Outcomes of limited stage primary bone diffuse large B-cell lymphoma in the rituximab era: a multicenter, retrospective study.

Primary bone diffuse large B cell lymphoma (DLBCL) is a rare variant of extranodal non-Hodgkin lymphoma (NHL) historically treated with induction chemotherapy followed by consolidative radiation therapy (RT). It remains unknown whether RT confers additional benefit following rituximab-based chemoimmunotherapy (CIT) induction in patients with limited-stage disease. We conducted a multicenter retrospective analysis of patients treated between 2005 and 2019 using rituximab-based CIT regimens with or without consolidative RT to discern whether consolidative RT adds benefit in patients with stage I-II disease that could be encompassed in one radiation field. A total of 112 patients were included: 78 received CIT and radiation (RT group), and 34 received CIT alone (no RT group). The OS at 10 years was 77.9% in the RT group and 89.0% in the no RT group (p = 0.42). The RFS at 10 years was 73.5% in the RT group and 80.3% in the no RT group (p = 0.88). Neither improved OS nor RFS was associated with the addition of consolidative RT. Subgroup analysis of patients only achieving a partial response after CIT suggests that these patients may benefit from consolidative RT.

Tumor-Infiltrating Normal B Cells Revealed by Immunoglobulin Repertoire Clonotype Analysis Are Highly Prognostic and Crucial for Antitumor Immune Responses in DLBCL.

PURPOSE: Tumor-infiltrating B lymphocytes (TIL-B) have demonstrated prognostic and predictive significance in solid cancers. In this study, we aimed to distinguish TIL-Bs from malignant B-cells in diffuse large B-cell lymphoma (DLBCL) and determine the clinical and biological significance. EXPERIMENTAL DESIGN: A total of 269 patients with de novo DLBCL from the International DLBCL R-CHOP Consortium Program were studied. Ultra-deep sequencing of the immunoglobulin genes was performed to determine B-cell clonotypes. The frequencies and numbers of TIL-B clonotypes in individual repertoires were correlated with patient survival, gene expression profiling (GEP) data, and frequencies of DLBCL-infiltrating immune cells quantified by fluorescent multiplex IHC at single-cell resolution. RESULTS: TIL-B abundance, evaluated by frequencies of normal B-cell clonotypes in the immunoglobulin repertoires, remarkably showed positive associations with significantly better survival of patients in our sequenced cohorts. DLBCLs with high versus low TIL-B abundance displayed distinct GEP signatures, increased pre-memory B-cell state and naïve CD4 T-cell state fractions, and higher CD4+ T-cell infiltration. TIL-B frequency, as a new biomarker in DLBCL, outperformed the germinal center (GC) B-cell-like/activated B-cell-like classification and TIL-T frequency. The identified TIL-B-high GEP signature, including genes upregulated during T-dependent B-cell activation and those highly expressed in normal GC B cells and T cells, showed significant favorable prognostic effects in several external validation cohorts. CONCLUSIONS: TIL-B frequency is a significant prognostic factor in DLBCL and plays a crucial role in antitumor immune responses. This study provides novel insights into the prognostic determinants in DLBCL and TIL-B functions with important therapeutic implications.

Validation of Immunotherapy Response Score as Predictive of Pan-solid Tumor Anti-PD-1/PD-L1 Benefit.

