The evolution of non-small cell lung cancer metastases in TRACERx
An Overview Of The Types Of Lung Cancer
The two main types of lung cancer are small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). However, there are various other subtypes and rarer types.
Lung cancer starts in the lungs or the main airways and leads to uncontrolled cell growth. This can cause tumors to form. While anyone can get lung cancer, the risk is much higher for smokers and those experiencing exposure to secondhand smoke, certain chemicals, or toxins.
In the United States, lung cancer is a leading cause of cancer deaths.
This article explores the main types of lung cancer, including their definitions, prevalence, causes, subtypes, and treatments.
Approximately 15% of all lung cancers are SCLC. This type forms part of a group of cancers that originate from neuroendocrine cells, including neuroendocrine tumors (NETs). These are rare tumors that develop in cells of the neuroendocrine system, which is responsible for hormone production.
SCLC is known for its aggressive nature and rapid growth. It tends to spread quite early on.
CausesThe main cause of SCLC is smoking. It is rare among non-smokers. Other contributing factors may include exposure to carcinogens and a family history of cancer.
While smoking is the largest known risk factor, there are people with an SCLC diagnosis who have never smoked. There are a few known risk factors for non-smokers, though women who are non-smokers are much more likely than male non-smokers to have an SCLC diagnosis.
Carcinogens are substances capable of causing cancer.
SCLC begins in the bronchi, one of the main air passages in the lungs.
SubtypesThere are two subtypes of SCLC: oat cell carcinoma and combined SCLC.
TreatmentTreatment largely depends on the stage of SCLC. Due to its aggressive nature, doctors often treat it with:
NSCLC is a term describing a group of several subtypes of lung cancer. It is the most common type, accounting for approximately 80 to 85% of all lung cancer cases.
Symptoms of NSCLC include a persistent cough and shortness of breath.
CausesThe primary causes of NSCLC include exposure to carcinogens such as:
Genetic factors and a history of lung diseases can also increase the risk.
SubtypesNSCLC includes several subtypes that originate from different types of lung cells, including:
Treatment options for NSCLC include:
The choice of treatment depends on the stage of cancer and a person's overall health.
Pancoast tumors, also known as superior sulcus tumors, are a rare form of lung cancer, accounting for approximately 5% of lung cancer cases. They start developing at the top of the lungs.
The tumor invades nearby areas, such as the ribs and spine. The majority of Pancoast tumors are a type of NSCLC.
CausesThe primary risk factors include smoking and exposure to industrial chemicals or asbestos. Pancoast tumors may also occur from other diseases, such as lymphoma or tuberculosis.
TreatmentTreatment for Pancoast tumors usually involves a combination of radiation therapy and surgery. Doctors may also recommend chemotherapy if the cancer has spread.
Carcinoid tumors of the lung are very rare, accounting for less than 2% of all lung cancers. They tend to grow slowly and are more common in younger people.
Approximately 80% of these tumors occur centrally in the lung, while 20% are in other parts of the body.
CausesThe exact cause of carcinoid tumors is unclear, though research suggests a potential link to smoking. Genetic factors and family history can also play a role.
SubtypesCarcinoid tumors divide into two subcategories: typical and atypical.
Typical carcinoids tend to grow slowly and rarely spread beyond the lungs. Atypical carcinoids tend to grow faster and are more likely to spread.
TreatmentSurgical removal is the primary treatment for carcinoid tumors. Depending on the case, doctors may also consider radiation therapy and chemotherapy.
To determine the type of lung cancer a person has, doctors use several diagnostic tests, including:
These tests can identify the specific cause, type, and subtype of cancer, which helps doctors recommend the best treatment options.
In this section, we answer some frequently asked questions about lung cancer.
What is the most aggressive form of lung cancer?Healthcare professionals consider SCLC to be the most aggressive form due to its rapid growth and tendency to spread early.
What is slow-growing lung cancer called?Carcinoid tumors are known for their slow growth, so doctors consider them a type of slow-growing lung cancer.
What are the three main types of lung cancer?The three main types of lung cancer:
Life expectancy varies greatly depending on the type and stage of lung cancer at diagnosis, the patient's overall health, and response to treatment. Early stage lung cancers have a more positive outlook, while lung cancers at an advanced stage usually have a lower survival rate.
