Initial Clinical Results of a Novel Immuno-PET Theranostic Probe in Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer.

This prospective study evaluated the imaging performance of a novel pretargeting immunologic PET (immuno-PET) method in patients with human epidermal growth factor receptor 2 (HER2)-negative, carcinoembryonic antigen (CEA)-positive metastatic breast cancer, compared with CT, bone MRI, and 18F-FDG PET. Methods: Twenty-three patients underwent whole-body immuno-PET after injection of 150 MBq of 68Ga-IMP288, a histamine-succinyl-glycine peptide given after initial targeting of a trivalent anti-CEA, bispecific, antipeptide antibody. The gold standards were histology and imaging follow-up. Tumor SUVs (SUVmax and SUVmean) were measured, and tumor burden was analyzed using total tumor volume and total lesion activity. Results: The total lesion sensitivity of immuno-PET and 18F-FDG PET were 94.7% (1,116/1,178) and 89.6% (1,056/1,178), respectively. Immuno-PET had a somewhat higher sensitivity than CT or 18F-FDG PET in lymph nodes (92.4% vs. 69.7% and 89.4%, respectively) and liver metastases (97.3% vs. 92.1% and 94.8%, respectively), whereas sensitivity was lower for lung metastases (48.3% vs. 100% and 75.9%, respectively). Immuno-PET showed higher sensitivity than MRI or 18F-FDG PET for bone lesions (95.8% vs. 90.7% and 89.3%, respectively). In contrast to 18F-FDG PET, immuno-PET disclosed brain metastases. Despite equivalent tumor SUVmax, SUVmean, and total tumor volume, total lesion activity was significantly higher with immuno-PET than with 18F-FDG PET (P = 0.009). Conclusion: Immuno-PET using anti-CEA/anti-IMP288 bispecific antibody, followed by 68Ga-IMP288, is a potentially sensitive theranostic imaging method for HER2-negative, CEA-positive metastatic breast cancer patients and warrants further research.

Treatment and outcomes in patients with central nervous system metastases from breast cancer in the real-life ESME MBC cohort.

AIM: The aims of the present study were to describe treatment patterns and survival outcomes in patients with central nervous system metastases (CNSM) selected among metastatic breast cancer (MBC) patients included in a retrospective study from the Epidemiological Strategy and Medical Economics (ESME) MBC cohort. METHODS: Neurological progression-free survival (NPFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Significant contributors to NPFS were determined using a multivariate Cox proportional hazards model. RESULTS: After a median follow-up of 42.8 months, of 16 701 patients included in the ESME MBC database, CNSM were diagnosed in 24.6% of patients. The most frequent treatments after diagnosis of CNSM were whole-brain radiotherapy (WBRT) (45.2%) and systemic treatment (59.3%). Median OS and NPFS were 7.9 months (95% CI: 7.2-8.4) and 5.5 months (95% CI: 5.2-5.8), respectively. In multivariate analysis, age >70 years (vs <50 years; HR = 1.40; 95% CI: 1.24-1.57), triple-negative tumours (vs HER2-/HR+; HR = 1.87; 95% CI: 1.71-2.06), HER2+/HR-tumours (vs HER2-/HR+; HR = 1.14; 95% CI: 1.02-1.27), ≥3 metastatic sites (vs < 3; HR = 1.32; 95% CI: 1.21-1.43) and ≥3 previous treatment lines (vs < 3; HR = 1.75; 95% CI: 1.56-1.96) were detrimental for NPFS. A time interval between selection and CNSM diagnosis superior to 18 months (vs <9 months; HR = 0.88; 95% CI: 0.78-0.98) was associated with longer NPFS. CONCLUSIONS: This study describes current treatment patterns of MBC patients in a "real life" setting. Despite advances in stereotactic radiation therapy, most of the patients still received WBRT. More research is warranted to identify patient subsets for tailored treatment strategies.