Lower Pathologic Complete Response Research Articles

Residual tumor characteristics of esophageal squamous cell carcinoma after neoadjuvant chemoradiotherapy

ObjectiveThe study was to investigate the characteristics of residual tumors of esophageal squamous cell carcinoma after neoadjuvant chemoradiotherapy. MethodsThe resection specimens of 187 patients undergoing surgery after neoadjuvant chemoradiotherapy in Zhongshan Hospital of Fudan University were reevaluated. Tumor regression grade determined by residual tumor ratios was scored for each specific layer of the esophageal wall and all removed lymph nodes for 4 grades as tumor regression grade 1, 0% residual tumors, tumor regression grade 2, less than 10%; tumor regression grade 3, 10% to 50%; tumor regression grade 4, greater than 50%. The pretreatment pathologic tumor stage and pretreatment pathologic lymph node stage before neoadjuvant chemoradiotherapy were recorded reflecting the original depth of primary tumor and number of originally involved lymph nodes, respectively. According to regression directionality, regression pattern was classified into 4 categories as type I: regression toward the lumen, type II: regression toward the invasive front, type III: concentric regression, and type IV: scattered regression. Statistical analyses were performed using Mann–Whitney, chi-square, Cochran Q tests, and Kendall τ-b coefficient, appropriately. ResultsA total of 138 patients have residual tumors, and 97 patients (70.3%), 100 patients (72.5%), 89 patients (64.5%), 63 patients (45.7%), and 68 patients (49.3%) have malignant cells in mucosa, submucosa, muscularis propria, adventitia/surrounding stroma, and lymph nodes, respectively. A total of 115 patients (83.3%) had residual tumors in the mucosa or submucosa, but 63 (54.8%) were graded as tumor regression grade 2 with small amounts of tumors in these 2 layers, 9 patients (6.5%) had residual tumors only in the deep 2 layers, and 14 patients (10.1%) had residual tumors only in lymph nodes. Overall, 86 patients (62.7%) with residual tumors are difficult to identify via present techniques. In patients with tumors that involved all esophageal layers before neoadjuvant chemoradiotherapy, only muscularis propria contained residual tumors significantly more frequently than the adventitia/surrounding stroma (P < .001). The random type IV and nonrandom regression patterns of type I to III were comparable with 48.9% and 51.1%, respectively. In patients with positive lymph node before neoadjuvant chemoradiotherapy, only a small portion of patients (29.2%, 28/96) achieved ypN0 status (nodes pathological complete response), even worse than the primary lesions (33.6%, 63/187) in esophageal squamous cell carcinoma. ConclusionsThe small amount of viable tumor cells in the superficial layers, low pathological complete response rate of lymph nodes, and diverse regression patterns lead to difficulty of detecting residual tumors in esophageal squamous cell carcinoma.

Comprehensive profiling of androgen receptor-positive (AR+) triple-negative breast cancer (TNBC) patients (pts) treated with standard neoadjuvant therapy (NAT) +/- enzalutamide.

517 Background: The luminal androgen receptor (LAR) subtype of TNBC has a low pathologic complete response (pCR) rate after NAT. We determined the pCR rate of the enzalutamide and paclitaxel (ZT) regimen for pts with anthracycline-insensitive AR+ TNBC (NCT02689427), and related biomarkers. Methods: ARTEMIS (NCT02276443) is a non-randomized trial to determine if NAT can be used to personalized therapy. Pts received 4 cycles of doxorubicin-based NAT (AC). Pts with insensitive disease by imaging were offered clinical trials as the second phase of NAT based upon molecular profiling of pre-treatment biopsies. Immunohistochemistry (IHC) of AR+≥10% was the threshold for selecting ZT (enzalutamide 160 or 120 mg PO qD + paclitaxel 80 mg/m2 qW for 12 cycles). pCR was determined by surgery after NAT. Trial had two-stage Phase II design, and we report the completed first stage. We evaluated the concordance between Vanderbilt LAR subtype by molecular profiling (microarray and RNAseq) and IHC %AR+ cells. Frequency of PI3K pathway alterations within the LAR subtype was assessed. Results: 267 pts had tumors profiled by IHC, 220 by microarray, 187 by RNAseq and 197 by whole exome sequencing. 96 pts had post-AC RNAseq. LAR scores from both RNAseq and microarray profiling (n = 139) were highly concordant (R = 0.89, P &lt; 0.001) and identified ~10% of TNBCs tested as LAR. The %AR+ cells from IHC correlated with LAR subtype scores according to RNAseq (R = 0.6, P &lt; 0.001), with a cut-point of ≥30% AR+ having the best concordance with LAR subtype. Unlike other subtypes, by serial profiling, LAR TNBCs did not change subtype signatures after exposure to AC. LAR TNBCs had low rates of pCR (23%) and high rates of PI3K pathway activating aberrations (85%); however PI3K aberrations did not correlate with pCR. Seventeen patients with AC-insensitive TNBC received ZT. Five of 15 patients (33.3%) had responses (pCR or RCB-I). Toxicities are Grade (Gr) 4 syncope (n = 1), Gr3 abnormal liver function (n = 2), Gr3 neutropenia (n = 4). IHC &amp; LAR subtype scores did not statistically associate with response to ZT (P = 0.8, P = 0.9). However, all responders to ZT had an upregulated androgen response pathway (ssGSEA Z &gt; 1) as measured by transcriptomic analysis in pre-treatment biopsies analysis (P = 0.05, ppv = 0.56, npv = 1). Conclusions: The LAR TNBC subtype has a low pCR rate to NAT. Among pts with AC-insensitive TNBC, baseline upregulated androgen response pathway and LAR subtype may benefit from the ZT regimen, potentially by PI3K targeting. Clinical trial information: NCT02689427 .

