What challenges are there in the diagnosis of small cell lung cancer?

Estelamari Rodriguez, US

Know Lung Cancer spoke with Dr Estelemari Rodriguez, a thoracic oncologist at Sylvester Comprehensive Cancer Center, University of Miami, Miami, US. We asked, What challenges are there in the diagnosis of small cell lung cancer? 

Dr Rodriguez explains that small cell lung cancer is a less common but aggressive type of lung cancer, accounting for around 20% of cases. Early diagnosis is therefore important, as the cancer can grow and spread quickly, and symptoms should be investigated as early as possible.   

One of the challenges in diagnosing small cell lung cancer is that symptoms, such as shortness of breath and feeling generally unwell, can look similar to other health problems, such as pneumonia or heart-related conditions. In some people, small cell lung cancer may also cause symptoms that are not directly related to the lungs. This is known as paraneoplastic syndrome, where the cancer affects the body in other ways, such as muscle weakness or difficulties with movement.  

Dr Rodriguez emphasized that if symptoms continue or do not have a clear explanation, it is important for patients to speak to a doctor promptly, particularly if they have a history of smoking. Although small cell lung cancer can progress rapidly, it can also respond quickly to therapy, which makes early recognition, diagnosis, and getting started with the right course of treatment especially important. 

This educational resource is independently supported by Amgen. All content is developed by SES in collaboration with our expert ambassador group. Funders are allowed no influence. 

References 

1. Cancer Research UK. Types of lung cancer. https://www.cancerresearchuk.org/about-cancer/lung-cancer/stages-types/types. Updated Jan 13, 2026. Accessed May 29, 2026.