Endocrine adverse events related with immune checkpoint inhibitors: an update for clinicians

A Concerted Vision to Advance the Knowledge of Diabetes Mellitus Related to Immune Checkpoint Inhibitors

The rubric of immune-related (ir) diabetes mellitus (DM) (irDM) encompasses various hyperglycemic disorders related to immune checkpoint inhibitors (ICPis). Beyond sharing similarities with conventional DM, irDM is a distinct, yet important, entity. The present narrative review provides a comprehensive overview of the literature regarding irDM published in major databases from January 2018 until January 2023. Initially considered rare, irDM is increasingly being reported. To advance the knowledge of irDM, the present review suggests a concerted vision comprising two intertwined aspects: a scientific-centered and a patient-centered view. The scientific-centered aspect addresses the pathophysiology of irDM, integrating: (i) ICPi-induced pancreatic islet autoimmunity in genetically predisposed patients; (ii) altered gut microbiome; (iii) involvement of exocrine pancreas; (iv) immune-related acquired generalized lipodystrophy. The patient-centered aspect is both nurtured by and nurturing the four pillars of the scientific-centered aspect: awareness, diagnosis, treatment, and monitoring of irDM. The path forward is a multidisciplinary initiative towards: (i) improved characterization of the epidemiological, clinical, and immunological profile of irDM; (ii) standardization of reporting, management, and surveillance protocols for irDM leveraging global registries; (iii) patient stratification according to personalized risk for irDM; (iv) new treatments for irDM; and (v) uncoupling ICPi efficacy from immunotoxicity.

Refining personalized diagnosis, treatment and exploitation of hypothyroidism related to solid nonthyroid cancer

Hypothyroidism in the setting of cancer is a puzzling entity due to the dual role of the thyroid hormones (TH) in cancer – promoting versus inhibitory – and the complexity of the hypothyroidism itself. The present review provides a comprehensive overview of the personalized approach to hypothyroidism in patients with solid nonthyroid cancer, focusing on current challenges, unmet needs and future perspectives. Major electronic databases were searched from January 2011 until March 2022. The milestones of the refinement of such a personalized approach are prompt diagnosis, proper TH replacement and development of interventions and/or pharmaceutical agents to exploit hypothyroidism or, on the contrary, TH replacement as an anticancer strategy. Further elucidation of the dual role of TH in cancer – especially of the interference of TH signaling with the hallmarks of cancer – is anticipated to inform decision-making and optimize patient selection.

The continuum of care of anticancer treatment-induced hypothyroidism in patients with solid non thyroid tumors: time for an intimate collaboration between oncologists and endocrinologists

INTRODUCTION

Hypothyroidism is a common adverse event of various anticancer treatment modalities, constituting a notable paradigm of the integration of the endocrine perspective into precision oncology.

AREAS COVERED

The present narrative review provides a comprehensive and updated overview of anticancer treatment-induced hypothyroidism in patients with solid non-thyroid tumors. A study search was conducted on the following electronic databases: PubMed, Google Scholar, Scopus.com, ClinicalTrials.gov, and European Union Clinical Trials Register from 2011 until August 2021.

EXPERT OPINION

In patients with solid non-thyroid tumors, hypothyroidism is a common adverse event of radiotherapy, high dose interleukin 2 (HD IL-2), interferon alpha (IFN-α), bexarotene, immune checkpoint inhibitors (ICPi), and tyrosine kinase inhibitors (TKIs), while chemotherapy may induce hypothyroidism more often than initially considered. The path forward for the management of anticancer treatment-induced hypothyroidism in patients with solid non-thyroid tumors is an integrated approach grounded on 5 pillars: prevention, vigilance, diagnosis, treatment and monitoring. Current challenges concerning anticancer treatment-induced hypothyroidism await counteraction, namely awareness of the growing list of related anticancer treatments, identification of predictive factors, counteraction of diagnostic pitfalls, tuning of thyroid hormone replacement, and elucidation of its prognostic significance. Close collaboration of oncologists with endocrinologists will provide optimal patient care.

