What is stomach cancer?
Stomach cancer develops when cells in any part of the stomach grow
and divide in an abnormal way. Tumours can begin anywhere in the
stomach, although most start in the stomach’s inner layer (mucosa). This
type of cancer is called adenocarcinoma of the stomach (also known as
gastric cancer). If it is not found and treated early, stomach cancer
can spread to nearby lymph nodes or to other parts of the body, such as
the liver and lungs as a secondary or metastatic cancer. It may also
spread to the lining of the wall of the abdomen (peritoneum). Rarely, it
can grow through the stomach wall into nearby organs such as the
pancreas and bowel.
You can access further information about stomach cancer, including
risk factors, symptoms, diagnosis and treatment from
Cancer
Council Victoria. You can also
call
our trusted cancer nurses on 13 11 20 for support and to learn about
our range of services for people affected by cancer.
The Victorian Cancer Registry also operates an interactive web
portal,
Data
Explorer, which provides more trends and statistics than published
here.
How common is stomach cancer?
In 2023, 851 Victorians were diagnosed with stomach cancer. Of these,
there were 516 males and 335 females, representing 60.6% and 39.4% of
the total Victorian stomach cancer diagnoses, respectively. Currently,
stomach cancer is diagnosed at a rate of 13.1 per 100,000 males and 7.7
per 100,000 females. The median age at diagnosis of stomach cancer is 70
years in males and 73 in females (Figure 1 & 2). Accounting for 2.2%
of all cancers diagnosed and 3.5% of all cancer-related deaths in 2023,
stomach cancer was the 11th most commonly diagnosed cancer and the 7th
most common cause of cancer-related deaths in Victoria.
Trends in stomach cancer over time
Figure 3a shows for males between 2017 to 2023 the age standardised
incidence rate of stomach cancer increased by an average of 1.3% per
year. However this result was not statistically significant, meaning the
change cannot be confidently considered real and may be due to random
fluctuations.
For females between 2020 to 2023 the age standardised incidence rate
of stomach cancer increased by an average of 11.2% per year.
Stomach cancer morphology
Figure 4 provides a summary of the different types of cells
(morphology) which have caused stomach cancers among all cases. Most
stomach cancer tumours, 80.3%, present as adenocarcinoma tumours.
Geographical variance in stomach cancer by local government
area
Figure 5 demonstrates variation in age-standardised incidence rates
of stomach cancer, by local government areas. Darker shading indicates
areas with higher rates of stomach cancer.
Stomach cancer in people born overseas
Figure 6 shows the age standardised incidence rates of stomach
cancers in Australian-born Victorians compared to other major migrant
groups, over the five-year period 2018 to 2022. The highest age
standardised incidence rate for stomach cancers was 18.2 for males born
in the Southern Europe region and the lowest rate of 1.7 was observed in
males born in the North America region. The highest age standardised
incidence rate of stomach cancers was 13.9 for females born in the South
and Central America region and the lowest rate of 2.4 was observed in
females born in the North America region.
Stomach cancer five-year relative survival
Figure 7 shows the change in 5-year survival for stomach cancer, and
the 5-year survival trend for all cancers over the same time period. It
demonstrates that five-year relative survival has increased for stomach
cancer between 1983-1987 and 2018-2022 from 19% to 37%.