Akademik Veri Yönetim Sistemi
San Antonio Breast Cancer Symposium 2025, Texas, Amerika Birleşik Devletleri, 9 - 12 Aralık 2025, ss.23, (Özet Bildiri)
Background: Pts with HER2+ early BC who achieve pCR following neoadjuvant chemotherapy (NACT) with HP routinely continue dual anti-HER2 therapy, although the added benefit of continuing HP versus H alone in this setting remains uncertain, with added cost and toxicity. PEARL-HER2 aims to clarify this question by evaluating whether adjuvant HP provides additional clinical benefit compared to H alone. Here, we report a preliminary cross-country comparison of clinical practices. Method: PEARL-HER2 is an international, retrospective cohort study including pts with HER2+ early BC who achieved pCR (ypT0/isN0) after NACT and HP. Eligible pts started NACT between Jan-2014 and Dec-2023. This descriptive analysis, data cut-off of 20-Jun-2025, summarizes diagnostic, and treatment data stratified by country. Results: Of 1045 pts screened, 649 with pCR were eligible for this analysis. Country-level characteristics are shown in Table 1. Differences in baseline characteristics included a higher proportion of pre-/perimenopausal pts in Argentina (56%), higher ER positivity in Belgium (58%) and lower Ki-67 expression in Turkey (21%). Imaging practices also differed: breast MRI was routinely used in Spain, Portugal, and Belgium, but infrequent in Turkey (15%). Staging with FDG-PET was more commonly employed in Turkey (65%) and Belgium (44%), whereas CT and bone scan were predominant elsewhere. Anthracycline-free regimens were more frequent in Argentina (100%) and Belgium (34%), contrasting with near-universal anthracycline use in Portugal and Turkey. Adjuvant HP was continued in >90% of pts in Belgium vs. <9% in Iberian countries, highlighting disparities in access. Among ER+ patients, ET use was near-universal (97%), though OFS-based combinations were infrequent even in very young pts. With a median follow-up of 44 months (IQR 29-67), only 35 relapses (5.4%) were reported, 18 (51%) of which in the central nervous system (CNS).Conclusion: This preliminary analysis reveals marked international variability in post-pCR management of HER2+ early BC. These findings should be interpreted with consideration of the unequal distribution of patients across countries, with Portugal contributing over two-thirds of the cohort. Differences in imaging and tumor burden likely reflect national screening and staging practices, while variation in adjuvant P use likely reflects national funding policies, with routine access in Belgium but limited or no reimbursement in Iberian countries. Notably, over half of reported relapses occurred in the CNS. PEARL-HER2 continues to accrue and follow patients to clarify the role of adjuvant P in this setting.
| Characteristics | Total (n=649) | Argentina (n=18) | Belgium (n=86) | Portugal (n=437) | Spain (n=80) | Turkey (n=28) | p-value |
| Age at diagnosis in years, median (IQR) | 51.9 (44.4-62.0) | 52.9 (40.9-63.2) | 52.7 (43.9-64.2) | 52.1 (45.0-61.4) | 53.8 (42.5-62.1) | 48.6 (45.2-57.9) | 0.729 |
| Pre-/peri-menopausal status, n (%) | 303 (46.7) | 10 (55.6) | 36 (41.9) | 208 (47.7) | 35 (43.8) | 14 (50.0) | 0.039 |
| NST subtype, n (%) | 595 (91.8) | 15 (88.2) | 81 (94.2) | 396 (90.6) | 75 (93.8) | 28 (100.0) | 0.788 |
| Lobular subtype, n (%) | 18 (2.8) | 1 (5.9) | 4 (4.7) | 11 (2.5) | 2 (2.5) | 0 (0.0) | – |
| Grade 3, n (%) | 322 (49.7) | 8 (47.1) | 54 (62.8) | 216 (49.4) | 31 (38.8) | 13 (46.4) | 0.318 |
| ER-negative, n (%) | 314 (48.4) | 14 (77.8) | 36 (41.9) | 207 (47.4) | 39 (48.8) | 18 (64.3) | <0.001 |
| Ki-67 <20%, n (%) | 58 (10.2) | 0 (0.0) | 7 (8.1) | 30 (8.3) | 15 (18.8) | 6 (21.4) | <0.001 |
| DCIS present, n (%) | 191 (29.5) | 0 (0.0) | 32 (37.2) | 113 (25.9) | 39 (48.8) | 7 (25.0) | <0.001 |
| Tumor size in mm, median (IQR) | 32.0 (23.0-50.0) | 52.0 (25.0-66.0) | 31.0 (22.0-47.0) | 32.0 (23.0-49.0) | 28.0 (21.0-52.5) | 30.0 (23.0-40.0) | 0.246 |
| Clinical N0, n (%) | 251 (38.8) | 2 (11.1) | 16 (18.6) | 185 (42.3) | 37 (46.3) | 11 (42.3) | <0.001 |
| Genetic testing performed, n (%) | 185 (28.5) | 5 (27.8) | 27 (31.4) | 122 (27.9) | 26 (32.5) | 5 (18.5) | 0.667 |
| Breast MRI performed, n (%) | 552 (85.2) | 13 (72.2) | 80 (93.0) | 375 (85.8) | 80 (100.0) | 4 (14.8) | <0.001 |
| FDG-PET used, n (%) | 144 (22.3) | 5 (27.8) | 38 (44.2) | 65 (14.9) | 19 (23.8) | 17 (65.4) | <0.001 |
| Anthracycline-based NACT, n (%) | 536 (82.6) | 0 (0.0) | 56 (65.1) | 396 (90.6) | 57 (71.3) | 27 (96.4) | <0.001 |
| Adjuvant pertuzumab, n (%) | 137 (21.1) | 14 (77.8) | 81 (94.2) | 37 (8.5) | 5 (6.3) | 0 (0.0) | <0.001 |
| ET use among ER+, n (%) | 336 (96.8) | 5 (83.3) | 45 (91.8) | 231 (97.9) | 44 (100.0) | 11 (91.7) | 0.028 |
| OFS use among pre/peri, n (%) | 74 (22.0) | 0 (0.0) | 10 (22.3) | 46 (19.9) | 16 (36.4) | 2 (18.2) | 0.042 |