Immunotherapy response score (IRS) integrates tumor mutation burden (TMB) and quantitative expression biomarkers to predict anti-PD-1/PD-L1 [PD-(L)1] monotherapy benefit. Here, we evaluated IRS in additional cohorts. Patients from an observational trial (NCT03061305) treated with anti-PD-(L)1 monotherapy were included and assigned to IRS-High (-H) versus -Low (-L) groups. Associations with real-world progression-free survival (rwPFS) and overall survival (OS) were determined by Cox proportional hazards (CPH) modeling. Those with available PD-L1 IHC treated with anti-PD-(L)1 with or without chemotherapy were separately assessed. Patients treated with PD-(L)1 and/or chemotherapy (five relevant tumor types) were assigned to three IRS groups [IRS-L divided into IRS-Ultra-Low (-UL) and Intermediate-Low (-IL), and similarly assessed]. In the 352 patient anti-PD-(L)1 monotherapy validation cohort (31 tumor types), IRS-H versus IRS-L patients had significantly longer rwPFS and OS. IRS significantly improved CPH associations with rwPFS and OS beyond microsatellite instability (MSI)/TMB alone. In a 189 patient (10 tumor types) PD-L1 IHC comparison cohort, IRS, but not PD-L1 IHC nor TMB, was significantly associated with anti-PD-L1 rwPFS. In a 1,103-patient cohort (from five relevant tumor types), rwPFS did not significantly differ in IRS-UL patients treated with chemotherapy versus chemotherapy plus anti-PD-(L)1, nor in IRS-H patients treated with anti-PD-(L)1 versus anti-PD-(L)1 + chemotherapy. IRS associations were consistent across subgroups, including both Europeans and non-Europeans. These results confirm the utility of IRS utility for predicting pan-solid tumor PD-(L)1 monotherapy benefit beyond available biomarkers and demonstrate utility for informing on anti-PD-(L)1 and/or chemotherapy treatment. Significance: This study confirms the utility of the integrative IRS biomarker for predicting anti-PD-L1/PD-1 benefit. IRS significantly improved upon currently available biomarkers, including PD-L1 IHC, TMB, and MSI status. Additional utility for informing on chemotherapy, anti-PD-L1/PD-1, and anti-PD-L1/PD-1 plus chemotherapy treatments decisions is shown.

Determining clinical course of diffuse large B-cell lymphoma using targeted transcriptome and machine learning algorithms.

Multiple studies have demonstrated that diffuse large B-cell lymphoma (DLBCL) can be divided into subgroups based on their biology; however, these biological subgroups overlap clinically. Using machine learning, we developed an approach to stratify patients with DLBCL into four subgroups based on survival characteristics. This approach uses data from the targeted transcriptome to predict these survival subgroups. Using the expression levels of 180 genes, our model reliably predicted the four survival subgroups and was validated using independent groups of patients. Multivariate analysis showed that this patient stratification strategy encompasses various biological characteristics of DLBCL, and only TP53 mutations remained an independent prognostic biomarker. This novel approach for stratifying patients with DLBCL, based on the clinical outcome of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone therapy, can be used to identify patients who may not respond well to these types of therapy, but would otherwise benefit from alternative therapy and clinical trials.

Genetic Subtyping and Phenotypic Characterization of the Immune Microenvironment and MYC/BCL2 Double Expression Reveal Heterogeneity in Diffuse Large B-cell Lymphoma.

PURPOSE: Diffuse large B-cell lymphoma (DLBCL) is molecularly and clinically heterogeneous, and can be subtyped according to genetic alterations, cell-of-origin, or microenvironmental signatures using high-throughput genomic data at the DNA or RNA level. Although high-throughput proteomic profiling has not been available for DLBCL subtyping, MYC/BCL2 protein double expression (DE) is an established prognostic biomarker in DLBCL. The purpose of this study is to reveal the relative prognostic roles of DLBCL genetic, phenotypic, and microenvironmental biomarkers. EXPERIMENTAL DESIGN: We performed targeted next-generation sequencing; IHC for MYC, BCL2, and FN1; and fluorescent multiplex IHC for microenvironmental markers in a large cohort of DLBCL. We performed correlative and prognostic analyses within and across DLBCL genetic subtypes and MYC/BCL2 double expressors. RESULTS: We found that MYC/BCL2 double-high-expression (DhE) had significant adverse prognostic impact within the EZB genetic subtype and LymphGen-unclassified DLBCL cases but not within MCD and ST2 genetic subtypes. Conversely, KMT2D mutations significantly stratified DhE but not non-DhE DLBCL. T-cell infiltration showed favorable prognostic effects within BN2, MCD, and DhE but unfavorable effects within ST2 and LymphGen-unclassified cases. FN1 and PD-1-high expression had significant adverse prognostic effects within multiple DLBCL genetic/phenotypic subgroups. The prognostic effects of DhE and immune biomarkers within DLBCL genetic subtypes were independent although DhE and high Ki-67 were significantly associated with lower T-cell infiltration in LymphGen-unclassified cases. CONCLUSIONS: Together, these results demonstrated independent and additive prognostic effects of phenotypic MYC/BCL2 and microenvironment biomarkers and genetic subtyping in DLBCL prognostication, important for improving DLBCL classification and identifying prognostic determinants and therapeutic targets.

