Abstract Introduction Spontaneous regression (SR) of cancer denotes the partial or complete disappearance of a malignancy without any effective medical treatment. It is an extremely rare phenomenon. In particular, spontaneous regression of non-small cell lung cancer (NSCLC) has been scarcely reported. It can be either temporary or, in very rare cases, permanent. During temporary resolution , available literatures indicate it can last anywhere from a few months to years. Here, we present a case of spontaneous dramatic regression of advanced metastatic adenocarcinoma with out any medical treatment. Case Body/Discussion A 70 year old female reviewed for 20mm cavitary right upper lobe lung lesion with extensive mediastinal lymphadenopathy. Her only medical history was hypertension and arthritis. Functionally she was a very fit. EBUS histology confirmed metastatic Adenocarcinoma of lung origin. PDL-1 was 100% positive. PET CT scan showed Metastatic lung cancer with multiple bony, mediastinal and cervical lymph node metastasis. She was diagnosed with metastatic adenocarcinoma of lung origin with staging of T1bN3M1c. Simultaneously, she was also found to have Papillary urothelial Carcinoma Grade 2 for which she was being evaluated by the uro-oncologist. For personal reasons, she decided not to have any form of anticancer treatment but agreed to follow-up interval scans with the oncologist. She had repeat scan in 1 year where surprisingly she was found to have dramatic spontaneous regression of her malignant disease. Her cavitary lesion was regressed to 5mm with no sign of metastatic disease. Images of PET scans showing FDG avid lesion on Left and repeated PET scan in 1 year showing resolution of lesion Discussion We chose to present this case due to its rarity as well as incomplete understanding of the process surrounding this phenomenon. There are hypothesis such as immunologic modulation which is often thought to play an important role through mediating T-cell activation and release of cytokines, such as interleukin-2 . There are other hypothesis that there may be an immunological association between the stimulus of the biopsy and disruption of the tumour microenvironment leading to spontaneous regression. Further understanding into what makes certain cancers regress could open novel anti cancer treatment strategies and further expand the ever-growing modalities for anticancer treatment. For our case, there were some radiological signs of disease progression on subsequent scans, but due to absence of extensive disease still her life expectancy was deemed to be better than previous state. This abstract is funded by: None
Chukwuka et al. (2026) studied this question.