The diagnosis of lung cancer involves conducting standard tests and following some protocols. It also involves scanning by the doctors to determine the primary cause of the medical issue. The specialist carries out different tests for identifying and diagnosing cancer. The doctors are also doing tests to learn the spread of cancer to other body parts and its origin. This condition is metastasis.
The most common test for lung cancer diagnosis is the imaging test, which shows the level of spread of the tumor cells. But the imaging tests are never in use alone to diagnose the NSCLC. The imaging tests have shown pictures of the inside features of the body. Hence, the doctors suggest the best-suited treatment by learning through several tests. You can’t diagnose lung cancer through routine blood testing. Instead, the doctors should conduct blood tests to identify genetic mutations among individuals already who have lung cancer.
Susceptible Factors
Several diagnostic tests are available for non-small cell lung cancer (NSCLC). But not every test will be useful for every individual. Hence, certain factors are studied while choosing the appropriate diagnostic tests for lung cancer. These factors are below:
- Type of non-small cells lung cancer (NSCLC) suspected
- Signs and symptoms among the individual
- Age and general health information of the individual
- Results of prior medical tests
The diagnosis of NSCLC initiates within the lungs as the diagnosis of many other types of cancer starts from different body parts 1. You can initiate the diagnosis by communicating with the doctors. The doctors look into the signs and symptoms experienced by the individual along with the analysis of their medical history, physical examination, imaging reports of the tumor cells observed by x-rays and scans, and determination of the risk factors of the NSCLC 2. Doctors recommend the pathologists to conduct tests on the biopsy sample to identify the appropriate cancer region.
Also, the doctors guide some other tests to find out specific types of cancer. Even after considering this, if the doctor is unsure about the cancer development, the doctor provides another diagnosis for metastatic cancer of unknown primary. Most of the treatments for metastatic cancer of unknown primary with initial detection within the chest region showing similarities with the metastatic lung cancer. Some of the significant tests that the doctors perform for the diagnosis of NSCLC are below:
Imaging tests
The imaging tests include the scans considered significant towards showing appropriate care to the individuals suffering from NSCLC. They carry out imaging tests by determining the samples of biopsy. The chest x-rays and scan results in combination with the medical history of the individuals along with other physical examination, blood tests, and information from the biopsy to get complete details regarding the beginning of the cancer development and its level of spread within the body 3. Some of the imaging tests are below:
Computed tomography (CT or CAT) scan
It aims to produce images that help the doctors determine the size and location of the tumor cells in the lungs. It takes pictures of the inside portion of the body using x-rays taken from different angles. Along with the photographs, the computer forms a detailed, 3-dimensional image representing any abnormalities or presence of tumor cells. The main use of the CT scan is to estimate the actual size of the tumor. Contrast medium, a dye helps to attain a clear image before scanning. They inject this dye into the vein of the suspect or give it in the form of pills and liquid that they swallow.
Positron emission tomography (PET) scan
It can also be in combination with a CT scan known as a PET-CT scan. It aims for generating pictures of the organs and tissues within the body. A small amount of radioactive sugar is injected into the suspect’s body. The cells utilize this sugar substance, which uses the maximum energy. As cancer cells can take up the point actively, it also absorbs the maximum of the radioactive substance. Later, the scanner can detect the radioactive substance for producing images of the inside of the body.
Magnetic resonance imaging (MRI) scan
It aims to produce images for allowing the doctors to see the location of the tumor cells within the lungs and its measurement. The MRI utilizes magnetic fields and not x-rays to produce detailed body images. Before scanning, a contrast medium helps to get an acceptable image form. But, MRI rarely helps to look at the interior features of the lungs as it does not show effective results to take up with the pictures of different body parts that show continuous movement, such as lungs. Hence, MRI has been practical to detect lung cancer spreading to the brain and bones.