Gene changes in the cancer cells can also affect life expectancy.
Lung cancer has various types and subtypes, each with distinct characteristics, risk factors, and treatment options.
Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, followed by small cell lung cancer (SCLC), which is more aggressive.
Pancoast tumors and carcinoid tumors represent rarer forms with specific treatment strategies. Early detection and accurate diagnosis are crucial in managing lung cancer effectively.
An Overview Of Large Cell Lung Carcinoma (LCLC)
Large cell lung carcinoma is a common type of lung cancer that may spread rapidly. An early diagnosis can help improve treatment outcomes.
There are many forms of lung cancer, but each has its own characteristics.
Large cell lung carcinoma (LCLC) is one form of non-small cell lung cancer that tends to grow more quickly and spread more aggressively than some other forms.
LCLC is a catch-all diagnosis for large cell lung cancers that can't be classified into other specific subgroups.
In this article, learn about the differences between small and large cell carcinomas in the lung, how LCLC is diagnosed and treated, and what to expect if you receive this diagnosis.
LCLC is a type of cancer that affects the lungs. It can form anywhere in the lung but is more common on the outer edges.
Non-small cell carcinomas, like LCLC, are the most common form of lung cancer, making up 80% to 85% of all lung cancers.
There are three major types of non-small cell carcinomas:
AdenocarcinomaAdenocarcinoma is the most common type of lung cancer and is classified as a non-small cell lung cancer. It usually begins in the outer sections of the lung. It's the type of lung cancer most often found in nonsmokers.
Adenocarcinoma makes up about 40% of all non-small cell lung cancers.
Large cell carcinomaThis type of lung cancer is named so because of its large, abnormal-looking cells. These cells can be found throughout the lungs. They also tend to grow more quickly and spread faster than other forms of non-small cell lung cancers.
LCLC makes up 10% to 15% of all non-small cell lung cancers.
Squamous cell carcinomaSquamous cell carcinoma is another large cell carcinoma that is sometimes referred to as epidermoid carcinoma. This type of non-small cell lung cancer usually begins in the middle structures of the lung, like the bronchi. Squamous cell carcinomas make up about one-quarter of all non-small cell lung cancers.
Other forms of lung cancerOutside of LCLC, there are several other forms of lung cancer. These include:
Despite their unique qualities, LCLCs and other forms of non-small cell lung cancers share the same symptoms, which may include:
Many cancer symptoms are fairly vague. A cough, wheezing, or loss of appetite can appear with many conditions. This is why many cases of lung cancer aren't detected in the early stages. This can delay diagnosis and mean that cancers aren't detected until they're already at a later stage.
Seek emergency care if you experience the following symptoms:
These symptoms can lead to medical emergencies and affect your ability to breathe. They require immediate medical assessment and treatment.
Ideally, non-small cell lung cancers are diagnosed in the early stages, when there are more and better treatment options.
However, since many symptoms are common to other conditions, often a diagnosis isn't made until the later stages of non-small cell lung cancer.
If you're at high risk of developing lung cancer, such as if you smoke or work around airborne chemicals, annual screenings can help your doctor make a diagnosis early.
You can take this free quiz from the American Lung Association to see whether you're at high risk.
Annual screenings are done through imaging technologies like low dose CT scans. They are recommended for people at high risk between 55 and 80 years old. Many insurance companies will cover the cost of the scan.
If you're not in a high risk group, your doctor will ask you about your medical history, lifestyle, and family history. They will also perform a physical exam and may order a chest X-ray or CT scan if they suspect lung cancer.
Your doctor may also choose to test fluids or cells from your lungs more directly by performing a biopsy. This can be done using a number of procedures, such as:
A biopsy can help your doctor examine the specific biomarkers of the cancer to target treatment and to better understand the stage. Biomarkers can help doctors determine which treatment is best for the type of cancer you have.
Many things can cause lung cancer, but smoking is by far the greatest risk factor.
Roughly 80% of lung cancer deaths are attributed to smoking, reports the American Cancer Society.
Other risk factors include:
Here are some of the main types of treatment for non-small cell lung cancers like LCLC.
