Lung Cancer Causes Symptoms Treatment and Prevention

Lung cancer stands as one of the most prevalent types of cancer globally, contributing significantly to cancer-related fatalities. It originates in the lungs and is the most common cancer with respect to incidence and mortality worldwide. GLOBOCAN reported 2,206,771 new cases and 1,796,144 deaths in 2020. While being the most common cancer among men, it ranks as the third most common cancer in women in India. Here, it is the fourth most common cancer, with 72,510 cases and 66,279 deaths in 2020. In India, lung cancer comprises 6.9% of new cancer cases and 9.3% of cancer-related deaths in both genders each year. Mizoram reported the highest incidences among both males and females. 

The trends in lung cancer demonstrate a noteworthy increase in Delhi, Chennai, and Bengaluru for both sexes. Incidence and patterns vary geographically and ethnically, closely mirroring smoking prevalence and patterns. Approximately 50% of cases are diagnosed at an advanced stage, underscoring the importance of early detection through awareness of warning signs. However, early signs may not always be evident, and symptoms often manifest in advanced stages. Adhering to the proverb "prevention is better than cure," it is crucial to manage preventable risk factors like active and passive smoking and occupational exposure to carcinogens such as asbestos. Therefore, Medflick brings you some deep details and facts you must know about lung cancer.

Cancer is a condition characterized by the uncontrolled growth of cells in the body. When this abnormal cell growth originates in the lungs, it is identified as lung cancer. Initiating in the lungs, lung cancer has the potential to extend to lymph nodes or other organs, including the brain. Conversely, cancer originating in other organs may also metastasize (spread) to the lungs. While lung cancer can be life-threatening, advancements in diagnosis and treatments are enhancing the overall prognosis.

There exist two primary categories of lung cancer.

1. Non-small cell lung cancer (NSCLC): NSCLC accounts for approximately 80% to 85% of lung cancer cases. Its main subtypes include adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. Despite originating from different lung cell types, they are collectively classified as NSCLC due to similarities in treatment and prognosis.

• Adenocarcinoma: Arising from cells responsible for secreting substances like mucus, this lung cancer type is prevalent in both current and former Smokers. It is more frequent in women, tends to affect younger individuals, and is often detected in the lung periphery before spreading. 
• Squamous cell carcinoma: Originating in flat cells lining the lung airways, squamous cell carcinomas are associated with a history of smoking. They typically manifest in the central lung near major airways (bronchi).
• Large cell (undifferentiated) carcinoma: Appearing in various lung regions, large cell carcinoma exhibits rapid growth and spread, posing challenges in treatment. A subtype, large cell neuroendocrine carcinoma (LCNEC), closely resembles small cell lung cancer in its fast-growing nature.

2. Small cell lung cancer (SCLC): Comprising 10% to 15% of all lung cancers, SCLC is sometimes referred to as oat cell cancer. SCLC tends to grow and spread more rapidly than NSCLC, often extending beyond the lungs upon diagnosis. While this fast growth makes it responsive to chemotherapy and radiation therapy, the cancer commonly recurs in most individuals at some point.

What are the stages of lung cancer?

Following are lung cancer stages:

• Stage 0 (in-situ): The cancer is present in the top lining of the lung or bronchus, without spreading to other lung parts or beyond.
• Stage I: Cancer remains confined within the lung, with no spread outside.
• Stage II: Cancer surpasses Stage I in size, involves lymph nodes within the lung, or presents multiple tumors in the same lung lobe.
• Stage III: Cancer exceeds Stage II in size, extends to neighboring lymph nodes or structures, or exhibits multiple tumors in a different lobe of the same lung.
• Stage IV: Cancer has disseminated to the other lung, the fluid surrounding the lung, the fluid around the heart, or distant organs.

Limited vs. extensive stage

Although small cell lung cancer is now categorized using stages I through IV, it may also be referred to as a limited or extensive stage based on the treatability with a single radiation field.

• Limited stage SCLC is confined to one lung, occasionally involving lymph nodes in the middle of the chest or above the collarbone on the same side.
• Extensive stage SCLC has spread extensively within one lung or to the other lung, lymph nodes on the opposite side, or other parts of the body.

Metastatic lung cancer originates in one lung but extends to the other lung or other organs. Treating metastatic lung cancer is more challenging compared to cancer that remains confined to its initial site.

Lung cancer arises from cells that continue to divide abnormally, bypassing the built-in mechanisms for halting division (senescence) or inducing cell death (apoptosis). While all cells undergo normal division, the off switch is activated when a cell has undergone excessive divisions or accumulated too many mutations. Cancer cells, having lost this off switch due to mutations, multiply uncontrollably, disrupting the normal functioning of surrounding cells. These cancerous cells can enter the bloodstream or lymph nodes, spreading to different areas of the body and causing widespread damage.

