Lung cancer is the deadliest type of cancer in both, men and women. Each year, more people die of it than breast, colon and prostate cancers combined. Though cigarette smoking has been the leading cause of lung cancer, there have been occurrences amongst non-smokers as well. While lung cancer is asymptomatic in the early stages, it can be detected via X-ray.
Some of the common symptoms of lung cancers are:
Cigarette smoke contains over 60 known carcinogens, including radioisotopes from the radon decay sequence, nitrosamine, and benzopyrene. Additionally, nicotine appears to depress the immune response to cancerous growths in exposed tissue. It is not surprising then that smoking accounts for 80–90% of lung cancer cases.
Passive smoking – it is the inhalation of smoke resulting from another person smoking nearby. It is a known cause of lung cancer in non-smokers. A passive smoker can be classified as someone living or working with a smoker.
Those who live with smokers have a 20-30% higher risk while those in second hand smoke environment have 16-19% higher risk compared to non-smokers who are away from such environments.
Radon is a colourless and odourless gas generated by the breakdown of radioactive radium. The radiation decay products ionise genetic material, causing mutations that sometimes turn cancerous.
For every increase of radon concentration by 100 Becquerel per atomic mass, the risk increases 8-16%. Becquerel is a derived unit for measuring radioactivity.
Asbestos can cause a variety of lung diseases, including lung cancer. Tobacco smoking and asbestos have a synergistic effect on the formation of lung cancer.
Asbestos can also cause cancer of the pleura (a thin lining between the lung and the chest wall). An aggressive cancer of the pleura is called mesothelioma which affects the lungs, heart or abdomen.
Outdoor air pollution has a small effect on increasing the risk of lung cancer. Fine particulates (PM2.5) and Sulphate aerosols, which are released in traffic exhaust fumes, increase the risk of lung cancer.
An increment of 10 parts per billion of Nitrogen Dioxide increases the risk of lung cancer by 14%. Outdoor air pollution is estimated to account for 1–2% of lung cancers.
There is evidence to prove that an increased risk of lung cancer is attributed to air pollution such as burning of wood, charcoal, dung or crop residue for cooking and heating. Women who are exposed to indoor coal smoke have about twice the risk. Also, a number of by-products of burning biomass are known for suspected carcinogens.
It is estimated that 8-14% of lung cancer is due to inherited factors. In relatives of people with lung cancer, the risk is increased 2.4 times. This is likely due to a combination of genes.
Numerous other substances, occupations and environmental exposures have been linked to lung cancer which are:
Adenocarcinoma -This type of cancer develops in the bronchioles and is usually located in the outer layers of the lungs. This type of lung cancer has a slow rate of growth and women tend to be at a higher risk of getting adenocarcinoma. It typically begins in the glandular cell and some internal organs with a possibility of treatment.
Adenocarcinoma is a type under NSCLC (Non-small cell lung cancer) which accounts for 80-85% of all lung cancers. In cases where adenocarcinoma has spread to a larger extent then it is known as advanced non-small cell lung cancer. Adenocarcinoma lung cancer treatment is subject to severity and the modalities may vary as per the prognosis.
During the advanced stage or 4th stage of lung cancer it turns into large cell lung carcinoma where the cancerous cells have spread widely within in the lungs from the point of origin. In such cases the course of lung cancer treatment varies.
Small Cell Lung Cancer - One of the common culprits to cause this cancer is smoking and its symptoms include coughing, shortness of breath & acute chest pain.
Usually in small cell lung cancer, there is uncontrolled growth of cells which form a tumour in the lungs. About 10-15% is small cell lung cancer and SCLC in short is also known as oat cell cancer. When oat cell cancer has spread extensively then it is known as advanced small cell lung cancer.
Performing a chest radiograph is one of the first investigative steps when a person reports symptoms that may suggest lung cancer. This may reveal an obvious mass, widening of the mediastinum (suggestive of spread to lymph nodes there), atelectasis (collapse), consolidation (pneumonia), or pleural effusion. CT imaging is used to provide more information about the type and extent of disease. Bronchoscopy or CT-guided biopsy is often used to sample the tumour for histopathology.
Lung cancer often appears as a solitary pulmonary nodule on a chest radiograph. However, the differential diagnosis is wide. Many other diseases can also give this appearance, including tuberculosis, fungal infections and pneumonia. Less common causes of a solitary pulmonary nodule include hamartomas, bronchogenic cysts, adenomas, arteriovenous malformation, pulmonary sequestration, rheumatoid nodules, Wegener's, or lymphoma and the treatment could vary. Lung cancer can also be an incidental finding, as a solitary pulmonary nodule on a chest radiograph or CT scan done for an unrelated reason. The definitive diagnosis of lung cancer is based on histological examination of the suspicious tissue in the context of the clinical and radiological features. It is important to note that detailed diagnosis is necessary for increasing the effectiveness lung cancer treatment.
When it comes to treating lung cancer, one has to understand the cancer's specific cell type, how far it has spread and the person's overall health. In cases where the cancer has spread to other organs, it is termed as metastatic lung cancer. Common lung cancer treatments include palliative care, surgery, chemotherapy, and radiation therapy. The treatment is entirely dependent on the stage of lung cancer.
If investigations confirm NSCLC (non-small-cell lung carcinoma), the stage is assessed to determine whether the disease is localised and can be treated by surgery or if it has spread to the point where it cannot be addressed surgically which is commonly known as metastatic non-small cell lung cancer.
To determine the stage of lung cancer, CT scan and Positron Emission Tomography are commonly used. If mediastinal lymph node involvement is suspected, mediastinoscopy may be used to sample the nodes and assist staging for lung cancer treatment. Blood tests and pulmonary function testing are used to assess whether a person is well enough for surgery during the lung cancer treatment. If pulmonary function tests reveal poor respiratory reserve, surgery may not be a possibility.
In most cases of early-stage NSCLC, removal of a lobe of the lung (lobectomy) is the surgical treatment of choice and is part of stage 1. In people who are unfit for a full lobectomy, a smaller sub-lobar excision may be performed. However, wedge resection has a higher risk of recurrence than lobectomy. Rarely, removal of a whole lung (pneumonectomy) is performed. Video-assisted thoracoscopic surgery and VATS lobectomy use a minimally invasive approach to lung cancer surgery. VATS lobectomy is equally effective, as compared to conventional open lobectomy, with less postoperative illness.
In SCLC (small-cell lung carcinoma), chemotherapy and/or radiotherapy is used. However, the role of surgery in SCLC is being reconsidered. Surgery might improve outcomes when added to chemotherapy and radiation in early stage SCLC. In cases where the small-cell lung carcinoma has becomemetastatic, the treatment options include chemotherapy & radiation therapy.
To avoid complications, it is advised that you visit the doctor. Cancer treatment becomes easy during the early stages of detection.
Radiotherapy is often given together with chemo treatment in lung cancer and may be used with curative intent in people with NSCLC who are not eligible for surgery. This form of high-intensity radiotherapy is called radical radiotherapy. A refinement of this technique is Continuous Hyperfractionated Accelerated Radiotherapy (CHART), in which a high dose of radiotherapy is given in a short time period.
If cancer growth blocks a small section of bronchus, brachytherapy (localised radiotherapy) may be given directly inside the airway to open the passage. Compared to external beam radiotherapy, brachytherapy allows a reduction in treatment time and reduced radiation exposure to healthcare staff.
Some of the advances in lung cancer treatments include recent improvements in targeting and imaging which have led to the development of stereotactic radiation in the treatment of early-stage lung cancer. In this form of radiotherapy, high doses are delivered in a small number of sessions using stereotactic targeting techniques. Its use is primarily in patients who are not surgical candidates due to medical comorbidities.
Other advancements include CyberKnife treatment which is designed to streamline and optimize SBRT (stereotactic body radiation therapy). SBRT is a method of delivering targeted radiation therapy for treating lung cancer tumours effectively.
This latest lung cancer treatment is capable of adjusting the beams based on the minor movements made by the patients and also the movement of the tumor caused by breathing during treatment. This precise delivery method quickly allows the tumor to receive the full dose of radiation.
For both NSCLC and SCLC patients, smaller doses of radiation to the chest may be used for symptom control (palliative radiotherapy).
The chemotherapy regimen depends on the tumour type. Both Small-cell lung carcinoma (SCLC) & Non-small cell lung carcinoma can be treated with chemotherapy and radiation. In advanced non-small cell lung carcinoma (NSCLC), chemotherapy treatment improves the survival rate and is used as the first-line treatment versus radiation.
While treating metastatic small cell lung cancer, a check is run to see whether the patient is fit enough to be treated. Fitness is an important factor to determine the survival of patient.
Adjuvant chemotherapy refers to the use of chemotherapy, after the curative surgery, to improve the outcome. Typically, the chemotherapy is provided as the next step of lung cancer treatment after surgery. In NSCLC, samples are taken from nearby lymph nodes, during surgery, to assist staging. If stage II or III disease is confirmed, adjuvant chemotherapy improves survival by 5% at five years. Adjuvant chemotherapy as a lung cancer treatment option during stage IV cancer is debatable, as clinical trials have not clearly demonstrated a survival benefit or a standard success rate. Trials of pre-operative chemotherapy (neo-adjuvant chemotherapy) have been inconclusive.
Patients subject to chemotherapy may experience side effects during this type of lung cancer treatment like Hair Loss, Mouth Sore, Loss of Appetite, Nausea and even Vomiting to name a few.