PDFs by language
Our 24/7 cancer helpline provides support for people dealing with cancer. We can connect you with trained cancer information specialists who will answer questions about a cancer diagnosis and provide guidance and a compassionate ear.
Chat live online
Select the Live Chat button at the bottom of the page
At our National Cancer Information Center trained Cancer Information Specialists can answer questions 24 hours a day, every day of the year to empower you with accurate, up-to-date information to help you make educated health decisions. We connect patients, caregivers, and family members with valuable services and resources.
Or ask us how you can get involved and support the fight against cancer. Some of the topics we can assist with include:
For medical questions, we encourage you to review our information with your doctor.
Cancer is nearly always diagnosed by an expert who has looked at cell or tissue samples under a microscope. In some cases, tests done on the cells’ proteins, DNA, and RNA can help tell doctors if there’s cancer. These test results are very important when choosing the best treatment options.
Tests of cells and tissues can find many other kinds of diseases, too. For instance, if doctors are not sure a lump is cancer, they may take out a small piece of it and have it tested for cancer and for infections or other problems that can cause growths that may look like cancer.
Lumps that could be cancer might be found by imaging tests or felt as lumps during a physical exam, but they still must be sampled and looked at under a microscope to find out what they really are. Not all lumps are cancer. In fact, most tumors are not cancer.
The American Cancer Society medical and editorial content team
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.
Last Revised: July 30, 2015
American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.