Impact of body composition on toxicity and pathological complete response in locally advanced breast cancer (BC).

593 Background: Obesity, defined as body mass index (BMI) &gt; 30 kg/m2, has been associated with inferior outcomes in localized breast cancer (BC), including lower pathological complete response (pCR) to neoadjuvant chemotherapy (NAC). High BMI is usually associated with excess adipose tissue (AT), but also reflects skeletal muscle (SM) mass. Low SM mass (sarcopenia) has also been associated with inferior outcomes and more chemotherapy-associated toxicity. We aimed to evaluate the association of BMI, AT and SM tissue with pCR and toxicity after NAC for stage II-III breast cancer (BC). Methods: 191 patients with stage II-III BC received NAC, had information regarding baseline BMI, toxicity and pCR to NAC at surgery, and, had abdominal computerized tomography (CT) prior to NAC. Total AT (TAT), visceral AT (VAT), subcutaneous AT (SAT), SM area (SMA) and SM density (SMD) were measured by CT at the L3 level using the TOMOVISION software. SM index (SMI) was calculated (SMA/height) to assess for sarcopenia (SMI &lt; 40). Association linking BMI, SAT, VAT, SMA and SMD to pCR and severe toxicity (ST ≥ grade 3) was evaluated using logistic regression models. Results: Patients were predominantly black (51%) with a median age of 54 years (interquartile range = 45-63). pCR was achieved in 31% (60/191) of patients. Of those, 47% (n = 28/60), 40% (n = 24/60) and 13% (n = 8/60) corresponded to HER2(+), triple negative, and hormone receptor-HR(+)/HER2(-) tumors, respectively. ST occurred in 38% (n = 73/191) of patients. Obesity and sarcopenia were present in 52% (n = 100/191) and 14% (n = 27/191) of patients, respectively. There was a statistically significant association between VAT and pCR (median VAT 95.3 cm2 vs. 121.8 cm2 in the pCR vs. no-pCR groups, respectively, p = 0.03). This association remained after adjusting for age, race, tumor grade, stage, BMI, SMD, HR and HER2 status (p = 0.04). There was a statistically significant association between SMA and ST (mean SMA 123 cm2 vs. 130 cm2 in the ST vs. no-ST groups, respectively, p = 0.03). This association disappeared after adjusting for age, race, BMI, VAT, SAT, and SMD (p = 0.21). Conclusions: This study provides evidence that in patients with stage II-III BC receiving NAC, excess VAT is associated with significantly lower pCR rates, and low SMA is associated with ST. Additional research is needed to elucidate the pathophysiologic mechanisms contributing to these associations.

Abstract OT2-02-03: NSABP FB-13: An assessment of the biological and clinical effects of palbociclib with ovarian suppression and letrozole in the neoadjuvant treatment of pts (pts) with premenopausal (preM) estrogen-receptor positive/HER2-negative primary breast cancer

Abstract Background: There have been few studies of neoadjuvant endocrine therapy in premenopausal (preM) women despite low pathologic complete response (pCR) rates using neoadjuvant chemotherapy in ER+/HER2− pts. Suppression of Ki67, particularly complete cell cycle arrest (CCCA) defined as Ki67 &amp;lt;2.7% after 2 wks of neoadjuvant endocrine therapy has been demonstrated to correlate with recurrence-free survival. PALLET, a randomized, neoadjuvant endocrine trial evaluated letrozole (AI) v palbociclib (pal) in combination with AI for 14 wks in post-menopausal women. This study demonstrated a modest improvement in clinical response (54.3% with the combination v 49.5% with AI alone) but showed a significant difference in achievement of CCCA (Ki67&amp;lt;2.7%) with the combination of pal and AI v AI alone (90% v 59%). We seek to evaluate this combination, given over a longer duration in the neoadjuvant setting, in preM women with early-stage breast cancer. Trial design: FB-13 is a phase II, open-label study to examine the biological and clinical effect of neoadjuvant endocrine therapy with AI, pal, and ovarian suppression in preM pts with ER+, HER2-negative early invasive breast cancer. 76 pts will be stratified into one of two approximately equal sized cohorts based on Oncotype DX Breast Recurrence Score (RS) (cohort 1: pts with RS &amp;lt;11 or cohort 2: pts with RS 11 to &amp;lt;26). A baseline tumor biopsy prior to start of therapy (tx) for RS and Ki67 will both be centrally determined. Pts in both cohorts will receive letrozole 2.5 mg by mouth daily, pal 125 mg by mouth daily for 21 days of a 28-day cycle, and goserelin 3.6 mg SQ injection every 28 days. At wk 6, pts will have core-cut biopsies for real-time evaluation of Ki67. Pts from both cohorts who have Ki67 &amp;lt;10% will continue tx for a total of 6 cycles. Pts with a persistent Ki67 ≥10% will permanently discontinue tx and begin neoadjuvant chemotherapy or proceed to surgery at physician discretion. Eligibility: FB-13 is enrolling preM women newly diagnosed with ER+/HER2− early breast cancer who are candidates for neoadjuvant endocrine therapy. Pts must be preM based on standard definitions. Primary tumor size must be &amp;gt;2 cm. RS must be &amp;lt;26. Mandatory pre-treatment and post-surgical samples will be collected and analyzed for RS and Ki67, as well as additional biomarkers to correlate with response. Blood will be collected at baseline, 4 wks, and at 24 wks for estradiol levels to demonstrate ovarian suppression. A 4-wk estradiol level in the postmenopausal range will be required to receive further treatment. Specific aims: The primary aim is to determine complete cell cycle arrest as indicated by a Ki67 &amp;lt;2.7% at 6 wks. Secondary aims are to determine overall response rate (ORR) by clinical exam and ultrasound, the pCR, to generate a Preoperative Endocrine Prognostic Index (PEPI score), to compare the change in Ki67 at baseline, after 6 wks and 24 wks, and to determine the rate of breast-conservation therapy. Statistical methods: We anticipate that the addition of palbociclib to ovarian suppression and AI will result in a measurable drop in Ki67 and a high ORR. The null hypothesis is ORR &amp;lt;40% and alternative hypothesis is ORR &amp;gt;60%. We anticipate that &amp;gt;60% of pts in each cohort will have 6 wk Ki67 &amp;lt;2.7% and clinical response &amp;gt;35%. Present accrual and target accrual: Currently 12 of a planned 76 pts have been enrolled. NSABP Operations contact information: Diana Gosik, Diana.Gosik@nsabp.org NCT03628066 SUPPORT: Genomic Health Inc, Pfizer, NSABP Foundation Citation Format: Shannon Puhalla, Greg Yothers, Amy P Sing, Thomas B Julian, Norman Wolmark, Samuel A Jacobs. NSABP FB-13: An assessment of the biological and clinical effects of palbociclib with ovarian suppression and letrozole in the neoadjuvant treatment of pts (pts) with premenopausal (preM) estrogen-receptor positive/HER2-negative primary breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT2-02-03.