Real-World Performance of a Comprehensive Genomic Profiling Test Optimized for Small Tumor Samples.

PURPOSE: Tissue-based comprehensive genomic profiling (CGP) is increasingly used for treatment selection in patients with advanced cancer; however, tissue availability may limit widespread implementation. Here, we established real-world CGP tissue availability and assessed CGP performance on consecutively received samples. MATERIALS AND METHODS: We conducted a post hoc, nonprespecified analysis of 32,048 consecutive tumor tissue samples received for StrataNGS, a multiplex polymerase chain reaction (PCR)-based comprehensive genomic profiling (PCR-CGP) test, as part of an ongoing observational trial (NCT03061305). Sample characteristics and PCR-CGP performance were assessed across all tested samples, including exception samples not meeting minimum input quality control (QC) requirements (< 20% tumor content [TC], < 2 mm2 tumor surface area [TSA], DNA or RNA yield < 1 ng/µL, or specimen age > 5 years). Tests reporting ≥ 1 prioritized alteration or meeting TC and sequencing QC were considered successful. For prostate carcinoma and lung adenocarcinoma, tests reporting ≥ 1 actionable or informative alteration or meeting TC and sequencing QC were considered actionable. RESULTS: Among 31,165 (97.2%) samples where PCR-CGP was attempted, 10.7% had < 20% TC and 59.2% were small (< 25 mm2 tumor surface area). Of 31,101 samples evaluable for input requirements, 8,089 (26.0%) were exceptions not meeting requirements. However, 94.2% of the 31,101 tested samples were successfully reported, including 80.5% of exception samples. Positive predictive value of PCR-CGP for ERBB2 amplification in exceptions and/or sequencing QC-failure breast cancer samples was 96.7%. Importantly, 84.0% of tested prostate carcinomas and 87.9% of lung adenocarcinomas yielded results informing treatment selection. CONCLUSION: Most real-world tissue samples from patients with advanced cancer desiring CGP are limited, requiring optimized CGP approaches to produce meaningful results. An optimized PCR-CGP test, coupled with an inclusive exception testing policy, delivered reportable results for > 94% of samples, potentially expanding the proportion of CGP-testable patients and impact of biomarker-guided therapies.

Genomic complexity is associated with epigenetic regulator mutations and poor prognosis in diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma with high mutation burdens but a low response rate to immune checkpoint inhibitors. In this study, we performed targeted next-generation sequencing and fluorescent multiplex immunohistochemistry, and investigated the clinical significance and immunological effect of mutation numbers in 424 DLBCL patients treated with standard immunochemotherapy. We found that KMT2D and TP53 nonsynonymous mutations (MUT) were significantly associated with increased nonsynonymous mutation numbers, and that high mutation numbers (MUThigh) were associated with significantly poorer clinical outcome in germinal center B-cell-like DLBCL with wild-type TP53. To understand the underlying mechanisms, we identified a gene-expression profiling signature and the association of MUThigh with decreased T cells in DLBCL patients with wild-type TP53. On the other hand, in overall cohort, MUThigh was associated with lower PD-1 expression in T cells and PD-L1 expression in macrophages, suggesting a positive role of MUThigh in immune responses. Analysis in a whole-exome sequencing dataset of 304 patients deposited by Chapuy et al. validated the correlation of MUT-KMT2D with genomic complexity and the significantly poorer survival associated with higher numbers of genomic single nucleotide variants in activated B-cell-like DLBCL with wild-type TP53. Together, these results suggest that KMT2D inactivation or epigenetic dysregulation has a role in driving DLBCL genomic instability, and that genomic complexity has adverse impact on clinical outcome in DLBCL patients with wild-type TP53 treated with standard immunochemotherapy. The oncoimmune data in this study have important implications for biomarker and therapeutic studies in DLBCL.

