THE LUNG PROJECT
Basic Facts and Statistics
LUNG CANCER INFORMATION
This section provides an overview of lung cancer facts, incidence, risks factors and provided guidance regarding the diagnosis and staging of lung cancer
LUNG CANCER BASICS
STATISTICS
•Based on the American Cancer Society, there are an estimated 224, 390 new cases of lung cancer expected in 2016 (117,920 in men and 106,470 in women). (ACS Cancer Statistics)
•Lung cancer is the most common cancer worldwide, with 1.8 million cases a year.
•In 2016, it is estimated that 158,080 patients will die from lung cancer (ACS Cancer statistics). This number of lives lost to lung cancer is higher than the lives lost from colon, breast and prostate cancer combined.
•The reason for such high mortality in lung cancer is due to the late stage at diagnosis in most patients (50% diagnosed with stage IV disease) and the aggressive nature of the disease.
•However, early detection and treatment can save lives, with up to 90% cure rate in patients diagnosed with stage I cancers smaller than 1 cm (Henschke et al.)
GENDER AND LUNG CANCER
•The lifetime risk of a man developing lung cancer is 1 in 14 and the risk in women is 1 in 17. However, the risk of developing lung cancer in women is rising.
•Contrary to what most people think, lung cancer is the main cause of cancer death in women, NOT breast cancer. However, lung cancer is the second most frequent cancer in women, after the more common breast cancer.
•Women tend to develop adenocarcinoma (a type of lung cancer) are usually younger age at diagnosis
•In never smokers, women are more likely than men to develop lung cancer, and their prognosis tends to be better.
PROGNOSIS AND SURVIVAL
•Overall survival in lung cancer remains poor, mainly due to the fact that only 20% of patients are diagnosis at early or stage I disease.
•Understanding lung cancer survival is difficult at times, since the results or prognosis is presented as “5-year survival”. The reason is that the statistical tool used to calculate survival (Kaplan-Meier Method) uses the 5-year mark as a time point to declare someone a cancer survivor. But many people with treatment live longer than the commonly used 5-year mark, and end up living a normal fulfilling life. For example, if the 5-year survival for stage IIA non-small cell lung cancer is 50%, this means that in a large group of patients with that stage, 50% die of their disease in less than 5 years. Some of those patents may have died 1 year after diagnosis or 4 years after diagnosis. The rest of the group or the other 50% reach that time point alive and well, therefore are likely cured from their disease. The mean survival (in years) for that stage is another way to look at prognosis.
•It I important to understand that survival is only estimated and many factors affect the prognosis including the tumor characteristics, the overall condition of the patient, and their ability to tolerate the necessary treatment. Only after careful review of your particular case by you doctor, your estimated chance for survival can be assessed.
•The other important factor in understanding prognosis is the accuracy of staging. Suboptimal staging of the disease can overestimate or underestimate survival and prognosis. Ultimately, the best predictor of survival is the absence of disease recurrence after careful follow up after treatment
RISK FACTORS
a.Smoking- There is no doubt that smoking is the biggest risk factor for lung cancer, with more than 80% of lung cancer patients having a smoking history. Smokers have a 15-30fold higher risk of developing lung cancer. However, after quitting smoking, the risk decreases significantly to slightly higher than a non smoker. There are several resources available to help you quit smoking, and the sooner the better. (Links smoking cessation help)
b.Lung cancer in non-smokers- Lung cancer can occur to anyone, and 20% of newly diagnosed cases have never smoked. In addition, patients exposed to second hand smoke have a slightly higher risk, with 7,300 cases new lung cancer related second hand smoke exposure, many of the exposed as children.
c.Environmental Exposure
•Radon-radon is an inert odorless gas that originates in the soil and rocks during the breakdown of Uranium, and can get trapped in houses and buildings. According to the U.S. Environmental Protection Agency, radon is responsible for approximately 20,000 cases of lung cancer per year. It is thought that 1 of every 15 homes in the U.S> is thought o have elevated radon levels.
•Chemicals- Personal exposure to silica, arsenic, fiberglass, diesel exhaust and chromium are some of the industrial chemicals that can elevate the risks of lung cancer, particularly if combined with smoking.
•Asbestos- Asbestos is a well documented risks for developing malignant pleural mesothelioma, which is a disease of the lung lining, however, it is also known to cause lung cancer, in particular in smokers who have had asbestos exposure.