Abstract ES5-2: Regional Management of the Axilla prior to Systemic Therapy

Abstract There is growing interest in personalizing axillary management strategies based on anatomic staging and receptor profile to minimize surgical morbidity and maximize oncologic outcomes. Axillary treatment decision making has become increasing complex given the variation in indications for axillary lymph node dissection (ALND) among clinically node negative patients based on treatment strategy. Current techniques to minimize the likelihood of requiring an ALND include application of the ACOSOG Z011 or AMAROS data for women undergoing surgery first or use of neoadjuvant chemotherapy (NAC) in attempts to downstage microscopic nodal disease. Hormone receptor positive, HER2 negative tumors have low pathologic complete response rates to NAC and therefore have low rates of axillary downstaging with this approach. We have evaluated the likelihood of requiring an ALND by receptor profile for differing management strategies. Given the low response rates to NAC among women with hormone receptor positive, HER2- tumors, use of NAC for this subtype is associated with a threefold increase in the receipt of ALND compared to those treated with upfront breast conserving surgery. In this session I will review the current strategies to minimize the likelihood of requiring an ALND among clinically node negative patients found to have a positive sentinel lymph node including application of the ACOSOG Z0011 and AMAROS strategies. I will also review the impact of axillary imaging and/or a positive lymph node needle biopsy on axillary surgery outcomes among clinically node negative patients. Having an understanding of these differing options will aid in personalizing axillary management recommendations to safely minimize the likelihood of ALND and the resultant risk of lymphedema. Citation Format: M Pilewskie. Regional Management of the Axilla prior to Systemic Therapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr ES5-2.

Abstract P2-10-10: Lower pathologic complete response rate with dual-HER2 blockage and chemotherapy in African Americans and ethnic minorities

Abstract Introduction: Racial disparities in breast cancer outcomes are well documented with age-adjusted mortality among African American (AA) women 40% higher than Caucasian women. Some studies have demonstrated poor response to neoadjuvant chemotherapy in AA with triple negative breast cancer but data regarding pathologic complete response rate (pCR) in HER2 positive disease are lacking. TRYPHAENA trial demonstrated a high pCR rate after treatment with dual HER2 blockage along with chemotherapy. Due to underrepresentation of African Americans and minorities in the trials leading to the approval of dual HER2 blockage (Gianni et al; Lancet Oncology;13: 25-32) in early stage breast cancer, data is lacking on the efficacy and tolerability of this treatment in this subgroup of patients. Methods: After IRB approval, pharmacy records were utilized to identify patients treated with dual HER2 blockade in neoadjuvant setting at our institution. Individual patient charts were reviewed to identify AA patients and other ethnic minorities. We also obtained details of the patient age, clinical stage, pathological stage, ER/PR status, treatment received, side effects leading to dose reductions if any. pCR was defined as absence of invasive or noninvasive cancer in the breast and lymph nodes (ypT0N0). Results:50 patients with a median age of 53 years met our inclusion criteria. 86% patients self-reported as AA and 14% were other minorities as recorded in EMR. 90% patients were treated with Taxotere, Carboplatin, Trastuzumab and Pertuzumab (TCHP) and 10% received Adriamycin, Cyclophosphamide, Paclitaxel, Trastuzumab and Pertuzumab (AC-THP) chemotherapy. Clinical staging was: Stage I- 4 %; Stage II- 84 %, and Stage III- 12 %. 46% of patients had hormone receptor (HR) positive tumors and 54% patients were HR negative. 30% (15/50) of patients required dose reduction or omission for diarrhea, neuropathy, or cytopenia. 18%(9/50) patients had doses omitted. The overall observed pCR rate (ypT0N0) was 42%(21/50). As expected, the pCR rate was higher in patients with HR negative/HER2 positive breast cancer compared to HR positive/HER2 positive breast cancer. 44% (12/27) vs. 39% (9/23), respectively.Conclusion: Dual HER2 blockade was associated with a lower pCR rate (42%) in AA and other minorities compared to rate of 52% as reported by TRYPHAENA trial (n=77). The treatment was well tolerated but higher percent of patients required a dose reduction or omission (Tiwari et al; Breast Cancer Res Treat; 158:189-193).The most common side effects were diarrhea, neuropathy and cytopenias. Further prospective studies are needed to elucidate the role of biologic differences in chemosensitivity and balancing the variables of increased number of dose reductions and effect of socioeconomic differences in an underserved minority population. Citation Format: Shruti R Tiwari, Prasun Mishra, Asma Dilawari, Christopher M Gallagher, Ami Chitalia, Patricia Wehner, Marc E Boisvert. Lower pathologic complete response rate with dual-HER2 blockage and chemotherapy in African Americans and ethnic minorities [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-10-10.