Aggressive B-cell Lymphoma with MYC/TP53 Dual Alterations Displays Distinct Clinicopathobiological Features and Response to Novel Targeted Agents.

Diffuse large B-cell lymphoma (DLBCL) is the major type of aggressive B-cell lymphoma. High-grade B-cell lymphoma (HGBCL) with MYC/BCL2 double-hit (DH) represents a distinct entity with dismal prognosis after standard immunochemotherapy in the current WHO lymphoma classification. However, whether TP53 mutation synergizes with MYC abnormalities (MYC rearrangement and/or Myc protein overexpression) contributing to HGBCL-like biology and prognosis is not well investigated. In this study, patients with DLBCL with MYC/TP53 abnormalities demonstrated poor clinical outcome, high-grade morphology, and distinct gene expression signatures. To identify more effective therapies for this distinctive DLBCL subset, novel MYC/TP53/BCL-2-targeted agents were investigated in DLBCL cells with MYC/TP53 dual alterations or HGBCL-MYC/BCL2-DH. A BET inhibitor INCB057643 effectively inhibited cell viability and induced apoptosis in DLBCL/HGBCL cells regardless of MYC/BCL2/TP53 status. Combining INCB057643 with a MDM2-p53 inhibitor DS3032b significantly enhanced the cytotoxic effects in HGBCL-DH without TP53 mutation, while combining with the BCL-2 inhibitor venetoclax displayed potent therapeutic synergy in DLBCL/HGBCL cells with and without concurrent TP53 mutation. Reverse-phase protein arrays revealed the synergistic molecular actions by INCB057643, DS3032b and venetoclax to induce cell-cycle arrest and apoptosis and to inhibit AKT/MEK/ERK/mTOR pathways, as well as potential drug resistance mechanisms mediated by upregulation of Mcl-1 and RAS/RAF/MEK/ERK pathways. In summary, these findings support subclassification of DLBCL/HGBCL with dual MYC/TP53 alterations, which demonstrates distinct pathobiologic features and dismal survival with standard therapy, therefore requiring additional targeted therapies. IMPLICATIONS: The clinical and pharmacologic studies suggest recognizing DLBCL with concomitant TP53 mutation and MYC abnormalities as a distinctive entity necessary for precision oncology practice. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/molcanres/19/2/249/F1.large.jpg.

External Validation of AJCC Eighth Edition of Non-small-cell Lung Cancer Staging Among African Americans.

INTRODUCTION: The American Joint Committee on Cancer (AJCC) eighth staging classification system for non-small-cell lung cancer was based on data from a multinational study consisting of 94,708 patients. African Americans were not included in this large database. MATERIALS AND METHODS: The authors aimed to compare the performance of the AJCC eighth staging system with that of the seventh in predicting overall survival among African Americans utilizing the National Cancer Database. Cases with T- and M- categories were classified into 2 groups based on the AJCC seventh and eighth edition staging systems. Kaplan-Meier curves for overall survival were then constructed for each subgroup. Concordance index was computed using Uno's methodology to assess the overall performance between the 2 staging systems in predicting the mortality. Time-dependent area under the curve was calculated at each follow-up event for the seventh and eighth edition clinical and pathologic staging using an inverse probability of censoring weighted methodology. A 2-sided P-value < .05 was considered to show statistical significance. RESULTS: The database identified a total of 70,606 African American patients in the study period of 2004 through 2014. Area under the curve values were consistently higher for the eighth edition scheme compared with the seventh edition (concordance 0.630 vs. 0.624, respectively; P < .0001 for clinical staging scheme and 0.596 vs. 0.591, respectively; P = .01 for pathologic staging scheme). CONCLUSION: The AJCC eighth edition staging system showed better prognostic value in predicting overall survival when compared with the AJCC seventh edition staging scheme among African American patients with non-small-cell lung cancer.