SurgerySurgery may be one of the first treatment steps if cancer is detected early and hasn't spread. Your doctor may be able to remove the tumor or, if the cancer is more widespread, entire sections or lobes of the lung.
Radiation therapyWhen tumors have grown too large to remove, or when trying to avoid removing large sections of lung, radiation therapy may be used to try and control cancer growth.
With this treatment, radiation waves are directed at the area to kill existing cancer cells and prevent new ones from forming.
ChemotherapyChemotherapy involves the use of a number of medications that kill fast-growing cells like cancer. It can affect other cells that grow fast, too, like skin and hair.
There are many types of chemotherapy. Your doctor or care team may recommend trying more than one. Depending on which therapy is chosen, chemotherapy may be given as an implant, orally, or intravenously.
You may receive chemotherapy alone or with radiation therapy.
Targeted therapyWith some cancers, like those caused by genetic mutations, special medications that target cancer cells but spare healthy cells may be used. These medications typically don't cure cancer but control growth and spread.
ImmunotherapyImmunotherapy is a growing area of medicine. In this therapy, your immune system is programmed to fight a variety of conditions.
Several immunotherapy medications are currently being used in the United States to treat lung cancer.
Some cancers are slow-growing and unlikely to spread. LCLC, however, tends to be more aggressive and can spread quickly.
Early diagnosis is key to a good outlook.
Overall, according to figures from the National Cancer Institute, about a quarter of the people with some form of non-small cell lung cancer live for at least 5 years after their diagnosis, up from about 16% in the 1970s.
One 2020 study using data from 2004 to 2015 reports an overall 5-year survival rate of 19% for LCLC.
People with LCLC tend to be on the lower end of that survival spectrum, especially with certain types of this cancer. For example, large cell neuroendocrine carcinoma, a rare type of LCLC, has a median survival rate of about 6 months after diagnosis.
Many individual factors, as well as diagnosis and treatment, all play a role in your prognosis with LCLC. Survival rates are improving with advanced treatments.
Coping with a lung cancer diagnosis is another element of the disease. Make sure you're comfortable with the doctor and treatment plan, and explore all options available to you.
Your doctor may also be able to direct you to local resources or support groups to help you process everything that comes along with this condition.
Symptoms of lung cancer may develop without notice for some time, making diagnosis more difficult.
Talk with a doctor to find out whether you meet the criteria for annual lung cancer screenings, especially if you are or were a heavy smoker. Annual screenings may help detect lung cancer early, improving the chances of a positive outcome.
Survival rates for all forms of lung cancer are increasing due to new medications and treatments.
What Black Americans Need To Know Clinical Trials For Lung Cancer
Lung cancer, or bronchogenic carcinoma, is the collective name for cancers that start in the lungs— usually in the airways (bronchi or bronchioles) or small air sacs (alveoli). Lung cancer is known for its aggressive nature and high mortality rate.
Eric Singhi, M.D., Assistant Professor at the Department of Thoracic, Head, and Neck Medical Oncology, at the University of Texas MD Anderson Cancer Center, says more people die from lung cancer than from breast, prostate, and colon cancers combined. "This type of cancer can metastasize early and widely, leading to frequent late-stage diagnosis."
Dr. Singhi explains, "There are different types of lung cancer, which we generally categorize into non-small cell lung cancer (NSCLC), which represents 85 percent of all cases of lung cancer, and small cell lung cancer (SCLC). NSCLC tends to spread more slowly than SCLC. However, both NSCLC and SCLC can be aggressive, with SCLC often being particularly fast-growing and prone to early spread/metastasis."
Despite medical advancements in treatments beyond conventional chemotherapy, such as targeted therapies and immunotherapy, Dr. Singhi says many lung cancers eventually become resistant to treatment, requiring ongoing research into new solutions.
What are clinical trials?Clinical trials are research studies that evaluate the safety and efficacy of new treatments, including procedures, drugs, and therapies. They may also explore combinations of treatments and medications that are already available. These trials progress through several main stages: Phase I, II, and III, with some trials combining phases or including additional stages such as Phase 0 and Phase IV.