Thyroid-related adverse events induced by immune checkpoint inhibitors

Immune checkpoint inhibitors, namely anti-CTLA-4, anti-PD-1 and anti-PD-L1 monoclonal antibodies, have emerged in the last decade as a novel form of cancer treatment, promoting increased survival in patients. As they tamper with the immune response in order to destroy malignant cells, a new type of adverse reactions has emerged, known as immune-related adverse events (irAEs), which frequently target the endocrine system, especially the thyroid and hypophysis. Thyroid irAEs include hyperthyroidism, thyrotoxicosis, hypothyroidism and a possibly life-threatening condition known as the "thyroid storm". Early prediction of occurrence and detection of the thyroid irAEs should be a priority for the clinician, in order to avoid critical situations. Moreover, they are recently considered both a prognostic marker and a means of overseeing treatment response, since they indicate an efficient activation of the immune system. Therefore, a multidisciplinary approach including both oncologists and endocrinologists is recommended when immune checkpoint inhibitors are used in the clinic.

Honegger J, M. Weber M, Kroiss M. The Diagnosis and Management of Endocrine Side Effects of Immune Checkpoint Inhibitors

BACKGROUND

The immunologically mediated side effects of immune checkpoint inhibitors (CPI) often involve the endocrine system as well, and they can even be fatal, as in the case of unrecognized hypophysitis. Distinguishing such side effects from tumor-related changes is often difficult, because their clinical features can be nonspecific.

METHODS

This review is based on publications retrieved by a selective search in PubMed, with special attention to international recommendations.

RESULTS

Depending on their target molecules, the CPI now in use differ from one another in the incidence of side effects such as autoimmune thyroid disease (4-16%), hypophysitis (0.1- 18%), adrenalitis (0.7-8%), and autoimmune diabetes mellitus (0.5-2%). The typical clinical warning signs and laboratory constellations of hypophysitis include exhaustion, hyponatremia, and headache. Hypo- and hyperthyroidism and primary adrenocortical insufficiency likewise have nonspecific manifestations. Autoimmune diabetes mellitus often takes a fulminant course. Patients being treated with CPI should be monitored at close intervals, at least as frequently as the administration of the drug, so that endocrine side effects can be recognized in time. In case of doubt, glucocorticoid supplementation should be given whenever hypocortisolism is suspected, even before endocrine evaluation is completed and the results are available. Interrupting or discontinuing CPI treatment is rarely indicated.

CONCLUSION

With the increasing number of patients being treated with CPI, more and more physicians from a wide variety of specialties, not necessarily working in specialized centers, now have to consider immunologically mediated endocrine side effects in the differential diagnosis, and treat them properly when they arise. These things should be done in collaboration with endocrinologists. The ongoing study of such side effects of the CPI now in use, and of those that will be introduced in the future, is important and will lead to improved understanding.

Reversible primary adrenal insufficiency related to anti-programmed cell-death 1 protein active immunotherapy: Insight into an unforeseen outcome of a rare immune-related adverse event

The immune checkpoint inhibitors (ICPi) revolutionize the cancer therapeutics, though not being devoid of toxicity. The immune-related primary adrenal insufficiency (PAI) is a rare, yet potentially life-threatening, adverse event, posing diagnostic and therapeutic challenges. We report the first case of reversible PAI related to nivolumab (programmed cell-death 1 protein inhibitor) in a 42-year-old male with metastatic rectal adenocarcinoma. PAI manifested as profound fatigue, disorientation, hypotension, hyperpigmentation of palmar creases, and hyponatremia without hyperkalemia 16 weeks after initiation of nivolumab. Due to impending adrenal crisis, intravenous stress doses of hydrocortisone and hydration with normal saline were initiated. When the state of patient was stabilized, PAI was confirmed through 250 μg Synacthen test 24 h after temporary cessation of hydrocortisone. Hydrocortisone was fixed at maintenance dose, while mineralocorticoid substitution was not required. PAI was ascribed to nivolumab based on history, physical examination, and laboratory work-up with emphasis on positivity of anti-21-hydroxylase antibodies and exclusion of other causes of PAI by normal imaging of adrenal glands on computed tomography (CT). Reevaluation of adrenal function during follow up demonstrated complete recovery. A review of literature concerning the immune-related PAI indicated that the complete recovery of adrenal function, the normal CT imaging, and the positivity of anti-21-hydroxylase antibodies observed in our patient are exceptional findings of immune-related PAI. Finally, heightened suspicion of immune-related PAI in case of hyponatremia without hyperkalemia and constant vigilance for diagnosis of rare, but real, reversibility of immune-related PAI are of paramount importance.