Real-World Perspectives and Practices for Pneumonitis/Interstitial Lung Disease Associated With Trastuzumab Deruxtecan Use in Human Epidermal Growth Factor Receptor 2-Expressing Metastatic Breast Cancer.

Trastuzumab deruxtecan (T-DXd) is an antibody drug conjugate with a topoisomerase I payload that targets the human epidermal growth factor receptor 2 (HER2). T-DXd is approved for patients with previously treated HER2-positive or HER2-low (immunohistochemistry [IHC] 1+ or IHC 2+/ISH-) metastatic/unresectable breast cancer (BC). In a second-line HER2-positive metastatic BC (mBC) population (DESTINY-Breast03 [ClinicalTrials.gov identifier: NCT03529110]), T-DXd demonstrated significantly improved progression-free survival (PFS) over ado-trastuzumab emtansine (12-month rate: 75.8% v 34.1%; hazard ratio, 0.28; P < .001), and in patients with HER2-low mBC treated with one prior line of chemotherapy (DESTINY-Breast04 [ClinicalTrials.gov identifier: NCT03734029]), T-DXd demonstrated significantly longer PFS and overall survival than physician's choice chemotherapy (10.1 v 5.4 months; hazard ratio, 0.51; P < .001, and 23.4 v 16.8 months; hazard ratio, 0.64; P < .001, respectively).Interstitial lung disease (ILD) is an umbrella term used for a group of diseases characterized by lung injury including pneumonitis, which can lead to irreversible lung fibrosis. ILD is a well-described adverse event associated with certain anticancer therapies, including T-DXd. An important part of T-DXd therapy for mBC consists of monitoring for and managing ILD. Although information on ILD management strategies is included in the prescribing information, additional information on patient selection, monitoring, and treatment can be beneficial in routine clinical practice. The objective of this review is to describe real-world, multidisciplinary clinical practices and institutional protocols used for patient selection/screening, monitoring, and management related to T-DXd-associated ILD.

The impact of chemotherapy sequence on survival in node-positive invasive lobular carcinoma.

BACKGROUND AND OBJECTIVES: We sought to evaluate the impact of chemotherapy sequence on survival by comparing node-positive invasive lobular carcinoma (ILC) patients who received neoadjuvant (NACT) and adjuvant (ACT) chemotherapy. METHODS: cT1-4c, cN1-3 ILC patients in the National Cancer Data Base (2004-2013) who underwent surgery and chemotherapy were divided into NACT and ACT cohorts. Kaplan-Meier curves and Cox proportional hazards modeling were used to estimate unadjusted and adjusted overall survival (OS), respectively. RESULTS: Five thousand five hundred fifty-one (35.6%) of 15 573 ILC patients treated with chemotherapy received NACT. NACT patients had similar rates of pT3/4 disease (26.6% vs 26.2%), nodal involvement (median 3 vs 4), and number of lymph nodes examined (median 13 vs 14) but higher rates of mastectomy (81.8% vs 74.5%, P < 0.001) vs ACT patients. 3.4% of NACT patients experienced pathologic complete response (pCR). Unadjusted 10-year OS was worse for NACT vs ACT patients (65.1% vs 54.4%, log-rank P < 0.001). After adjustment for known covariates, NACT continued to be associated with worse OS (hazard ratio [HR], 1.38; 95% confidence interval [CI], 1.25-1.52). CONCLUSIONS: In node-positive ILC, NACT yielded low rates of pCR, was not associated with lower rates of mastectomy or less extensive axillary surgery, and was associated with worse survival vs ACT, suggesting limited benefit for these patients.