Bone scan
It utilizes a radioactive tracer to determine the inside features of the bones. The radiation emitted from the tracer is very low to cause any harm to the individuals. This tracer is injected into the suspect’s vein and is then collected in regions of bones that can be detected through the camera. The diagnosis helps for the identification of healthy and unhealthy bones. The healthy bones appear lighter to the camera, while the cancerous region within the bones stands out in the image. PET scans have now replaced the bone scans for diagnosing the NSCLC spread into the bones.
The doctors have also followed tissue collection protocols to diagnose NSCLC and suggest the appropriate treatment. The doctors need to check the suspicious cells that may develop into lung cancer, for which they need to study the tissue or fluid from and around the lungs. The utilization of different protocols has allowed the doctors to remove cells or use biopsy from the body and determine them under the microscope for cancer determination. Some of the tests are:
Biopsy
It mainly removes a small amount of tissue for carrying out its examination under a microscope. The larger tumor samples help determine the subtypes of NSCLC and carry out additional molecular testing. And so, at times the tumors removal is necessary to carry out the tests. The pathologists are to analyze the samples after the biopsy. The pathologist helps interpret the laboratory tests and evaluate cells, tissues, and organs to diagnose the NSCLC.
Bronchoscopy
A surgeon or pulmonologist uses a thin, flexible tube with a light towards the end. It is inserted into the mouth or nose that goes down through the main windpipe and then into the breathing passages of the lungs. The pulmonologist is an expert in the diagnosis and treatment of lung disease. This test helps visualize the inside features of the lungs and later helps examine the presence of tumors in the lungs.
Endobronchial ultrasound (EBUS)
The use of small tools inserted through the mouth or nose and later passed out into the windpipe and chest region helps take up the fluid or tissue samples for further examining the specimens. The lymph nodes are most often discussed, and the biopsies are taken through ultrasound to guide the bronchoscopy. It is known as endobronchial ultrasound (EBUS). The patients are provided with mild doses of anesthesia and sedation.
Needle aspiration/core biopsy
A interventional radiologists makes the skin numb. And also removes lung cancer cells as a sample for testing. This test is with smaller sized needles or large-sized needles, whose size varies as per the sample size. The radiologists utilize a chest CT scan or a particular x-ray machine called a fluoroscope to guide needles in removing samples. Hence, the use of core biopsy helps prove large tissue samples. These extracted tissue samples are further helps for the diagnosis and molecular testing of NSCLC.
Thoracentesis
It is mainly carried out by numbing the skin on the chest region and then inserting a needle through the space between the chest wall and the lung consisting of a fluid collection region. This fluid is later removed and used for the detection of cancer cells.
Thoracoscopy is the testing
Performed in the operating room while providing local anesthesia to the patient. A small cut is made in the chest wall region, and a unique instrument with a video camera is inserted to examine the inside part of the chest. The recovery time among the patients tends to be shorter while using thoracoscopy due to the smaller incisions in the testing. Hence, this type of testing is, video-assisted thoracoscopic surgery or VATS. Robotic-assisted surgery is another type of invasive surgery which has replaced thoracoscopy.
Mediastinoscopy
It is another type of diagnostic test in an operating room as it involves a surgical procedure. The patient is given local anesthesia. The expertise is responsible for taking up the lymph node samples from beneath the center of the chest region towards the breastbone by making a small insertion at the top of the breastbone.
Thoracotomy
This diagnostic test is also within the operating room. And the patients are also given local anesthesia. The incision within the patient’s chest is to examine the lung directly and later takes tissue samples for testing. It is not most often for NSCLC diagnosis but majorly to remove lung tumors.
Sputum cytology
This diagnostic test requires collecting the mucus sample from the patient’s cough, which is the sputum or phlegm and later examined under a microscope. It will further help check the presence of tumor cells within the lungs.
Tests for determining the extent of cancer:
The diagnosis of lung cancer among individuals leads towards the detection of the extent of cancer that has spread within the body of the individuals. And so, the diagnosis of the cancer stage helps provide the appropriate type of treatment for the patients. The tests involved in staging include the imaging tests, which also allows the doctors in determining the spread of cancer beyond the lungs of the patients. CT, MRI, positron emission tomography (PET) and bone scans have been the most common imaging techniques for diagnosing the different stages of lung cancer.