XPO1 expression worsens the prognosis of unfavorable DLBCL that can be effectively targeted by selinexor in the absence of mutant p53.

The XPO1 inhibitor selinexor was recently approved in relapsed/refractory DLBCL patients but only demonstrated modest anti-DLBCL efficacy, prompting us to investigate the prognostic effect of XPO1 in DLBCL patients and the rational combination therapies in high-risk DLBCL. High XPO1 expression (XPO1high) showed significant adverse prognostic impact in 544 studied DLBCL patients, especially in those with BCL2 overexpression. Therapeutic study in 30 DLBCL cell lines with various molecular and genetic background found robust cytotoxicity of selinexor, especially in cells with BCL2-rearranged (BCL2-R+) DLBCL or high-grade B-cell lymphoma with MYC/BCL2 double-hit (HGBCL-DH). However, expression of mutant (Mut) p53 significantly reduced the cytotoxicity of selinexor in overall cell lines and the BCL2-R and HGBCL-DH subsets, consistent with the favorable impact of XPO1high observed in Mut-p53-expressing patients. The therapeutic effect of selinexor in HGBCL-DH cells was significantly enhanced when combined with a BET inhibitor INCB057643, overcoming the drug resistance in Mut-p53-expressing cells. Collectively, these data suggest that XPO1 worsens the survival of DLBCL patients with unfavorable prognostic factors such as BCL2 overexpression and double-hit, in line with the higher efficacy of selinexor demonstrated in BCL2-R+ DLBCL and HGBCL-DH cell lines. Expression of Mut-p53 confers resistance to selinexor treatment, which can be overcome by combined INCB057643 treatment in HGBCL-DH cells. This study provides insight into the XPO1 significance and selinexor efficacy in DLBCL, important for developing combination therapy for relapsed/refractory DLBCL and HGBCL-DH.

A refined cell-of-origin classifier with targeted NGS and artificial intelligence shows robust predictive value in DLBCL.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous entity of B-cell lymphoma. Cell-of-origin (COO) classification of DLBCL is required in routine practice by the World Health Organization classification for biological and therapeutic insights. Genetic subtypes uncovered recently are based on distinct genetic alterations in DLBCL, which are different from the COO subtypes defined by gene expression signatures of normal B cells retained in DLBCL. We hypothesize that classifiers incorporating both genome-wide gene-expression and pathogenetic variables can improve the therapeutic significance of DLBCL classification. To develop such refined classifiers, we performed targeted RNA sequencing (RNA-Seq) with a commercially available next-generation sequencing (NGS) platform in a large cohort of 418 DLBCLs. Genetic and transcriptional data obtained by RNA-Seq in a single run were explored by state-of-the-art artificial intelligence (AI) to develop a NGS-COO classifier for COO assignment and NGS survival models for clinical outcome prediction. The NGS-COO model built through applying AI in the training set was robust, showing high concordance with COO classification by either Affymetrix GeneChip microarray or the NanoString Lymph2Cx assay in 2 validation sets. Although the NGS-COO model was not trained for clinical outcome, the activated B-cell-like compared with the germinal-center B-cell-like subtype had significantly poorer survival. The NGS survival models stratified 30% high-risk patients in the validation set with poor survival as in the training set. These results demonstrate that targeted RNA-Seq coupled with AI deep learning techniques provides reproducible, efficient, and affordable assays for clinical application. The clinical grade assays and NGS models integrating both genetic and transcriptional factors developed in this study may eventually support precision medicine in DLBCL.

Acquisition of Cabozantinib-Sensitive MET D1228N Mutation During Progression on Crizotinib in MET-Amplified Triple-Negative Breast Cancer.

