NUT carcinoma: Survival outcomes and epidemiology.

e22540 Background: NUT carcinoma (NC) or NUT midline carcinoma is an extremely rare, undifferentiated or a poorly differentiated squamous cell malignancy that can arise anywhere in the body, but often originates along the midline structures (head, neck or lungs). It is characterized by chromosomal rearrangement of NUT gene, commonly BRD3 or BRD4 gene. This fusion oncogene produces abnormal NUT (Nuclear protein in testis) protein causing dysplastic squamous cell proliferation. NC presents at later stages with B-symptoms and symptoms specific to the organ of origin. The purpose of this study is to determine epidemiology and factors affecting survival in NC. Methods: We extracted cases of NUT carcinoma diagnosed after the age of 20 years, using the ICD Code 8023/3, from Surveillance, Epidemiology and End Result database Research Plus Data, 17 Registries, Nov 2023 Sub (2000-2021). The data was stratified based on age, sex, race, laterality, primary site labelled, stage, median household income inflation adjusted to 2022, and treatment modalities used. Survival curves were compared using Log-Rank test (GraphPad Prism). Results: Only 49 cases of NUT carcinoma were found from 2000 to 2021. Of these cases, 69.4% were males and 30.6% were females. Racial distribution in descending order was noted as: White (59.18%) patients followed by Hispanics (20.41%), Asians/Pacific Islanders (16.33%), and Blacks (4.1%). No cases were reported in Alaskans or Native Americans. Over 90% of the cases had positive regional lymph nodes at the time of diagnosis. The median age of diagnosis was 54 years. The overall median of survival (MoS) was 10 months, with a 1-year survival of 0.415 (CI 95%, 0.26-0.563), 3-year survival of 0.29 (CI 95%, 0.14-0.46). The median of survival (MoS) based on age, race, gender, laterality and median household income showed no statistical significance. MoS for primary site was significant for head & neck (14), GI (<1), lungs (8), peritoneum (1.5) and unknown site (undefined, due to no reported death in this category) (p <0.0001). Analysis based on stage revealed higher MoS for localized while lowest MoS for distant disease (p 0.0088). Treatment base survival was calculated as: chemotherapy (14) vs no chemotherapy (1) (p <0.0001), and radiation therapy (14) vs no XRT (2) (p 0.0009). Similarly, survival calculated for surgery was significantly higher than without it (p 0.0173). Conclusions: NUT carcinoma is an ultra-rare malignancy with only 49 cases reported in the past two decades in SEER database. This aggressive neoplasm favoured males and Caucasians race. Overall, better survival outcomes were associated with earlier stages, tumors originating from head & neck or lungs, and management involving either surgery, chemotherapy or radiotherapy. Prognosis was independent of age, gender, race, laterality and income. Further research is warranted to determine the impact of next generation sequencing based immunotherapy on the survival outcomes.