Proceedings of the 40th Annual ASTRO Meeting 109 ELEVATED FREQUENCY OF GERMLINE BRCA1/BRCA2 GENE MUTATIONS IN LOCALLY RECURRENT BREAST CANCER PATIENTS FOLLOWING LUMPECTOMY AND RADIATION THERAPY: IMPLICATIONS FOR BREAST CONSERVING MANAGEMENT IN AFFECTED PATIENTS. B.C. Tumer 1, M.D., Ph.D., E. Harrold 1, B.S., A.A. Gumbs 1, B.S., Ellen Matloff 2, M.S., B.E. Ward 3, Ph.D., A. Thomas 3, Ph.D., P.M. Glazer 1,2, M.D., Ph.D., and B.G. Haffty l, M.D. Department of Therapeutic Radiology 1, and Genetics 2, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520 and Myriad Genetics 3, Inc., 320 Wakara Way, Salt Lake City, UT 84108. Purpose: Breast cancer patients (BCPs) treated, with lumpectomy and radiation therapy (LRT) have a lifetime risk of ipsilateral breast tumor recurrence (IBTR) of approximately 10-15%. Although clinical, pathological, and recently molecular variables have been shown to be predictive of IBTR, only young age but not family history of early onset breast cancer has been shown to be consistently predictive of local breast tumor relapse. The treatment outcome of BCPs treated with LRT with BRCA1/BRCA2 deleterious mutations has not been previously determined. Materials and Methods: From our breast cancer data base, we identified 121 BCPs with IBTR and 52 surviving patients (index cases) who were not selected for family history of early onset breast/ovarian cancer agreed to participate. We also identified 14 matching control BCPs under age 40 who were matched tothe index cases for age, histology, stage, systemic chemotherapy, and margin resection status. These BCPs underwent informed consent, pedigree analysis, and blood for BRCA1/BRCA2 analysis was obtained. The lymphocyte DNA was purified and comprehensive DNA sequencing was performed using 82 pairs of PCR primers of exons 2-24 of BRCA1 and exons 2-27 of BRCA2 followed by dye primer sequencing of all coding and splice regions. Results: We identified 8/52 (15%) BCPs with IBTR following LRT to have deleterious BRCA1/BRCA2 mutations. By age group there were 6/14 (43%) BCPs age 40 or under, 1/15 (6.6%) women age 40-50, and 1/10 (10%) age greater than 50 with BRCA1/BRCA2 deleterious mutations. The specific definitive deleterious mutations included two patients with the Ashkenazi specific truncating BRCA1 185delAG mutation, one patient with BRCA1 truncating 3875de14 mutation, two patients with the BRCA2 1222delA and L2865X truncating mutations, two patients with the BRCA1 IVS8+2T>A splice site mutation resulting in protein truncation, and one patients with the BRCA2 Y42C mutation resulting in transcriptional inactivation. In a matched case-control study of BCPs under age 40, in comparison to the 6/14 (43%) of patients with local breast tumor relapse found to have deleterious BRCA1 or BRCA2 mutations, only 1/14 (7%) matched control BCPs without IBTR had a deleterious BRCA1 mutation (p=0.05). We found that 10/14 (71%) index cases had a family history of breast cancer compared to 8/14 (57%) control cases (p=NS). Both cohorts had 3/14 (21%) patients with Ashkenazi ancestry. The mean time to IBTR for BCPs treated with LRT with deleterious BRCA1/BRCA2 mutations was 7.5 years, compared to 4.5 years for BCPs without BRCA1/BRCA2 mutations (p=0.02). All patients with BRCA1 or BRCA2 mutations and IBTR underwent successful salvage mastectomy at the time of IBTR, and remain alive without evidence of further local or systemic progression with a median post breast relapse follow-up of 7.7 years. The 10-year distant disease free survival for BCPs with BRCAIlBRCA2 deleterious mutations is 100% compared to 88% for BCPs without BRCA1/BRCA2 mutations. Conclusion: In this matched case-control study, we found an elevated frequency of BRCAIlBRCA2 deleterious mutations in early stage breast cancer patients treated with LRT who developed late local tumor relapse. These late breast tumor relapses probably represent new primary breast cancers. Our findings fit with the biology of germline BRCAIlBRCA2 mutations in which all residual breast cells harbor the dominant mutation and remain at risk for malignant transformation. BCPs with early onset cancer experiencing IBTR have a disproportionally high frequency of BRCA1 IBRCA2 deleterious mutations and young BCPs undergoing conservative therapy should consider BRCA1/BRCA2 testing to help guide treatment decisions. 179 110 THE RELATIONSHIP BETWEEN NM23, ANGIOGENESIS, AND THE METASTATIC PROCLIVITY OF NODE-NEGATIVE BREAST CANCER Ruth Heimann ~Donald Ferguson2 Samuel Hellman ~ Departments of Radiation and Cellular Oncology,i Surgery,2 The Pritzker School of Medicine, The University of Chicago, Chicago, 1L. Purpose: Distant metastases are the major cause of morbidity and mortality in women with breast cancer. The prediction of this metastatic proclivity is essential in determining prognosis and identifying the patients with occult metastases, as well as sparing systemic therapy in those patients whose tumors have not developed the capacity for distant spread. Our goal is to evaluate the significance of rim23, an antimetastatic suppressor gene, and angiogenesis in the metastatic cascade and to assess whether rim23 contributes additional prognostic information to angiogenesis. patients and Methods: We use the data-base of patients treated with mastectomy between 1927 - 1987. Satisfactory archival material was identified from 163 node-negative breast cancer patients for the rim23 studies. All patients underwent mastectomy and received no adjuvant chemotherapy, hormone, or radiation therapy. The median follow-up is 14 years. Immunohistochemistry was used to detect nm23H-1 expression, while angiogenesis was determined by microvessel count (MVC). Immunohistochemistry using anti-CD34 antibody was used to highlight the vessels. Multivariate analysis was performed to identify the significant prognostic variables. Results: We find a trend for small, or low grade tumors to have high nm23:51% of tumors _<2cm had high nm23 compared to 37% of > 2 cm tumors, 60% of low grade and and 43% of high grade tumors had high nm23. There is no correlation between patient age and nm23 or angiogenesis and rim23, but there is a positive correlation between rim23 and estrogen receptor status: 55% of ER positive and 36% of ER negative are high nm23. The 15 year disease-free survival (DFS) is significantly better in patients with high nm23 compared with low nm23 (91% compared to 70%, P = 0.008). The extent of angiogenesis also has significant prognostic value. The 15 year DFS of patients with low MVC is 92% while in those with high MVC is 70% (P 0.03). In those patients with high MVC, high nm23 has additional prognostic value and allows the identification of a subgroup with significantly higher DFS (90% compared to 66%, P = 0.02). Also, among high nuclear grade (NG) tumors if nm23 is high, then the DFS is significantly better (89% compared to 68%, P = 0.03). Thus, nm23 is associated with excellent survival even when there is unfavorable angiogenesis or nuclear grade. The multivariate analysis confirms that nm23 and MVC are important prognostic factors. Conclusions:Nm23 identifies a group of patients with favorable outcome even when MVC is high or the NG is high. Angiogenesis appears to be an early event in the metastatic progression. Hence, high MVC appears necessary, but not sufficient for metastasis to occur, while low nm23 may further contribute to the metastatic progression. Both nm23 and MVC contribute valuable information in characterizing the malignant phenotype.