Differentiating Small Cell Lung Cancer and Non-Small Cell Lung Cancer

Kathryn Gold, MD: In your clinical practice, how do the small cell and the non–small cell patients differentiate? What are the differences in staging and prognosis between small cell and non–small cell? Konstans, I’ll let you take this one.

konstantinos Leventakos, MD, PhD: In general, the patients with small cell, especially once they become symptomatic, they’re quite sick, and we will be discussing more about that. When it comes to staging, we always advise to have a full-body staging, including a CT [computerized tomography] of the chest, abdomen, and pelvis, or a PET [positron emission tomography] scan done in comparison with an MRI of the head because we know how common it is for small cell to cause brain metastases. Even though we like TNM the tumor, node, metastasis staging system and it is important for registration reasons, it is important to differentiate between limited and extensive stage. This is more practical, it has been validated in many clinical cohorts, and we differentiate the staging between non–small cell and small cell because small cell will use limited versus extensive staging.

We can discuss what is limited and extensive. We define limited stage as the disease that is in the ipsilateral hemithorax and in lymph nodes that could be safely encompassed into radiation; also, we can do the radiation and chemotherapy that Taofeek discussed. Do we still find any value in the TNM? I would say yes, mainly in the very early small cell lung cancers, the ones that would be T1, T2. We might have potential room for surgery still, and these are the patients who do better than anybody. I would say yes, let’s keep the TNM, but for our clinical practice, the distinction between limited and extensive stage is the most important.

Kathryn Gold, MD: When you’re seeing a patient in the clinic, what do you quote for expected prognosis in limited-stage versus extensive-stage small cell?

Konstantinos Leventakos, MD, PhD: When it comes to limited stage, not a lot of things have changed. For limited stage, we have an overall survival of 17 months, with a 5-year survival of 20%. The survival curves totally change depending on the stage. We have much better prognosis for patients who are diagnosed early, usually through screening or for another reason. These patients can do very well with surgery and always adjuvant chemotherapy. For limited stage, not a lot of things have happened, since immunotherapy has changed things mainly in the extensive stage. This is where we will be quoting the new survival rates that we’ll be talking about.

Transcript Edited for Clarity