Genetic testing in women with early-onset breast cancer: a Traceback pilot study

Evaluating the Effectiveness of Cyclin-Dependent Kinase 4/6 Inhibitors in Early- and Very Early-Onset Metastatic Breast Cancer: A Multicenter Study

Background and Objectives: Early-onset breast cancer (EOBC), particularly in patients under 40, presents with distinct biological characteristics and worse survival outcomes compared to late-onset cases. Despite intensive treatments, EOBC patients, especially those with hormone receptor-positive, HER2-negative (HR+/HER2-) subtypes, show poorer prognosis. CDK4/6 inhibitors, combined with endocrine therapy (ET) have become the standard for HR+/HER2- metastatic breast cancer, yet younger patients are underrepresented in clinical trials. This study aims to evaluate the efficacy of ribociclib and palbociclib with ET in HR+/HER2- metastatic breast cancer, addressing the critical gap in understanding treatment outcomes in younger patient populations. Materials and Methods: This multicenter, retrospective study evaluated the efficacy and safety of cyclin-dependent kinase 4 and 6 (CDK 4/6) inhibitors, ribociclib, and palbociclib, in combination with endocrine therapy in patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative metastatic breast cancer. Results: A total of 198 patients treated between 2019 and 2023 were analyzed for progression-free survival, overall survival, and prognostic factors. Very early-onset breast cancer, which is diagnosed before the age of 35, was identified as an independent prognostic factor for poor progression-free survival. Additional factors associated with poorer outcomes included liver metastasis, progesterone receptor negativity, high tumor grade, and the concurrent use of fulvestrant with CDK4/6 inhibitors. Both ribociclib and palbociclib demonstrated similar efficacy, and dose reductions due to treatment-related adverse events did not compromise therapeutic outcomes. Conclusions: This study is the first to focus specifically on the treatment of early-onset breast cancer with CDK4/6 inhibitors, providing critical insights into the unique challenges faced by this patient population. The findings underscore the urgent need for personalized treatment strategies, routine genetic testing, and dedicated clinical trials designed to address the specific needs of these high-risk subgroups. By advancing our understanding of the clinical and molecular landscape of early-onset breast cancer and very early-onset breast cancer, this study lays the groundwork for improving outcomes in these underserved patients through tailored therapeutic approaches.

The association of genetic testing timing and mutation type on breast cancer management in patients with breast cancer-related mutations

BACKGROUND

We aim to characterize breast management for patients with genetic mutations and concurrent breast cancer (BC) or prior BC treatment.

METHODS

Adults with a BC-related mutation and prior/concurrent BC diagnosis were identified. Groups were stratified by mutation type [BRCA1/2, high penetrance mutation (HPM), moderate penetrance mutation (MPM)] and timing of genetic testing (concurrent with BC versus after BC treatment). Outcomes were compared.

RESULTS

Among 338 patients included, 63 ​% had BRCA1/2 mutations, 9 ​% HPM, and 28 ​% MPM. Approximately 38 ​% had testing concurrent with a BC diagnosis and 62 ​% after BC treatment. Patients with concurrent testing favored bilateral mastectomy (57 ​%) versus 26 ​% lumpectomy, and 16 ​% unilateral mastectomy, which varied by mutation type. Patients previously treated preferred surveillance (92 ​% vs. 8 ​% additional surgery), regardless of mutation type.

CONCLUSION

The timing of a significant BC-related genetic test result and mutation type may be associated with management decisions among patients with breast cancer.

Histopathological phenotyping of cancers in PTEN Hamartoma Tumor Syndrome for improved recognition: A single-center study

PTEN hamartoma tumor syndrome (PHTS) has a broad clinical spectrum including various benign and malignant tumors at varying age of diagnosis. Many patients remain unrecognized, unaware of their increased cancer risk. We aimed to describe the cancer spectrum, age of onset and histopathological cancer characteristics to assess whether specific cancer characteristics could improve PHTS recognition. Genetic testing results and pathology reports were collected for patients tested for germline PTEN variants between 1997 and 2020 from the diagnostic laboratory and the Dutch nationwide pathology databank (Palga). The cancer spectrum and age of onset were assessed in patients with (PTENpos) and without (PTENneg) a germline PTEN variant. Histopathological cancer characteristics were assessed in a nested cohort. 341 PTENpos patients (56% females) and 2882 PTENneg patients (66% females) were included. PTENpos patients presented mostly with female breast (BC, 30%), endometrial (EC, 6%), thyroid (TC, 4%) or colorectal cancer (4%). PTENpos were significantly younger at cancer onset (43 vs. 47 years) and had more often (46% vs. 18%) a second BC than PTENneg. PTEN detection rates were highest for BC <40 years (9%), TC <20 years (15%) and EC <50 years (28%), and dropped to 6%, 4%, and 15% by age 60. Histopathological characteristics were similar between groups. No histopathological cancer characteristics were distinctive for PHTS. However, PTENpos were significantly younger at cancer onset. Therefore early-onset BC, EC, or TC warrants consideration of PHTS diagnostics either through a pre-screen for other PHTS features or direct germline testing.