•Pollution and smog- environmental pollution is playing a more important role in the higher rates of lung cancer. The World Health Organization has classified environmental pollution as a carcinogen. This is more evident in countries like China, it is expected that they will have an increase of around 100, 000 cases of lung cancer due to pollution, with an estimated 800,000 lung cancer cases by the year 2020.
•Family History- having a family member with lung cancer is considered a risk factor for development of lung cancer, particularly if the family member was a never smoker. This is due to the role genetics and the ability to repair genetic mutation damage have in the formation of lung cancer.
LUNG CANCER SYMPTOMS
•Lung cancer is difficult to diagnose, since only 15% present with symptoms
•The great majority of lung cancer patients (85%) have no symptoms at all, and are often diagnosed incidentally when x-rays are obtained for another reason
•Because lung cancer typically does not cause symptoms at an early stage, the majority of patients are diagnosed with advanced disease (stage III and stage IV)
•Efforts in lung cancer screening with low dose CT in high risk smokers can help detect the disease at an earlier stage and reduce mortality, but we have no evidence yet to offer screening in patient who have not smoked or at at low risk.
•By the time someone is diagnosed with a stage IA lung cancer (lung mass of 1-3 cm in size), the tumor has been present and forming over 18-24 months.
•The most common symptoms related to lung cancer are:
⎫Shortness of breath
⎫Chest pain
⎫Coughing blood
⎫Hoarseness
⎫Persistent pneumonia or bronchitis
⎫Changes in your cough (frequency or severity)
⎫Unexplained weight loss, fatigue, headaches, new bone pains
CT SCREENING
a.CT screening NLST- The National Lung Screening Trial (NLST) was a study completed in 2006 and published in 2011 (New England Journal of Medicine, 2011), where 54,000 current or former heavy smokers had either a yearly chest x ray(CXR) or a low dose CT (LDCT) to screen for cancer. They found that CT scans were better at detecting unsuspected lung nodules and therefor early stage lung cancer, which resulted in a 20% reduction in lung cancer mortality. This does not sound like a large reduction, but compared to the impact of screening programs for breast, prostate and colon cancer, it was more significant.
b.Criteria: To be eligible for lung cancer screening, patients have to meet the following criteria
•Age 55-79 years
•Current of previous smokers (quit within the past 15 years)
•History of heavy smoking (30 pack years, which means 2 packs a day for 15 years or an equivalent, for example 1 pack a day for 30 years, or 3 packs for 10 years)
•No symptoms or history of a know lung nodule
•Patients younger than 55 (50-79) with an additional risks factor such as family history of lung cancer or additional environmental exposures
c.Benefits of screening: patients who enrolled in low dose CT screening, have a higher chance of detecting lung nodules (about 25% of patients will have a positive scan for nodules). The majority of those nodules detected are small (6-10 mm) and 96% of the time they are benign and non cancerous. However, there is a 3 to 4% chance that a nodule found may turn out to be a lung cancer. It is important to have a doctor or a team with expertise in lung cancer and lung cancer screening evaluate your results, in order to avoid unnecessary test or invasive procedures, yet achieve an early diagnosis if something is detected.
d.Risks of screening: the main risks of CT screening for lung cancer, is the risk of harm in the process of diagnosis. The typical rate for intervention or biopsy of detected nodules is less than 10%, and the serious risks of those procedure are usually less than 1%. There is the low risk of radiation exposure which is small with such scans. There is some degree of anxiety related to the process particularly if a small nodule is found, however, the risk of lung cancer in most small nodules is exceedingly low.
e.How to get screened? It is advisable to ask your doctor on how to get screened for lung cancer, and if you are a good candidate for lung cancer screening. Medicare and many insurance carriers cover the test, and there is often a self pay option for a modest price in most screening centers. The most important step in addition to getting screened is to STOP smoking if you still do so. Nothing will prevent a cancer if the main risks factor is still active.