Biomarker testing in NSCLC
Some doctors suggest conducting running tests regarding the tumor sample to identify specific genes, proteins, and other related factors showing similarities with the tumor. Hence, it is referred to as molecular testing of the tumor within the lungs.
Different genes show variability known as mutations within the lung tumor, leading to the growth and spread of cancer. However, these mutational changes are primarily in the form of tumor development and not within the body’s healthy cells. Targeted therapies are being helpful for different mutations responsible for causing lung cancer. The mutational genes responsible for causing lung cancer include EGFR, ALK, KRAS, BRAF, HER2, ROS1, RET, MET, and TRK, and the diagnosis for such gene occurrence is the most common one. The individuals suffering from adenocarcinoma NSCLC and those who do not have the habit of smoking, with targeted therapy and molecular mutational testing is still effective.
Doctors recommend integrating PD-L1 testing for diagnosing the tumors within the lungs. PD-L1 is the type of protein mainly on the surface of some cancer cells and immune cells of the body. This protein shows efficacy in protecting the immune cells against the mechanism of cancerous cells. Some of the significant biomarker tests are :
Comprehensive biomarker testing
This test initiates with the removal of tissues during the biopsy process for diagnosing NSCLC with analysis of possible genetic changes that may contribute to the development of lung cancer.
Liquid biopsy
This test is mainly concerned with diagnosing specific genetic changes among individuals suffering from NSCLC. The determination of circulating tumor DNA is taken up for diagnosing cancer. The cancer cells also die like the healthy cells and are later replaced. These dead cells, when broken down, are released into the primary bloodstream. Hence, small pieces of DNA are detected in the bloodstream from these cells. The liquid biopsies are less invasive when compared to other types of biopsies, along with possessing less risk. The liquid biopsies are usually performed as the initial diagnosis and can be carried out multiple times during the treatment. Doctors can also use this test to check the progress of tumors and determine the wellness of therapy.
Diagnostic Evaluation for NSCLC
Three significant steps in the diagnostic evaluation of lung cancer are:
Tissue diagnosis
The type of lung cancer diagnosis by doctors depending on the tissue sample’s clinical presentation and radiographic appearance 4. Molecular testing needs many tissue samples so that appropriate diagnosis for the same is carried out. Targeted therapies can increase the treatment options for patients suffering from poor functional status. The use of molecular testing is also a standardized diagnostic test even for the non-smokers who possess squamous cell tumors, representing a large amount of tissue sample among them.
Different diagnostic methods are available for yielding the cytology samples and small biopsy samples. The selection of adequate diagnostic procedures entirely relies on the type, location, and size of the tumor, comorbidities, and accessibility of metastasis 5,6. Conventional bronchoscopy shows effective results for the central lesions, while CT-guided transthoracic needle aspiration is integrated for peripheral lesions. Endobronchial ultrasound and electromagnetic navigation have been the modern diagnostic method that improves the diagnostic yield of bronchoscopy for choosing patients with mediastinal or peripheral lesions.
Staging
The determination of the clinical stage is concerned with the related information obtained from the prior treatment protocols, reports of CT and PET scan along with the invasive staging, including the mediastinoscopy 7. Following the surgical incision process, the pathologic stage tends to either upgrade or downgrade the clinical staging. NSCLC is concerned with the staging level as per the system of tumor size, nodes, metastasis. The American College of Chest Physicians (ACCP) guidelines have suggested using the 7th edition TNM staging system for prognosis and placement into clinical trials 8,9. The expertise has most commonly used the use of Veterans Administration Lung Study Group classification systems to determine lung cancer stages in the treatment process 10.
Functional capacity
Some of the patients suffering from ageing issues, poor nutritional status, and different comorbidities are unable to tolerate lung resection, radiation, or chemotherapy. Hence, specific treatment should be provided for particular patients as per their requirements. The reports of Eastern Cooperative Oncology Group Performance Status is an effective tool for predicting the tolerance or extent of chemotherapy provided to the patients 11.