BACKGROUND: Targeting of somatic MET mutations using crizotinib has led to strong clinical responses, most frequently in patients with lung cancer, raising the possibility of adopting similar treatment strategies in patients with MET alterations in other cancer types. PATIENT AND METHODS: We describe a patient with advanced triple-negative breast cancer with a 30-fold amplification of MET. Next-generation sequencing of pre- and postprogression biopsies was performed to identify the resistance mechanism emerging after an initial exceptional response to crizotinib. The response of the resistance mutant to type I and II MET inhibitors was assessed in cultured cells. RESULTS: After progressing on crizotinib, a MET-D1228N mutation was detected, which is located in the crizotinib-binding region of the MET kinase domain. Experimental studies demonstrated that this mutation confers complete resistance to crizotinib yet retains cabozantinib sensitivity. Treatment of the patient with cabozantinib led to a subjective improvement in clinical symptoms, but the patient progressed after 7 weeks. CONCLUSION: Although MET mutations are rare in breast cancer, these patients may experience substantial clinical benefit from crizotinib treatment. Nevertheless, drug resistance owing to on-target MET mutations will likely be frequently encountered and comprehensive mechanistic studies to assess sensitivity of these mutants to a series of potential second-line therapies may help guide subsequent treatment for these patients.

Utilization of Surgery and Its Impact on Survival in Patients With Early Stage Small-cell Lung Cancer in the United States.

INTRODUCTION: For patients with T1 or T2 N0 M0 small-cell lung cancer (SCLC), lobectomy followed by chemotherapy is the standard of care. However, because of its tendency for early dissemination, patients are often treated with concurrent chemo-radiation without surgery. This study was conducted to evaluate the utilization of surgery and its impact on survival in patients with early stage SCLC. MATERIALS AND METHODS: The National Cancer Database was queried to identify patients with T1 or T2 N0 M0 SCLC diagnosed from 2004 to 2013. Multivariate logistic regression modeling was utilized to identify factors associated with receipt of surgery. Patients were stratified into 3 groups: chemo-radiation, surgery followed by chemotherapy, and surgery followed by chemotherapy and prophylactic cranial irradiation (PCI). Kaplan-Meier estimators and Cox proportional-hazards regression were used to compare overall survival. Patients were matched on the propensity score. RESULTS: A total of 3879 SCLC cases were identified. Of those cases, 80.7% received chemo-radiation. Surgery followed by chemotherapy with or without PCI was associated with better median overall survival (93.0 months [lower 95% confidence interval (CI), 72.5] and 61.7 months [95% CI, 51.8-76.5], respectively) compared with chemo-radiation (31.2 months [95% CI, 26.3-37.0]). PCI offered survival benefit in addition to surgery and chemotherapy (hazard ratio, 0.75). CONCLUSIONS: Our study showed a significant survival benefit with surgery (lobectomy or more), adjuvant chemotherapy, and PCI in patients with T1-T2 N0 M0 SCLC.

Sequential treatment failures in response to BRAF/MEK and immune checkpoint inhibitors mediated by MAP2K2 and B2M mutations in melanoma.

Although the treatment of metastatic melanoma has been significantly improved by both anti-BRAF/MEK and checkpoint immunotherapies, resistance to these treatment modalities remains a substantial clinical problem. Multiple clinical studies are addressing the optimal sequencing of these agents in larger patient cohorts, but successful long-term individualized treatment will likely require the elucidation of resistance mechanisms from post-progression samples. Here, we describe a patient with BRAF-V600E-positive metastatic melanoma who was sequentially treated with BRAF/MEK inhibitors (dabrafenib/trametinib) and checkpoint inhibitor immunotherapy (nivolumab, followed by pembrolizumab). After the emergence of resistance, whole exome sequencing was performed, implicating MAP2K2 and B2M mutations in loss of response to anti-BRAF/MEK and anti-PD1 therapies, respectively.

A Reappraisal of the Comparative Effectiveness of Lumpectomy Versus Mastectomy on Breast Cancer Survival: A Propensity Score-Matched Update From the National Cancer Data Base (NCDB).

