Lung Cancer—Most Prevalent Cancer Worldwide
According to the International Agency for Research on Cancer (IARC) lung cancer has become the leading global cause of cancer death.
The enormous burden of lung cancer obscures the fact that most cases are avoidable. The principal risk factor for developing lung cancer remains tobacco smoking, which is responsible for approximately 85% of all cases. Other common causes include exposure to contaminants such as second-hand tobacco smoke, outdoor and indoor air pollution, diesel engine exhaust, welding fumes, and asbestos.
Lack of awareness about disease symptoms, a limited screening adherence of high-risk persons, and a late referral to specialists are the major reasons for delayed diagnosis and poor outcome for lung cancer patients.
Lung Cancer in MENA and the United Arab Emirates
The good news first: Lung cancer in the MENA region is less frequent than international rates. A research review by Abdulrahman R. Jazieh and colleagues from universities and medical facilities in Saudi Arabia and Egypt published in 2019 shows a sixfold higher rate of lung cancer in US, China, or France compared to the GCC countries, including UAE.
However, there is also bad news: In MENA and the UAE, the rate of new diagnoses (scientifically termed “incidence”) of lung cancer is rising. In addition, four out of five lung cancer patients are diagnosed at a late cancer stage, resulting in limited treatment options and poor 5-year survival rate of less than 10%. Therefore, although lung cancer is only ranked 6th of all cancer disease in UAE, it has been calculated as the second leading cause of deaths due to cancer in 2020.
Lung Cancer Types: SCLC versus NSCLC
Lung cancer is not always the same. There are several types, and each has its own characteristics and needs when it comes to treatment. Lung cancer diagnoses are broken down into two main groups: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).
Small Cell Lung Cancer (SCLC)
is typically caused by tobacco smoking. It often starts in the bronchi – the airways that lead from the trachea into the lungs and then branch off into progressively smaller structures. After affecting the bronchi, SCLC quickly grows and spread to other parts of the body, including the lymph nodes. This type of lung cancer represents fewer than 20% of lung cancers. However, SCLC has the highest lung cancer mortality, as almost all tumors recur after initial chemotherapy and then are resistant to further therapy.
Non-Small Cell Lung Cancer (NSCLC)
accounts for around eight or nine out of every 10 diagnoses and typically grows at a slower rate than SCLC. However, this type of lung cancer often causes few or no symptoms until it has advanced and is also diagnosed at a late stage. There are three main types of NSCLC: adenocarcinoma of the lung, squamous cell, and large-cell undifferentiated carcinoma.
Adenocarcinoma is the most common form of lung cancer, accounting for 40% of all non-small cell lung cancers. This type of cancer is also found in other common cancers, including breast cancer and prostate cancer. In NSCLC, it is found in the outer region of the lung, in glands that secrete mucus.
Squamous cell lung cancer is responsible for about 30% of all non-small cell lung cancers and is generally linked to smoking. This type of cancer begins in the center of the lung.
Large-cell undifferentiated carcinoma lung cancer accounts for approximately 10-15% of all NSCLC diagnoses. It can begin in any part of the lung and is known to grow and spread quickly.
Symptoms of Lung Cancer: What Are Alert Signs?
Lung cancer can cause several symptoms that may indicate a problem in the lungs. They include
- cough that does not go away
- chest pain
- shortness of breath
- coughing up blood
- fatigue (being exhausted and tired)
- weight loss with no known cause
- lung infections that keep coming back.
Often, these symptoms may be caused by common respiratory issues. Therefore, early symptoms of lung cancer can be dismissed, leading to delayed diagnosis.
Major Risk Factors of Lung Cancer
Around 85% of lung cancer are caused by exposure to tobacco smoke and other airborne chemicals such as air pollution. There is a 20- to 50-fold greater risk of developing lung cancer in continuous smokers compared to never-smokers, with duration of smoking being the strongest determinant of lung cancer risk.
Risk factors such as genetic susceptibility, advanced age (55 to 74 years), poor diet, indoor and outdoor air pollution, occupational exposure to carcinogens (such as asbestos, silica, radon, heavy metals, polycyclic aromatic hydrocarbons, ionizing radiation), and chronic lung inflammation may act independently or in association with tobacco smoking to increase the risk of lung cancer.
Who Should Be Screened for Lung Cancer?
The recommended test to screen for lung cancer is a low-dose computed tomography (also called a low-dose CT scan, or LDCT). The X-ray machine uses a very low dose of radiation to make a detailed image of the lungs. This type of scan takes only a few minutes, and it is not painful.
Screening criteria vary depending on governmental regulations. In the UAE, low-dose CT scans are recommended for smokers and those who have quit if they fall into one of the following “high-risk” groups.
High-risk candidates of lung cancer aged 55-75 years with:
- 30 pack-year history of smoking and/or tobacco cessation <15 years.
- 20 pack-year history of tobacco use and/or tobacco cessation <15 years
and one additional risk factor;
- 20-year history of water pipe (shisha) and/or dokha, medwakh and/or all other forms of smoked tobacco use.
