Distinct p53 transcriptional programs dictate acute DNA-damage responses and tumor suppression.

The molecular basis for p53-mediated tumor suppression remains unclear. Here, to elucidate mechanisms of p53 tumor suppression, we use knockin mice expressing an allelic series of p53 transcriptional activation mutants. Microarray analysis reveals that one mutant, p53(25,26), is severely compromised for transactivation of most p53 target genes, and, moreover, p53(25,26) cannot induce G(1)-arrest or apoptosis in response to acute DNA damage. Surprisingly, p53(25,26) retains robust activity in senescence and tumor suppression, indicating that efficient transactivation of the majority of known p53 targets is dispensable for these pathways. In contrast, the transactivation-dead p53(25,26,53,54) mutant cannot induce senescence or inhibit tumorigenesis, like p53 nullizygosity. Thus, p53 transactivation is essential for tumor suppression but, intriguingly, in association with a small set of novel p53 target genes. Together, our studies distinguish the p53 transcriptional programs involved in acute DNA-damage responses and tumor suppression-a critical goal for designing therapeutics that block p53-dependent side effects of chemotherapy without compromising p53 tumor suppression.

Lymphopenia and clinical outcomes in patients with residual nodal disease after neoadjuvant chemotherapy for breast cancer.

BACKGROUND: Patients with residual nodal disease after neoadjuvant chemotherapy for breast cancer have a poor prognosis. We wanted to evaluate whether lymphopenia after treatment for breast cancer impacted clinical outcomes. MATERIALS AND METHODS: We assessed 99 patients with node-positive disease after neoadjuvant chemotherapy. Absolute lymphocyte count was recorded 1 year after radiation. Dates of local, regional, and distant failure were recorded. Time to event outcomes were evaluated using Kaplan-Meier analysis. Multivariable analysis determined factors predictive for overall survival. RESULTS: Median follow-up was 44 months (range 3-150). Median age was 48 years (range 23-79). Twenty-six patients (26%) had lymphopenia 1 year after RT. Patients with lymphopenia had a greater incidence of regional (p = 0.03) and distant failure (p = 0.009) compared to those with normal lymphocyte counts and had a 6.05 greater risk of death (p = 0.0002). CONCLUSIONS: In patients with residual nodal disease after neoadjuvant chemotherapy, lymphopenia after breast cancer treatment was associated with overall survival. The relationship between lymphopenia and breast cancer outcomes warrants further investigation.

Inappropriate p53 activation during development induces features of CHARGE syndrome.

CHARGE syndrome is a multiple anomaly disorder in which patients present with a variety of phenotypes, including ocular coloboma, heart defects, choanal atresia, retarded growth and development, genitourinary hypoplasia and ear abnormalities. Despite 70-90% of CHARGE syndrome cases resulting from mutations in the gene CHD7, which encodes an ATP-dependent chromatin remodeller, the pathways underlying the diverse phenotypes remain poorly understood. Surprisingly, our studies of a knock-in mutant mouse strain that expresses a stabilized and transcriptionally dead variant of the tumour-suppressor protein p53 (p53(25,26,53,54)), along with a wild-type allele of p53 (also known as Trp53), revealed late-gestational embryonic lethality associated with a host of phenotypes that are characteristic of CHARGE syndrome, including coloboma, inner and outer ear malformations, heart outflow tract defects and craniofacial defects. We found that the p53(25,26,53,54) mutant protein stabilized and hyperactivated wild-type p53, which then inappropriately induced its target genes and triggered cell-cycle arrest or apoptosis during development. Importantly, these phenotypes were only observed with a wild-type p53 allele, as p53(25,26,53,54)(/-) embryos were fully viable. Furthermore, we found that CHD7 can bind to the p53 promoter, thereby negatively regulating p53 expression, and that CHD7 loss in mouse neural crest cells or samples from patients with CHARGE syndrome results in p53 activation. Strikingly, we found that p53 heterozygosity partially rescued the phenotypes in Chd7-null mouse embryos, demonstrating that p53 contributes to the phenotypes that result from CHD7 loss. Thus, inappropriate p53 activation during development can promote CHARGE phenotypes, supporting the idea that p53 has a critical role in developmental syndromes and providing important insight into the mechanisms underlying CHARGE syndrome.

SATB2 and CDX2 are prognostic biomarkers in DNA mismatch repair protein deficient colon cancer.

DNA mismatch repair protein deficient colon cancer frequently displays reduced CDX2 expression, and recent literature has suggested that negative CDX2 expression is a poor prognostic biomarker in colon cancer. We have recently demonstrated that SATB2 is an immunohistochemical marker that is complementary to CDX2. Using a tissue microarray approach, we evaluated SATB2 and CDX2 immunohistochemical expression in 514 patients with colonic adenocarcinoma including 146 with mismatch repair protein deficient tumors and correlated expression with histopathologic variables, molecular alterations, and survival. Overall, SATB2-negative and/or CDX2-negative expression was identified in 33% of mismatch repair protein deficient tumors compared with only 15% of mismatch repair protein proficient tumors (p < 0.001) and in 36% of BRAF V600E mutated compared with only 13% of BRAF wild-type tumors (p < 0.001). Both SATB2-negative and CDX2-negative colonic adenocarcinomas more often displayed lymphatic invasion, venous invasion, and perineural invasion (all with p < 0.05). SATB2-negative expression was also more frequently identified in tumors with mucinous or signet ring cell differentiation (p < 0.01 for both). In a multivariable analysis of survival in patients with mismatch repair protein deficient tumors (n = 131), only tumor stage (p = 0.01) and SATB2-negative and/or CDX2-negative expression (p = 0.009) independently predicted disease-specific survival. Of the 99 patients with stage II or III mismatch repair protein deficient tumors, death from disease only occurred in patients with either SATB2-negative or CDX2-negative tumors, and no patients with SATB2-positive/CDX2-positive tumors developed recurrence or died of disease. SATB2 and CDX2 expression had no effect on patient survival in mismatch repair protein proficient, BRAF-mutated, or KRAS-mutated tumors. In summary, our results suggest that SATB2 and CDX2 are prognostic biomarkers in patients with mismatch repair protein deficient colon cancer and that inclusion of SATB2 and CDX2 immunohistochemistry may be helpful as part of a comprehensive pathologic risk assessment in mismatch repair protein deficient colon cancer.