BACKGROUND: Recent observational studies are concerning because they document rising mastectomy rates coinciding with more than a dozen reports that lumpectomy has better overall survival (OS) than mastectomy. Our aim was to determine if there were differences in OS of matched breast cancer patients undergoing lumpectomy versus mastectomy in the National Cancer Database (NCDB). PATIENTS AND METHODS: A retrospective cohort of patients with stage I-III breast cancer in the NCDB (2004-2013) was identified. Propensity score matching (PSM), Kaplan-Meier, and multivariate Cox proportional hazards models were used to examine OS by type of surgery. RESULTS: Of 845,136 patients, 464,052 (54.9%) underwent lumpectomy and 381,084 (45.1%) underwent mastectomy. After PSM, the hazard ratio (HR) and confidence interval (CI) for OS in all patients comparing lumpectomy with mastectomy was 1.02 (CI, 1.00-1.04; P = .002). In patients with stage I, II, and III, they were HR 1.27 (CI, 1.23-1.36; P < .001), HR 0.98 (CI, 0.95-1.01; P = .21), and HR 0.83 (CI, 0.80-0.86; P < .001), respectively. In subgroup analyses of all patients by estrogen receptor (ER) status, they were HR 1.05 (CI, 1.03-1.07; P < .001) and HR 1.00 (CI, 0.96-1.03; P = .65) in ER+ and ER- patients. CONCLUSION: In our primary model of all stage I-III matched patients, using the most recent NCDB data and the largest observational sample size to date, the OS after mastectomy was not inferior to lumpectomy. This finding can be reassuring to patients and providers. In subgroup analyses, the association between type of surgery and OS differed by cancer stage and hormone receptor status.

MTORC1/2 Inhibition as a Therapeutic Strategy for PIK3CA Mutant Cancers.

PIK3CA mutations are common in clinical molecular profiling, yet an effective means to target these cancers has yet to be developed. MTORC1 inhibitors are often used off-label for patients with PIK3CA mutant cancers with only limited data to support this approach. Here we describe a cohort of patients treated with cancers possessing mutations activating the PI3K signaling cascade with minimal benefit to treatment with the MTORC1 inhibitor everolimus. Previously, we demonstrated that dual PI3K/mTOR inhibition could decrease proliferation, induce differentiation, and result in a treatment response in APC and PIK3CA mutant colorectal cancer. However, reactivation of AKT was identified, indicating that the majority of the benefit may be secondary to MTORC1/2 inhibition. TAK-228, an MTORC1/2 inhibitor, was compared with dual PI3K/mTOR inhibition using BEZ235 in murine colorectal cancer spheroids. A reduction in spheroid size was observed with TAK-228 and BEZ235 (-13% and -14%, respectively) compared with an increase of >200% in control (P < 0.001). These spheroids were resistant to MTORC1 inhibition. In transgenic mice possessing Pik3ca and Apc mutations, BEZ235 and TAK-228 resulted in a median reduction in colon tumor size of 19% and 20%, respectively, with control tumors having a median increase of 18% (P = 0.02 and 0.004, respectively). This response correlated with a decrease in the phosphorylation of 4EBP1 and RPS6. MTORC1/2 inhibition is sufficient to overcome resistance to everolimus and induce a treatment response in PIK3CA mutant colorectal cancers and deserves investigation in clinical trials and in future combination regimens.

A US Registry-Based Assessment of Use and Impact of Chemotherapy in Stage I HER2-Positive Breast Cancer.