To calculate your “pack-year”, multiply the number of years you smoked by the number of packs of cigarettes you smoked a day.
Examples:
20 years of smoking x ½ pack a day = 10 pack-years
Or calculate online at: Pack Years Calculator (mdcalc.com)
If you belong to a high-risk group, as an inhabitant of UAE you can subscribe online and book a screening appointment at www.haad.ae/simplycheck.ae.
If you are not sure about your personal risk, talk to your doctor!
Diagnosis of Lung Cancer–What Staging Means
Staging is the process of defining to which extend the cancer has already progressed. It is essential in determining the treatment plan. According to Cancer Research UK the definition of stages of lung cancer are:
Stage 1
The lung cancer is found only in the part of the body where it started, ie the lung. This is called localized disease. There are 4 different sub-stage groups.
At stage 1A1 the cancer
- is 1cm or less at its widest part
- has not grown into the membranes that surround the lungs (pleura)
- has not grown into the main branches of the airways
- has not spread to nearby lymph nodes
- has not spread to distant parts of the body
At stage 1A2 the cancer
- is between 1cm and 2cm
- has not grown into the membranes that surround the lungs (pleura)
- has not grown into the main branches of the airways
- has not spread to nearby lymph nodes
- has not spread to distant parts of the body
At stage 1A3 the cancer
- is between 2cm and 3 cm
- has not grown into the membranes that surround the lungs (pleura)
- has not grown into the main branches of the airways
- has not spread to nearby lymph nodes
- has not spread to distant parts of the body
At stage 1B means one or more of the following:
- the cancer is between 3cm and 4cm
- it is smaller than 4cm and has grown into the main airway of the lung (main bronchus)
- it is smaller than 4cm and has grown into the membrane covering the lung (visceral pleura)
- it is smaller than 4cm and has caused the lung to partly or completely collapse by blocking the airway or causing inflammation of the lung tissue (pneumonitis)
Stage 2
At this stage the tumor is mostly between 3 – 5 cm,
- or has spread to regional lung lymph nodes,
- or has grown into the main airway of the lung (main bronchus), the membrane covering the lung (visceral pleura),
- or has caused the lung to partly or completely collapse by blocking the airway or causing inflammation of the lung tissue (pneumonitis).
Stage 3
is sometimes called locally advanced cancer.
The expansion of the tumor is like stage 2, but more lymph nodes, especially those in the tissues between the two lungs, contain cancer cells.
Stage 4
is also called metastatic (distant advanced) lung cancer.
The cancer has spread to one or more different parts of the body. This is called regional or distant or advanced disease. It might have spread to additional nearby lymph nodes, to the other lung, or to several areas outside the chest such as distant lymph nodes or other organs.
Lung Cancer Staging and Survival Rates
When patients and their families are confronted with an advanced cancer disease, they may ask “How Long Have I Got?” A difficult question. With no easy answer.
Health organizations and researchers watch what happens to people with cancer in the years after their diagnosis. 5 years is a common time point to measure survival. Survival statistics available for people diagnosed for each stage of lung cancer in England between 2016 and 2020 give a rough idea about the statistical chances to survive a lung cancer diagnosis.
- Stage 1: Around 65 out of 100 people (almost 65%) with stage 1 lung cancer will survive their cancer for 5 years or more after they’re diagnosed.
- Stage 2: Around 40 out of 100 people (around 40%) with stage 2 lung cancer will survive their cancer for 5 years or more after they’re diagnosed.
- Stage 3: Around 15 out of 100 people (around 15%) with stage 3 lung cancer will survive their cancer for 5 years or more after they’re diagnosed.
- Stage 4: Around 5 out of 100 people (around 5%) with stage 4 lung cancer will survive their cancer for 5 years or more after they’re diagnosed.
However, be aware that survival rates are statistical probabilities, and some people live much longer than this.
Survival is depending on many factors such as
- the stage of the cancer when it was diagnosed.
- the type of cancer.
- the general health and fitness. The fitter a patient is, the better they may be able to cope with the cancer disease and the treatment.
- genetic changes (mutations) within the tumor cells as treatment options depend on them.
- The introduction of a new therapeutic treatment may result in much better survival rates than historical data suggest.
An international research group from China, Norway, Italy and US tried to answer the “Doctor, How Long Have I Got?” question for stage 4 non-small cell lung cancer (NSCLC). Patients worldwide have a poor survival in this situation. 25%–30% die within the first three months after diagnosis, making stage 4 NSCLC one of the deadliest cancers. Yet, of those surviving longer than 3 months, 10%–15% survive much longer, around 5% even 10 years. None of these patients surviving 10 years was disease free. However, the metastases were dormant, and one may expect even longer survival than 10 years (which was the maximum follow-up in the current study).
With all the researchers analysis published in Frontiers in Oncology in December 2021 about the differences between the short and long time surviving patients, they found no reliable predictive parameters. Currently, the question “Doctor, how long do I still have?” cannot be accurately answered. And even in advanced cancer with no cure in sight, there is always hope for many good years.