Strategies for Increasing the Effectiveness of Aromatase Inhibitors in Locally Advanced Breast Cancer: An Evidence-Based Review on Current Options.

Neoadjuvant hormonal therapy (NEO-HT) is a possible treatment option for breast cancer (BC) patient with estrogen receptor positive (ER+) and HER2 negative (HER2-) disease. The absence of solid data on the type of drugs to be used and duration of treatment as well as lack of clear evidence of effectiveness of NEO-HT compared to chemotherapy (CT) reserve its use for patients with old age or frail conditions. However, the low pathologic complete response rate (pCR) obtained with tamoxifen or aromatase inhibitors (AIs) alone does not make NEO-HT as a suitable option for the neoadjuvant treatment of HR+ HER2-. The use of the cyclin-dependent kinase 4 and 6 (CDK 4/6) inhibitors palbociclib, ribociclib and abemaciclib of the mammalian target of rapamycin (mTOR) inhibitor everolimus and of the phosphoinositide 3 kinase (PI3K) inhibitor taselisib together with endocrine therapy (ET) has become a standard in advanced breast cancer, showing clinical effectiveness and significantly prolonging median progression-free survival compared to ET only. In the early phase disease, the use of ET together with CDK 4/6, mTOR and PI3K inhibitors is still investigational. Data from recent studies are promising even though less impressive than in metastatic setting. In this context, the use of genomic-transcriptomic tools (such as ONCOTYPE, PAM50) and the identification of novel biomarkers (ESR1, PI3Kca, PDGF-R) on tissue or with liquid biopsy could help to select patient prone to respond to endocrine-combined therapy and able to achieve pCR. With our review, we aimed at evaluating the current state of the art in the treatment of locally advanced breast cancer with NEO-HT.

Polo-like kinase 1 (Plk1) inhibition synergizes with taxanes in triple negative breast cancer.

Within triple negative breast cancer, several molecular subtypes have been identified, underlying the heterogeneity of such an aggressive disease. The basal-like subtype is characterized by mutations in the TP53 gene, and is associated with a low pathologic complete response rate following neoadjuvant chemotherapy. In a genome-scale short hairpin RNA (shRNA) screen of breast cancer cells, polo-like kinase 1 (Plk1) was a frequent and strong hit in the basal breast cancer cell lines indicating its importance for growth and survival of these breast cancer cells. Plk1 regulates progression of cells through the G2-M phase of the cell cycle. We assessed the activity of two ATP-competitive Plk1 inhibitors, GSK461364 and onvansertib, alone and with a taxane in a set of triple negative breast cancer cell lines and in vivo. GSK461364 showed synergism with docetaxel in SUM149 (Combination Index 0.70) and SUM159 (CI, 0.62). GSK461364 in combination with docetaxel decreased the clonogenic potential (interaction test for SUM149 and SUM159, p<0.001 and p = 0.01, respectively) and the tumorsphere formation of SUM149 and SUM159 (interaction test, p = 0.01 and p< 0.001). In the SUM159 xenograft model, onvansertib plus paclitaxel significantly decreased tumor volume compared to single agent paclitaxel (p<0.0001). Inhibition of Plk1 in combination with taxanes shows promising results in a subset of triple negative breast cancer intrinsically resistant to chemotherapy. Onvansertib showed significant tumor volume shrinkage when combined with paclitaxel in vivo and should be considered in clinical trials for the treatment of triple negative cancers.

252P - Clinical features of early-stage (I-III) triple-negative breast cancer (TNBC) patients with tumours exhibiting low-overall change in molecular profile after neoadjuvant therapy

BackgroundSeth et al. (ASCO 19) identified four biologic classes based on longitudinal molecular profiling of TNBC tumors pre- and post- neoadjuvant adriamycin/cyclophosphamide (AC). The four groups were defined based on the enriched and depleted hallmark pathways that were observed. The low-overall change (LOC) group was defined as having no significant change in the pathways in pre- and post-AC biopsies. Of note, this group of patients had lower pathological complete response (pCR) rates. The aim of this study is to describe the clinical features of early-stage (I-III) TNBC patients with tumors exhibiting LOC in their biopsies with neoadjuvant therapy. MethodsWe analyzed the clinical characteristics of 48 patients with early stage (I-III) TNBC enrolled in the ARTEMIS trial (NCT02276443). All patients received neoadjuvant AC; 48% of patients were subsequently treated on a clinical trial and 52% received standard taxane-based chemotherapy. We compared the clinical characteristics of 17 patients in the LOC group with 31 patients in the other three biologic classes. Two-group comparison was performed using Chi-squared test. ResultsAge at diagnosis, histology, Vanderbilt subtype, Ki-67, sTIL levels and vimentin expression were similar between the groups. Median age at diagnosis in the LOC group was 58 (range, 27-74). All patients in this group were stage II-III, with no stage I identified. 59% of patients in the LOC group had stage III disease compared with 26% in the other groups (p=0.02), Also, 47% of patients in this group had AR≥10% compared to 19% in the other biological groups (p=0.04).Table252PTableVariableGroupLow-Overall Change Group (n=17)%Other Biologic Classes (n=31)%pAge at diagnosis≤60105925810.10>60741619StageI00619N/AII74117550.36III10598260.02HistologyInvasive ductal158826840.23Metaplastic00413Apocrine1600Other1613Vanderbilt subtypeBL3188260.24LAR42426M/MSL3181135IM212412Ki-67 (%)≥ 5084721680.16< 509531032Androgen Receptor Expression (%)≥ 108476190.04< 109532581Vimentin Expression (%)≥502124130.91<5015882787sTILLow (<5)74115480.37Moderate (≥5-30)9521135High (>30)0013 ConclusionsPatients with low-overall change in their tumors had later-stage disease and higher AR expression. Previous analysis by Seth et al. has demonstrated a lower pCR rate in this group with standard neoadjuvant chemotherapy. This analysis highlights the potential role of androgen deprivation in this class of tumors. Legal entity responsible for the studyThe authors. FundingThe University of Texas MD Anderson Cancer Center Moonshots Program and a CPRIT Multi-Investigator Research Award (MIRA). DisclosureS. Moulder: Research grant / Funding (self): Pfizer; Research grant / Funding (self): Genentech; Research grant / Funding (self): Novartis; Research grant / Funding (self): Seattle Genetics; Research grant / Funding (self): EMD Serono; Research grant / Funding (self): Bayer; Research grant / Funding (self): AstraZeneca. All other authors have declared no conflicts of interest.

