Lung Cancer Diagnosis
Lung Cancer Diagnosis
Jay M. Lee (Surgical Director, Thoracic Oncology Program, UCLA) gives expert video advice on: How is lung cancer diagnosed?; What are some common non-surgical procedures used to diagnose lung cancer?; Can waiting for a lung cancer diagnosis cause a dangerous delay in treatment? and more...
What are the symptoms of lung cancer?
About ten percent of the patients will actually not have any symptoms. The other ninety percent will have symptoms, and these include coughing, streaking of blood in the sputum (called hemoptysis), shortness of breath, or breathlessness, and loss of appetite and weight loss are some non-specific symptoms that may be related to, or attributed to lung cancer.
How is lung cancer diagnosed?
Lung cancer is diagnosed by use of usually radiologic imaging studies that include either a chest x-ray or chest CT scan. Often this is prompted by a symptom that you may be having, or if you're a high risk patient for developing lung cancer your physician may order these studies.
What is a 'lung nodule' or 'mass'?
A lung nodule or a mass is a radiologic finding. It is something that is seen on a chest X-Ray or a CT scan. It does not imply or mean that you necessarily have lung cancer. It may be a benign diagnosis like a granuloma or it may be lung cancer, but a lung nodule doesn't equal lung cancer until a biopsy is taken to look at the cells under a microscope by a pathologist.
What is an 'endobronchial mass'?
Lung cancer can arise in the lung itself or it may be a cancer in the airway, called the bronchus. Endobronchial mass is when a lung cancer arises in the airway itself. This can cause bleeding and present itself as streaking, or blood, in your sputum. It can be seen by a variety of diagnostic procedures like bronchosopy, that the physicians can do.
What are some common non-surgical procedures used to diagnose lung cancer?
The diagnose of lung cancer requires a tissue or cytologic diagnosis. Another words, seeing the cancer cells underneath a microscope and seeing that this is definitely cancer. There is a variety of ways that we go about making a diagnosis and these can include bronchoscopy, where a slender camera tube is inserted into the airway, and we look in the airway and a needle is then used to biopsy the lung tissue and the abnormality. Other ways to do this is to use a CT guided or a radiologic guided biopsy of the lung tumor or lung mass across the chest. And this is done by a radiologist. It is also an outpatient procedure and diagnosis can be made that way. And finally, there are other non invasive ways to make a diagnosis and these things can include thorocentisis, where a needle can be inserted into the plural space which is the space between the lining of the lung and the chest wall. And if there is fluid there then that fluid can be sent off to look for cytology for the presence of any cancer cells.
What are some common surgical procedures used to diagnose lung cancer?
There are two surgical procedures that are currently used to diagnose lung cancer. Mediastinoscopy is an outpatient procedure, where an incision is made at the base of the neck, and lymph nodes in the center of the chest, called the mediastinum, are sampled, and sometimes a diagnosis of lung cancer can be made this way. The other route is called thoracoscopy, or Video Assisted Thoracic Surgery, which is often referred to as Video-Assisted Thoracoscopic Surgery (VATS) surgery. This is a minimally invasive surgery where small incisions are made in the side or towards the back of your chest, and the lung tissue or the lung nodule itself is actually biopsied itself, and a diagnosis of lung cancer can be made by that route as well.
Can waiting for a lung cancer diagnosis cause a dangerous delay in treatment?
Lung cancer management requires a staging, and staging requires a number of studies to be obtained, mostly in the form of radiologic studies or some noninvasive or less invasive ways to obtain a tissue diagnosis. The process of getting the entire workup can take time to do, and it is acceptable that this is in the order of several weeks. Ideally, we would like to get this done in a period of two to four weeks, but this is a guideline and during that period it is unusual that your cancer or your prognosis is going to be changed by obtaining these studies. Overall, most physicians out there feel that this will not impact or delay your treatment.
What are the current diagnostic stages of lung cancer?
There are several stages of lung cancer, stages 1, 2, 3 & 4. And within those stages 1, 2 & 3 there are subtypes A & B. Its a complex staging system that physicians use as a common language to predict prognosis. This is based on what's called a TNM staging. T is referred to as the tumor, which is the lung tumor itself and it describes the location and the local advancement of the tumor. It describes what the lung cancer itself is currently. N staging is the nodule staging that refers to lymph nodes not only in the lung but also lymph nodes in the center of the chest, called the mediastinum. And finally M sub classification refers to metastasis. So the combination of TNM will define what stage you are, whether it be 1, 2, 3 or 4.
Why does the diagnostic staging of lung cancer change from time to time?
Lung cancer staging changes because the clinical stage and the pathologic stage may be different. The clinical stage is defined by what we see radiographically. But the presence of tumor in certain areas may not necessarily turn out to be cancer at the end. So, what we often refer to as a pathologic stage, whereafter a biopsy procedure is done, either surgically or by less invasive way. This is the goal standard to stage a patient. Staging sometimes changes from a clinical to pathologic staging, because what we see by radiologic studies does not necessarily turn out to be cancer in those areas.
Which tests are done to detect if lung cancer has mestastisized?
There are a number of tests that are done to work up patients with lung cancer or suspected to have lung cancer. One aspect is radiologic studies and these things include a combination of CT scans, MRIs, PET CTs and regular X-Rays. You may not necessarily need all four of those types of imaging studies but it may involve a combination of those things. The other staging modality that's important is a surgical type and it's called mediastinoscopy. It's where lymph nodes in the center of the chest called the mediastinum are sampled and it's because lung cancer is in the lung tissue itself that are in the chest off to your sides drain into the lymph nodes in the center of the chest called the mediastinum and biopsying these lymph nodes is important because it gives a better stage, a pathologic stage of how extensive your cancer may be.
