November 15, 2017 / All Stories

Five Reasons Why Small Cell Lung Cancer is Tough to Treat

Researchers continue to bring into focus the reasons why small cell lung cancer is tough to treat – and what can be done about it.

The biggest news about small cell lung cancer (SCLC) in the last 15 years is that there’s been no news at all. No improvement in survival rates, no new treatments approved1 and, making up only about 10 to 15 percent of all lung cancers2, conversations around the topic until recently were limited. This aggressive form of lung cancer almost exclusively impacts smokers or former smokers and has a devastatingly low five-year survival rate of about two percent.3

Here are five reasons why SCLC is difficult to treat and ways researchers are trying to break the slow news cycle:

1. Screening is Uncommon

Unlike mammograms that screen for breast cancer and colonoscopies to screen for colon cancer, there is no widespread screening process for lung cancer.

2. Fast Growing

All types of lung cancer are aggressive and typically spread to other parts of the body, but SCLC is particularly aggressive. Normal lung cells turn cancerous for two broad categories of reasons. Using car troubles as an analogy, they develop “brake” failures or lose control of the “engine RPM.” In some instances, it’s a combination of both.

3. Stage of Diagnosis

Small cell lung cancer grows quickly and symptoms may seem run of the mill until they worsen. By the time of diagnosis, the majority of people with SCLC may have an advanced stage of the disease, which has a very low survival rate.

4. Resistance to Treatments

Small cell lung cancer initially responds well to radiation and chemotherapy, improving symptoms and shrinking tumors. What remains a mystery is that SCLC develops resistance to these treatments and comes back quickly.4

5. New Treatments for the Toolbox Needed

Nearly all SCLC patients relapse after their first-line treatment, chemotherapy, and have only one U.S. Food and Drug Administration-approved option for second-line treatment, with no approved options for third-line treatment of the disease.

AbbVie is exploring approaches that may slow the progression of SCLC in different ways. One approach is to block an enzyme called PARP to stop the repair of faulty DNA in cancer cells. Left unchecked, PARP would allow cancer cells to repair and grow but if it’s inhibited, chemotherapy, which damages cancer cell DNA, may be more effective.

Another potential solution lies in a protein called DLL3 that’s only found on the surface of tumor cells of SCLC and some other cancers. Cytotoxins (molecules like chemotherapy) attach to a DLL3-binding antibody that may specifically target and destroy DLL3-expressing tumor cells at their roots.

Outside of AbbVie, researchers continue to add to the understanding of how SCLC grows and the new ways doctors might be able to treat it. One example is immunotherapies, which work in other types of cancer like non-small cell lung cancer by reactivat ing the immune system’s response so that it will find and destroy cancer cells. Studies are examining the effectiveness of immunotherapies in SCLC, particularly in combination with other treatments.5

While SCLC is tough to treat today, researchers are forging ahead with more than 700 clinical studies seeking new ways to treat this devastating disease and break the slow news cycle for good.

Media inquiries


Sign Up

Kelli Teno
Call: +1 847-935-9593
  Stay up to date on recent news, stories and more by signing up for our topic alerts.
  1. Koinis, Filippos; Kotsakis, Athanasios; Georgoulias, Vasileios. Transl Lung Cancer Res. 2016 Feb; 5(1): 39–50. Small Cell Lung Cancer (SCLC): No Treatment Advances in Recent Years. Accessed November 13, 2017. Available
  2. American Cancer Society. Key Statistics for Small Cell Lung Cancer. Accessed November 13, 2017. Available
  3. American Cancer Society. Small Cell Lung Cancer Survival Rates, by Stage. Accessed November 13, 2017. Available
  4. Yu-Juan Jin, Chao Zheng, Hong-Bin Ji. Recent Advances in Cancer Research and Therapy, 2012. 20.8. Perspective. Molecular and Cellular Characteristics of Small Cell Lung Cancer: Implications for Molecular-Targeted Cancer Therapy.
Share this Story: Share to Facebook Share to Twitter Share to Linkedin Email