Browsing by Author "Gradishar, William J."

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    Circulating tumour DNA characterisation of invasive lobular carcinoma in patients with metastatic breast cancer
    (Elsevier, 2022) Davis, Andrew A.; Gerratana, Lorenzo; Clifton, Katherine; Medford, Arielle J.; Velimirovic, Marko; Hensing, Whitney L.; Bucheit, Leslie; Shah, Ami N.; D’Amico, Paolo; Reduzzi, Carolina; Zhang, Qiang; Dai, Charles S.; Denault, Elyssa N.; Bagegni, Nusayba A.; Opyrchal, Mateusz; Ademuyiwa, Foluso O.; Bose, Ron; Gradishar, William J.; Behdad, Amir; Ma, Cynthia X.; Bardia, Aditya; Cristofanilli, Massimo; Medicine, School of Medicine
    Background: Limited data exist to characterise molecular differences in circulating tumour DNA (ctDNA) for patients with invasive lobular carcinoma (ILC). We analysed metastatic breast cancer patients with ctDNA testing to assess genomic differences among patients with ILC, invasive ductal carcinoma (IDC), and mixed histology. Methods: We retrospectively analysed 980 clinically annotated patients (121 ILC, 792 IDC, and 67 mixed histology) from three academic centers with ctDNA evaluation by Guardant360™. Single nucleotide variations (SNVs), copy number variations (CNVs), and oncogenic pathways were compared across histologies. Findings: ILC was significantly associated with HR+ HER2 negative and HER2 low. SNVs were higher in patients with ILC compared to IDC or mixed histology (Mann Whitney U test, P < 0.05). In multivariable analysis, HR+ HER2 negative ILC was significantly associated with mutations in CDH1 (odds ratio (OR) 9.4, [95% CI 3.3-27.2]), ERBB2 (OR 3.6, [95% confidence interval (CI) 1.6-8.2]), and PTEN (OR 2.5, [95% CI 1.05-5.8]) genes. CDH1 mutations were not present in the mixed histology cohort. Mutations in the PI3K pathway genes (OR 1.76 95% CI [1.18-2.64]) were more common in patients with ILC. In an independent cohort of nearly 7000 metastatic breast cancer patients, CDH1 was significantly co-mutated with targetable alterations (PIK3CA, ERBB2) and mutations associated with endocrine resistance (ARID1A, NF1, RB1, ESR1, FGFR2) (Benjamini-Hochberg Procedure, all q < 0.05). Interpretation: Evaluation of ctDNA revealed differences in pathogenic alterations and oncogenic pathways across breast cancer histologies with implications for histologic classification and precision medicine treatment.
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    Identifying homologous recombination deficiency in breast cancer: genomic instability score distributions differ among breast cancer subtypes
    (Springer, 2023) Lenz, Lauren; Neff, Chris; Solimeno, Cara; Cogan, Elizabeth S.; Abramson, Vandana G.; Boughey, Judy C.; Falkson, Carla; Goetz, Matthew P.; Ford, James M.; Gradishar, William J.; Jankowitz, Rachel C.; Kaklamani, Virginia G.; Marcom, P. Kelly; Richardson, Andrea L.; Storniolo, Anna Maria; Tung, Nadine M.; Vinayak, Shaveta; Hodgson, Darren R.; Lai, Zhongwu; Dearden, Simon; Hennessy, Bryan T.; Mayer, Erica L.; Mills, Gordon B.; Slavin, Thomas P.; Gutin, Alexander; Connolly, Roisin M.; Telli, Melinda L.; Stearns, Vered; Lanchbury, Jerry S.; Timms, Kirsten M.; Medicine, School of Medicine
    Purpose: A 3-biomarker homologous recombination deficiency (HRD) score is a key component of a currently FDA-approved companion diagnostic assay to identify HRD in patients with ovarian cancer using a threshold score of ≥ 42, though recent studies have explored the utility of a lower threshold (GIS ≥ 33). The present study evaluated whether the ovarian cancer thresholds may also be appropriate for major breast cancer subtypes by comparing the genomic instability score (GIS) distributions of BRCA1/2-deficient estrogen receptor-positive breast cancer (ER + BC) and triple-negative breast cancer (TNBC) to the GIS distribution of BRCA1/2-deficient ovarian cancer. Methods: Ovarian cancer and breast cancer (ER + BC and TNBC) tumors from ten study cohorts were sequenced to identify pathogenic BRCA1/2 mutations, and GIS was calculated using a previously described algorithm. Pathologic complete response (pCR) to platinum therapy was evaluated in a subset of TNBC samples. For TNBC, a threshold was set and threshold validity was assessed relative to clinical outcomes. Results: A total of 560 ovarian cancer, 805 ER + BC, and 443 TNBC tumors were included. Compared to ovarian cancer, the GIS distribution of BRCA1/2-deficient samples was shifted lower for ER + BC (p = 0.015), but not TNBC (p = 0.35). In the subset of TNBC samples, univariable logistic regression models revealed that GIS status using thresholds of ≥ 42 and ≥ 33 were significant predictors of response to platinum therapy. Conclusions: This study demonstrated that the GIS thresholds used for ovarian cancer may also be appropriate for TNBC, but not ER + BC. GIS thresholds in TNBC were validated using clinical response data to platinum therapy.