August 1, World Lung Cancer Day: Why Does It Matter and What Should We Know?

📊 Lung Cancer: Its Public Health Importance and Current Data

Lung cancer, is a serious global public health problem. According to World Health Organization (WHO) data, in 2020 there were 2.2 million new cases worldwide and 1.8 million deaths. These figures put lung cancer first among causes of cancer-related death .

Worldwide, the most common cancer in men is lung cancer, while it ranks third in women. In Turkey, 21% of all cancers in men originate in the lung. Although incidence is lower in women, it has shown an upward trend over the years . Changes in smoking patterns and environmental exposures may contribute to this increase.

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🔬 Types of Lung Cancer: Small Cell and Non-Small Cell

Lung cancer is divided into two main groups according to the microscopic appearance and biological behavior of tumor cells: Small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Of cases, 80-85% are NSCLC, while SCLC represents approximately 15% .

🧬 Subtypes of Non-Small Cell Lung Cancer

NSCLC is divided into three main histological subtypes :

• Adenocarcinoma: The most common subtype. It develops in the outer parts of the lung and is also frequently found in people who do not smoke . It accounts for approximately 50% of all lung cancers. In this type, genetic mutations (EGFR, ALK, etc.) can often be identified.
• Squamous Cell Carcinoma: It generally arises from the inner lining of the bronchi . It is associated with long-term smoking. Early symptoms may include cough and coughing up blood. It accounts for approximately 20-25% of all lung cancers.
• Large Cell Carcinoma: It is a rare NSCLC subtype. It is named for the lack of clear morphological differentiation of its cells. It occurs in approximately 5-10% of cases and may be central or peripheral.

🧪 The Importance of Genetic Subtypes (EGFR, ALK, ROS1 and Others)

Classifying lung cancer solely by its microscopic appearance is no longer sufficient. Genetic changes at the molecular levelhave become decisive in treatment selection, particularly in non-small cell lung cancer .

Research has revealed that genetic changes known as “driver mutations” are common in lung adenocarcinoma. These mutations activate intracellular signaling pathways, triggering cancer cell growth and spread.

Why is identifying these genetic subtypes critical? Because specific targeted treatments have been developed for each genetic alteration. For example, patients with an EGFR mutation can receive targeted drugs in pill form ; drugs specific to ALK or ROS1 are preferred for patients with these fusions.

This makes it possible to achieve much better outcomes compared with chemotherapy in both survival and quality of life .

Although these rates may appear low, patients with these mutations have substantial treatment opportunities because much more effective than standard chemotherapy are the targeted treatment options available.

🌫️ Risk Factors Beyond Smoking: Environmental and Genetic Factors

Although the first thing that comes to mind with lung cancer is smoking , this disease does not occur only in people who smoke . Tobacco products are of course the most important risk factor – approximately 90% of cases are directly associated with cigarettes or other tobacco products.

However, the idea that “people who do not smoke cannot get lung cancer” is wrong. In North America, among patients diagnosed with lung cancer, 10–15% have never smoked in their lives.

In addition, exposure to certain industrial chemicals is an important risk factor. These include:

• Arsenic
• Beryllium
• Cadmium
• Nickel
• Chromate
• Coal smoke
• Diesel exhaust particles

In particular, air pollutionis a significant threat to people living in cities. Diseases such as tuberculosis that cause permanent lung tissue damage may also increase the risk of cancer developing in the affected area years later.

People with a family history should therefore discuss screening strategies and preventive measures with their doctors.

📍 The Importance of Early Diagnosis and the Lifesaving Effect of Low-Dose CT Screening

In lung cancer, early diagnosis saves lives – this short phrase reflects a powerful truth. Unfortunately, lung cancer is often an insidious, slowly progressing disease; it may cause no symptoms early on, and patients are often diagnosed at an advanced stage.

Stage 1A (very early-stage) lung cancer has 5-year survival >75% , whereas in stage 4 (metastatic) disease, this rate falls below 5% . Timely diagnosis therefore saves lives.