Low Total Pathologic Complete Response (tpCR) Rate to Preoperative Chemotherapy in Patients with Invasive Lobular Carcinoma of Breast (ILC): Analysis of Subgroup of Three Phase II Trials

Low Total Pathologic Complete Response (tpCR) Rate to Preoperative Chemotherapy in Patients with Invasive Lobular Carcinoma of Breast (ILC): Analysis of Subgroup of Three Phase II Trials

Neoadjuvant trastuzumab (H), pertuzumab (P), and chemotherapy versus trastuzumab emtansine (T-DM1) and P in human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC): Final outcome results from the phase III KRISTINE study.

500 Background: KRISTINE compared neoadjuvant chemotherapy plus dual HER2- blockade (HP) with T-DM1 plus P (T-DM1+P), a targeted regimen that omits standard chemotherapy. T-DM1+P resulted in a lower pathologic complete response (pCR) rate, but a more favorable safety profile. Here we present the final outcomes from KRISTINE. Methods: KRISTINE (NCT02131064) was a randomized study of T-DM1+P versus docetaxel, carboplatin, and H plus P (TCHP). Patients with HER2-positive stage II–III BC received 6 cycles of neoadjuvant T-DM1+P or TCHP q3w. Patients receiving T-DM1+P continued adjuvant T-DM1+P; patients receiving TCHP received adjuvant HP, for 12 cycles in each arm. Patients in the T-DM1+P arm without pCR were encouraged to receive standard adjuvant chemotherapy before adjuvant T-DM1+P. Secondary endpoints, analyzed with descriptive statistics, included event-free survival (EFS; all events pre- and post-surgery), invasive disease-free survival (IDFS; invasive events post-surgery), overall survival and safety. Results: At median follow-up of 37 months, EFS favored TCHP (HR = 2.61 [95% CI: 1.36–4.98]), due to more locoregional progression events in the T-DM1+P arm before surgery (6.7% vs 0; Table). pCR was associated with reduced risk of an IDFS event (HR = 0.24 [95% CI: 0.09– 0.60]) regardless of treatment arm. There were 5 deaths (2.3%) in the TCHP arm and 6 (2.7%) in the T-DM1+P arm. There were more grade ≥3 AEs with TCHP but a higher rate of AEs leading to treatment discontinuation with T-DM1+P. Conclusions: EFS numerically favors TCHP due to locoregional progression events with T-DM1+P prior to surgery. T-DM1+P was associated with fewer grade ≥3 AEs but increased treatment discontinuation. Clinical trial information: NCT02131064. [Table: see text]

Prognostic significance of history of nonmuscle invasive bladder cancer in patients with muscle invasive bladder cancer treated with neoadjuvant chemotherapy followed by surgery.

375 Background: Efficacy of cisplatin-based neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) for T2-4aN1M0 muscle-invasive bladder cancer (MIBC) was proved by randomize controlled trials. Recent retrospective studies suggested that MIBC patients who had a history of non-muscle invasive bladder cancer (NMIBC) had lower pathologic complete response and worse overall survival rate to NAC and RC. This study aimed to compare clinical outcomes between MIBC that progressed from NMIBC (secondary MIBC) and primary MIBC. Methods: A retrospective analysis of patients with urothelial carcinoma (cT2-4aN0-1M0) who received neoadjuvant chemotherapy from January 2011 and December 2017 in Asan Medical Center was conducted. Clinicopathologic outcomes were compared between 187 patients with primary MIBC and 38 patients with secondary MIBC. Results: Baseline characteristics are well balanced between the groups. Downstaging rate ( &lt; ypT2 and no N upstaging) are 46.7% for secondary MIBC group, 55.6% for primary MIBC group (p = 0.390), and positive pathologic metastatic nodes (ypN1+) are observed in 23.3% for secondary MIBC group, 18.3% for primary MIBC group (p = 0.523). There were no differences in overall survival (OS) (3 year OS 69.3% for secondary MIBC, 70.3% for primary MIBC, p = 0.420), disease-free survival (DFS) (3 year DFS 57.7% vs 56.6%, p = 0.880) between the groups. History of NMIBC is not independent prognostic factor for OS on multivariable analysis. Conclusions: Patients with secondary MIBC treated with NAC showed no differences in NAC response, pathologic downstaging rate, OS, DFS compared to patients with primary MIBC. Prospective or larger cohort study are required in the future. Genomic analysis is ongoing to identify genetic differences between two groups.

