Medical History and Physical Test
If you exhibit symptoms or signs relating to lung cancer, your physician would like to take a look at your medical past to detect risk factors and get to know your symptoms better. The examination is also conducted to scout for lung cancer signs and other medical issues.
If the physical and health exam results indicate you could be diagnosed with lung cancer, further investigatory tests will be carried out. These may comprise of imaging exams or/and acquiring lung tissue biopsies.
Imaging exams employ magnetic fields, X-rays, radioactive substances or sound waves to develop images of your body’s internals. These imaging exams could be conducted for multiple reasons — both after and before lung cancer diagnosis, which includes –
- To help locate a suspicious cancerous spot
- To understand the extent to which the cancer has spread
- To ascertain if the cancer treatment was effective
- To check for any possible cancer signs resurfacing post treatment
A chest x-ray is often the first exam your physician would conduct to find any spots or masses on the lungs. Plain chest x-rays could be performed at hospitals, imaging centers, and also some doctor offices. If there is no issue found in the x-ray, you are probably not a lung cancer patient (although few lung cancers don’t show up on x-rays). If there is something suspicious, more tests could be ordered by your doctor.
Computed Tomography (CT) Scan
A CAT or CT scan is more likely to reveal lung tumors when compared to standard chest x-rays. CT scans could also offer specific data about the lung tumors’ shape, size, and position and help locate lymph nodes that may contain cancer and have branched out from the lung. The particular test is also employed for detecting masses in liver, adrenal glands, the brain, and various other internal organs that may have been courtesy lung cancer spread.
CT scans utilize x-rays for producing sharp cross-sectional body images. Instead of a single image, similar to traditional X-rays, CT scanners take multiple images as the machine starts rotating around your still body.. A computer later amalgamates these images into picture slices of the body parts under study. Unlike typical x-rays, CT scans conjure precise visuals of the tender body tissues.
Prior to a CT scan, you could be given a contrast solution or have the solution injected via an intravenous (IV) line. This assists with better outlining your body structures. The contrast could instigate a bit of flushing (warmness, particularly in the facial region). People with a history of allergies may develop hives. It’s rare to see major adverse reactions such as low blood pressure or troubled breathing occurring. Make sure you inform the doctor about any past allergic reactions you’ve had to x-ray contrast material.
CT scanning machines look like a big donut, with a table sliding out and in of the opening. When the scan is in progress, you should lie flat, motionless on the table. CT scans are time-intensive, which makes it difficult to stay within the confined space for an elongated period.
CT-Guided Needle Biopsy: If a suspicious cancerous spot is entrenched inside the body, CT scans can be used for directing the biopsy needle accurately towards the intended region. You must remain still on the scanning table for this procedure while the physician is busy inserting the needle inside the skin, directed at the mass. The CT scan is carried on repeatedly until the needle gets properly inserted inside the mass. A biopsy specimen is then taken out and viewed via a microscope.
Magnetic Resonance Imaging (MRI) Scan
MRI scans are typically used to find out any possibilities of a lung cancer growth in the spinal cord or brain.
Similar to CT scans, MRIs also offer clear pictures of soft body tissues. However, MRI scans use strong magnets and radio waves in place of x-rays. The radio wave’s energy is absorbed and released in a format created by specific diseases and body tissue type. A computer is used to translate the format into an extremely crisp image of the body parts. Gadolinium, a contrast substance, is typically administered into the vein prior the scan to help view the details better.
An MRI scan takes much longer compared to a CT scan (60 minutes, on an average) and can also be marginally uncomfortable. You must lie down within a straightened tube, which can make many feel claustrophobic. Unique “open” MRI equipment could at times assist with this, if required; however, the pictures may not always come out clear. MRI devices make clicking and buzzing noises; therefore, some health centers offer earplugs to cut out the noise.
Positron Emission Tomography (PET) Scan
For people in the initial stages of lung cancer, a PET scan could be vital. Your physician could utilize this test to check if the lung cancer has branched out and infected surrounding areas, such as nearby lymph nodes. This helps ascertain if an operation could be an alternative. The test also helps get a clearer picture of whether a strange spot on a CT scan or chest x-ray could be cancer.
A PET scan may also come handy if your physician believes the lung cancer could have spread its wings but not sure where exactly. PETs could expose cancer infection to the bones, liver, adrenal glands, or other body organs. The scan may not come handy with the brain, as brain cells excessively use glucose.
