Table of Contents Table of Contents
Previous Page  10-11 / 92 Next Page
Information
Show Menu
Previous Page 10-11 / 92 Next Page
Page Background

8

9

NCCN Guidelines for Patients

®

Stomach Cancer, Version 1.2016

NCCN Guidelines for Patients

®

Stomach Cancer, Version 1.2016

1 Stomach cancer basics

Cancer's threat

Cancer’s threat

Cancer cells don’t behave like normal cells in three

key ways. First, mutations in genes cause cells to

grow more quickly and live longer. Normal cells grow

and then divide to form new cells when needed. They

also die when old or damaged as shown in

Figure 3

.

In contrast, cancer cells make new cells that aren’t

needed and don’t die quickly when old or damaged.

Over time, stomach cancer cells form a mass called

the primary tumor.

The second way cancer cells differ from normal

cells is that they can grow into nearby tissues. If not

treated, the primary tumor can extend beyond the

wall of the stomach and into nearby structures. The

nearby structures into which stomach tumors grow

are described in

Part 2 Cancer staging.

Third, unlike normal cells, cancer cells can travel

to other parts of the body. This process is called

metastasis. In this process, cancer cells break away

from the tumor and merge with blood or lymph. Then,

the cancer cells travel in blood or lymph through

vessels to other sites. In other sites, the cancer cells

may form secondary tumors, replace many normal

cells, and cause major health problems.

Illustration Copyright © 2016 Nucleus Medical Media, All rights reserved.

www.nucleusinc.com

1 Stomach cancer basics

A disease of cells

A disease of cells

Cancer is a disease of cells. Inside of cells are coded

instructions for building new cells and controlling

how cells behave. These instructions are called

genes. Genes are a part of DNA (

d

eoxyribo

n

ucleic

a

cid), which is grouped together into bundles called

chromosomes.

See Figure 2

. Abnormal changes

(mutations) in genes cause normal cells to become

cancer cells. Researchers are still trying to learn what

causes genes to mutate and cause cancer.

Almost all stomach cancers are adenocarcinomas.

Adenocarcinomas are cancers of cells that line glands

and, in the case of stomach cancer, make mucus.

Adenocarcinomas of the stomach are the focus of this

book. Visit

NCCN.org/patients

for patient guides of

lymphomas and sarcomas.

There are two major types of stomach

adenocarcinomas. Cells of the intestinal-type stick

together and form tube- and gland-shaped structures.

Cells of the diffuse-type don't stick together and easily

grow into nearby structures.

Many cancers that start in the stomach are treated as

stomach cancers. However, tumors that start in the

top part of the stomach and cross over into the EGJ

(

e

sophago

g

astric

j

unction) are treated as esophageal

cancers. The EGJ is the area between the esophagus

and stomach. Read the

NCCN Guidelines for

Patients: Esophageal Cancer

to learn the treatment

options for these cancers.

Illustration Copyright © 2016 Nucleus Medical Media, All rights reserved.

www.nucleusinc.com

Figure 2.

Genetic material in cells

Most human cells contain the

“blueprint of life”—the plan by

which our bodies are made and

work. The plan is found inside of

chromosomes, which are long

strands of DNA that are tightly

wrapped around proteins. Genes

are small pieces of DNA that

contain instructions for building

new cells and controlling how cells

behave. Humans have about 24,000

genes.

Illustration Copyright © 2016 Nucleus Medical Media, All rights reserved.

www.nucleusinc.com

Figure 3.

Normal cell growth vs.

cancer cell growth

Normal cells increase in number

when they are needed and die

when old or damaged. In contrast,

cancer cells quickly make new

cells and live longer because of

abnormal changes in genes.