Correction: HER2-Overexpressing Breast Cancers Amplify FGFR Signaling upon Acquisition of Resistance to Dual Therapeutic Blockade of HER2

Purpose: Dual blockade of HER2 with trastuzumab and lapatinib or pertuzumab has been shown to be superior to single-agent trastuzumab. However, a significant fraction of HER2-overexpressing (HER2+) breast cancers escape from these drug combinations. In this study, we sought to discover the mechanisms of acquired resistance to the combination of lapatinib + trastuzumab.Experimental Design: HER2+ BT474 xenografts were treated with lapatinib + trastuzumab long-term until resistance developed. Potential mechanisms of acquired resistance were evaluated in lapatinib + trastuzumab-resistant (LTR) tumors by targeted capture next-generation sequencing. In vitro experiments were performed to corroborate these findings, and a novel drug combination was tested against LTR xenografts. Gene expression and copy-number analyses were performed to corroborate our findings in clinical samples.Results: LTR tumors exhibited an increase in FGF3/4/19 copy number, together with an increase in FGFR phosphorylation, marked stromal changes in the tumor microenvironment, and reduced tumor uptake of lapatinib. Stimulation of BT474 cells with FGF4 promoted resistance to lapatinib + trastuzumab in vitro Treatment with FGFR tyrosine kinase inhibitors reversed these changes and overcame resistance to lapatinib + trastuzumab. High expression of FGFR1 correlated with a statistically shorter progression-free survival in patients with HER2+ early breast cancer treated with adjuvant trastuzumab. Finally, FGFR1 and/or FGF3 gene amplification correlated with a lower pathologic complete response in patients with HER2+ early breast cancer treated with neoadjuvant anti-HER2 therapy.Conclusions: Amplification of FGFR signaling promotes resistance to HER2 inhibition, which can be diminished by the combination of HER2 and FGFR inhibitors. Clin Cancer Res; 23(15); 4323-34. ©2017 AACR.

Abstract P5-08-05: The interplay between stromal density, epithelial mesenchymal transition and chemoresistance in breast cancer

Abstract Epithelial Mesenchymal Transition (EMT) refers to the transition of cells from a more differentiated epithelial phenotype to a less differentiated mesenchymal phenotype, a process that may be triggered by a range of therapeutic interventions including cytotoxic treatment, and which we have previously linked to poor breast cancer (BrCa) outcome after neoadjuvant chemotherapy (NAC)1. Mammographic breast density (MBD)represents the white radiographic appearance of epithelial and stromal breast tissue on a mammogram. High MBD in patients being treated for BrCa also associates with chemoresistance, correlating with lower pathological complete response rates (pCR)2. Linking these two stimuli, EMT can also be induced by artificial high-density stroma, where it also leads to chemoresistance in vitro3. Here we set out to validate the link between poor outcome after NAC and EMT in a larger validatory patient cohort, and to ascertain the molecular drivers through which EMT is triggered in this setting. Further we look to confirm the association of high MBD with poor chemoresponse in the same cohort, and to assess whether this chemoresistance is mediated through EMT with the same drivers. In a pilot cohort of 50 NAC-treated locally advanced BrCas with a pCR rate of 20%, pre-NAC biopsies and post-NAC surgical specimens were analysed for expression changes in a panel of EMT-related markers across treatment using 230 Nanostring assays. This included the EMT-driving transcription factors TWIST 1 and 2, SNAIL 1, 2 and 3 and ZEB 1 and 2, which were correlated with risk of relapse. Snail-3 showed significantly greater induction in relapsers compared to non-relapsers (OR=1.8, p=0.04) with a borderline significantly greater induction of TWIST-1 (OR=2.4, p=0.08) in relapsers in addition. In a subsequent 240-patient validation cohort with a pCR rate of 18%, contralateral cranio-caudal view mammograms from the time of diagnosis have been collated and digitized with MBD assessment employing Cumulus software ongoing. Percent breast density will be assessed both as a continuous variable and by quartiles. Immunohistochemistry on pre- and post-operative tissue sections with pan-cytokeratin-vimentin co-staining to identify EMT and staining for SNAIL-3 and TWIST-1 is also in progress. Associations between MBD, EMT before and after chemotherapy, pCR and relapse-free survival will be presented. The role of Snail-3 and TWIST-1 in the interplay between MBD, EMT and outcome is being explored and will be reported. Citation Format: Agarwal V, Spalding LJ, Blick T, Dobrovic A, Thompson EW, Redfern A. The interplay between stromal density, epithelial mesenchymal transition and chemoresistance in breast cancer [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 P5-08-05.

Clinicopathological analysis of homologous recombination-deficient breast cancers with special reference to response to neoadjuvant paclitaxel followed by FEC.

