcinoma: a population-based study in Taiwan over a 25-year period (1979-2003).
BACKGROUND
Very few reports are available on the incidence and risk of second primary cancers in nasopharyngeal carcinoma (NPC) cases, and most of these are single-institution reviews with relatively small case numbers and short follow-up.


METHODS
A population-based study was conducted. We quantified standardized incidence ratios (SIRs) and cumulative incidence of second cancers among 23 639 individuals with initial diagnoses of NPC.


RESULTS
We found a 24% increased risk of second cancers in NPC patients compared with the general population [SIR = 1.24, 95% confidence interval 1.15-1.33]. Elevated SIRs were observed in the following second primary cancers: oral/pharyngeal, salivary gland, sarcoma, skin and leukemia/lymphoma. The cumulative incidence >10 years was 3.26%. The risk was higher in younger patients, especially those <40 years old. After diagnosis of second cancers, the median survival time was 1.7 years.


CONCLUSIONS
This is the largest population-based study to date from a high-incidence area. We found that NPC is associated with an increased risk of second malignancies, which had a negative impact on the survival of patients who survived NPC.
Chen
M-C
MC
Department of Public Health and Biostatistics Consulting Center, School of Medicine, Chang Gung University, Tao-Yuan, Taiwan.
Feng
I-J
IJ
Lu
C-H
CH
Chen
C-C
CC
Lin
J-T
JT
Huang
S-H
SH
Lee
K-D
KD
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000453:epidemiology*; D016609:Neoplasms, Second Primary / Q000453:epidemiology*; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology