Lung Cancer

What is Lung Cancer?

Lung cancer is the formation of malignant cells caused by the uncontrolled proliferation of cells in the lungs.

What Causes Lung Cancer?

The leading cause of lung cancer is smoking. However, lung cancer can also occur in non-smokers. In fact, about 15% of all lung cancer cases are found in individuals who have never smoked. Being exposed to environments where smoking occurs (passive smoking) also increases the risk of developing lung cancer.

Aside from cigarettes, products such as pipes, cigars, and hookahs are proven significant risk factors for cancer. Other causes of lung cancer include genetic predisposition, asbestos, radon gas, air pollution, and high levels of arsenic in drinking water.

Radiation from any source can damage lung tissue, leading to cell abnormalities and tumor formation.

What are the First Signs of Lung Cancer?

The first sign of lung cancer is a persistent cough.

Symptoms of Lung Cancer In addition to persistent coughing, common symptoms of lung cancer include chest pain, shortness of breath, coughing up blood, hoarseness, loss of appetite, weight loss, swelling of the face and neck, shoulder and arm pain, back pain, and difficulty swallowing.

How is Lung Cancer Diagnosed?

If a patient visits the doctor due to complaints or as part of a general health screening, the doctor will first request a chest X-ray based on the findings. Following this, a lung CT scan is performed to determine the approach to the identified mass, and a biopsy is planned.

If the mass is in a location accessible via bronchoscopy (in the bronchi or lymph nodes),a biopsy is taken from the mass or lymph node using a bronchoscope. If the mass is located near the lining of the lung and is inaccessible by bronchoscopy, a biopsy is performed through the back under the guidance of a CT scan. After the cancer diagnosis is confirmed through pathology, further tests such as PET/CT and brain MRI are requested to check if the cancer has spread to other organs.

Stages of Lung Cancer

• Stage 1: Tumor smaller than 4 cm, not spread to the lymph nodes.
• Stage 2: Cancer is present in the lung and nearby lymph nodes.
• Stage 3: Cancer is found in the lung and the lymph nodes in the center of the chest, considered locally advanced. Stage 3 is divided into two subtypes: Stage 3A occurs when the cancer has spread only to the lymph nodes on the same side of the chest where it started, while Stage 3B is when it has spread to lymph nodes on the opposite side or above the collarbone.
• Stage 4: The most advanced stage of lung cancer, where the cancer has spread to both lungs, the fluid surrounding the lungs, or to other parts of the body such as the liver or other organs.

Types of Lung Cancer

There are two types of lung cancer: small cell lung cancer and non-small cell lung cancer.

The majority of lung cancers (about 88%) are non-small cell lung cancers. The three common subtypes of non-small cell lung cancer are adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.

How is Lung Cancer Treated?

The treatment for lung cancer varies depending on factors such as the patient's general health, the type of cancer, and its stage. Treatment options include surgery, radiotherapy, chemotherapy, and immunotherapy. These treatments may be used individually or in combination.

Surgery for Lung Cancer

Surgery is a treatment option for early-stage lung cancers. The type of surgery depends on the location of the cancer in the lung. If an entire lobe is removed, it is called a lobectomy. If one of the lungs is removed, it is called a pneumonectomy. Some tumors cannot be surgically removed due to their location, size, or the patient's overall health.

Chemotherapy for Lung Cancer

Chemotherapy is the destruction of cancer cells using medication. It usually involves two drugs and is administered by specially trained nurses. Chemotherapy is given in cycles (called "courses") every 21 to 28 days.

Chemotherapy is typically given intravenously or in pill form at outpatient treatment centers. In some cases, due to the patient's condition or the nature of the medications, chemotherapy is given while the patient is hospitalized.

The decision about whether a patient will receive chemotherapy after surgery, and if so, how many courses, is based on the characteristics of the tumor in the pathology report. The patient’s age and overall condition are also important factors in these decisions.

Targeted Therapies and Smart Drugs

In the past 15 years, new therapies have been developed based on understanding the molecular and biological characteristics of lung cancer. These therapies, known as "targeted treatments" or "personalized medicine," target specific genetic mutations responsible for the formation of cancer cells.

The most important feature of these targeted drugs is their ability to eliminate cancer cells based on the specific genetic mutation found in the patient's lung cancer. Unlike chemotherapy, which affects both normal and cancerous cells, targeted drugs mostly affect cancer cells and have minimal to no impact on normal cells. This results in fewer side effects, such as hair loss, nausea, vomiting, diarrhea, or mouth sores.

These treatments are primarily used for non-small cell lung cancers, excluding the squamous (flat) cell type. They are not suitable for small cell or squamous cell lung cancers.

Lung Cancer Metastasis

Metastasis occurs when cancer cells break away from the main malignant tumor and spread throughout the body via the bloodstream or lymphatic system. Lung metastasis may not always show symptoms, but when it does, it depends on the affected area. Symptoms may include headaches, dizziness, balance issues, back and hip pain, swollen lymph nodes in the neck, fatigue, unexplained weight loss, among others. Lung cancer in advanced stages can metastasize to many tissues and organs, commonly spreading to the adrenal glands, bones, brain, other lungs, lymph nodes, and the pleura (the membrane surrounding the lungs).

Life Expectancy for Lung Cancer Patients

In small cell lung cancer, the average survival time with limited-stage chemotherapy is between 14 to 20 months, while in advanced-stage, the survival time is about 9 to 11 months.

In extensive-stage small cell lung cancer, the two-year survival rate is around 4%. In non-small cell lung cancer, the five-year survival rate is 18%, but for patients in stages 1 and 2 who undergo anatomical resection, the survival rate can reach 60-80%.

How to Prevent Lung Cancer

The most important cause of lung cancer is the use of tobacco and tobacco products. Therefore, the key to preventing lung cancer is to avoid smoking and to help those who do smoke to quit. It's important to avoid exposure to radiation. Preventing exposure to asbestos, radon, harmful gases, and chemicals can also reduce the risk of cancer.

People exposed to asbestos fibers in their environment or workplace should use professional protective respiratory masks. Moving away from areas with high air pollution is also important. People who have been heavy smokers, have had occupational exposure to various chemicals, or who quit smoking in the last 15 years and are between the ages of 55 and 80 should have regular check-ups.

Is It Possible to Completely Cure Lung Cancer?

Although lung cancer is one of the leading causes of cancer-related deaths, early detection and successful surgical treatment can lead to a cure in 80-90% of cases. Even in cases where surgery is possible but not in the early stages, the success rates are still significant.