LAUSR

Introduction and importance Spontaneous regression (SR) of cancer is extremely rare in non-small cell lung cancer and the exact pathogenesis is unclear. Case presentations A 69-year-old man underwent a right upper lobectomy for a squamous cell carcinoma histologically confirmed 8 weeks prior. A histopathological examination of the surgical specimen revealed no viable cancer. He remains disease free at 5 years after surgery. A 77-year-old man presented with a metastatic bone tumor compatible with a non-small cell lung cancer origin. He had undergone a surgical biopsy for a right lung nodule of which the histopathological examination revealed only scar tissue a year prior. He died of cancer 4 months after the diagnosis of a bone metastasis. Clinical discussion The unknown etiology of an SR of cancer is still to be resolved. Conclusion Patients with an SR of cancer may yield a variety of clinical outcomes and a meticulous observation is essential.