What the different stages of cancer mean

A woman undergoes breast cancer screening in Kampala. As part of the NMG annual cancer awareness campaign, some hospitals are offering free or subsidised cancer screening services. FILE PHOTO

What you need to know:

Unaware. We have heard about stages of cancer once diagnosis is done. However, not many of us know what these stages mean or the basis on which they are done. As such, we are not sure of what to expect or what to do when we get the news. Dr Noleb Mugisha, the head of comprehensive community cancer programme at the Uganda Cancer Institute (UCI), shares about this and more.

For close to three years, Maggie Lwantale had a lump in her left breast that all ultrasound scans showed was nothing to worry about.
However, when she started experiencing sharp pain, coupled with darkening of her areola and a discharge, her gynaecologist sent her for a test.
“From a calm face, to a somewhat worried one, the look on the radiographer got me worried. From then on, everything moved at a fast-paced manner until I was sitting in the doctor’s office alongside an oncologist. ‘Maggie, I am sorry, but you have Stage Two cancer,” the gynaecologist told her.

“I am not certain I remember what he said thereafter, but my mind whirled in a series of thoughts and lamentations that it took a rather hard nudge to get me back to the room. The days that followed felt like I was preparing for someone’s funeral inasmuch as the team that was working on me assured me that my case was manageable,” she says.
“Staging is used to classify a cancer to its extent; how much and how far the cancer has grown, the body parts which it has invaded and the size of tumour for cancer which form swellings. While the general staging is 1-4, it is for simplicity because some cancers are staged differently,” Dr Noleb Mugisha, the head of comprehensive community cancer programme at the Uganda Cancer Institute, says.

Staging is not meant to scare off people but rather help the cancer care team to come up with a treatment plan, predict chances of recovery, and make predictions on how well the treatment plan will work. More to that, seeing that most cancer treatment is got through research, staging helps doctors to create groups to ease studying, as well as clinical trials.

How stages are got
Before a cancer is classified or given a stage, in addition to physical examination, Dr Mugisha says an oncologist will have to carry out different tests which may include ultra sound scanning, X-rays, blood tests and others, depending on the cancer.

Staging systems
“As earlier stated, different cancers are staged differently hence different staging systems. The most commonly used worldwide is the TNM (tumour, lymphnode, metastasis) system and it is ideal for staging most solid tumour cancers such as breast cancer. That said, there are other systems used to stage other solid tumour cancers, as well as blood cancers,” he says.
With TNM system, the doctor will have to answer some questions with the help of staging investigation results.

These questions include: How large the main tumour (T) is and has the tumour spread to the lymphnodes (N)? If yes, where and to what extent?
Also, have the cancer cells spread to other body parts (M)? If yes, where and to what extent?
Is there presence of bio or tumour markers linked to the cancer that may make monitoring of the cancer progression or response to treatment easier? These are substances found in the urine or blood of a patient suffering from cancer that only increase when one has the particular cancer type.

What TNM means
T (tumour) - describes the size of the main tumour. T usually has a number from one to four and the higher the number, the bigger the tumour, and sometimes the deeper into the organ or nearby tissue it has grown.
N (lymphnode) - helps to show if the cancer has spread to surrounding lymph nodes. It has numbers from zero to three, where N0 means the cancerous cells have not yet gone to any of the lymph nodes. The numbering also shows the size and location of the lymphnodes.
M (metastasis) - helps to show if the cancer has gone to any other body part through the blood and it has numbering such as M0 where there is no spread, while M1 means spread to other body parts.

Other staging factors
Apart from the factors above, there are other factors that are considered when staging cancers. These include:
• Grade: This is the appearance of the cancerous cells under a microscope. For example, they could be low grade if they look more like normal cells, they are high grade when they look totally abnormal. That said, while high grade cancer cells grow and spread very fast, low grade cancer cells are slower in growth and spread.
• Location: the location of the tumour may either make it harder or easier to deal with.

• Genetics: The DNA changes in the cancer cells will help the doctor know if it will spread easily, as well as the ideal treatment plan.
With all these ascertained, then staging can be done.
Staging might also be pathologic, as well as clinical.
• Pathologic stage: It is on the basis of results from tests and exams on finding the cancer, as well as what the doctors learn about the cancer during and after surgery. It is more informative compared to clinical staging.

• Clinical stage: It is given before treatment commences based on imaging test results at the time of diagnosis. While it is less informative, doctors use it to choose a treatment plan.
That said, Dr Mugisha says the two stages can give a different picture. “For example, surgery may unearth something that an MRI test missed, hence the result from the pathologic stage may be a higher stage than was presented by the clinical stage.”

Stage grouping
Dr Mugisha shares that the TNM description is ideally the general way of grouping as it assigns numbers between zero and four.
“However, sometimes, these stages are subdivided using letters – A, B, C as is seen in cervical cancer which is staged as stage 1, stage 2A, stage 2B, stage 2C, stage 3 and stage 4,” he says.

That said, on a whole, stage 0 shows a precancerous change, stage 1 shows that the tumour is usually small and has not grown outside of the organ it started in, stages 2 and 3 show that the tumour is larger or has grown outside of the organ it started in to nearby tissue. However, for cervical cancer, while stage 2A is early, stage 2B and C are late.
Stage 4 means the cancer has spread through the blood stream to other parts of the body.

Other systems

Number. Apart from TMN, there are several other systems used to stage cancers and these include:
• International Federation of Gynaecology and Obstetrics (FIGO) staging system: It is used for ovarian, endometrial, cervical, vaginal and vulvar cancers. This stage, though for reproductive organ cancers, gets its precedence from the TNM system.
• Ann Arbor Staging System: It is used when staging Non-Hodgkin lymphoma.

• Cotswold staging system: It is used to stage Hodgkin lymphoma.
• Rai and Binet staging systems: These are used to stage chronic lymphocytic leukaemia (CLL).
• International and the Durie-Salmon staging systems: They are used to stage multiple myeloma.

However, these systems are not exhaustive as several cancers are staged differently using different systems. “It is also important to note that cancer stages never change. For example, if one is diagnosed with stage 2 cancer and gets treatment of the same but it reoccurs, even when it spreads to other parts, it will still be considered stage 2 cancer but metastatic,” Dr Mugisha asserts that the none-changing factor is because the stage of diagnosis is used in cancer research to look at survival rates, as well as find out more about treatment for that stage.

Restaging: That said, there is restaging. “It does not mean that stage 2 cancer becomes stage 3 cancer but when it reoccurs or advances, it helps oncologists plan better for the new development. While the stage will never change, if the tumour gets bigger or spreads more, it will say, move from T1 to T2.”
In all this, Dr Mugisha emphasises that the earlier the diagnosis, the better for longer survival.