Background: Despite the paucity of evidence supporting chemotherapy in the treatment of node-negative, HER2-positive breast cancer measuring <2 cm, use of trastuzumab-based chemotherapy has increased over the past decade. Therefore, we used the National Cancer Database to evaluate the use and impact of chemotherapy on survival in this population. Methods: We identified female patients aged 18 to 70 years with node-negative, HER2-positive breast cancer measuring <2 cm. A propensity-matched cohort model was used to control for risk factors known to influence survival. Primary end points assessed were receipt of chemotherapy and overall survival (OS). Results: In our propensity-matched cohort model (n=8,222), adjuvant chemotherapy (ACT) was associated with a lower 5-year OS rate in T1mi breast cancer (n=626; 89.1% [95% CI, 81.8%-93.5%] vs 99.1% [96.6%-99.8%]), no significant effect in T1a disease (n=2,901; 95.4% [93.2%-96.9%] vs 96.9% [94.1%-98.3%]), and improved 5-year OS in T1b (n=2,340; 97.1% [95.1%-98.4%] vs 92.3% [88.5%-94.9%]) and T1c tumors (n=2,355; 95.9% [93.5%-97.5%] vs 91.5% [88.4%-93.9%]). In the entire cohort of 21,148 patients who met the inclusion criteria, ACT was associated with lower 5-year OS in T1mi (89.6% [83.7%-93.4%] vs 98.1% [96.6%-98.9%]) and T1a tumors (94.9% [92.9%-96.3%] vs 96.5% [94.6%-97.7%]), and improved 5-year OS in T1b (96.8% [95.6%-97.7%] vs 92.3% [88.7%-94.8%]) and T1c tumors (95.8% [94.9%-96.5%] vs 91.6% [88.5%-93.9%]). Increased use of ACT was observed over the study period. From 2010 to 2013, annual treatment rates were 71.5%, 72.4%, 73.3%, and 74.4%, respectively (trend test, P<.0001). Conclusions: Our data support the use of ACT for HER2-positive, node-negative T1b and T1c breast cancer, whereas no benefit was observed for ACT in T1mi and T1a HER2-positive, node-negative breast cancer. Although use of ACT is increasing in node-negative, HER2-positive breast cancer <2 cm, our findings caution against its use in the smallest of these tumors (T1mi and T1a) due to lack of survival benefit.

A Strategy for Changing Adherence to National Guidelines for Decreasing Laboratory Testing for Early Breast Cancer Patients.

INTRODUCTION: Past studies indicate delays in adoption of consensus-based guideline updates. In June 2016, the National Comprehensive Cancer Network changed its guidelines from routine testing to omission of ordering complete blood cell count (CBC) and liver function tests (LFT) in patients with early breast cancer. In response, we developed an implementation strategy to discontinue our historical practice of routine ordering of these tests in asymptomatic patients. METHODS: The ordering of CBC and LFT for clinical stage I-IIIA breast cancer patients was audited in 2016. In June 2016, we utilized the levers of the National Quality Strategy implementation methodology to enact a system-wide change to omit routine ordering. To measure the plan's effectiveness, guideline compliance for ordering was tracked continually. RESULTS: Of 92 patients with early stage cancer in 2016, the overall rate of compliance with guidelines for ordering a CBC and LFT was 82% (88/107) and 87% (93/107), respectively. Segregated by the pre- and post-guideline change time period, the compliance rates for ordering a CBC and LFT were 78% and 87% (P = 0.076). CONCLUSION: In contrast to historical reports of delays in adoption of new evidence-based guideline changes, we were able to quickly change provider practice during the transition from routine ordering to omission of ordering screening blood tests in newly diagnosed patients with early breast cancer.

Fewer Reoperations After Lumpectomy for Breast Cancer with Neoadjuvant Rather than Adjuvant Chemotherapy: A Report from the National Cancer Database.

BACKGROUND: Reoperations occur frequently after initial lumpectomy for breast cancer. The authors hypothesized that the receipt of neoadjuvant chemotherapy (NAC) is associated with fewer reoperations. METHODS: The association between timing of chemotherapy and reoperation rates (ROR) after lumpectomy was investigated for patients with stages 1-3 breast cancer in the National Cancer Database (NCDB) from 2010 to 2013 by multivariable logistic regression modeling. Then propensity score-matching was performed. RESULTS: The unadjusted ROR for 71,627 stages 1-3 patients was 11.4% for those who had NAC compared with 20.3% for those who had postoperative chemotherapy (p < 0.001) (odds ratio [OR] 0.53; 95% confidence interval [CI] 0.49-0.57; p < 0.001). The ORs for the reoperations performed for patients with stages 1, 2, and 3 cancers who received NAC were respectively 0.65 (95% CI 0.56-0.75), 0.50 (95% CI 0.45-0.56), and 0.27 (95% CI 0.19-0.38) The p values for all were lower than 0.001. CONCLUSION: For a population of patients receiving chemotherapy, the receipt of chemotherapy before instead of after surgery was associated with fewer reoperations after initial lumpectomy for breast cancer.