How Long Does It Take To Diagnose Lung Cancer

What is Lung Cancer?

Lung cancer is a growth of malignant cells in the lungs.

You see, throughout your life the cells in your body continually divide and reproduce. Believe it or not, every minute of your life this process takes place ten million times. Think about it … ten million times a minute! Not only is that incredible, it’s a demonstration of how complex your body really is.

Now, for the most part, this all takes place in an orderly manner as your cells go about doing their job of meeting the needs of your body. Occasionally, however, a cellular mutation will occur and rather than maturing and dying as it was intended to do, a cell continues reproducing. This is cancer … the uncontrolled reproduction and growth of abnormal cells in the body.

Lung cancer is the growth of these malignant cells in the lungs.

Most often, the malignant cells are believed to form in the epithelial lining of the airways, where the oxygen is extracted from the air we breathe. This is why lung cancer is sometimes referred to as bronchogenic carcinoma (cancer arising from the bronchia). A relatively small percentage of lung cancer (10% or less) begins in the pleura, the thin tissue sac that surrounds the lungs. These cancers are called mesothelioma. The most common form of mesothelioma is linked to exposure to asbestos. The rarest form of begins in the blood vessels or other supporting tissues of the lungs.

How long does lung cancer take to develop?

The time taken for lung cancer to develop is variable. It takes several years for cancer to develop in the lungs. Early lung cancer does not alert obvious physical changes. Moreover, patients can live with lung cancer for many years before they show any signs or symptoms. 

For example, it takes around eight years for a type of lung cancer known as squamous cell carcinoma to reach a size of 30 mm when it is most commonly diagnosed.

Signs and Symptoms

In many cases, symptoms do not appear until the cancer is at its peak stage. However, by the time a tumor does cause changes within the lungs.
Signs are:

  • Coughing with blood in sputum;
  • Chest, arm or shoulder pain;
  • Loss of appetite;
  • Weight loss;
  • Recurring pneumonia ;
  • SOB (shortness of breath);
  • Bone pain;
  • Hoarseness;
  • Fatigue;
  • Swelling of neck or face;
  • Headaches.

Types of Lung Cancer

There are two main types – small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).

SCLC is the less common of the two, which is good, because it’s also the more deadly. Less than one percent of SCLC is diagnosed in non-smokers. This means that smoking is the primary culprit behind this type of lung cancer. SCLC is aggressive and fast-moving. It rapidly metastasizes to other organs, and is often not discovered until the cancer is already widespread throughout the body.

Non-small cell lung cancer accounts for approximately 80% of diagnosed lung cancer cases. Within this category, there are three main sub-categories … squamous cell cancer, adenocarcinomas, and large cell carcinomas. Sometimes two or even all three can appear together.

Finally, there are some less common types such as bronchial carcinoids (small tumors that are most often found in people under 40 years of age). These tend to be less aggressive, grow slowly, and often can be effectively treated.

What produces a lung cancer diagnosis? 

The physician evaluates a person’s medical history, smoking history, exposure to environmental and occupational substances, and family history of cancer as well as a physical examination and chest X-ray to find the cause of the symptoms. Other tests may also be performed as needed.

Patient’s history – If the doctor suspects lung cancer, they will: Investigate your medical history; Perform a thorough physical examination; Order further specialized medical tests. As part of your medical history, your doctor will ask: If you smoke or have smoked previously; Your occupation and

place of work; If you have been exposed to occupational hazardous substances or radiation; Whether you have a family history of lung cancer.

Diagnosing Lung Cancer

Screening helps to discover cancer at an earlier stage when it is treatable by a series of tests performed before a person shows any symptoms. Early detection of abnormal tissue or cancer proves favorable of curing the cancer completely as opposed to detection during symptoms when the cancer might have spread.

There are several ways of diagnosing if someone is in the early stages of lung cancer. A physical examination and history taking: A physical examination checking for general signs of health or ill health such as disease and unusual lumps, bumps and anything else that seems atypical. The doctor will also get the history of personal health habits, any past illnesses and treatments given for those illnesses.

Laboratory tests

Procedures for testing samples of tissue, blood, urine, and other substances in the body. The tests will also help to diagnose the disease as well as assist in the planning, management and monitoring of it.

Sputum test

This can show evidence of cancer cells in the lungs. To ensure a more accurate diagnosis with a single sputum collection, the sputum is usually collected over a three-day period.

Fiberoptic bronchoscopy

An examination using a small flexible lighted tube to pass into the nasal canal and then into the appropriate bronchus (airway) down to the cancer. If cancer is detected then a small piece of the cancer is removed for a biopsy examination so the exact type of cancer can be determined and appropriate treatment given.

Percutaneous needle biopsy

This examination involves inserting a thin needle through the skin and chest wall into the tumor. This test is for tumors that are close to the surface of the lung and often used in conjunction with a CAT scan to assists in guiding the needle into the tumor.

