If you are asking about yourself, stomach cancer
would be exceedingly rare at age 23.
Stomach cancers in the us have dropped off significantly since the 1930's. It is more common in other countries such as japan. It is not in the top 10 cancers in the us. Only 8-16 people in 100, 000 get it in us. Five year survival has increased from 15% to 27% in past 30 years. About 10, 000 die of it in us yearly.