🔬 Low-Dose CT Screening: A Powerful Tool in Modern Medicine

In recent years, low-dose computed tomography (CT)has become one of the most effective methods for early lung cancer detection in high-risk individuals. This screening method:

• Is sensitive enough to detect millimeter-sized nodules
• Uses much less radiation than conventional CT
• Extends survival by detecting early-stage cancer

📌 Who Is Eligible for Screening?

Lung cancer screening is recommended for high-risk individuals , rather than the entire population. Who belongs to this group?

• People aged 50–80
• With a smoking history of 30 pack-years or more
• Who still smoke or quit within the last 15 years

People meeting these criteria should undergo low-dose CT screening once a year. Screening others may cause harms such as unnecessary radiation, false-positive results and unnecessary procedures.

Authorities worldwide recommend two core strategies for tackling lung cancer:

• 🚭 First level: Tobacco control
• 🔎 Second level: Low-dose CT screening in high-risk individuals

Although Turkey does not yet have a nationwide screening program, various pilot studies are underway. Wider implementation is expected to achieve a substantial reduction in lung cancer deaths in the future.

💊 Modern Treatments: Targeted Therapies, Immunotherapy and Personalized Oncology

Lung cancer treatment has seen, over the past 10–15 years, groundbreaking innovations . Previously, patients diagnosed with advanced disease were offered only chemotherapy and radiotherapy; today, “targeted drugs” and immunotherapies allow much more effective and personalized treatment.

🎯 Targeted Therapies

These treatments work by targeting specific genetic changes in cancer cells. For example:

• EGFR mutations can be treated with tyrosine kinase inhibitors,
• ALK and ROS1 fusions with drugs inhibiting these targets.

These treatments are more selective than chemotherapy and may therefore have both fewer adverse effectsand higher success rates .

🛡️ Immunotherapy: Mobilizing the Immune System Against Cancer

The immune system can normally recognize and destroy abnormal cells. However, cancer cells manage to evade immunity. Immunotherapy drugs (for example, PD-1 / PD-L1 inhibitors) block this escape and reactivate the body's defenses.

These data show that immunotherapy is a game-changing treatment for lung cancer . In some patients, lung cancer can now be managed over a long period like a chronic disease .

🧬 Personalized Oncology: An Individual Approach for Every Patient

Each patient's cancer differs in its genetic structure, biomarker profile and clinical status . Modern oncology therefore aims to provide:

• The right patient with
• The right drug
• At the right time .

This approach achieves maximum benefit while avoiding unnecessary adverse effects.

📊 Improved Survival with New Treatments: Examples and Promising Developments

How early diagnosis and modern treatments make a difference in real life is shown by concrete data . In recent years in particular, lung cancer has seen substantial improvements in survival rates .

🛡️ Long-Term Responses to Immunotherapy

In advanced non-small cell lung cancer, atezolizumab immunotherapy has increased 3-year survival almost twofold :

• 🔬 Immunotherapy arm: ~19% survival
• 💉 Chemotherapy arm: ~10% survival

Patients with advanced disease surviving longer than 5 years are no longer exceptional. Immunotherapy can control tumors for years , allowing patients to maintain a good quality of life over a long period.

🎯 Greater Success with Targeted Therapies

Modern targeted treatments have also led to striking improvements in survival:

• In patients with EGFR mutations, osimertinib provides median survival of ~3 years
• In ALK-positive patients, ALK inhibitors provide survival of ~5 years

By contrast, in the early 2000s, average survival for metastatic lung cancer patients was less than 1 year.

🔭 Looking to the Future with Hope

Of course, not every case is diagnosed early, not every cancer carries a mutation, and some subtypes may be resistant. However, the overall picture is promising. The notion that “lung cancer diagnosis is a death sentence” is becoming an outdated notion.

Many innovations continue to be developed worldwide:

• Next-generation targeted drugs
• Cancer vaccines
• AI-assisted screening systems

Thanks to targeted drugs and immunotherapies, many patients have an opportunity to spend longer, better-quality time with their loved ones. An aware and informed societyis the strongest tool in tackling lung cancer.

🎗️ On this important day, let us increase awareness and share what we have learned with those around us. Because every case diagnosed early is a life saved.