For this particular exam, a kind of radioactive sugar (called FDG or fluorodeoxyglucose) is administered into the blood. (The radioactivity level used is fairly low and which exits the body within a few days.) Since the cancerous cells develop rapidly, they take in the majority of the radioactive substance. After close to an hour, you would be shifted to a PET scanner table. You must stay flat on the table for 30 minutes; a specialized camera device would take images of your body spots replete with radioactivity. The image is not as crystal-clear as the ones from an MRI or CT scan, but the information presented is sufficient enough.
Often, PET scans are merged with CT scans with a special device that can carry out both CT & PET scans simultaneously. This helps the physician cross-check higher radioactivity spots on a PET scan with a much clearer image of the spot on a CT. This kind of PET scan is commonly used for lung cancer patients.
Bone scans help determine if cancer has hit the bones or not.
For the scan, a minor portion of low-intensity radioactive substance is administered into a vein (IV or intravenously). The material resides in every part of the altered bone structure, over the next two hours. You would then rest on a table for approximately 30 minutes, making it easier for a special camera to locate the radioactivity and make images of your body.
Active bone alteration spots absorb the radioactivity and pop up in the form of “hot spots.” These spots could indicate metastatic cancer, but other bone ailments such as arthritis could cause identical patterns. To differentiate these scenarios, the cancer institute could utilize other imaging exams like MRI scans or standard x-rays to understand the lit-up areas better, or the bone’s biopsy samples could also be taken.
A bone scan is often not the norm as a PET scan, which often gets conducted in individuals with non-small cell lung cancer, usually to help determine if the cancer has made it to the bones. A bone scan is mainly done when the probabilities of a bone cancer are impressive (due to symptoms like bone pain), which the other medical test results aren’t clearing out.
Tests for Diagnosing Lung Cancer
The outcome and signs of a few tests could strongly suggest the possibilities of lung cancer; however, the real detection of non-small cell lung cancer is done by inspecting the lung cells through a microscope.
The cells could be extracted from lung discharges (phlegm or sputum), found in liquid taken out from a spot surrounding the lung (thoracentesis), or taken out from a circumspect spot with the help of surgery (called a biopsy) or a needle. The decision to choose a particular test is based on the scenario.
A sputum sample (coughed up mucus from the lungs) is observed through a microscope to check if it comprises cancer cells. The ideal way to get this done is to take your early morning specimens consecutively for three days. This examination is more likely to help detect cancers that begin in your lung’s major airways, like a majority of squamous cell lung cancers. It could not be as beneficial for locating other non-small cell lung cancer types.
If there’s a fluid buildup surrounding your lungs (pleural effusion), physicians could carry out thoracentesis to determine if the accumulation was courtesy of the cancer broadening to the lungs’ linings (pleura). The accumulation could also be due to other conditions, like an infection or a heart failure.
For this method, the skin is deadened, and an empty needle is pushed through the middle of the ribs to clear out the fluid. (In pericardiocentesis, a similar test, the liquid is drained out from inside the sac surrounding the heart). The liquid is inspected through a microscope to detect the existence of any cancer cells. The fluid’s chemical tests are also at times beneficial in indicating a cancerous pleural outflow from a non-cancerous one.
If a cancerous pleural outflow is diagnosed, thoracentesis could be done again to drain out additional fluid. The fluid growth could prevent the lungs from getting inflated. Thoracentesis chips in and enhances the breathing experience.
Physicians typically use an empty needle to extract a minor sample from a doubtful spot (mass). In FNA or fine needle aspiration biopsy, the physician employs a syringe attached to a hollow, thin needle (even thinner when compared to blood test usage needles) to extract small tissue fragments and cells. In hardcore biopsies, bigger needles are used for removing one or additional small tissue cylinders. A core biopsy offers a bigger sample compared to an FNA biopsy, making it more popular.
A needle biopsy’s advantage is they do not need a surgical cut. The disadvantage, however, is that only a marginal tissue portion is removed. In particular cases (especially with an FNA biopsy), the tissue portion extracted may not be sufficient to both diagnose and classify DNA alterations in the cells, which could assist physicians pick anticancer medicines.
If the accused tumor is part of the lungs’ external portions, both types of biopsy needles would be fine for insertion inside the chest wall. This procedure is referred to as transthoracic needle biopsy. The spot that takes in the needle should first be desensitized with a local anesthesia. The physician then directs the needle inside the spot while seeing a real-time motion image of the lungs through either fluoroscopy (similar to an x-ray, but conjures up a motion picture on the computer screen instead of a single image) or a CT scan. Not like fluoroscopy, CT does not offer a constant image. Therefore, if CT is utilized, the needle goes in the direction of the mass; a CT picture is captured and the needle’s direction gets determined depending on the picture. This process gets repeated till the needle enters the mass.
