Antibody–drug conjugates (ADCs) represent a novel class of targeted anti-tumor medications that utilize the covalent linkage between monoclonal antibodies and cytotoxic agents. This unique mechanism combines the cytotoxic potency of drugs with the targeting specificity conferred by antigen recognition. However, it is essential to recognize that many ADCs still face challenges related to off-target toxicity akin to cytotoxic payloads, as well as targeted toxicity and other potential life-threatening adverse effects, such as treatment-induced interstitial lung injury. Currently, of the four approved ADC drugs for breast cancer, several reports have documented post-treatment lung injury-related fatalities. As a result, treatment-induced interstitial lung injury due to ADC drugs has become a clinical concern. In this review article, we delve into the factors associated with ADC-induced interstitial lung injury in patients with advanced-stage breast cancer and highlight strategies expected to decrease the incidence of ADC-related interstitial lung injury in the years ahead. These efforts are directed at enhancing treatment outcomes in both advanced and early-stage cancer patients while also providing insights into the development and innovation of ADC drugs and bolstering clinicians’ understanding of the diagnosis and management of ADC-associated interstitial lung injury.

Background: Thyroid hormone sensitivity, reflected by the free triiodothyronine-to-free thyroxine ratio (FT3/FT4), plays a critical role in metabolic regulation. This study aimed to investigate the association between FT3/FT4 and obesity in euthyroid patients with type 2 diabetes. Methods: A total of 1,408 euthyroid patients with type 2 diabetes were included. Multivariable linear regression, subgroup, mediation, and nonlinear analyses were performed to examine the associations between FT3/FT4 and body mass index (BMI). Results: FT3/FT4 was positively and independently associated with BMI in fully adjusted models (β = 7.03, 95% CI: 2.53–11.53, P = 0.0023). Subgroup analyses showed consistent associations across age, sex, and drinking categories, with no significant interactions. Mediation analyses indicated that waist circumference and visceral fat mediated 43.6% and 50.5% of the total effect, respectively, whereas subcutaneous fat was not significant. Nonlinear curve fitting revealed a threshold at FT3/FT4 = 0.41, below which FT3/FT4 was positively associated with BMI, while above it, the association plateaued. Conclusions: FT3/FT4 is independently associated with obesity in euthyroid patients with type 2 diabetes. Its partial mediation through central adiposity and threshold-dependent pattern suggest that FT3/FT4 may serve as a practical biomarker for early risk identification and personalized obesity management. Clinical trial number: not applicable.