This study aimed to elucidate the clinicopathological characteristics of breast tumors with homologous recombination deficiency (HRD) and the sensitivity to neoadjuvant paclitaxel followed by fluorouracil, epirubicin, and cyclophosphamide (P-FEC). Tumor biopsy samples obtained before P-FEC from 141 patients with stages II-III breast cancer including the luminal (n = 76), luminal-HER2 (n = 13), HER2 (n = 17), and triple-negative (TNBC, n = 35) subtypes were subjected to assay for HRD score using the OncoScan CNV FFPE Assay Kit. HRD score was a simple sum of NtAI, LOH, and LST (cutoff, 42). TNBCs were also subjected to the gene expression assay using the Affymetrix microarray (U133 plus 2.0) and to the BRCA1 promoter methylation assay using the methylation-specific real-time PCR. Of the 141 breast tumors, 45 samples (32%) had high HRD scores and were associated with high histological grade (P = 0.001), negative progesterone receptor (P = 0.018), high Ki67 index (P = 0.032), and BRCA1 promoter methylation (P = 3.6e-07). The proportion of tumors with high HRD scores was significantly higher in the TNBC subtype than the others (P = 0.006). In the TNBC subtype, but not the others, high HRD scores were significantly (P = 0.001) associated with a low pathological complete response rate to P-FEC. Among the molecular TNBC subtypes, a majority of tumors belonging to the basal-like 1, immunomodulatory, mesenchymal, mesenchymal stem-like, but not luminal androgen receptor (LAR), subtypes had high HRD scores. Approximately one-third of sporadic breast tumors show a high HRD score, indicating the presence of homologous recombination dysfunction, and they are characterized by biologically aggressive phenotypes, most commonly in the TNBC subtype, and less sensitive to P-FEC.

Low total pathologic complete response rate to preoperative chemotherapy in patients with invasive lobular carcinomaof the breast.

IntroductionTotal pathologic complete response (tpCR; ypT0/is ypN0) after preoperative chemotherapy (PCT) is associated with better outcome in locally advanced breast cancers. However, the tpCR rate according to histology is not usually considered in trials.Material and methodsPatients with invasive lobular breast carcinoma (ILC), who were included in three phase II trials (AT, ATX, and TXH), were eligible. Expression of markers and clinical phenotypes (CPh) were determined by immunohistochemistry. The primary endpoint was tpCR rate in patients with ILC. Secondary endpoints were breast-conserving surgery rate (BCSR), event-free survival (EFS), and overall survival (OS).ResultsIn the subgroup of patients with ILC (n = 16) the median age was 50 years, 56.25% were premenopausal, median tumour size was 5 cm, and 68.75% had clinically node involvement. Six patients (37.5%) had clinical stage II, and 10 (62.5%) had clinical stage III. Hormone receptor-positive disease was present in 93.75% of the patients, and median Ki-67 was 25%. CPh were Luminal A-like in 37.5%, Luminal B-like in 50%, HER2-positive in 6.25%, and triple negative in 6.25% of tumours. Only one patient (6.25%) had a tpCR, and another patient had a pathologic complete response (pCR) only in the breast. With a median follow-up of 146 months, median EFS was 120 months (95% CI: 68–139), and median OS was not reached. Ten-year EFS and OS probability were 47% and 60%, respectively. BCSR was only 12.5%.ConclusionsPCT in patients with ILC is associated with low tpCR rate because the majority of these patients have Luminal tumours with low chemo-sensitivity.

Neo-adjuvant treatment of adenocarcinoma and squamous cell carcinoma of the cervix results in significantly different pathological complete response rates

BackgroundPrevious studies on cervical cancer reported a worse outcome for adenocarcinoma (AC) compared with squamous cell carcinoma (SCC). Nevertheless, standard treatment remains identical. Insight in the impact of histological types on biological behavior and pathological complete response rates might result in a treatment paradigm shift.MethodsClinicopathological characteristics, survival rates and relapse patterns were compared between AC (n = 36) and SCC (n = 143) cervical cancer patients. Pathological response to treatment was evaluated in the patient subgroup treated with neo-adjuvant chemoradiation followed by surgery (NA-CRT group; n = 84).ResultsIn the entire cohort, 5y Disease Specific Survival (DSS) was 97.1 and 84% for AC and SCC respectively (p = 0.150). In the NA-CRT group 5y DSS was 100 and 75.5% for AC and SCC respectively (p = 0.059). Relapse patterns did not differ significantly between AC and SCC in the entire cohort, or in the NA-CRT group. Adenocarcinoma patients treated with NA-CRT showed significantly less pathological complete response compared with SCC patients (AC = 7%, SCC = 43%, p = 0.027).ConclusionsThere were no statistically significant differences regarding relapse and DSS rates between SCC and AC in the entire cohort, or the NA-CRT group. However, a trend to better 5y DSS of AC in the NA-CRT group was observed. This analysis showed significant differences in treatment responses after NA-CRT: patients with AC responded remarkably less to chemoradiation, resulting in a significantly lower pathological complete response rate. These findings imply a need for a paradigm shift in the treatment of cervical AC patients.

The value of neutrophil-to-lymphocyte ratio for response and prognostic effect of neoadjuvant chemotherapy in solid tumors: A systematic review and meta-analysis.

Introduction: The neutrophil-to-lymphocyte ratio (NLR) has been found to be an indicator of poor prognosis in many tumour types. However, little is known about the relationship between the NLR and patients with tumours who receive neoadjuvant chemotherapy (NAC) in terms of response rate and prognostic ability. We thus performed this meta-analysis to further investigate this relationship.Methods: An electronic systematic literature search for articles published before September 2017 was performed to explore the association between the pretreatment NLR and outcome in patients treated with NAC. Data were extracted by the reported odds ratios (ORs) and hazard ratios (HRs) with their 95% confidence intervals (CIs) for the response rate and the survival outcome, respectively. The results were pooled using the random-effect or fixed-effect model.Results: Thirty-three studies were eventually included in our study, and all were published no earlier than 2011. An NLR that was higher than the cut-off was associated with a lower pathological complete response (pCR) rate in patients with cancer (OR = 1.72, 95% CI, 1.26-2.33). A lower NLR was associated with better overall survival (OS) (HR = 1.58, 95% CI, 1.34-1.86), cancer-specific survival (CSS) (HR = 2.22, 95% CI, 1.32-3.74), disease-free survival (DFS) (HR = 1.32, 95% CI, 1.10-1.59) and recurrence-free survival (RFS) (HR = 1.90, 95% CI, 1.50-2.40).Conclusion: Overall, an NLR lower than the cut-off value indicated a greater chance for pCR and may predict good survival outcomes after NAC for patients with solid tumours. The use of the NLR for risk stratification before NAC should be further demonstrated by future large-scale prospective studies.