The procedure may get complicated if air exits the lung at the biopsy spot and inside the area between the chest wall and lung. This could cause a portion of the lung to break down and lead to breathing troubles. This complication is known as pneumothorax, which tends to get better with time sans any treatment. If things don’t improve, a small tube is inserted inside the chest area to suck out air over a couple of days, after which the healing happens on its own.
FNA biopsies could also be carried out to detect cancer in the inter-lung lymph nodes:
Transbronchial or trans tracheal FNA is conducted by inserting the needle via the trachea (windpipe) or bronchi wall during endobronchial ultrasound or bronchoscopy.
In specific scenarios, FNA biopsies are done at the time of endoscopic esophageal ultrasound, by putting the needle via the esophagus wall.
A bronchoscopy could assist a physician locate some blockages or tumors in the bigger lung airways that could often get biopsied in the course of the procedure.
For this test, a flexible, lighted fiber-optic tube (referred to as bronchoscope) is put through the nose or mouth down within the bronchi and windpipe. The throat and mouth are first sprayed with a desensitizing medicine. The medicine could also be administered via an IV or intravenous line to help you relax.
Small tools could be put down the bronchoscope for taking biopsies (tissue samples). The physician could also take cell samples from the airways lining with the help of a small brush (called bronchial brushing) or having the airways rinsed with infertile saltwater (bronchial washing). These cell and tissue samples later get viewed through a microscope.
Tests to determine the spread of lung cancer in the chest region
An ultrasound is a kind of imaging that utilizes sound waves for creating internal body images. For the test, a microphone-like, small instrument referred to as a transducer emits sound waves and catches the echoes when they rebound off body tissues. A computer converts the echoes into black and white pictures on the screen.
For endobronchial ultrasound, the bronchoscope is attached to an ultrasound transducer near the edge and is directed inside the windpipe. This is conducted in combination with a desensitizing drug (local anesthesia) and minor sedation.
The transducer could be directed at multiple directions to observe the lymph nodes and distinct mediastinum (a region between lungs) structures. If the ultrasound shows up suspicious spots like amplified lymph nodes, an empty needle could be put via the bronchoscope and directed into these spots to procure a biopsy. The samples then get sent to the laboratory for a thorough investigation.
Endoscopic Esophageal Ultrasound
The test is similar to an endobronchial ultrasound, with the exception of the physician passing an endoscope (a flexible, lighted scope) inside the throat and down the esophagus (a tube linking the throat and stomach). This is carried out with a desensitizing drug (local anesthesia) and some frugal sedation.
The esophagus is positioned in the back of the windpipe and is nearby a few lymph nodes within the chest which can also get affected by lung cancer. Just as with an endobronchial ultrasound, the transducer could be directed at various directions to view lymph nodes and compositions within the chest that could comprise lung cancer. If an ultrasound shows up enlarged lymph nodes, an empty needle could be put via the endoscope to acquire their biopsy samples. The specimens are then looked through a microscope in a lab.
Mediastinoscopy and Mediastinotomy
These medical procedures could be carried out to view directly and acquire mediastinum (an inter-lung area) specimens. The procedures are conducted inside an operation theater when you are in deep sleep or under the influence of general anesthesia. The major differences between the procedures lie in the incision’s size and location.
Mediastinoscopy: A minor incision is done at the front portion of the neck, with a hollow, thin, lighted tube. This tube is pushed inside the breastbone or sternum, and before the windpipe, to properly view the spot. Medical tools could be pushed via the tube for removing lymph node tissue specimens along the primary bronchial tube and windpipe areas. Taking a look at the specimens through a microscope determines the presence of cancer cells if any.
Mediastinotomy: The doctor makes a marginally bigger cut (generally close to 2 inches in length) between the third and left second ribs besides the breastbone. This allows the doctor to access lymph nodes that aren’t reachable through mediastinoscopy.
Thoracoscopy could be carried out to determine if the cancer has made its way into the areas between the chest wall and lungs, or these spaces’ linings. It could also be utilized for sampling tumors on the lungs’ external portions and also the surrounding fluid and lymph nodes, and to determine if the tumor is branching out to the closely located organs or tissues. The procedure is not typically carried out only for diagnosing lung cancer, except if other medical tests like a needle biopsy are not able to procure sufficient diagnosis samples.
Thoracoscopy is carried out in an operating area while you’ve been subjected to general anesthesia. A little incision is done in the chest wall’s side. (At times, multiple incisions are made.) The surgeon then puts through a lighted, thin tube that has a mini video camera attached to one end of its chassis to observe the area lying between the chest wall and lungs. With this method, the surgeon may see likely cancer signs on the chest wall or lung’s linings and take out small tissue samples for an inspection via the microscope. (When specific spots aren’t accessible with thoracoscopy, the doctor may have to make a bigger chest wall cut, called the thoracotomy.)