Phase I trials are the initial stage, where a new treatment is tested on a small group of 15 to 50 people. The primary goals of Phase I trials are to evaluate the treatment's safety, determine the best method of administration (such as oral or intravenous), and identify any side effects. This phase can take several years to complete.
In Phase II, the focus shifts to assessing the treatment's effectiveness against lung cancer. This phase involves a larger group of over 100 people and continues to gather information on possible side effects to further examine the treatment's safety.
Phase III trials expand the treatment's testing to even larger groups. The objectives in this phase are to confirm the treatment's efficacy, monitor side effects, compare it to commonly used treatments, and collect comprehensive information to ensure its safe use. After completing Phase III, the U.S. Food and Drug Administration (FDA) reviews the trial results to determine whether the treatment is safe and effective enough for public use. Based on this review, the FDA decides whether to approve the treatment for general use.
Phase IV trials, also known as "post-marketing surveillance," are conducted after the treatment has been licensed and approved by the FDA. These trials gather additional information on the treatment's effects in various populations and monitor any long-term side effects. Phase IV trials may also study the treatment's effectiveness against different types of cancer.
Clinical trials are a key element of developing new treatments, as they provide the necessary data for regulatory approval and public access to potentially life-saving therapies. They offer some patients the opportunity to access experimental treatments, contributing to medical knowledge and potentially saving many lives.
Benefits of participating in a lung cancer clinical trialDr. Singhi says, "There are many benefits to enrollment in clinical trials, such as potentially more effective or safer treatments, active involvement in health care decisions, and a direct contribution to advanced understanding and potential improvements in disease management."
Potential risks include unknown side effects, ineffective treatment, and time and financial losses during the trial. However, these concerns are outlined before a patient gives informed consent.
"Barriers to clinical trial enrollment include lack of awareness among health care clinicians and patients about available trials, eligibility criteria that can limit participation, time and travel commitments, the financial burden associated with travel, language and cultural challenges, and patients' distrust of researchers and clinicians," states Dr. Singhi.
Types of clinical trials for lung cancerLung cancer clinical trials frequently focus on cutting-edge approaches.
For example, targeted therapy trials usually investigate new drugs that interfere with specific molecules responsible for tumor growth. Immunotherapy trials aim to enhance the body's immune response to lung cancer cells. These trials often explore treatments like checkpoint inhibitors, cancer vaccines, and adoptive T-cell therapy, all of which are designed to boost the immune system's ability to fight cancer. Additionally, other trials investigate new combinations of chemotherapy drugs.
Ongoing lung cancer clinical trials are being conducted at leading institutions, including the National Cancer Institute, MD Anderson Cancer Center, and Memorial Sloan Kettering Cancer Center. You can learn more about clinical trials offered in the United States by visiting the NIH National Cancer Institute website.
Finding a lung cancer clinical trialFinding a suitable clinical trial can be challenging.
The first step is to talk to your doctor or health care provider. They can help you understand your options and recommend specific trials. They might also assist in submitting your name for approval, especially for invitation-only trials.
Several resources are available to help patients and their families find clinical trials. Before you begin searching, gather your medical information to quickly check eligibility. Online databases offer comprehensive listings of clinical trials, including details about eligibility, locations, and contact information. ClinicalTrials.Gov is the most extensive database, allowing you to search by tumor type and other criteria.
The National Cancer Institute provides resources and support for finding clinical trials. Larger cancer centers, including the Mayo Clinic Lung Cancer Program, Memorial Sloan Kettering Cancer Center, and Stanford Medicine, also maintain databases of lung cancer clinical trials offered at their institutions. Also, search BlackDoctor.Org's vetted list of clinical trials aimed at Black Americans.
Considerations for participation in lung cancer clinical trialsBefore deciding to participate in a clinical trial, it is best to consider several factors. One is the eligibility criteria. Each trial has specific requirements based on age, type of cancer, stage of cancer, and overall health. Understanding these criteria will help you decide if and when a trial is suitable for you.
Another important consideration is the potential risks. Clinical trials can involve unknown side effects and the possibility that the new treatment just doesn't work. It is crucial to discuss these risks with your family and health care team.
Additionally, many patients fear receiving a placebo or the impact treatment may have on their daily lives. Addressing these concerns with your doctor can help you make a well-informed decision.
Comments
Post a Comment