The Clinical Relevance of the NATALEE Study: Application of the NATALEE Criteria to a Real-World Cohort from Two Large German Breast Cancer Centers.

The NATALEE study showed a significant benefit in invasive disease-free survival (iDFS) for patients with HR+/HER2- early breast cancer (eBC) at intermediate and high risk of recurrence who were treated with the CDK4/6 inhibitor Ribociclib in combination with endocrine therapy (ET). This retrospective study aims to apply the NATALEE inclusion criteria to a representative real-world cohort to estimate the proportion of HR+/HER2- breast cancer patients eligible for adjuvant Ribociclib therapy. Patients who underwent full surgical treatment for eBC between January 2018 and December 2020 at two large German university breast cancer centers (University of Ulm, University of Tuebingen) were included. Descriptive statistics were used to characterize the patient population eligible for Ribociclib treatment based on the NATALEE study's inclusion criteria. Out of 2384 enrolled patients, 1738 had HR+/HER2- eBC, of whom 43% (747/1738) met the NATALEE inclusion criteria. Of note, these patients were older, received less chemotherapy and presented with less advanced tumor stages compared to the NATALEE study cohort. Additionally, compared to the NATALEE study cohort, fewer patients had lymph node involvement (72.4% vs. 88.7%). Our analysis suggests that approximately 43% of all HR+/HER2- breast cancer patients will qualify for Ribociclib treatment. Given the numerous treatment options for patients with HR+/HER2- eBC, as well as the differences between the NATALEE cohort and patients in the real-world clinical setting, future analyses will be needed to determine which patients would benefit most from adjuvant CDK4/6 inhibitor treatment.

Curative Polyendocrine Therapy in a 21-year-Old Patient with Endometrial Carcinoma: Case Report and Review of the Literature.

INTRODUCTION: As the numbers of young patients diagnosed with early-stage endometrial carcinoma continue to rise, the question regarding fertility-preserving therapeutic options will increasingly gain significance in the future. CASE PRESENTATION: Here, we present the case of a 21-year-old patient diagnosed with symptomatic atypical endometrial hyperplasia. After 4 months of treatment with medroxyprogesterone acetate, a follow-up dilatation and curettage revealed early-stage, well-differentiated endometrioid endometrial carcinoma. Despite national guidelines recommending hysterectomy, the nulliparous patient expressed a desire to preserve her fertility. Subsequently, she underwent polyendocrine therapy with letrozole, everolimus, metformin, and Zoladex. Forty-three months after diagnosis, the patient successfully gave birth to a healthy child, and there have been no indications of recurrence thus far. DISCUSSION: This case suggests that triple endocrine therapy may be an option for selected patients with early endometrial cancer and a desire for fertility-sparing therapy.

Hormone Receptor and HER2 Status Switch in Non-pCR Breast Cancer Specimens after Neoadjuvant Therapy.

Introduction: This project aimed to identify the frequency of a switch of hormone receptor (HR) and/or HER2 status after neoadjuvant chemotherapy (NAC) for early breast cancer. Methods: Tumor samples from patients without pathological complete response (non-pCR) were evaluated. Pathological complete response (pCR) was defined as no invasive tumor in breast and lymph nodes (ypT0/is ypN0). HR and HER2 status determined before NAC was compared with the corresponding receptor status determined in the surgical specimen after NAC. Results: 245 consecutive patients with primary invasive breast cancer, treated with NAC with/without targeted therapy between January 1, 2016 and December 31, 2019, at the LMU Breast Center, Munich, Germany, were identified. In 128 patients (52%), surgery revealed non-pCR after completed NAC. In 35 cases (27%), a switch of either HR and/or HER2 status between the initial biopsy and the surgical specimen was detected. Twenty cases had a switch in HR status, while 15 cases had a switch in HER2 status. Conclusion: In a substantial number (27%) of non-pCR cases, a switch in biomarker status after completed neoadjuvant treatment was detected. These results are consistent with prior evidence. Yet, routine reevaluation of HR and HER2 status is not recommended in guidelines so far. Future research needs to address the impact of HR and HER2 status switch on therapy adaptation and on subsequent patient outcome. Particularly, in view of the recent therapy advances, it will be critical to evaluate whether individualization of treatment concepts based on the biology of the non-pCR specimens is preferable to the initial therapy concept based on the pathology at primary diagnosis.

The use of breast ultrasound for prediction of pathologic complete response in different subtypes of early breast cancer within the WSG-ADAPT subtrials.

OBJECTIVE: We assessed the value of breast ultrasound (US) performed at week 3 and 6 and at the end (EOT) of neoadjuvant therapy (NAT) for prediction of pathologic complete response (pCR, ypT0/is ypN0) in patients with HR+/HER2+, HR-/HER2-or HR-/HER2+ early breast cancer enrolled in the WSG-ADAPT subtrials. METHODS: US was performed at week 3 and 6 of NAT and at EOT in 401, 517, and 553 patients, respectively. Tumors with complete or partial response by US (RECIST 1.1) were classified as responders and those with stable or progressive disease as non-responders. RESULTS: pCR rate was higher in US responders than in non-responders. US tended to yield the highest positive predictive value in HR-/HER2+ (69%) and HR-/HER2-tumors (65%) at week 3, and the highest negative predictive value in HR+/HER2+ tumors at week 6 and at EOT (88.9% and 86.9%, respectively) and in HR-/HER2-tumors at EOT (87.9%). Multivariable analysis of patients with US at week 3 and 6 identified tumor subtype (HR-/HER2+ vs HR+/HER2+; odds ratio (OR) 2.77, 95%CI 1.45-5.29, and OR 4.17, 95%CI 2.26-7.68, respectively) and each 10% change in lesion dimension on US from baseline (OR 1.15, 95%CI 1.08-1.24, and OR 1.25, 95%CI 1.16-1.35, respectively) as parameters associated with pCR. CONCLUSIONS: Our data support the use of week 3 and EOT US for prediction of pCR in response-guided NAT and in planning of breast-conserving surgery. Change in tumor diameter on US as a continuous variable could be a valuable alternative to categorical RECIST 1.1 criteria.