The Grading Tool
The grading tool is:
- 0: Implicates the completely active, with the capability of carrying activities of pre-disease without restriction
- 1: Implicates the restrictions in physically strenuous activity but is ambulatory and capable of performing light or sedentary work
- 2: Ambulatory and capability of showing self-care but unable to carry out any work activities, up and about more than 50% of waking hours
- 3: Implicates the capability of showing only limited self-care, confined to a bed or chair more than 50% of waking hours
- 4: Implicates the complete disability, incapable of showing any self-care, totally confined to a bed or chair
- 5: Death
The patients with lung resection often require standard preoperative evaluation along with pulmonary function testing and carbon monoxide diffusion within the lung measurements for determining post-surgical lung reserve (Detterbeck et al., 2013). The integration of brain management resonance imaging is considered the standardized method for evaluating patients suffering from stage IA NSCLC (Detterbeck et al., 2013).
Coping strategies for NSCLC diagnosis
The patients going through the diagnosis of NSCLC are generally under very stressful conditions. The patients with NSCLC are often have with psychological issues such as anxiety and depression. Hence, the patients and their families should integrate towards building effective communication with the healthcare team and explaining the patients’ experiences of the cancer journey. And so, the healthcare team with special training and experience, helps the patients and their families cope with stressful conditions.
The healthcare team provides the providence of all critical information and emotional support. The doctors can provide supportive services and palliative care specialists for enhancing self-care among the patients. The patients and their families use the available resources within the community for helping the other individuals who have lung cancer. Some of the patients share their overall experience of their cancer journey with the healthcare team to increase awareness regarding lung cancer and further help the other patients dealing with lung cancer issues.
Hence, the diagnosis of NSCLC is a serious concern. Nevertheless, the doctors are looking forward to offering effective cancer treatment. Also, several advances in diagnosing and treating NSCLC, helps the patients provide more opportunities for the cure.
References
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- HICKS RJ, LAU E, ALAM NZ, CHEN RY. Imaging in the diagnosis and treatment of non-small cell lung cancer. Respirology. Published online March 2007:165-172. doi:10.1111/j.1440-1843.2006.01012.x
- Rivera MP, Mehta AC, Wahidi MM. Establishing the Diagnosis of Lung Cancer. Chest. Published online May 2013:e142S-e165S. doi:10.1378/chest.12-2353
- Lamprecht B, Porsch P, Pirich C, Studnicka M. Electromagnetic Navigation Bronchoscopy in Combination with PET-CT and Rapid On-site Cytopathologic Examination for Diagnosis of Peripheral Lung Lesions. Lung. Published online October 5, 2008:55-59. doi:10.1007/s00408-008-9120-8
- Herth FJF, Eberhardt R, Vilmann P, Krasnik M, Ernst A. Real-time endobronchial ultrasound guided transbronchial needle aspiration for sampling mediastinal lymph nodes. Thorax. Published online September 1, 2006:795-798. doi:10.1136/thx.2005.047829
- Detterbeck FC, Lewis SZ, Diekemper R, Addrizzo-Harris D, Alberts WM. Executive Summary. Chest. Published online May 2013:7S-37S. doi:10.1378/chest.12-2377
- Detterbeck FC, Postmus PE, Tanoue LT. The Stage Classification of Lung Cancer. Chest. Published online May 2013:e191S-e210S. doi:10.1378/chest.12-2354
- Mirsadraee S. The 7th lung cancer TNM classification and staging system: Review of the changes and implications. WJR. Published online 2012:0. doi:10.4329/wjr.v4.i4.128
- Stahel RA, Ginsberg R, Havemann K, et al. Staging and prognostic factors in small cell lung cancer: a consensus report. Lung Cancer. Published online December 1989:119-126. doi:10.1016/0169-5002(89)90156-6
- Oken M, Creech R, Tormey D, et al. Toxicity and response criteria of the Eastern Cooperative Oncology Group. Am J Clin Oncol. 1982;5(6):649-655. https://www.ncbi.nlm.nih.gov/pubmed/7165009