What is a 'mediastinoscopy'?
A mediastinoscopy is a surgical procedure to stage the lung cancer. An incision is made at the base of the neck and this is done by a thoracic surgeon. A camera scope is inserted and lymph nodes in the center of the chest, called the mediastynum, are sampled. This is important because it stages your cancer pathologically. We determine definitively whether there's involvement of these lymph nodes in the center of the chest. Lung cancers which are out in the periphery in your lung tissue drain into these lymph nodes in the center of the chest, so it's important to sample these lymph nodes so that we have accurate staging. This then determines the order of your treatment, whether it be chemotherapy first, then surgery, or if you need just surgery alone.
Why is lung cancer so hard to detect?
Lung cancer is difficult to detect because currently there are no recommended screening studies that are endorsed by any of the major organizations, so often lung cancer is detected while patients are systematic and often this is at a more advanced stage.
Why are there no recommended screening tests for lung cancer?
There are currently no endorsed official screening programs for lung cancer, and this is based on four major randomized studies in the 1970s and 80s, which showed no reduction in mortality (or death) attributed to lung cancer when they used sputum samples or x-rays to see if this would improve patients' survival. However, all four of those studies were limited, and there is a great deal of controversy and problems with how those studies were designed. As a result, currently there is a large national lung cancer screening trial, which has enrolled over 50,000 patients and many physicians eagerly await the results of that study. This study utilized chest CT scans which is a far better and more accurate study than chest x-rays, and of course, sputum samples. In practice, many physicians screen patients for lung cancer if they are high risk. But this is individual physician practices and often practiced by many physicians out there, but officially, none of the major organizations currently endorse a set screening protocol.
What is a 'helical low-dose CT scan'?
A helical low-dose CT scan is a very high resolution imaging study. It is a CAT scan to look at your lungs to detect lung nodules. In today's age, our technology's gotten so good that we're able to detect even very small nodules in the lung itself. So this has pushed physicians to order these studies for high risk patients, current smokers or former smokers that are clearly at risk of developing lung cancer. So this has raised the issue of utilizing these CT scans as a screening tool and as a result there is a national study currently evaluating the efficiency and how effective this is in terms of reducing patient mortality. But at the current time it is not officially endorsed that patients should undergo routine screening.
Why are biopsies done to diagnose lung cancer?
Biopsies of the lung tumour are done often when there's a dilemma in the diagnosis. If it changes the treatment for you, then we will persue a diagnosis with that lung nogual. For instance, if it appears that radio graphically you have a lung tumour, but you don't have a diagnosis of lung cancer, but it's at an advance stage, then you'll need treatment and we'll then we need to make a diagnosis. Histologically, by getting a biopsy, so we can start your treatment. On the other hand there are scenarios where the lung tumour itself looks very suspicious for lung cancer. Radio graphically it appears to be at an early stage and you're at an acceptable risk for undergoing surgery, then these patients will go straight to surgery where staging made is gonosapy. We sample the lyphmnodes in the center of the chest and then to actually surgically biopsies or reset the lung module. And both routes are acceptable ways of pursuing and working up patients with lung modules and providing treatment, but a biopsy is not always necessary.
How long will it take to receive the results of a lung biopsy?
Generally after getting a lung biopsy by a number of modalities, whether it be surgical, or whether it be non-invasive or less invasive ways of getting a diagnosis, it will take several days for the pathologist to make a diagnosis. Although there is, what's called, a "frozen section analysis", where the pathologist can take a quick look, and make a diagnosis of whether it's cancer or not and this is often very accurate. However, the type of cancer requires further studies, and these things may include things like immunohistochemistry, so further work needs to be done, and as a result it can take several days for the pathologist to make a final determination that you have lung cancer.
Do all patients need to have a biopsy of the lung before surgery?
Not all patients need to have a biopsy or a diagnosis of lung cancer before having surgery. In other words, needle biopsies can be falsely negative. In some reports, as high as twenty to thirty percent of needle biopsies can be negative. This has to do with the number of technical reasons and the size of your lung nodule or mass. As a result, even if you get a negative diagnosis, a negative biopsy result, it doesn't mean necessarily that you don't have cancer. So in patients who are relatively early stage, and this is a clinical stage determined radiographically with the use of a number of radiologic studies. And if you're an acceptable candidate for surgery, with low comoridities, and the appearance of your lung nodule or mass is very suspicious that this may be lung cancer, then in those situations it's very reasonable to proceed directly to surgery without having a biopsy or a diagnosis to say that you have lung cancer.
Should I get a second opinion on my lung cancer diagnosis?
You should do what is most appropriate and comfortable to the patient. If a patient desires to have a second opinion, we certainly encourage that, and we recommend other local experts in lung cancer who deal with this, and get another reasonable opinion. The patient should go along with a physician, or a team of physicians, that they feel most comfortable with, and that is foremost. What is important is what is going to provide the best care for you.
What's the average life expectancy for someone diagnosed with lung cancer?
The average life expectancy for somebody with lung cancer is variable, and it depends on the T and M staging for your lung cancer. Overall, for all stages combined, the overall life expectancy is about 13 %. So that's a very low figure, but if we look at some of the earlier stages, for instance stage 1A, these patients have a five year survival of anywhere between 60% to 80%. So it's a large spectrum; the prognosis depends very much on your disease stage.
Will there ever be a breath test for lung cancer detection?
There's a great deal of research currently going on trying to detect lung cancer, not only with a breath test, but looking at sputum samples, or looking in the peripheral blood. Currently all of these things remain investigational and there are some promising, potentially useful things in the future. But right now we are far from taking this as a standard of care to make a diagnosis of lung cancer.