Tyrosine kinase inhibitors (TKIs) are emerging as potentially effective options in the treatment of cancer, acting on the pathways involved in growth, avoidance of apoptosis, invasiveness, angiogenesis, and local and distant spread. TKIs induce significant adverse effects, that can negatively affect patients’ quality of life. The most common adverse events (AEs) include fatigue, hand–foot skin reaction, decreased appetite, nausea, diarrhoea, hypertension, vomiting, weight loss, endocrinopaties and metabolic disorders.
Patients in therapy with TKIs can develop endocrine-metabolic disorders, including dyslipidemia (∼50%), diabetes (∼15–40%), and dysthyroidism (∼20%). In some cases, patients show an improved glycemia or hypoglycemia. The effects of TKIs on adrenal or gonadal function are still not completely known. It was shown a higher prevalence of subclinical hypocortisolism in patients treated with imatinib, while an increase of cortisol was reported in patients receiving vandetanib. Long-term treatment with imatinib could impact significantly the ovarian reserve and embryo developmental capacity.
It is important to evaluate patients, measure glucose levels, and manage hyperglycemia. Mild treatment-related hyperglycemia can be controlled modifying the diet and with exercise, while grade 3 and 4 hyperglycemia can lead to dose reductions and/or oral antihyperglycemic therapy.
Regarding thyroid dysfunctions, it is recommendable to measure the thyroid-stimulating hormone (TSH)/free thyroxine (FT4) levels before starting the therapy, and every 3–4 weeks during the first 6 months as changes in FT4 levels precede the changes in TSH by 3–6 weeks.
Additional studies are necessary to definitely clarify the mechanism of TKIs-induced endocrine-metabolic effects.