Genetic Testing Uptake among Ovarian Cancer Survivors in the Genetic Risk Analysis in Ovarian Cancer (GRACE) Study

BACKGROUND

Recommendations state all people with ovarian cancers (OCs) receive genetic counseling, but testing uptake is only between 15 and 31%. Those with a prior diagnosis of OC who have not received genetic testing represent a missed opportunity for life-saving genetic risk information. The Genetic Risk Analysis in ovarian CancEr (GRACE) study aimed to evaluate the feasibility of the retrospective identification ("Traceback") of individuals diagnosed with OC.

METHODS

This nonrandomized intervention study within two integrated health care systems identified participants with a history of OC between 1998 and 2020 who did not have genetic testing or testing limited to BRCA1/2. Participants received clinical genomic sequencing via a custom 60 gene panel. This study measured the feasibility of the Traceback methodology in OC survivors.

RESULTS

The initial cohort included 929 individuals, of which 57% had no prior genetic testing. Of the 302 eligible for recruitment, 88 consented to participate. We were able to outreach 97% of the eligible population using contact information from medical records. The stage at diagnosis was the only factor associated with consent. Of the 78 who returned their saliva sample, 21% had pathogenic/likely pathogenic variants, and 79% had negative results.

CONCLUSION

The GRACE study resulted in a 29% uptake of genetic testing in OC survivors. The time since diagnosis did not have an impact on consent or ability to contact. GRACE can inform the implementation of future Traceback programs, providing guidance on how to prevent and mitigate the burden of OC and other hereditary cancers.

Genetic counseling and genetic testing for pathogenic germline mutations among high-risk patients previously diagnosed with breast cancer: a traceback approach

Genetic counseling and testing are more accessible than ever due to reduced costs, expanding indications and public awareness. Nonetheless, many patients missed the opportunity of genetic counseling and testing due to barriers that existed at that time of their cancer diagnoses. Given the identified implications of pathogenic mutations on patients' treatment and familial outcomes, an opportunity exists to utilize a 'traceback' approach to retrospectively examine their genetic makeup and provide consequent insights to their disease and treatment. In this study, we identified living patients diagnosed with breast cancer (BC) between July 2007 and January 2022 who would have been eligible for testing, but not tested. Overall, 422 patients met the eligibility criteria, 282 were reached and invited to participate, and germline testing was performed for 238, accounting for 84.4% of those invited. The median age (range) was 39.5 (24-64) years at BC diagnosis and 49 (31-75) years at the date of testing. Genetic testing revealed that 25 (10.5%) patients had pathogenic/likely pathogenic (P/LP) variants; mostly in BRCA2 and BRCA1. We concluded that long overdue genetic referral through a traceback approach is feasible and effective to diagnose P/LP variants in patients with history of BC who had missed the opportunity of genetic testing, with potential clinical implications for patients and their relatives.

Retrospective genetic testing (Traceback) in women with early-onset breast cancer after revised national guidelines: a clinical implementation study

PURPOSE

This study focused on identifying a hereditary predisposition in women previously diagnosed with early-onset breast cancer through a retrospective outreach activity (Traceback). The objectives were to evaluate the possible clinical implementation of a simplified Traceback strategy and to identify carriers of pathogenic variants among previously untested women.

METHODS

Three hundred and fifteen Traceback-eligible women diagnosed with breast cancer at 36-40 years in Southern Sweden between 2000 and 2019 were identified and offered an analysis of the genes ATM, BARD1, BRCA1, BRCA2, CHEK2, PALB2, RAD51C, and RAD51D through a standardized letter. Women who chose to participate were asked about their experiences through a questionnaire. The workload for the study personnel was measured and recorded.

RESULTS

One hundred and seventy-six women underwent genetic testing and pathogenic variants were identified in 9.7%: ATM (n = 6), BARD1 (n = 1), BRCA1 (n = 3), CHEK2 (n = 5), and PALB2 (n = 2). Women with normal test results were informed through a standardized letter. Carriers of pathogenic variants were contacted by telephone and offered in-person genetic counseling. One hundred and thirty-four women returned the subsequent questionnaire. Most study participants were satisfied with both written pre- and post-test information and many expressed their gratitude. The extra workload as compared to routine clinical genetic counseling was modest (8 min per patient).

CONCLUSION

The insights from the participants' perspectives and sentiments throughout the process support the notion that the Traceback procedure is a safe and an appreciated complement to routine genetic counseling. The genetic yield of almost 10% also suggests that the associated extra workload for genetic counselors could be viewed as acceptable in clinical implementation scenarios.