SCLC vs. NSCLC: Which Lung Cancer Type is More Aggressive?

While NSCLC is the more common type of lung cancer, it is slow-growing and far less aggressive than SCLC.

Non-small cell lung cancer (NSCLC) carries a better prognosis than small cell lung cancer (SCLC). NSCLC is slow-growing, whereas SCLC grows far more aggressively. Additionally, NSCLC is the more common type, accounting for 85 percent of cases, whereas SCLC is rarer, accounting for 10 to 15 percent of cases.

The prognosis of NSCLC depends largely on the tumor, node, metastasis (TNM) stage at presentation:

• T describes the size of the tumor and any spread of cancer into nearby tissue.
• N describes the spread of cancer to the nearby lymph nodes.
• M describes the spread of cancer to other parts of the body (metastasis).

How well the lung cancer patient can perform their daily activities independently can predict their lifespan, regardless of the disease stage. Weight loss is also associated with a poor prognosis in NSCLC patients.

Other factors that determine prognosis include age and smoking cessation. Old age and continued smoking is associated with a bad prognosis, whereas young age and quitting smoking generally offer a better prognosis.

In patients with SCLC, the extent of the disease (stage) at presentation is the most important factor that determines prognosis:

• For patients with the limited-stage disease, median survival ranges from 15 to 20 months (which means only half of the patients can survive for 15 to 20 months after diagnosis). 
• For patients with the extensive-stage disease, the median survival is 8 to 13 months (which means only half of the patients will survive for 8 to 13 months after the diagnosis).

An inability to carry out daily activities independently and weight loss can shorten the patient’s lifespan.

How are non-small cell lung cancer and small cell lung cancer staged?

Staging of cancer is done to describe how far it has spread within the body. A simple way to stage this includes the three stages of cancer:

• Localized: Cancer has not spread outside the lung.
• Regional: Cancer has spread to nearby structures or lymph nodes.
• Distant: Cancer has spread to distant parts of the body, for example, to the liver, bones, etc.

Stages of non-small cell lung cancer (NSCLC)

For this type of cancer, doctors usually use a four-stage system:

• Stage I: Cancer is only in one lung.
• Stage II: Cancer has spread to the nearby lymph nodes.
• Stage III: Cancer has reached other lymph nodes in the chest (the middle or the other side of the chest).
• Stage IV: Cancer has spread to both lungs, other parts of the body or both.

Stages of small cell lung cancer (SCLC)

Doctors generally categorize small cell lung cancer in two stages:

• The limited stage: Cancer is limited to only one side of the chest, which means it may be in one lung and, possibly, in the nearby lymph nodes.
• The extensive stage: Cancer has spread throughout the lungs, other parts of the chest and other distant organs.

What are the survival rates of non-small cell lung cancer and small cell lung cancer?

The survival rate is analyzed in a large study, in which the lifespan of a large population, after the diagnosis of cancer, is observed for a specific timeframe. It is generally presented as a five-year survival rate (what percentage of people lived for at least five years after the diagnosis).

Localized
63

Regional
35

Distant
7

All stages combined
25

*NCI: National Cancer Institute

According to the National Cancer Institute (NCI), the overall five-year survival rate for NSCLC is 25 percent. This means 25 out of 100 people with NSCLC can survive for at least five years after their diagnosis.

Localized
27

Regional
16

Distant
3

All stages combined
7

*NCI: National Cancer Institute

According to the National Cancer Institute (NCI), the overall five-year survival rate for NSCLC is only seven percent. This means 7 out of 100 people with NSCLC can survive for at least five years after their diagnosis. It also means that people with NSCLC have only a seven percent chance that they will survive for at least five years after the diagnosis.

Survival rates for cancer are often used as predictors of patients’ lifespan (usually at least five years) after the diagnosis. However, these may vary depending on the patient’s age, overall health and response to treatments. Hence, patients need to discuss all these factors with their doctor to know about their life expectancy.

Patients should remember that survival rates are calculated at a particular point in time. Therefore, it may be possible that advances in treatments in the later years might have improved survival rates. Hence, patients must always ask their doctor even after they know the general survival rates.

Overall, lung cancer causes more deaths than breast, prostate, colorectal and brain cancers combined. However, more people are surviving after diagnosis, probably due to treatment advances and decreases in smoking.

Lung cancer is a disease in which lung cells grow abnormally in an uncontrolled way.
See Answer

Do non-small cell lung cancer and small cell lung cancer differ in their treatments?

Treatment of non-small cell lung cancer (NSCLC) does differ from small cell lung cancer (SCLC) in the following ways:

Treatment of non-small cell lung cancer (NSCLC)

For patients with NSCLC, doctors decide the initial management based on the stage of the disease and other comorbidities the patient has and may include:

• Early-stage disease: Surgical removal of the lung tumor carries the maximum chances of cure. Surgical removal and concurrent chemoradiotherapy (chemotherapy and radiotherapy) are preferred for those with a more extensive spread of tumors in the chest. Chemotherapy involves administering highly powerful medications to shrink the tumor, and radiation uses high-energy beams that are targeted toward the tumor to destroy the cancer cells.
• Advanced disease (Stage IV): Patients can choose to either take chemotherapy medications or opt for palliative care. Palliative care includes taking only those medications or undergoing only those procedures that manage the symptoms of cancer but do not cure it. Patients who chose palliative care over chemotherapy expect only a better quality of life in the time they have left.

Treatment of small cell lung cancer (SCLC)

• Limited-stage disease: Primarily treatment involves using a combination of chemotherapy and radiation therapy.
• Extensive-stage disease: A combination of chemotherapy and immunotherapy is used as the initial therapy. Patients can even opt for palliative care. Immunotherapy is a novel therapy that uses the patient’s immune system to fight cancer.

Doctors devise tailor-made approaches while treating and administering medications to each patient. The team of doctors, including an oncologist, pulmonologist, surgeon, radiologist and other team members, will discuss with the patient the best options that suit their problem.