If You Have Small Cell Lung Cancer

In general, lung cancer is categorized into two types: small cell lung cancer (SCLC), and non-small cell lung cancer (NSCLC). Although both types are microscopic, the cancerous cells of NSCLC are relatively larger. Conversely, the cells of SCLC are smaller and round, often called “oat cell” cancer. The main focus of this article will be SCLC, including its symptoms, causes, detection and diagnosis.

Small cell lung cancer is a form of highly aggressive lung cancer, meaning it

• has a rapid doubling time
• is highly invasive
• spreads quickly

It often starts in the bronchi, the airways that connect trachea (main windpipe) and the lungs.

Like many other cancers, SCLC often does not initially present noticeable symptoms. However, its aggressive nature can understandably cause concern. Within weeks, symptoms will begin as the disease progresses and worsens.

The common symptoms that occur in all types of lung cancer (including SCLC) are

• Persistent cough
• Shortness of breath (dyspnea)
• Fatigue
• Coughing up blood (hemoptysis)
• Chest pain
• Weight loss
• Change in voice (hoarseness)
• Wheezing when breathing and coughing

While suffering from lung cancer symptoms, about 10% SCLC patients develop superior vena cava at some point of their disease.

Superior vena cava syndrome. The superior vena cava is the major vein that brings blood from the upper body back to the heart. Compression of tumor on the superior vena cava typically causes:

• Edema of the face, neck and upper chest
• Dilated neck veins – a visible, prominent venous pattern from neck to chest
• Shortness of breath (dyspnea)

Superior vena cava syndrome is more prevalent among SCLC patients than that of NSCLC.

Related: Feeling Breathless? Do Not Ignore the Signs of Lung Cancer

Small cell lung cancer only accounts for 10-15% of all lung cancer cases. Tobacco smoking is strongly related to SCLC. Although smoking is the number one risk factor for all types of lung cancer, certain subtypes are more common among smokers or ex-smokers.

Historically, SCLC is rare among never smokers. This lung cancer typically begins in the main airways (bronchi). The toxins in cigarettes trigger gene mutations in cells that line the bronchi (bronchial epithelial cells) to behave abnormally.

Multiple genetic abnormalities have been detected in SCLC. Some directly result in tumor formation, whereas others are probably secondary events. The two common genetic characteristics of SCLC are:

• p53 mutations. Found in 75-98% of SCLC tumors
• Loss of function of RB1 (retinoblastoma gene) is found in almost all SCLC cases

These abnormalities are difficult to target using drugs. Therefore, there have not been any approved drugs for these abnormalities in SCLC.

Related: New updates of lung cancer risk factors that you need to know

Lung cancer is usually picked up by detection methods involving imaging of the chest, such as X-ray, CT scan, PET scan, MRI and ultrasound. But these methods are not definitive enough to distinguish SCLC from other subtypes.

Biopsy methods to obtain a tumor sample include bronchoscopy, needle and surgery. A definite diagnosis of SCLC is based on the microscopic appearance of tumor cells. Since SCLC tends to grow faster and spread before it is detected, most people are found at an advanced stage at the time of diagnosis. The staging of SCLC is somewhat unique among cancers in that there are only two stages: limited and extensive stage.

Unlike non-small cell lung cancer, where biomarkers are well established and incorporated into standard clinical practice, there is no approved biomarker test for SCLC.

The unique characteristics of SCLC differ the disease from other lung cancer subtypes. It also emphasizes that not all lung cancers can be detected using identical methods. While its two-stage diagnosis and a lack of a biomarker test may seem discouraging, early detection ensures improved survival and better treatment outcomes.

Related: Annual Screening For Smokers And Ex-smokers - A Key To Early Lung Cancer Detection