Contributor: Travis Barlock, MD Educational Pearls: Cancer-related emergencies can be sorted into a few buckets: Infection Cancer itself and the treatments (chemotherapy/radiation) can be immunosuppressive. Look out for conditions such as sepsis and neutropenic fever. Obstruction Cancer causes a hypercoagulable state. Look out for blood clots which can cause emergencies such as a pulmonary embolism, stroke, superior vena cava (SVC) syndrome, and cardiac tamponade. Metabolic Cancer can affect the metabolic system in a variety of ways. For example, certain cancers like bone cancers can stimulate the bones to release large amounts of calcium leading to hypercalcemia. Tumor lysis syndrome is another consideration in which either spontaneously or due to treatment, tumor cells will release large amounts of electrolytes into the bloodstream causing hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia. Medication side effect Immunomodulators can have strange side effects. A common one to know is Keytruda (pembrolizumab), which can cause inflammation in any organ. So if you have a cancer patient on immunomodulators with any inflammatory changes (cystitis, colitis, pneumonitis, etc), talk to oncology about whether steroids are indicated. Chemotherapy can cause tumor lysis syndrome (see above), and multiple chemotherapeutics are known to cause heart failure (doxorubicin, trastuzumab), kidney failure (cisplatin), and pulmonary toxicity (bleomycin). References Campello, E., Ilich, A., Simioni, P., & Key, N. S. (2019). The relationship between pancreatic cancer and hypercoagulability: a comprehensive review on epidemiological and biological issues. British journal of cancer, 121(5), 359–371. https://doi.org/10.1038/s41416-019-0510-x Gyamfi, J., Kim, J., & Choi, J. (2022). Cancer as a Metabolic Disorder. International journal of molecular sciences, 23(3), 1155. https://doi.org/10.3390/ijms23031155 Kwok, G., Yau, T. C., Chiu, J. W., Tse, E., & Kwong, Y. L. (2016). Pembrolizumab (Keytruda). Human vaccines & immunotherapeutics, 12(11), 2777–2789. https://doi.org/10.1080/21645515.2016.1199310 Wang, S. J., Dougan, S. K., & Dougan, M. (2023). Immune mechanisms of toxicity from checkpoint inhibitors. Trends in cancer, 9(7), 543–553. https://doi.org/10.1016/j.trecan.2023.04.002 Zimmer, A. J., & Freifeld, A. G. (2019). Optimal Management of Neutropenic Fever in Patients With Cancer. Journal of oncology practice, 15(1), 19–24. https://doi.org/10.1200/JOP.18.00269 Summarized by Jeffrey Olson MS2 | Edited by Meg Joyce & Jorge Chalit, OMSII