The key finding
A 2025 systematic review of 64 case reports spanning 2015-2024 found that immune checkpoint inhibitors—a class of cancer drugs that help the immune system fight tumors—can trigger adrenal insufficiency in some patients, a rare but potentially life-threatening complication. The condition appeared deceptively: fatigue affected 67.2% of patients, nausea 28.1%, loss of appetite 25%, and low blood pressure 21.9%. Most strikingly, 73.7% presented with three or more symptoms occurring together, yet the diagnosis was frequently delayed because these signs resembled common cancer treatment side effects. Only 40.6% of patients received proper hormonal testing to confirm the condition, and recovery of normal adrenal function occurred in just 9.4% of cases.
What the study looked like
Researchers conducted a meta-ethnographic synthesis—a qualitative approach that pulls narrative themes from published medical cases—examining 64 individual case reports of patients who developed adrenal insufficiency while receiving immune checkpoint inhibitors. These cases were published between 2015 and 2024 in medical journals worldwide. The investigators extracted detailed information about each patient’s demographics, cancer type, specific immunotherapy drugs used, initial symptoms, how doctors arrived at the diagnosis, hormone test results, imaging scans of the pituitary and adrenal glands, treatment approaches, and final outcomes. They also assessed the quality of each case report using a modified version of the CARE checklist, a tool designed to evaluate the completeness and reliability of published case studies. The narrative portions of these reports were then analyzed to identify patterns and contextual factors that contributed to delays in recognizing the condition.
Why researchers think this happened
The paper identified five recurring themes that explain why diagnosis was so often delayed. First, the symptoms themselves are nonspecific—fatigue, nausea, and appetite changes occur commonly in cancer patients for many reasons. Second, clinicians had low suspicion for this complication because adrenal insufficiency from immune checkpoint inhibitors remains relatively uncommon compared to other side effects. Third, hormonal testing was delayed or not ordered at all in many cases, meaning the definitive diagnosis couldn’t be made. Fourth, imaging studies frequently appeared normal, creating a false sense of reassurance; traditional scans of the pituitary gland didn’t reveal the problem because this type of adrenal insufficiency can occur through different mechanisms than typical pituitary disease. Finally, fragmented care across multiple specialists—oncologists, endocrinologists, primary care doctors—meant no single physician maintained oversight of the emerging symptom pattern. The researchers noted that because multiple symptoms clustered together in most patients, this pattern itself should have raised red flags earlier in the diagnostic process.
How to read this carefully
This study analyzed published case reports rather than conducting a prospective clinical trial, which means it’s subject to publication bias—doctors are more likely to write up unusual or severe cases than typical ones. The 64 cases represent a small fraction of the millions of patients who have received immune checkpoint inhibitors worldwide, so the true incidence of this complication remains uncertain. Additionally, case reports rely on physician memory and documentation, which may not capture every detail of the diagnostic journey. The finding that adrenal function rarely recovered could reflect both the severity of the condition and the follow-up practices in these particular cases rather than an absolute prognosis. Because symptoms overlapped substantially with other treatment effects, determining causation retrospectively presents challenges. Readers should understand this study identifies an important clinical pattern but cannot establish how frequently it occurs or predict individual risk.
What this means for everyday life
If you or a loved one is receiving immunotherapy for cancer, this research suggests it’s worth tracking symptoms carefully and reporting clusters of problems—especially the combination of persistent fatigue, digestive issues, and dizziness upon standing—to your medical team promptly. The study highlights that even experienced oncologists may not immediately connect these dots because the symptoms seem ordinary in the context of cancer treatment. Given that 60.9% of patients required hospitalization and adrenal function rarely returned to normal, early detection matters considerably. It might be worth asking your oncologist whether routine monitoring of adrenal hormones should be part of your care plan, particularly if you develop multiple new symptoms simultaneously. This isn’t about alarm, but about informed advocacy: understanding that some side effects require endocrine specialist evaluation rather than symptomatic management alone. The research underscores the importance of coordinated care—making sure all your doctors communicate about emerging symptoms rather than each addressing isolated complaints independently.