The exact factors triggering these changes leading to cancer remain uncertain, but certain elements, such as smoking tobacco products, pose a higher risk of cellular damage that may lead to lung cancer. Smoking any form of tobacco, including cigarettes, cigars, or pipes, stands as the predominant risk factor, contributing to an estimated 80% of lung cancer deaths. Additional risk factors encompass exposure to secondhand smoke, contact with harmful substances like air pollution, radon, asbestos, uranium, diesel exhaust, silica, and coal products, as well as a history of radiation treatments to the chest and a family history of lung cancer.

Most lung cancer symptoms resembles to symptoms of certain less serious illnesses. Many patients don’t get symptoms until the disease reaches the advanced stage. However, some people get early stage symptoms also and that are:

• Persistent and long-standing cough
• Shortness of breath 
• Chest pain 
• Wheezing
• Coughing up blood 
• Voice hoarseness
• Loss of appetite
• Excessive tiredness
• Unexplained weight loss.

Diagnosis and Tests for Lung Cancer

Lung cancer diagnosis is a multi-step process. Your healthcare provider will proceed with following:

• Listening to your symptoms
• Taking your health history 
• Performing a physical exam (like listening heart and lungs sounds)
• Prescribe blood tests and a chest X-ray.
• On the basis of blood tests and a chest X-ray reports, more imaging tests like a CT scan and a biopsy will be prescribed
• Other tests can also be prescribed including using a PET/CT scan to see if cancer has spread

How is Lung Cancer Treated?

Lung cancer can be addressed through various treatments, encompassing surgery, radiofrequency ablation, radiation therapy, chemotherapy, targeted drug therapy, and immunotherapy.

• Surgery is considered for non-small cell lung cancer (NSCLC) that hasn't spread or limited small cell lung cancer (SCLC) with a solitary tumor. Surgeons may remove the tumor along with a small portion of adjacent healthy tissue to ensure complete elimination of cancer cells. In certain cases, partial or complete lung resection (resection) might be necessary to minimize the risk of cancer recurrence.
• Radiofrequency ablation (RFA) is applied to treat NSCLC tumors situated near the outer edges of the lungs. This involves using high-energy radio waves to heat and eliminate cancer cells.
• Radiation therapy, utilizing high-energy beams, can be administered independently or in conjunction with surgery to enhance efficacy. It is also employed as palliative care to shrink tumors and alleviate pain, applicable to both NSCLC and SCLC.
• Chemotherapy, typically administered via IV, comprises a combination of medications designed to halt the growth of cancer cells. It can be given before or after surgery or in conjunction with other medications, including immunotherapy.
• Targeted drug therapy focuses on specific mutations in NSCLC cells, utilizing special drugs to impede or destroy cancer cells. Another category, angiogenesis inhibitors, prevents the formation of new blood vessels crucial for cancer growth.
• Immunotherapy aims to reveal cancer cells to the immune system, enabling the body to combat cancer by overcoming the mechanisms cancer employs to evade the immune system.
• Additionally, certain lung cancer treatments address symptom relief, such as pain and difficulty breathing. These include therapies to reduce or eliminate tumors obstructing airways and procedures to drain fluid from around the lungs and prevent its recurrence.

How to Prevent Lung Cancer?

As the definitive causes of most cancers remain uncertain, preventive efforts are centered on minimizing associated risks. Strategies to reduce the risk include:

• Abstaining from smoking or quitting if already a smoker. The risk of lung cancer begins to decrease within five years of smoking cessation
• Steering clear of secondhand smoke and other substances detrimental to lung health
• Adopting a nutritious diet and maintaining a healthy weight. Some studies indicate that consuming fruits and vegetables (in quantities ranging from two to six-and-a-half cups daily) may contribute to lowering cancer risk
• Undergoing lung cancer screening if identified as high risk

Cost of Lung Cancer Treatment in World

Best Hospitals Around World for Lung Cancer Treatment

Following are some of the best hospitals around world for lung cancer treatment:

• University of Texas MD Anderson Cancer Center, Houston, USA
• The Royal Marsden Hospital, United Kingdom
• Fortis Memorial Research Institute, India
• Memorial Sisli Hospital, Turkey
• Gleneagles Hospital, Singapore

Q1: Will lung cancer be cured?

A: Lung cancer is generally curable if diagnosed when its contained within the lung only. Lung cancer which spreads beyond the lung is generally not considered curable.

Q2: What are the 1st signs of lung cancer?

A: Chest pain, persistent cough, blood in cough, breathing difficulties, voice hoarseness, loss of appetite, unintended weight loss, and fatigue are the 1st signs of lung cancer.

Q3: Can you live 20 years with lung cancer?

A: Individuals identified with early-stage lung cancer through CT screening exhibit an 80 percent survival rate over a span of 20 years. In contrast, the average five-year survival rate for all lung cancer patients stands at 18.6 percent, primarily due to the fact that merely 16 percent of lung cancer cases are diagnosed in the early stages. 

Q4: At what age lung cancer occurs?

A: According to the American Cancer Society, the majority of individuals diagnosed with lung cancer are aged 65 and above.