Read more about Survival Rates in our Blog:
Treatment for Lung Cancer
Lung cancer therapy depends on several factors. These include the type of lung cancer, the stage, molecular changes in the tumor cells and the general health of the affected patient.
The most common treatments for small cell lung cancer are:
- chemotherapy
- radiotherapy
- surgery
- chemotherapy with radiotherapy (chemoradiotherapy)
- radiotherapy to the brain (prophylactic cranial irradiation – also called PCI)
- chemotherapy with or without immunotherapy
The most common treatments for non-small cell lung cancer are:
- surgery
- radiotherapy
- chemotherapy
- chemotherapy with radiotherapy (chemoradiotherapy)
- immunotherapy
- targeted cancer drugs
Treatment Option for Early-Stage Lung Cancer
The primary treatment for early-stage lung cancer (stage 1) is surgical removal of the tumor. Neoadjuvant therapy (chemotherapy and/or radiation therapy before surgery) can help reduce tumor size, making it more manageable for surgical removal. Adjuvant chemotherapy and/or radiation is very often recommended after surgery to reduce the risk of cancer recurrence.
In cases where surgery is not feasible, radiation therapy or stereotactic body radiation therapy (SBRT) may be used as the primary treatment. Targeted therapy and immunotherapy may also be considered based on specific tumor characteristics. Individualized treatment plans should be discussed with a multidisciplinary team of healthcare professionals. It also makes sense to ask for an independent second medical opinion to gather additional insight into the treatment options.
Treatment Option for Advanced Lung Cancer
When lung cancer has spread to lymph nodes or distant organs, treatment is based on various factors, including the patient’s overall health, the extent and location of metastases, histology, genetic profile, and individual preferences. The primary goal is to prolong survival, alleviate symptoms, and improve quality of life. Systemic therapies, such as chemotherapy, targeted therapy, and immunotherapy, play a crucial role in the treatment of metastatic lung cancer.
Lung Cancer and Chemotherapy
Chemotherapy is often the first-line treatment for the majority of patients with advanced lung cancer and involves the use of drugs that circulate throughout the body to kill cancer cells. Combination chemotherapy regimens are commonly used.
Lung Cancer and Targeted Therapy
Targeted therapy, designed to block the signaling pathways that drive the growth of cancer cells, is an important option for patients with specific genetic mutations or biomarkers identified in their tumor.
Lung Cancer and Immunotherapy
Immunotherapy, specifically immune checkpoint inhibitors, has revolutionized the treatment of metastatic lung cancer. These drugs help to stimulate the immune system to recognize and attack cancer cells.
Lung Cancer and Surgery or Radiation Therapy
Local treatments, such as radiation therapy and surgery, may be used to manage specific metastatic sites or alleviate symptoms caused by tumor growth.
Read more about targeted therapy or immunotherapy in our Blog Sarcomas: Rare and Complex Cancers Experience and Expertise | TheKnowHow
Lung Cancer and Clinical Trials
Clinical trials offer opportunities to access novel treatments or experimental therapies for patients. Participation in clinical trials helps advance medical knowledge and potentially offers new treatment options.
Being informed about advantages but also disadvantages of such a treatment option is important. Read more about clinical trials in our Blog: Ovarian Cancer – Coping with an advanced condition. | TheKnowHow.
Don´t Feel Guilty – Seek Help!
Lung cancer patients report the highest distress levels of all cancer groups. In addition to poor prognosis, the self-blame and stigma associated with smoking might partially account for that distress and prevent patients from requesting help and communicating with their family, friends or even doctors.
No one “deserves” lung cancer! A person’s smoking history is an important part of their medical history. But it is irrelevant to the level of care and concern a lung cancer patient has the right to receive.
TheKnowHow Independent Second Opinion Service
Are you or a loved one suffering from lung cancer and are unsure about the exact diagnosis or are concerned about your current treatment choices?
TheKnowHow Independent Second Opinion Service is not intended to take you away from your treating doctor but rather provide an extra level of competence. Get an unbiased assessment from an international expert without having to travel or schedule appointments. Our impartial specialists conduct a record-based assessment of your current health state and all available treatment options, including their advantages and potential hazards.
Read more on https://theknowhow.ae/second-medical-opinion/
https://theknowhow.ae/lung-cancer-awareness-mena/
Sources:
- Stages of lung cancer | Cancer Research UK
- Survival for lung cancer | Cancer Research UK
- “How Long Have I Got?” in Stage IV NSCLC Patients With at Least 3 Months Up to 10 Years Survival, Accuracy of Long-, Intermediate-, and Short-Term Survival Prediction Is Not Good Enough to Answer This Question – PMC (nih.gov)
- Lung Cancer Screening Service Specifications_Publish.pdf
- Meet 5 Inspirational Lung Cancer Survivors with Stories of Hope | LCFA (lcfamerica.org)
- Lung cancer (who.int)
- Small Cell Lung Cancer: Symptoms, Causes & Treatment (clevelandclinic.org)