LUNG CANCER DIAGNOSIS AND STAGING
THE LUNG NODULE
a.Definition: A lung nodule is a density or “spot” seen in a test such as a chest x ray or CT scan. Lung nodules range from 2 mm to 3 cm (11/2 inches). Densities larger than 3 cm are more commonly called lung masses. The words mass and tumor are often used for the same type of lesion. Most lung nodules, particularly if less than 1 cm are benign and not lung cancer.
b.Statistics of lung nodules benign vs malignant: Most lung nodules detected in chest CT are benign non-cancerous. The size, appearance and borders in the nodule affect the risk of malignancy or lung cancer. The smoking history as well as prior history of another cancer such as colon cancer, melanoma or sarcoma can affect the likelihood of the newly found nodule is malignant or not. When a nodule is calcified (solid calcium appearance on x-rays) the risk of malignancy is almost zero and is called a benign granuloma.
c.When to worry: it is important to discuss with your doctor whether a detected nodule warrants any follow up or intervention. Since most lung nodules are benign, a follow up study in several moths is usually the best and most common course of action. In the event that it grows over time, a more aggressive attempt for diagnosis may be necessary. Certain nodules can have more concerning features that can warrant more immediate investigation or testing such as speculated borders, growth, mixed ground glass nodule and size larger than 15 mm.
d.Options for diagnosis: The diagnostic approach and steps necessary to diagnose a lung cancer varies in every patient. Once a lung nodule is found, and the size warrants investigation or follow up, there are several options in general:
•Imaging: most small nodules, particularly if found during screening CT or are smaller tan 10 mm will be followed with serial CT scans of the chest. These can be performed in different intervals ranging from 3-12 months depending on the nodule size and characteristics. If there is no growth, the interval between scans can be increased and usually a nodule is declared benign if now growth in a 2 to 3 year period. Some nodule that a not solid (ground glass opacities or GGO) may need monitoring for a longer period of time. Some larger nodules (larger than 8 mm) may be evaluated with a more specialized test called a PET (positron emission tomography scan) which uses a radiolabeled dye that accumulates in cancer tissue or metabolic tissue.
•Biopsy: If a nodule has a larger size or features that make it more concerning, or is positive on PET scan, it may require biopsy. The biopsies are very safe, but some complications can occur, which you will discuss with your doctors. The biopsy approach varies in each case, but in general the options include:
⎫Bronchoscopy- a biopsy using a bronchoscopy (video telescope camera through the mouth or nose under anesthesia). A more advanced option sometimes uses navigation or links the CT scan images and uses guidance to reach more peripheral lung nodules.
⎫CT guided biopsy: the radiologist uses a live CT picture to pin point the nodule and sample the tissue with a needle inserted between the ribs under local anesthesia and sedation.
⎫Surgery or removal: When the likelihood of cancer is high, some patients will be offered surgery to directly remove the nodule to obtain a diagnosis and eradicate the disease one step. This more often requires removal of the nodule and a small amount of surrounding lung tissue (wedge resection) but may also require removal of a larger segment of the lung or the entire lobe (Lobectomy or art of the lung). The surgical approach is commonly done with a less invasive approach called VATS (video assisted thoracic surgery) with video cameras and small incisions placed on the side between the ribs.
LUNG CANCER DIAGNOSIS
a.Types of lung cancer: there are two main types of lung cancer
•Non-small cell lung cancer: about 85% of lung cancers are of the non-small cell type. It includes large cell carcinoma, squamous cell carcinoma and most commonly, adenocarcinoma. Other types of lung tumors such as carcinoid tumors represent less than 1-2% of all cancers.
•Small cell lung cancer: 15% of lung cancer are small cell. This tumor always occurs in smokers. This tumor is also called a poorly differentiated neuroendocrine carcinoma.
b.What is the best area to biopsy?
•The best area for biopsy to obtain a diagnosis is the site that provides the most information with the least risks. In patients with only a lung nodule, clearly that is the best and only site. But in someone with a lung nodule plus a lymph node plus a spot in the liver, a biopsy of the liver can provide tissue for diagnosis and also can confirm if the cancer has spread to another organ.
c.Biopsy options
•Bronchoscopy and navigation: simple bronchoscopy can be used for diagnosis or larger tumors and those close to the main bronchial tubes. For smaller nodules and more distant from the main airways, a navigation bronchoscopy uses the bronchoscopy view merged with a computer map using the CT scan which directs the path closest to the nodule. This is a reliable technique with low risk of complications and requires sedation and anesthesia.
•Lymph node biopsy (EBUS/Mediastinoscopy)- These techniques are used to evaluate lymph nodes located in a compartment between the lungs called the mediastinum. Cancer cells can sometimes spread to nearby lymph noses, and detecting cancer in these areas can affect the disease stage and treatment plan.
•Biopsy of sites outside of the chest- If a lesion or abnormality is found outside of the lung such as the brain, liver or bone it is important to confirm if it is truly a metastasis. It is therefore useful to obtain a biopsy of suspicious sites if possible to obtain an accurate diagnosis and stage.
