Increased survival rates in gastric cancer, with a narrowing
gender gap and widening socioeconomic status gap: A period
analysis from 1984 to 2013
Yifeng Liao,* Shuncong Wang,*
and Haiqing Ma*
Departments of *Oncology,
Gastrointestinal Surgery, The Fifth Afﬁliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, and
Gastroenterology, Cancer Hospital of Jiangxi Province, Nanchang, Jiangxi, China
gastric cancer, gastric cancer incidence, race,
socioeconomic status, survival rate.
Accepted for publication 10 October 2017.
Haiqing Ma, Department of Oncology, The Fifth
Afﬁliated Hospital of Sun Yat-Sen University,
Zhuhai, Guangdong 519000, China.
Yonghui Su, Department of Gastrointestinal Sur-
gery, The Fifth Afﬁliated Hospital of Sun Yat-Sen
University, Zhuhai, Guangdong 519000, China
Declaration of conflict of interest: The authors
declare no conﬂictofinterest.
These authors have contributed equally to this work.
Background and Aim: Gastric cancer (GC) has the ﬁfth highest incidence rate of all
cancers and has a poor prognosis. However, no recent large-scale and long-term studies
have evaluated the incidence and survival rates of individuals with GC.
Methods: In order to explore the change of GC incidence and survival rates by age,
gender, race, and socioeconomic status (SES), incidence data and survival status of patients
with GC between 1984 and 2013 were abstracted from the Surveillance, Epidemiology,
and End Results database. Totally, 87 242 cases of GC were exported and were analyzed.
Results: During these three decades, the incidence of GC was 7.4, 6.8, and 5.5 per 100 000
individuals in each decade. The 1-year relative survival rates (RSRs) improved from 42.4%
to 44.3% to 49.0% (P < 0.0001), with a larger increase seen in the third decade. However,
the long-term survival rates remained low (from 17.8% to 20.3% to 22.9% for the 5-year
RSRs, P < 0.0001; from 14.1% to 16.4% to 18.6% for the 10-year RSRs, P < 0.0001).
Conclusion: Our analysis demonstrated the decreased incidence and increased survival
rate of GC. In addition, lower SES was associated with lower survival rates. It is notable
that others (primarily for Asians) had the highest incidence rate but had better outcomes
than Whites and Blacks.
Both the morbidity and mortality of gastric cancer (GC) are higher
in developing countries than in developed countries.
GC is also
associated with a low long-term survival rate and is the third
leading cause of cancer-related death worldwide.
Because of the
lack of widespread screening, many patients, especially those in
lower socioeconomic regions, are diagnosed with advanced GC.
According to estimates, approximately 990 000 people worldwide
are diagnosed with GC each year, and approximately 738 000
die from the disease.
The 5-year survival rate is still dismal in
the USA, whereas the incidence of GC has been on the decline.
Increased attention has been focused on different races and
socioeconomic status (SES) levels, not only because of their effect
on the appearance and development of GC but also because of the
increasing evidence of their inﬂuence on various aspects of the
healthcare system of the USA.
However, no recent studies
with a large number of patients have reported the incidence and
survival rates of GC, as analyzed by age, sex, SES, and race over
a long follow-up period. Hence, our study used a period analysis to
assess the relative survival rates (RSRs) of patients with GC from
the Surveillance, Epidemiology, and End Results (SEER) program
of the National Cancer Institute who were categorized according
to age, sex, SES, and race.
Data from the Surveillance, Epidemiology, and End
Results database. All data of GC patients between 1984 and
2013 were obtained from the SEER program (SEER, version
8.3.2) of the National Cancer Institute of the United States. In
our study, the incidence data from patients registered at the
original nine SEER sites were retrieved, and survival data were
obtained from 18 registries. The location of the registries and the
ﬂowchart of our study were showed in Figure S1. And the
Table S1 showed the main characteristics of the sample selected.
Categorization of gastric cancer cases over three
decades. According to the criteria established by the World
Health Organization’s International Classiﬁcation of Oncology,
we obtained the data of GC patients in the SEER registries. Gastric
carcinoma was classiﬁed into the diffuse type and the intestinal
type. The diffuse type includes diffuse carcinoma (M8145), linitis
plastica (M8142), and signet ring cell carcinoma (M8490); the
intestinal type includes carcinoma, not otherwise speciﬁed
(M8010), adenocarcinoma, not otherwise speciﬁed (M8140), and
the intestinal (M8144) and tubular (M8211) types. We analyzed
GC patients who were diagnosed throughout three decades, from
Journal of Gastroenterology and Hepatology 33 (2018) 837–846
© 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd