Cafourek, Victoria

Abstract Background: The LAR subtype is a genomically distinct subset of TNBC. Using a large cohort of non-metastatic TNBC patients (pts) with long term follow-up, we sought to further characterize the clinicopathologic features and outcomes of LAR vs non-LAR TNBC. Methods: From a cohort of 9982 women with surgically-treated non-metastatic breast cancer, 605 met criteria for TNBC (ER/PR<1% and HER2-negative) by central pathology. RNA extracted from 304 FFPE tumor specimens using the HighPure RNA extraction kit was subjected to TruSeq RNA Access library preparation and sequencing on a HiSeq2500. Adequate RNA was available for 283 pts. Tumors were classified as LAR or non-LAR using a shrunken centroid model, CABAL (Clustering Among BAsal and Luminal androgen receptor). In addition to previously described analyses [Leon-Ferre et al, Breast Cancer Res Treat 2017], immunohistochemical (IHC) androgen receptor (AR) staining was performed and the impact of various parameters on invasive disease-free survival (IDFS) and overall survival (OS) was assessed using Cox proportional hazards models. Results: 58 (20%) tumors were classified as LAR and 225 (80%) as non-LAR. Compared to non-LAR, LAR pts were older (mean age 65 vs 54) and more often postmenopausal (79%vs53%), both p=0.01. Apocrine histology was more common among LAR tumors (21%vs0%), which were also lower grade (grade3: 69%vs95%) and had lower Ki-67 (Ki-67>15%: 64%vs82%), all p<0.01. Additionally, LAR tumors had lower median stromal tumor infiltrating lymphocytes (TILs, 20%vs25%) and were less frequently lymphocyte-predominant [≥50% stromal or intratumoral TILs (19%vs32%)], although neither reached statistical significance. AR IHC was available for 223 of 283 tumors. Median AR IHC score in LAR was 65% (range 0-100%) vs 0% (range 0-90%) in non-LAR. T/N stage, surgery type, and receipt of adjuvant chemotherapy (AdjCT) or radiotherapy were similar between LAR and non-LAR. LAR pts had shorter IDFS and OS compared to non-LAR (5.6 vs 11.8 yrs and 10.8 vs 20.8 yrs, respectively), although this did not reach statistical significance. Test of proportional hazard assumption was not significant for IDFS or OS (p = 0.30 and 0.09). IDFS estimates were numerically higher in LAR vs non-LAR (80.2%vs70.5%,p = 0.92) at 3yrs post-diagnosis; whereas the opposite was true (40.9%vs55.6%,p = 0.07) after 10yrs. OS estimates at 3 and 5yrs were similar between LAR and non-LAR, but at 10yrs OS was inferior in LAR (40.9%vs66.4%,p = 0.24). In a univariate analysis including both LAR and non-LAR, older age, higher N stage, lower TILs and absence of AdjCT were associated with poorer IDFS and OS. In a multivariate analysis, higher N stage and absence of AdjCT remained associated with both poorer IDFS and OS; while lower stromal TILs were associated with poorer IDFS (p=0.01), and with a trend towards poorer OS (p=0.07). Conclusions: LAR TNBCs occurred in older women, were lower grade, and had lower TIL density than nonLAR tumors. While significant differences in IDFS or OS were not demonstrated, LAR pts exhibited a numerically lower risk of a disease event at 3yrs, but higher risk by 10yrs compared to nonLAR pts. In the entire cohort, higher N stage, absence of AdjCT and lower TILs were independently associated with poorer outcomes. Citation Format: Leon-Ferre RA, Polley M-Y, Liu H, Kalari KR, Boughey JC, Liu MC, Cafourek V, Negron V, Ingle JN, Thompson KJ, Tang X, Barman P, Carlson E, Visscher DW, Carter JC, Couch FJ, Goetz MP. Characteristics, outcomes and prognostic factors of luminal androgen receptor (LAR) triple-negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-08-01.

533 Background: Current guidelines define TNBC as complete absence of estrogen (ER) and progesterone receptor (PR), without HER2 amplification. However, the prognostic impact of clinical and histopathological factors, sTILs, and AdjCT in TNBC meeting these strict criteria is unknown. Methods: From a cohort of 9985 women who underwent upfront surgery for M0 breast cancer (BC) at Mayo Clinic Rochester from 1985-2012, 1159 pts with ER negative or low (≤10%) BC were identified for central ER/PR/HER2 staining and HER2 FISH (IHC2+ only) to select those with TNBC by modern definitions. Cox proportional hazards models were used to assess the impact of clinicopathological variables on invasive disease-free (IDFS) and overall survival (OS). Results: Tumors from 605 pts (median age 56.3 yrs) met criteria for TNBC (ER < 1%, PR < 1% and HER2 0, 1 or 2+ and FISH negative). 51% were T1, 65% N0, 88% grade 3, and 75% had Ki67 > 15%. Histologically, 39% were anaplastic, 26% invasive ductal, 16% medullary, 8% metaplastic, 6% apocrine and 5% others. Median sTILs was 20% (0-90%). 55% pts received AdjCT [21% anthracycline (A), 19% A + taxane, and 15% other]. Median follow-up for IDFS and OS were 7.4 and 10.6 yrs, respectively. Multivariate analyses demonstrated that higher N stage (p < 0.01), lower sTILs (p = 0.01) and no AdjCT (p < 0.01) were independently associated with worse IDFS and OS. Histology (medullary subtype) was associated with better IDFS in univariate (HR 0.56, 95% CI, 0.35-0.89) but not in multivariate analyses, once sTILs were accounted for. Among systemically untreated pts (n = 182), higher N (p < 0.01) and lower sTILs (p = 0.04) were associated with worse IDFS. For systemically untreated T1N0 pts (n = 111), the 5-yr IDFS was 70% (95% CI, 61-81) [T1a: 83% (95% CI, 63-100), T1b: 68% (95% CI, 52-88) and T1c: 67% (95% CI, 55-83)], compared to 78% (95% CI, 68-84) for T1N0 pts treated with AdjCT. Conclusions: In TNBC pts, N stage, sTILs and receipt of AdjCT were independently prognostic for IDFS and OS. sTILs remained prognostic for IDFS in systemically untreated TNBC. In N0 TNBC, the risk of recurrence or death was substantial in the absence of chemotherapy, even for those with T1 tumors.

5 Background: Triple-negative breast cancer (TNBC) is an immunogenic breast cancer subtype, with a greater percentage of tumors containing tumor-infiltrating lymphocytes (TILs) compared to non-TNBC. TILs are prognostic for recurrence and predictive for chemotherapy benefit in TNBC, but not in estrogen receptor (ER)-positive tumors. A subset of TNBC expresses the androgen receptor (AR), and resembles ER-positive breast cancer in terms of demographics (older age) and clinical course (later recurrences that tend to involve bone). However, little is known regarding the association between TILs and AR expression in TNBC. Methods: From a cohort of 9982 women with surgically-treated non-metastatic breast cancer, patients who met criteria for TNBC (ER/PR < 1% and HER2-negative) by centralized-pathology review were included as previously published [Leon-Ferre et al, Breast Cancer Res Treat 2017]. Stromal TILs in these tumors were quantified on full-face hematoxylin and eosin sections from the surgical specimen, following the 2014 TIL Working Group recommendations [Salgado et al, Ann Oncol 2014]. The expression of AR [EPR1535(2), Abcam] was scored as a continuous variable (1% increments), and categorized as absent (0%), low (1-25% ), low-moderate (26-50%) moderate (51-75%) and high (> 75%) and correlated with TIL density. Results: 605 patients met criteria for TNBC. The median age was 56 years. Most tumors were T1-2 (95%), N0-1 (86%), and high grade (88%). The median stromal TIL content was 20% (0-90%). Tumor tissue was available for AR staining in 509/605 patients. 165 (32%) tumors expressed AR as follows: low: 12%, low-moderate: 7%, moderate: 5%, and high: 8%. Apocrine tumors (n = 30) expressed AR most frequently (86%) and at higher levels (AR high: 50%). For all 509 tumors, the median stromal TIL content according to AR expression was AR absent: 20%, AR low: 20%, AR low-moderate: 15%, AR high: 10%. AR and stromal TILs (both as continuous variables) demonstrated a weak inverse correlation (correlation coefficient -0.1064, p = 0.017). Conclusions: AR expression in TNBC is associated with lower levels of stromal TILs. Additional data correlating the AR, stromal TILs and outcomes in this cohort will be presented at the meeting.

Abstract Background: While TNBC remains the most aggressive type of breast cancer (BC), substantial heterogeneity in biology and outcomes exists among TNBC subtypes. Historically, risk stratification of TNBC has been based on anatomic factors such as tumor size, nodal involvement and presence of distant metastases. However, these features alone fail to accurately predict outcomes. Tumor immune infiltration (sTILs) and distribution of immune cell subsets in the perip heral blood (NLR) have emerged as variables reported to be associated with outcomes in TNBC. We sought to evaluate whether NLR and sTILs provided independent prognostic information in TNBC. Methods: From a cohort of 9,982 women who underwent BC surgery at Mayo Clinic, Rochester, MN between Jan 1985 and Dec 2012, we identified 605 centrally-confirmed TNBC tumors. Patients (pts) with prior BC, bilateral BC, non-invasive disease, stage IV, neoadjuvant therapy, endocrine therapy, or adenoid cystic histology were excluded. For eligible tumors, clinical and pathologic variables were evaluated, including peripheral blood NLR and central assessment of sTILs per the 2014 International TILs Working Group recommendations. We calculated the Pearson correlation coefficient (PCC) between NLR and sTILs and constructed Cox Proportional Hazards Models to evaluate their association with invasive-disease free (IDFS) and overall survival (OS). NLR and sTILs were both analyzed as continuous variables. Results: Most pts had T1-2 (95%) and N0-1 disease (86%). Median OS follow-up was 10.6yrs. Median IDFS was 12yrs (95%CI 10.2-16.7) and median OS was 18.8yrs (95%CI 15.6-20.8). NLR and sTILs were available in 408 and 599 pts, respectively. The median NLR and sTIL content were 2.29 (0.14-10.50) and 20% (0-90%), respectively. NLR and sTILs were poorly correlated (PCC 0.0237). On univariate analysis (UVA), a higher NLR was associated with worse IDFS (HR 1.13; 95%CI 1.02-1.26, p=0.02) and OS (HR 1.17; 95%CI 1.04-1.31, p=0.01). Each 1% increment in sTILs was associated with improved IDFS (HR 0.99; 95%CI 0.98-0.99, p&lt;0.001) and OS (HR 0.99, 95%CI 0.98-1.00, p&lt;0.001). Among pts with high sTILs (≥20%), a higher NLR remained significantly associated with worse IDFS (HR 1.21; 95%CI 1.05-1.38, p=0.007) and OS (HR 1.25; 95%CI 1.09-1.44, p=0.001). In contrast, among pts with low sTILs (&lt;20%), NLR was not associated with IDFS (HR 1.07; 95%CI 0.89-1.28, p=0.49) or OS (HR 1.07; 95%CI 0.88-1.30, p=0.49). The interaction test between NLR and sTILs did not reach statistical significance. A multivariate analysis (MVA; including age, menopausal status, histologic subtype, grade, tumor size, nodal stage, Ki-67, NLR, sTILs, adjuvant chemotherapy, type of surgery and adjuvant radiation) showed that sTILs remained independently associated with IDFS (HR 0.99, 95%CI 0.97-1.0, p=0.019) and OS (HR 0.99, 95% CI 0.97-1.0, p=0.044), whereas NLR did not. Conclusions: A lower NLR and a higher sTIL content were each associated with improved IDFS and OS among pts with nonmetastatic TNBC on UVA. However, when evaluated on a MVA, only sTILs remained independently associated with IDFS and OS. Our data suggest that the effect of sTILs on outcomes may not be modified by the NLR. Citation Format: Leon-Ferre RA, Polley M-Y, Liu H, Gilbert J, Cafourek V, Hillman D, Negron V, Boughey JC, Liu MC, Ingle JN, Kalari K, Couch FJ, Visscher DW, Goetz MP. Prognostic value of the neutrophil-to-lymphocyte ratio (NLR) and its relation to stromal tumor infiltrating lymphocytes (sTILs) in triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-05-06.

Abstract Background: Triple negative breast cancer (TNBC) represents 15% of all breast cancers, and is characterized by an aggressive clinical course. While efforts are ongoing to characterize the molecular basis for variation in TNBC, there are conflicting data regarding the impact of prognostic factors such as age and Ki-67 typically used for treatment decisions in other breast cancer subtypes. We identified a retrospective cohort of women with ER- breast cancer with long term follow-up, and performed central confirmation of ER, PR, HER2, Ki-67 and histological classification to assess the association of Ki-67 and histologic subtype on clinical outcome in TNBC pateints (pts). Methods: 9,836 women who underwent breast cancer surgery at Mayo Clinic Rochester from 1985-2005 were identified. Pts were excluded due to: ER+ disease (7363); prior cancer (553); non-invasive disease (465); bilateral breast cancer (167); metastatic disease [at diagnosis or within 60 days of surgery (110)]; ER- disease treated with neoadjuvant chemotherapy (121) or adjuvant hormonal therapy (112); or tumor block exhausted (94). For all others, centralized ER/PR/HER2 identified the following for exclusion, &gt;1% ER staining (n=76), &gt; 1% PR (n=14) and HER2+ (n=144) by IHC (3+) or FISH amplification. 225 cases are still undergoing review. For the centrally confirmed pts with TNBC (n=392), Ki-67 and histological characterization (WHO subtypes) were assessed. Results: Patient characteristics are listed in the table. The median age for all TNBC’s was 45 (range 29-88) and nearly all tumors were grade 3 (91%) with high proliferation (63% with Ki-67 &gt; 30%). The median follow-up was &gt;10 years, where 139 pts had a disease event: progression (86) or second primary (53) and 53 died without a disease event. The 10 yr DFS rate was 55.8% (95%CI: 48.8-63.9%) among the 238 pts who did not receive adjuvant chemotherapy (AdjCT) and 58.9% (95% CI: 48.9-70.9%) among the 102 pts administered AdjCT. In pts without adjCT, DFS was found to differ with respect to number of positive LNs (0 vs. 1-4 vs. 4+; log rank p=0.003) and medullary histology (log rank p=0.015) but not with age (&lt; 50 vs. ≥ 50), tumor size (&lt; 2.0 vs. 2-5 vs. ≥ 5.0 cm) or Ki-67 (0-15% vs. 15.1-30% vs. &gt;30 %). Conclusions: Our findings confirm the poor prognosis of TNBC. The medullary histological subtype is associated with significantly better prognosis than other TNBC subtypes (10 year DFS rate of 78.5%; 95%CI: 59.1-99.9% in pts not treated with adjCT). After central confirmation, neither age nor Ki-67 provide additional prognostic information. Patient characteristicsMedian Age (range)45(29-88) n%Histology Apocrine287.1Carcinoma, anaplastic or undiffrentiated9323.7Central scar/necrotizing348.7Clear Cell297.4Infiltrating ductal ca7118.1Large Cell neuroendocrine143.6Medullary and atypical medullary4311.0Metaplastic ca246.1Trabecular ca338.4other histologies235.9Grade 130.82317.9335891.3Tumor Size 0.1-2 cm19650&gt; 2.0 cm19549.6not stated10.3Nodal status 0251641-38220.94-9338.410+225.6not evaluated41.0Ki-67 0-157719.615.1-306516.6&gt;30%24763.3not done20.5Adjuvant Chemotherapy Yes10226.0No23860.7unknown5213.3 Citation Format: Ahmed Elkhanany, Vera J Suman, Victoria Cafourek, Judith A Gilbert, James N Ingle, Fergus Couch, Daniel W Vissscher, Matthew P Goetz. Triple negative breast cancer: The role of classic histological and prognostic factors on disease free survival [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-02-11.