Thoracoscopy could also be utilized as a division of the treatment to take out a segment of the lung in a few initial-stage lung cancers. This kind of operation, called video-assisted thoracic surgery or VATS, is thrown light upon in a much better way in the section “Surgery for Non-Small Lung Cancer.”
Biopsy Lab Tests and Other Specimens
Specimens amassed at the time of biopsies or other exams are forwarded to a pathology laboratory. A pathologist, a medical professional who utilizes lab tests for diagnosing diseases like cancer, observes the specimens through a microscope and could carry out other tests for better classification of the cancer. (Other organ cancer could reach the lungs. It’s critical to determine the cancer’s starting point, as treatments for various cancer types are different.)
The test results are clearly explained in pathology reports, which become available within a week. If you have doubts relating to your diagnostic tests or pathology results, get in touch with your doctor. If required, get a secondary opinion on your report by sending your tissue specimens to another pathologist lab, referred to you by your physician.
For this particular test, extremely fine slices of your specimen are appended to glass slides. The specimens are then subjected to unique proteins or antibodies that are designed to stick only to specific material found inside particular cancer cells. If the cancer cells of the patient comprise the substance, the cells will attract to the protein. Chemicals are put in so that the cell-attached special proteins change in color. The physician viewing the specimen through a microscope could detect the color variation.
In certain scenarios, the doctors may hunt for particular gene alterations within the cells, which help them confirm that specifically targeted drugs could cure the cancer.
For instance, EGFR or epidermal growth factor receptor is a protein showing up in huge quantities on cancer cells’ surface, helping them grow. A few latest cancer-cure drugs targeting EGFR apparently work well to cure lung cancers with making alterations in EGFR genes that are highly common in specific groups, like women, Asians, and non-smokers. But such drugs do not make much difference in patients whose cancerous cells entail alterations in KRAS gene. Several physicians now look for mutations in genes like KRAS and EGFR to ascertain if the newer medical procedures could offer any benefits.
Close to 5 percent of NSCLCs have rearrangements in the ALK gene. This alteration is commonly found in light smokers or non-smokers who have NSCLC’s adenocarcinoma subtype. Physicians could examine cancers for ALK gene alterations to check if drugs (like crizotinib) targeting the change could help.
Approximately 1 to 2 percent of NSCLCs have rearrangements within the ROS1 gene, which may push the tumor react to the intended crizotinib drug. A somewhat similar percentage have an RET gene rearrangement. Specific drugs targeting RET gene alteration cells could help with curing these tumors.
Newer laboratory exams for specific other proteins or genes could also assist in contemplating the treatment options. A few of them are explained in detail in the segment “What’s new in the research and treatment of non-small cell lung cancer?”
A blood test is not meant for diagnosing lung cancer. However, it could help get a feel of an individual’s holistic health; for instance, to determine if an individual is fit enough to undergo surgery.
A CBC or complete blood count confirms the presence of normal quantities of different cell types in your blood. For instance, it could indicate an active case of anemia (a lower red blood cell count), any bleeding troubles (courtesy a lower blood platelet number), or if the risks of infections are higher (due to a lower white blood cell count). The test is conducted multiple times during chemotherapy as these drugs can potentially impact the bone marrow’s blood-forming cells.
Tests for blood chemistry could help detect organ abnormalities — kidneys or liver. For instance, if the cancer has encompassed the bones and liver, it could give rise to irregular levels of specific chemicals within the blood, like a higher than average lactate dehydrogenase (LDH) level.
Pulmonary Function Tests
A pulmonary function test (PFT) is commonly conducted post a lung cancer diagnosis to check how normally the lungs are functioning (for instance, to check the level of chronic bronchitis or emphysema present). This is vital if surgery could be a cancer cure option. A surgery for removing lung cancer could mean removing a portion of the whole lung. Therefore, it’s critical to learn beforehand how efficiently the lungs have been functioning. Some individuals with bad lung function (akin to people with smoking-caused lung damage) do not have sufficient lung reserve to resist even a marginal extraction of the lung. Such tests help the doctor determine if surgery is ideal, and if yes, how much of it could safely be removed.
There are various PFT types, but all of them invariably put you through a breathing tube that is linked to a device measuring airflow.
At times, a PFT is coupled with an examination known as arterial blood gas. As part of this test, artery blood is removed (generally, vein blood is tubed out during blood tests) to calculate the level of carbon dioxide and oxygen it has.