Risk of second primary cancer among esophageal cancer patients: a pooled analysis of 13 cancer registries.
BACKGROUND
The objective of this study is to assess the risk of second primary cancers following a first primary esophageal cancer as well as the risk of esophageal cancer as a second primary, following first primary cancers of other sites.


METHODS
The present investigation is a multicenter study of 13 population-based cancer registries in Europe, Australia, Canada, and Singapore. To assess excess occurrence of second cancers after esophageal cancers, we calculated standardized incidence ratios (SIR) by dividing the observed numbers of second cancers by the expected number of cancers calculated from the accumulated person-years and the age-, sex-, calendar period-, and registry-specific first primary cancer incidence rates.


RESULTS
During the study period, 959 cases of second primary cancers occurred after an initial esophageal cancer, resulting in a SIR of 1.15 (95% confidence interval, 1.08-1.22). Second primary stomach cancers were associated with first primary esophageal adenocarcinomas (SIR, 2.13; 95% confidence interval, 1.26-3.37) and second primary cancers of the oral cavity and pharynx (6.68; 5.33-8.26), stomach (1.53; 1.14-2.01), larynx (3.24; 1.88-5.18), lung (1.55; 1.28-1.87), kidney (1.88; 1.18-2.85), and thyroid (2.92; 1.18-6.02) were associated with first primary squamous cell carcinomas of the esophagus. An excess of esophageal cancer as a second primary were observed following first primary cancers of the aerodigestive tract, female breast, cervix, testis, bladder, Hodgkin's lymphoma, and non-Hodgkin lymphoma.


CONCLUSIONS
We observed associations of esophageal cancer with second primary head and neck cancers and lung cancer regardless of years of follow-up, which may suggest that common risk factors play a role in multiple tumor development.
Chuang
Shu-Chun
SC
IARC, Lyon, France.
Hashibe
Mia
M
Scelo
Ghislaine
G
Brewster
David H
DH
Pukkala
Eero
E
Friis
Soren
S
Tracey
Elizabeth
E
Weiderpass
Elisabete
E
Hemminki
Kari
K
Tamaro
Sharon
S
Chia
Kee-Seng
KS
Pompe-Kirn
Vera
V
Kliewer
Erich V
EV
Tonita
Jon M
JM
Martos
Carmen
C
Jonasson
Jon G
JG
Dresler
Carolyn M
CM
Boffetta
Paolo
P
Brennan
Paul
P
D000368:Aged; D004938:Esophageal Neoplasms / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000453:epidemiology*; D012042:Registries; D012306:Risk; D012307:Risk Factors; D015996:Survival Rate