An intake of your medical history and a physical examination will help tell your doctor if diagnostic tests are needed to confirm a diagnosis of lung cancer. Taking your medical history gives the doctor an idea of your health based on past medical events, risk factors and existing symptoms [11].
The physical examination allows the doctor to look for any signs of lung cancer. Your doctor may check your breathing, feel the neck and area for swelling or enlarged lymph nodes, feel the abdomen for an enlarged liver or lump, check your blood pressure and pulse and listen to the heart [12].
Diagnostic tests are used when symptoms of lung cancer are present or the physician suspects lung cancer after taking the medical history and performing a physical exam of the patient [13]. Many of the same tests used to diagnosis lung cancer are also used to determine how far the cancer has progressed (this is called staging).
Screening procedures
Your physician may order a follow-up chest x-ray to look for anything abnormal in your lungs such as spots, tumours or other changes. It is often the first test done to diagnose lung cancer. Alternatively, a CT scan (computed tomography scan) may be used to find an early stage lung tumour if it not visible on a chest x-ray. Or a PET scan (positron emission tomography) scan may be used to find out if the lung cancer has spread to the lymph nodes or other parts of the chest [14].
Biopsies
If lung cancer is suspected as a result of a screening procedure (CT, MRI or PET scan), a small piece of tissue from the lung must be examined under a microscope to look for cancer cells. Called a biopsy, this procedure can be performed in different ways. In some cases, the doctor passes a needle through the skin into the lungs to remove a small piece of tissue; this procedure is often called a needle biopsy [15].
In other cases, a biopsy may be done during a bronchoscopy. With the patient under sedation, the physician inserts a small tube through the mouth or nose and into the lungs. The tube, which has a light, small camera and a surgical instrument on the end, allows the doctor to see inside the lung and remove a small tissue sample [16].
If cancer cells are found in the tissue sample, a genetic test may be performed. The information obtained from the test can help doctors choose the best treatment. It also helps discern the characteristics of the lung cancer such as the tumour type and how far it has advanced.
To find out more about specific kinds of biopsies, please visit Cancer Research UK.
[17] Information taken from lungcancer.org
A wide of tests are used to stage the lung cancer, the type of tumour present, genetic changes in the genes of cells, the overall health of the hearts and lungs and so on. To find out more about these types of tests, please visit the Canadian Cancer Society.
Grading and staging of lung cancer
Grading analyses cancer cells based on their appearance and behaviour when examined underneath a microscope. A grade is assigned to a tumour based on how the cells appear and behave when compared to normal cells (differentiation) [18]. This gives an idea of how quickly the cancer is growing and whether or not it will spread. The chart below shows the grades for NSCLC:
[19] Grades of Non–small Cell Lung Cancer
Staging
Staging is used to determine the spread of the cancer and is based on whether or not the cancer is only in the lungs or has spread to the lymph nodes and/or other organs. It can often take time to find the tumours because the lungs are large. Symptoms are often misdiagnosed and, for this reason, early stage lung cancers are more challenging to detect [20].
There are different staging systems used for lung cancer called the number system and the TNM staging system. The staging systems can be complicated and a patient will most likely be told the numbered stage of the cancer. The TNM staging system is more complex, as it takes into account several different factors such as [21]:
- The size of the tumour (T)
- Whether cancer cells have spread into the lymph nodes close to the cancer (N)
- And whether the tumour has spread anywhere else in the body (M)
Both the numbered and TNM systems are used for NSCLC and SCLC, but the most common system for NSCLC is the TNM system. The Union for International Cancer Control (UICC) uses the TNM system to describe the extent of many solid tumour cancers.
To find out more about TNM staging, please visit the Canadian Cancer Society
Numbered stages of lung cancer
Stage I: The cancer is located only in the lungs and has not spread to any lymph nodes.
Stage II: The cancer is in the lung and nearby lymph nodes.
[23-24] Stage 2A-B lung cancer
[25] Stage 2B lung cancer
Stage III: Cancer is found in the lung and in the lymph nodes in the middle of the chest, also described as locally advanced disease. Stage III has two subtypes:
- If the cancer has spread only to lymph nodes on the same side of the chest where the cancer started, it is called stage IIIA.
[26-28] Stage 3A lung cancer
- If the cancer has spread to the lymph nodes on the opposite side of the chest, or above the collar bone, it is called stage IIIB.
Simple staging for small cell lung cancer
Limited stage: In this stage, cancer is found on one side of the chest, involving just one part of the lung and nearby lymph nodes.
Extensive stage: In this stage, cancer has spread to other regions of the chest or other parts of the body.
The American Joint Commission on Cancer implemented a more detailed staging system in which the stages of small cell lung cancer are described using Roman numerals and letters (for example, Stage IIA). This is the same method that is used for non-small cell lung cancer in describing the growth and spread of the cancer [31].
To find out more information about staging, please visit Cancer Research UK
References
[11] Diagnosing Lung Cancer.” Canadian Cancer Society. Canadian Cancer Society, 2016. Web. 01 June 2016.
[12] ibid.
[13] ibid.
[14] “Tests for Non-small Cell Lung Cancer.” American Cancer Society. American Cancer Society, 16 May 2016. Web. 01 June 2016.
[15] ibid.
[16] “Lung Cancer Tests.” Cancer Research UK. Cancer Research UK, 4 Feb. 2015. Web. 01 June 2016.
[17] “Diagnosing Lung Cancer.” Lung Cancer 101. Lungcancer.org, 16 May 2016. Web. 01 June 2016.
[18] “Grades of Non–small Cell Lung Cancer.” Canadian Cancer Society. Canadian Cancer Society, 2016. Web. 01 June 2016.
[19] Grades of Non–small Cell Lung Cancer. Digital image. Canadian Cancer Society. Canadian Cancer Society, 2016. Web. 01 June 2016.
[20] “Tests for Non-small Cell Lung Cancer.” American Cancer Society. American Cancer Society, 16 May 2016. Web. 01 June 2016.
[21] “Lung Cancer Stages.” Cancer Research UK. Cancer Research UK, 26 Mar. 2014. Web. 01 June 2016.
[22] Stage 1A-B lung cancer. Digital image. Number Stages of Lung Cancer. Cancer Research UK, 26 Mar. 2014. Web. 1 June 2016.
[23] Stage 2A lung cancer. Digital image. Number Stages of Lung Cancer. Cancer Research UK, 26 Mar. 2014. Web. 1 June 2016.
[24] ibid.
[25] Stage 2B lung cancer. Digital image. Number Stages of Lung Cancer. Cancer Research UK, 26 Mar. 2014. Web. 1 June 2016.
[25] Stage 2B lung cancer. Digital image. Number Stages of Lung Cancer. Cancer Research UK, 26 Mar. 2014. Web. 1 June 2016.
[26] Stage 3A lung cancer. Digital image. Number Stages of Lung Cancer. Cancer Research UK, 26 Mar. 2014. Web. 1 June 2016.
[27] ibid.
[28] ibid.
[29] Stage 3B lung cancer. Digital image. Number Stages of Lung Cancer. Cancer Research UK, 26 Mar. 2014. Web. 1 June 2016.
[30] Stage 4 lung cancer. Digital image. Number Stages of Lung Cancer. Cancer Research UK, 26 Mar. 2014. Web. 1 June 2016.
[31] “More about Staging for Lung Cancer.” Cancer Research UK. Cancer Research UK, 26 Mar. 2016. Web. 01 June 2016.