Excision or surgical removal

This process can lead to further diagnosis of the suspected tumor via a small incision into the chest. A small thin video camera is inserted into the chest to assist in removing a small block of lung tissue using a mechanical surgical stapling device or laser with this clinical procedure.


This test helps evaluate how extensive the tumor is by looking into the mid portion of the chest through a small incision made just below the collar line. Samples are taken from the lymph nodes in the central part of the chest (mediastinum). The chance of surgically curing the lung cancer is automatically eliminated if the cancer has spread to the lymph nodes.


Unlike mediastinoscopy, the chest cavity is opened by cutting through the sternum (breastbone) and/or the ribs allowing the surgeon to reach and test more lymph nodes by removing samples of mediastinal lymph nodes. This is a complex test, and the patient has to undergo general anaesthesia.


A sample of fluid surrounding the lungs is taken using a needle to check for cancer cells.


To test for malignancy the chest wall has to be opened so this procedure is performed in hospital as a major operation.


A procedure using a thin, lighted tube connected to a video camera to monitor and view the space between the lungs and the chest wall.

Bone marrow biopsy

With a needle a sample of bone is removed usually measuring about 1/16 inch across and 1 inch long. This is often taken from the back of the hip bone. Microscopically the sample is checked for cancer cells. This procedure is performed predominantly to diagnose small cell lung cancer.

Blood tests

A complete blood test checks for an accurate number of different cell types by showing whether you have anaemia or other related problems. Blood chemistry tests show abnormalities in organs and other parts of the body. Blood tests are repeated regularly especially if someone is undergoing chemotherapy treatment. Chemotherapy drugs affect the blood-forming cells of the bone marrow and sometimes cause lots of problematic side effects. If cancer has spread to the liver and bones, it might cause certain chemical abnormalities in the blood and exacerbate any problems already suffered by the patient.

Other Tests and Procedures to Detect Lung Cancer Include:

Chest x-ray: Chest x-rays account for about half of all x-rays obtained in hospitals. The x-rays are typically performed to obtain an assessment of the lungs, heart and chest wall. A chest x-ray is the first test a physician will order to look for any tumor or spots on the lungs. If it is normal there is a high probably there is no lung cancer, but if anything suspicious is spotted, the doctor will order further tests. Pneumonia, heart failure, emphysema, other medical conditions, and lung cancer can all be located with a chest x-ray.

CT Scanning or Computed Tomography also known as CT or CAT Scan: This equipment is to obtain multiple cross-sectional images of organs and tissues of the body. A CAT scan is especially useful for diagnosing tumors as it is far more detailed than a conventional chest x-ray. It shows different types of body tissue including the lungs, heart, bones, soft tissues, muscle, and blood vessels at the same time.

Modern CT scans capture images of the chest from many different angles using a method called spiral (or helical) CT. With the assistance of a computer, it processes the images to create cross-sectional pictures or “slices” of the area causing concern. The images can then be printed out or examined on a monitor. To achieve a better picture, after the first set of scans are taken an intravenous injection of a radio-contrast agent is administered to help outline the structures within the body. A second set of pictures is then taken so they can be examined together.

Information on the size, shape, and position of a tumor are provided by the CT scan. This helps discover any enlarged lymph nodes, which could contain cancer, which has spread from the lung. When looking for early lung cancers and to ensure patients receive the treatment they need as soon as possible, CT scans are much more sensitive than an ordinary routine chest x-ray. In looking for tumors in the adrenal glands, brain, and other internal organs usually affected by lung cancer spread a CT scan is also useful.

Magnetic resonance imaging (MRI): MRI scans use radio waves and strong magnets instead of x-rays. The energy released from the radio waves is absorbed and re-released in a pattern shaped by the type of tissue and the disease being investigated.

A pattern of radio waves is given by the tissues and organs forming very detailed images of the parts of the body using a very sophisticated computer. This can also produce slices parallel with the length of the body just as a CT scanner produces cross sectional slices of the body.

Positron emission tomography (PET): This scan uses glucose, which is a form of sugar containing a radioactive atom. Large amounts of radioactive sugar are absorbed by the cancer cells and a special camera is then able to detect the radioactivity.

To discover if someone is suffering from early stage lung cancer a PET scan is a very useful test. It is often used to discover if the cancer has spread to the lymph nodes. PET scans are valuable in ascertaining whether a shadow on a chest x-ray is cancer or not. PET scans are also helpful when a doctor thinks the cancer has spread, but isn’t sure where the spread may be.

Because PET scans scan your whole body sometime they are used instead of several different x-rays. Bone scans: A radioactive substance (usually technetium diphosphonate) is injected into a vein. The radioactive substance builds up in bone areas suspected of having cancer metastasis, (spread). Due to the small amount of radioactivity used this does not cause any long-term effects.

Bone scan results need to be read in conjunction with results of other tests performed as other bone diseases can also cause abnormal scan results. Bone scans are usually performed on patients with small cell lung cancer and also in non-small cell lung cancer patients when other test results or symptoms suggest the cancer has spread to the bones – lung cancer diagnosis.

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