Everything you need to know about lung cancer

Dr WANBOR SUNGOH Assistant Professor, Department of Respiratory Medicine SMIMS, CRH Sikkim Manipal U

Lung cancer occurs when cells in the lungs divide uncontrollably because of gene mutation or change, causing tumours to grow. Anyone can develop lung cancer, but cigarette smoking and exposure to smoke, inhaled chemicals, or other toxins can increase the risk.

Lung cancer can be life threatening, but effective diagnoses and treatments, including chemotherapy and surgery, are improving the outlook.

Burden of lung cancer

Globally the most frequently diagnosed cancer is Lung cancer (11.4%). For men, lung cancer is the most prevalent form of cancer and third most common cancer for women following breast and colorectal cancer.

Lung cancer is at present the 6^th leading cause of deaths worldwide among all diseases and the leading cause of deaths among all cancers (according to GLOBOCAN 2020).

Types of lung cancer

The two main types of lung carcinoma are:

·       NSCLC (Non small cell lung cancer): Around 80% to 85% of lung cancer cases are NSCLC. The three main subtypes are:

o   adenocarcinoma

o   squamous cell carcinoma

o   large cell carcinoma

·       SCLC (small cell lung cancer): Around 10% to 15% of lung cancer cases are SCLC. This type tends to grow more quickly than NSCLC.

Age incidence of lung cancer

Age-specific incidence rates rise from around age 40-44 years and more than 65% of patients with lung cancer are more than 65 years with mean time at the age of diagnosis is 71 years, however it can occur at any age.

Causes and risk factors of lung cancer

Smoking tobacco  is the primary risk factor responsible for 87% and 70% of lung cancer deaths in males and females respectively. Excess risk of lung cancer among continuous smokers relative to never smokers is on the order of 10 to 20 fold.

However, not everyone with lung cancer smokes, and lung cancer can occur due to other factors, including:

·       exposure to chemicals such as: radon ,diesel exhaust ,asbestos, etc.

·       environmental factors, such as air pollution

·       inherited or acquired genetic changes

·       exposure to second-hand smoke

Symptoms of lung cancer

People with lung cancer do not typically experience symptoms until a later stage, when the cancer has spread (main reason for most cancer related death). However, potential symptoms include:

·       Cough that may worsen

·       coughing up blood

·       chest pain

·       appetite loss and weight loss

·       fatigue

·       shortness of breath and wheezing

·       voice changes

·       frequent chest infections (pneumonia)

In time, a person may also experience more severe symptoms, such as:

bone pain and bone fractures ,headaches  , muscle pain and swelling of face when the cancer spread to others organ.

Can white phlegm indicate lung cancer?

Coughing up phlegm, which may have blood in it, can indicate lung cancer. However, it can also be due to other causes like tuberculosis, Pneumonia, bronchiectasis etc. People should speak with a healthcare professional if they start to cough up phlegm, especially if they have other symptoms of lung cancer.

Lung cancer staging

Cancer staging describes its severity and how far it has spread through the body. Staging helps healthcare professionals and individuals decide on a course of treatment.

The most basic form of staging is as follows:

·       Localized: The cancer is within a limited area. ( stage-I)

·       Regional: The cancer has spread to nearby tissues or lymph nodes.(stage II to stage III)

·       Distant: The cancer has spread to other parts of the body.(stage IV)

Similar to this is the TNM staging system. Healthcare professionals the tumour’s size, whether it affects the lymph nodes, and whether it has spread elsewhere.

Lung cancer survival rates

(chances of surviving from lung cancer with treatment in 5 years?)

This depends on type of cancer, stage of disease at diagnosis and overall, general health condition. Survival rates reflect the chances of a person surviving with lung cancer compared with the chances of a person surviving without the condition (in percentage). The table below outlines the chances of surviving or longer after receiving a lung cancer diagnosis and treatment, as estimated by the ACS.

Can someone survive with lung cancer that doctors catch early?

Survival rates are generally better for people with a lung cancer diagnosis in the earlier stages with appropriate treatment.

Complications of lung cancer

Lung cancer complications may be due to the spread of cancer or treatment side effects. Some possible complications of lung cancer include:

·       spread to other parts of the body, such as the brain, bones, and adrenal glands   

·       tumours obstruct  blood flow leading to swelling of face and neck

·       Lung infections

·       high calcium levels in the blood

·       Blood clots

·       nerve pain, etc.

Lung cancer screening

Regular screening may benefit people with a high risk of developing lung cancer.

The American Lung Association (ALA) recommends screening for people who meet the following criteria:

·       people ages 50 to 80 years

·       a 20-pack-year history of smoking — which may mean smoking one pack of cigarettes daily for 20 years or two packs daily for 10 years

·       they currently smoke or have quit within the past 15 years

Lung cancer diagnosis

If a person has lung cancer symptoms or if screening shows something unusual,  the first step in diagnosing lung cancer is through the use of imaging tools to reveal areas of lung tissue with cancer, including:

·       X-ray

·       CT scan

·       PET scan

·       MRI

Scans can help track treatment progress and reveal changes to bones and other organs if the cancer has spread.

Tissue sampling

·        patient with suspected lung cancer require a tissue-based diagnosis. This can help confirm whether cancer is present and, if it is, determine its type and stage.

·        depending on site of lesion  a healthcare professional may wish to take a biopsy using a fine needle or a bronchoscope to check for cancer cells.

·        For less accessible lesions, they may use radial EBUS, navigation bronchoscope and more invasive surgical procedure, such as thoracoscopy or video-assisted thoracic surgery, to remove lung tissue.

·        Others sampling are sputum and pleural effusion.

Lung cancer treatment

Treatment will depend on various factors, including:

·       the type of cancer

·       the location and stage

·       the person’s overall health

·       their individual preferences

Some treatment options include:

·       surgery to remove part or all of a lung

·       chemotherapy, a drug treatment that can kill cancer cells and shrink tumours

·       radiation therapy, which uses high energy rays to kill cancerous cells

·       radiofrequency ablation, wherein a healthcare professional inserts a thin needle and uses an electric current to destroy cancer cells

·       targeted therapy, which targets a specific behaviour to prevent tumour growth

·       immunotherapy, which helps the body fight cancer cells

·       palliative therapy, such as pain relief, to manage symptoms

A healthcare professional can explain the pros and cons of each option and will work with the individual to adjust their treatment plan as their needs change.

Preventing lung cancer

Although it is not possible to prevent all lung cancers, but you may be able to reduce the risk by the following steps:

·        quit smoking, if applicable

·        avoid second-hand smoke

·        avoid radon and other toxins

·        eat a balanced diet

What is the quality of life for someone with lung cancer?

Lung cancer symptoms and treatments can cause distress and a poor quality of life for some people. Factors such as stress, social opportunities, and a patient’s perception of their treatment and condition may affect their quality of life. People with lung cancer can speak with their healthcare team about improving their quality of life.

Summary

·        Lung cancer may cause no symptoms until later stages, although some people may experience a chronic cough, changes to the voice, and fatigue.

·        People with a high risk of developing lung cancer can consider regular screening. This can help detect the early signs and allow for treatment before the cancer spreads.

·        Anyone with concerns about lung cancer can speak with a healthcare professional.