What’s Old Is New Again, Unfortunately

She was the first patient I remember receiving treatment and returning to share the news that her post-treatment scans showed no evidence of disease. The metastatic renal cell carcinoma was gone. The numerous pulmonary nodules—vanished. Her vibrancy in sharing the news was a welcomed 180-degree difference from the frail and critical woman I had cared for just months prior. As a novice acute care oncology nurse working in a community hospital in the early 2000s, I was astounded. The aldesleukin, a high-dose (HD) recombinant interleukin-2 (IL-2) immunotherapy, which was a newer drug classification at the time, and all our team’s care method changes had worked. Turning the medical-surgery oncology unit into a partial critical care unit, developing new care documentation templates, identifying the meticulous assessment and care management algorithms, planning the staffing variations across the three eight-hour shifts, and all the additional education—it made the difference. For her and many others.

Discovered in 1975, HD IL-2 was approved in 1992 by the U.S. Food and Drug Administration for metastatic renal cell carcinoma and in 1996 for metastatic melanoma. IL-2 is a cytokine that spurs the immune system to identify, find, and destroy cancer cells. The regimen goal included administration of HD IL-2 every eight hours for a maximum of 15 doses. HD IL-2 causes cytokine release, leading to IL-2’s most critical side effect: capillary leak syndrome (CLS) (Pachella et al., 2015).

CLS is a type of third spacing. It is apparent in sepsis, severe burns, and systemic inflammatory responses. This cytokine storm creates excessively permeable capillary walls, allowing plasma proteins, like albumin, to leak from the bloodstream. The oncotic pressure shifts, and fluid follows the protein into the third space. This results in widespread edema, hypoalbuminemia, and hypotension. It can lead to hypovolemic shock and multiple organ failure. Nursing management includes cautious fluid resuscitation, with hourly input and output measurements, to increase intravascular volume while addressing the underlying cause of CLS. In the case of HD IL-2 therapy, the treatment is the cause of CLS; it is a dose-limiting toxicity, and ceasing the treatment allows for clinical management and a carefully monitored reabsorption phase (Dutcher et al., 2014; Ezzone, 2007; Pachella et al., 2015; Portillas et al., 2017). Ceasing treatment can also be mentally and emotionally traumatic for patients and support systems.

In February 2024, lifileucel became the first U.S. Food and Drug Administration–approved tumor-infiltrating lymphocyte (TIL) cellular therapy for adult patients with unresectable metastatic melanoma after prior programmed cell death protein 1 treatment (U.S. Food and Drug Administration, 2024). TILs, types of white blood cells, can recognize and destroy cancer cells. After meeting eligibility criteria and medical clearance, clinicians share a portion of a patient’s resected tumor with the designated manufacturing facility where clinicians and technicians isolate and remove TILs and then duplicate the patient’s cells into the billions. The manufacturer develops this custom therapy into an infusion. Once the clinical team receives the manufactured treatment, a nurse conducts nonmyeloablative lymphodepletion with cyclophosphamide and fludarabine administration. Twenty-four hours or more later, the nurse infuses the TIL therapy. Within 3–24 hours post–TIL infusion, nurses administer a maximum of six IL-2 doses, immune system superboosters of sorts, every 8–12 hours or until reaching dose-limiting toxicities (Ferguson et al., 2025; Miller et al., 2024). As oncology nurses began administering TIL therapy and HD IL-2, many nurses expressed concern with CLS assessment and management.

When I first heard a colleague talk about it and how nervous her team was in the care, my mind raced back to my first nursing unit, the physician who spurred us to develop care management pathways for his patients in need of HD IL-2, the care method changes nursing services and all interdisciplinary departments put in place, and everything the unit team created over those years. Déjà vu. Oncology nursing has lived this experience before. I have heard from oncology nurse colleagues with far more experience than me share similar stories and how they are passing verbal history and information to oncology clinicians stepping into this care management that feels like new terrain in an even more complex healthcare environment.

Although there were some nursing publications on IL-2 management 20–25 years ago, the HD IL-2 literature from the early 2000s is sparse, particularly in comparison to the magnitude of acute care oncology nursing experience. A March 2, 2026, literature search of “capillary leak syndrome” and “nurs*” generated a scant 18 citations from 1987 through February 2026. Adding in variations of “interleukin-2” whittled the results to three. I was proud to see dear colleagues and Clinical Journal of Oncology Nursing authors in the list. For comparison, “tumor infiltrating lymphocyte” and “nurs*” generate more than 9,500 citations. Perhaps this is a semantics search issue or a sign of the proliferation of evidence as the internet and widespread digital networking have matured, but it is a stark contrast and a strong lesson for our profession.

When oncology nurses do not translate daily practice knowledge into peer-reviewed literature, we risk losing it. It becomes nontransferable, and the profession risks reinventing the wheel rather than building on historical work and outcomes. The learning curve for our future colleagues becomes unnecessarily and increasingly steeper.

As many oncology nurses are preparing for the 51st annual ONS Congress^® or other conferences, quality improvement initiatives, nursing grand rounds, and more, there is an opportunity. Turn the work and care into a springboard. Disseminate it at poster and podium sessions and then develop a manuscript to contribute to the body of evidence. If we do not take the time to disseminate the care our teams have poured their lives into, we will lose it, risking future colleagues having to rediscover what we have all learned through oncology nursing sweat, heart, and mind equity. And, then, instead of déjà vu, we can experience vuja de, encountering the familiar with a fresh prospective to propel forward.