Most people have probably heard of different stages of cancer, especially if you know anyone who’s dealt with the disease. The system that’s likely familiar for many is on a scale of 0 to IV, and it’s simple to intuit that a higher number generally refers to cancer which is more advanced. Outside that, the number probably doesn’t mean much to you. To doctors, though, it means a lot.

 If a person notices symptoms that may point to cancer, or has a regular examination that does, their doctor needs to figure out if what they’re experiencing is really due to cancer. According to the American Cancer Society, even the symptom which most viscerally indicates cancer in the public consciousness—a lump—may not always be caused by cancer. They say, “In fact, most tumors are not cancer.”

To make a diagnosis, a doctor generally has three options. Some or all may be used.

The first is imaging tests such as x rays, ct scans, MRIs, PET scans, or ultrasounds, all of which can be used to find various kinds of abnormal tissue.

The second is lab tests of bodily fluids like urine or blood. Some kinds of cancer can elevate the levels of chemicals naturally present in the body. Utah native and Olympian Jake Gibb was famously suspended from play by U.S. anti-doping officials a year before the 2012 London Olympics. During routine drug testing, they found elevated blood levels of two specific hormones which often indicate steroid use. Gibb had never done steroids, so he searched for other possible explanations. The real cause: testicular cancer.

To confirm the diagnosis Gibb’s doctors performed a biopsy, which is the final diagnostic method. Usually a small needle or endoscope are used to remove part of a suspected tumor. The doctor can then inspect it under a microscope and decide whether it indicates cancer. Regular cells tend to look very different than those that are cancerous. In other cases, a doctor may schedule a patient for surgery to remove a tumor and biopsy it after its removal.

It’s only after a diagnosis that cancer is staged. Staging is used as a short-hand way to communicate the extent of cancer—it’s size and spread. These factors have implications for treatment and how serious the disease is.

The most common staging system is the TNM system. Each letter is listed with either an X or a number after it to describe the characteristics of a person’s cancer: T describes the size of the main tumor, N describes whether the cancer has spread to nearby lymph nodes, and M describes whether the cancer has spread to distant areas.

So, if a cancer is staged as T1N0MX, that means doctors have found a small tumor which hasn’t spread to nearby lymph nodes, and they can’t measure whether it’s metastasized to distant parts of the patient’s body. If a cancer were staged at T3N1M0, that would mean a patient has a relatively large tumor which has spread to nearby lymph nodes but hasn’t metastasized.

The staging system likely familiar to most people is derived from the TNM system, with different stages grouped into less detailed categories for ease of communication.

Sources:

“Cancer Staging.”American Cancer Society, www.cancer.org/treatment/understanding-your-diagnosis/staging.html.

“Diagnosis.”National Cancer Institute, National Institutes of Health, 3 Mar. 2015, www.cancer.gov/about-cancer/diagnosis-staging/diagnosis.

Donaldson, Amy. “Bountiful native Jake Gibb meets challenges with confidence, positivity, leading him to third Olympic games.”Deseret News, 1 Aug. 2016, www.deseretnews.com/article/865659161/Bountiful-native-Jake-Gibb-meets-challenges-with-confidence-positivity-leading-him-to-third.html.

“Staging.”National Cancer Institute, National Institutes of Health, www.cancer.gov/about-cancer/diagnosis-staging/staging.