•CT guided Biopsy- The interventional radiologists specialize in performing needle biopsies of nodules or tumors in the lungs and other parts of the body. This is often done using CT scans for imaging guidance and is a technique with a low risk profile and usually well tolerated.
•Surgery- Surgery with a video assisted less invasive approach or open approach some times is used for both diagnosis and treatment of the disease at the same time, if the lesion is completely operable and highly concerning for malignancy. Not every patient is eligible for lung cancer surgery and this depends on several factors. A thoracic surgeon with expertise in lung cancer is able to assess each case and determine if surgery can be an option in each individual case.
•Blood tests- There are currently no tests that can reliably detect lung cancer. Often, laboratory abnormalities occur late in the disease, and at this there is no clinically available biomarker or screening blood test in lung cancer that is used routinely. There are some promising blood test options under investigation which may help in the diagnosis of lung cancer in the future.
LUNG CANCER STAGING
a.What is staging? Staging is the process of assigning a disease stage in cancer, by combining information from history, physical exam, imaging studies and biopsies. The staging system used in lung cancer is based on the TNM guidelines form the International Association for the Study of Lung Cancer (IASLC) and is based on assessment of the characteristics of the Tumor (T), lymph nodes (N) and Metastasis (M). The stages range from stage IA to stage IV.
b.Importance of staging- establishing an accurate stage is important in order to recommend the best treatment and avoid undertreating or over treating a patient. For example, if a patient is diagnosed with a lung nodule and a biopsy shows lung cancer (non-small cell). However, a PET scan shows a concerning spot in a rib. The patient is assigned a stage IV due to suspicion of a bone metastasis. This patient is now recommended for chemotherapy and no surgery for the cancer. A more clear evaluation determined that the patient had a fall with a rib fracture of that same rib, which can explain the PET scan findings. A biopsy of the rib did nor show malignancy, and he is now a stage IA patient with better prognosis and is a candidate for surgery. This is why having a correct stage with discussion in a multi-disciplinary team of doctors with expertise in lung cancer can guide patients in their treatment options based in a correct stage of disease.
c.Lung cancer stages- Lung cancer, particularly non-small cell lung cancer is classified in four main stage groups, which are then subdivided based on the extent of disease. The stages of lung cancer are the following
•Stage IA and IB- Tumor is located in the lung, surrounded by normal lung tissue and of a size of 0-3 cm (IA) or 3-5 cm (IB).
•Stage IIA and IIB- Tumor is localized to the lung but of much larger size, invades the lung lining (pleura), invades the ribs or other structure, or has spread to the local lymph nodes within the lung
•Stage IIIA- this group of patients is more complex and presentations vary in each case. The most common reason for someone being diagnosed with stage IIIA disease is due to cancer spread to the lymph nodes outside the lung called the mediastinum. Patients with stage IIIA disease usually require evaluation form a team of doctors including medical oncologists, radiation oncologist and surgeon to determine the treatment options based on the extent of disease.
•Stage IIIB- these patients usually have more extensive disease and more involvement of the lymph nodes in the chest now extending to the opposite site of the tumor and towards the neck. Like stage IIIA patients, a multi-disciplinary evaluation by several specialists is needed to formulate the optimal treatment plan.
•Stage IV- when lung cancer presents at an advanced stage, it can sometimes show evidence of spread to another organ or metastasis. This can affect any part of the body, but more commonly the brain, bone, liver and other sites. Not all patients with stage IV lung cancer have the same prognosis and individual evaluation is important to investigate treatment options and the tumor genetic profile, which can affect treatment recommendations.
d.Prognosis per stage: The prognosis of lung cancer depends on many factors, including the tumor characteristics, genetic profile, disease stage, the patient’s overall medical condition and activity level. The prognosis also depends on the type of treatment received. The change of survival of patient untreated or who did not pursue treatment is poor. Overall, the prognosis of lung cancer for stage I is 50%. However, patients with stage IA disease who have surgery can have a 5-year survival or cure rate of over 70%. Therefore, the prognosis depends of the stage of disease at presentation and the treatment effect on that individual patient.
Disclosure- The information presented here is a general guideline and opinion. The purpose is for education only. It is NOT a medical consultation and the information may not apply to your individual situation. The information here is not intended to replace medical professional advice or guide individual patient care. Please consult with a medical professional for an evaluation of your own individual case.