Brief Answer: You need to undergo chemoradiation Detailed Answer: First, the diagnosis is small cell carcinoma. These are generally more aggressive by nature. The blood tests, CT, MRI and PET are negative. That is good. Each test works either on anatomy (like CT, MRI) or on function (PET). The fact that all tests do not show any spread is a good sign. But you still need to undergo therapy. Each test requires certain volume of disease before it can pick up. For instance, CT scan would in the best of centres require a volume of 1-2cm sized nodule to pick up. That would mean a tumor cell count of upwards of 1,000,000. We do not have a test to pick up cancer at a level of single cell or a few cells. Hence, when cancer is detected anywhere, many times (not always, depends on the cancer of organ and type) it is presumed to be systemic disease at onset. Even in your case, it is presumably (not proven) a systemic disease and would be treated as such. It is presumed that micro metastasis (which cannot be detected by any test) are present at the time of diagnosis even though all tests are negative. Hence you would require radiation for local control and chemotherapy to attack systemic disease. Hope I have made myself clear. Regards

---