HER2-Overexpressing Breast Cancers Amplify FGFR Signaling upon Acquisition of Resistance to Dual Therapeutic Blockade of HER2.

Purpose: Dual blockade of HER2 with trastuzumab and lapatinib or pertuzumab has been shown to be superior to single-agent trastuzumab. However, a significant fraction of HER2-overexpressing (HER2+) breast cancers escape from these drug combinations. In this study, we sought to discover the mechanisms of acquired resistance to the combination of lapatinib + trastuzumab.Experimental Design: HER2+ BT474 xenografts were treated with lapatinib + trastuzumab long-term until resistance developed. Potential mechanisms of acquired resistance were evaluated in lapatinib + trastuzumab-resistant (LTR) tumors by targeted capture next-generation sequencing. In vitro experiments were performed to corroborate these findings, and a novel drug combination was tested against LTR xenografts. Gene expression and copy-number analyses were performed to corroborate our findings in clinical samples.Results: LTR tumors exhibited an increase in FGF3/4/19 copy number, together with an increase in FGFR phosphorylation, marked stromal changes in the tumor microenvironment, and reduced tumor uptake of lapatinib. Stimulation of BT474 cells with FGF4 promoted resistance to lapatinib + trastuzumab in vitro Treatment with FGFR tyrosine kinase inhibitors reversed these changes and overcame resistance to lapatinib + trastuzumab. High expression of FGFR1 correlated with a statistically shorter progression-free survival in patients with HER2+ early breast cancer treated with adjuvant trastuzumab. Finally, FGFR1 and/or FGF3 gene amplification correlated with a lower pathologic complete response in patients with HER2+ early breast cancer treated with neoadjuvant anti-HER2 therapy.Conclusions: Amplification of FGFR signaling promotes resistance to HER2 inhibition, which can be diminished by the combination of HER2 and FGFR inhibitors. Clin Cancer Res; 23(15); 4323-34. ©2017 AACR.

Abstract 3165: 3D culture may better represent trastuzumab resistance associated with PIK3CA mutation than 2D culture

Abstract Background: It is becoming clear that presence of PIK3CA mutations is associated with lower pathological complete response rate in patients with HER2-overexpressing breast cancer when treated with trastuzumab-based chemotherapy in neo-adjuvant settings. On the other hand, in in vitro studies using traditional 2-dimentional (2D) cell culture, differential cellular or biochemical response to trastuzumab between PIK3CA-mutant (mt) and -wild-type (wt) cells has not been clearly demonstrated. Further, while tumor shrinkage is occasionally observed in breast cancer patients who are treated with trastuzumab as a single agent, cyto-toxic effect of trastuzumab is not simulated in 2D culture models. Recently, many studies reported 3-dimensional (3D) cell culture mimics in vivo environment better than 2D culture. Therefore, we hypothesized that 3D culture better represents clinically-observed trastuzumab resistance associated with PIK3CA mutation than 2D culture, and decided to comparatively investigate cellular and biochemical response to trastuzumab in HER2-amlified PIK3CA-mt and -wt cell lines cultured in 2D and 3D environments. Method: HER2-amplified breast cancer cell lines, BT474 (PIK3CA-wt), and UACC893 and MDA-MB361 (PIK3CA-mt) were seeded (day 0) and allowed to grow in 2D and 3D (NanoCluture Plate®, ORGANOGENIX, Kanagawa, Japan) cell culture plates. On day 3, trastuzamab (10 µg/ml) and/or BKM120 (1 and 5 µM), a PI3K inhibitor, were added. The effect of the drugs on cell growth was evaluated with WST-8 assay on days 3 through 7. Apoptosis and cell signaling were evaluated using Western blot on day 6 and days 3 through 5, respectively. Result: In PIK3CA-wt BT474, treatment with trastuzumab led to decrease in cell number, indicating cyto-toxic effect, only in 3D culture but not in 2D culture. In PIK3CA-mt UACC893 and MDA-MB-361 cell lines, treatment with trastuzumab resulted in no cellular reduction either in 2D or 3D cultures. Consistently, increase in cleaved PARP, indicative for apoptosis, was observed only in 3D-cultured BT474 but not in 2D-cultured BT474 or two PIK3CA-mt cell lines. Furthermore, in BT474, greater decrease in phosphorylation of AKT (p-AKT) was observed in 3D culture than in 2D culture. In PIK3CA-mutant cell lines, trastuzumab did not change level of p-AKT regardless of cell culture conditions. In PIK3CA-mutant UACC893, combined treatment with trastuzumab and BKM120 resulted in greater increase in expression of cleaved PARP than either drug alone. Conclusion: Trastuzumab-induced inhibition of PI3K/AKT pathway and resultant apoptosis in HER2-overxpressing PIK3CA-wt cells may be observed in 3D culture, which may be simulating cyto-toxic effect of trastuzumab by itself observed in clinic. Furthermore, 3D cell culture represents the resistance to trastuzumab associated with PIK3CA mutation better than 2D cell culture. Citation Format: Takashi Tatara, Toru Mukohara, Rina Tanaka, Yohei Shimono, Masanori Toyoda, Naomi Kiyota, Midori Hirai, Yoshihiro Kakeji, Hironobu Minami. 3D culture may better represent trastuzumab resistance associated with PIK3CA mutation than 2D culture [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3165. doi:10.1158/1538-7445.AM2017-3165