Germline cancer susceptibility gene variants, somatic second hits, and survival outcomes in patients with resected pancreatic cancer.

PURPOSE: Germline variants in double-strand DNA damage repair (dsDDR) genes (e.g., BRCA1/2) predispose to pancreatic adenocarcinoma (PDAC) and may predict sensitivity to platinum-based chemotherapy and poly(ADP) ribose polymerase (PARP) inhibitors. We sought to determine the prevalence and significance of germline cancer susceptibility gene variants in PDAC with paired somatic and survival analyses. METHODS: Using a customized next-generation sequencing panel, germline/somatic DNA was analyzed from 289 patients with resected PDAC ascertained without preselection for high-risk features (e.g., young age, personal/family history). All identified variants were assessed for pathogenicity. Outcomes were analyzed using multivariable-adjusted Cox proportional hazards regression. RESULTS: We found that 28/289 (9.7%; 95% confidence interval [CI] 6.5-13.7%) patients carried pathogenic/likely pathogenic germline variants, including 21 (7.3%) dsDDR gene variants (3 BRCA1, 4 BRCA2, 14 other dsDDR genes [ATM, BRIP1, CHEK2, NBN, PALB2, RAD50, RAD51C]), 3 Lynch syndrome, and 4 other genes (APC p.I1307K, CDKN2A, TP53). Somatic sequencing and immunohistochemistry identified second hits in the tumor in 12/27 (44.4%) patients with germline variants (1 failed sequencing). Compared with noncarriers, patients with germline dsDDR gene variants had superior overall survival (hazard ratio [HR] 0.54; 95% CI 0.30-0.99; P = 0.05). CONCLUSION: Nearly 10% of PDAC patients harbor germline variants, although the majority lack somatic second hits, the therapeutic significance of which warrants further study.

Adjuvant treatment and survival in older women with triple negative breast cancer: A Surveillance, Epidemiology, and End Results analysis.

Patients with triple negative breast cancer were identified using the Surveillance, Epidemiology, and End Results database. Competing risks analysis was used to assess the cumulative incidence of breast cancer-specific mortality (BCSM). Multivariable Fine-Gray regression was used to identify predictors of BCSM. Women age 70+ (n = 4221) were less likely to receive chemotherapy and radiation treatment (P < 0.0001) and had higher BCSM compared to younger women (P < 0.0001). There were no differences in BCSM in patients who received adjuvant treatment (P = 0.10). Stage II patients derived the greatest relative and absolute benefit from adjuvant treatment. Age was not a significant predictor of BCSM.

Outcomes Following Neoadjuvant Chemotherapy for Breast Cancer in Women Aged 40 Years and Younger: Impact of Pathologic Nodal Response.

Purpose: We sought to evaluate whether pathologic nodal response was predictive of outcomes in women aged ≤40 years with breast cancer treated with neoadjuvant chemotherapy (NAC). Methods: A total of 220 patients treated with NAC between 1991 and 2015 were retrospectively reviewed. Pathologic complete response (pCR) was defined as no evidence of residual invasive tumor in the breast and lymph nodes (LNs) (ypT0/Tis ypN0); partial response if there was no tumor in the LNs but residual tumor in the breast (ypT+ ypN0) or residual tumor in the LNs (ypT0/Tis ypN+); and limited response if there was residual tumor in both the breast and the LNs (ypT+ ypN+). Kaplan-Meier and Cox proportional hazards analyses were performed to identify factors predictive for overall survival (OS). Results: A total of 155 patients were included. Following NAC, 39 patients (25.2%) achieved pCR, 57 (36.8%) achieved a partial response (either ypT+ ypN0 or ypT0/Tis ypN+), and 59 (38.1%) had a limited response. A total of 22 patients (14.2%) experienced local failure, 20 (12.9%) experienced regional failure, and 59 (38.1%) experienced distant failure. Median OS for patients who achieved pCR was not reached, and was significantly worse for patients who had residual disease in the breast and/or LNs (P<.001). No difference in OS was seen among patients who had residual disease in the breast alone versus those who remained LN-positive (97 vs 83 months, respectively; P=.25). Subset analysis did not reveal differences in OS based on year of treatment or cN1 disease at the time of initial diagnosis. Conclusions: Women aged ≤40 years who achieved pCR had excellent outcomes; however, those who achieved a pathologic response in the LNs but had residual disease in the breast continued to have outcomes similar to those who remained LN-positive.

Lymph node metastases in resected pancreatic ductal adenocarcinoma: predictors of disease recurrence and survival.

BACKGROUND: Few studies have simultaneously assessed the prognostic value of the multiple classification systems for lymph node (LN) metastases in resected pancreatic ductal adenocarcinoma (PDAC). METHODS: In 600 patients with resected PDAC, we examined the association of LN parameters (AJCC 7th and 8th editions, LN ratio (LNR), and log odds of metastatic LN (LODDS)) with pattern of recurrence and patient survival using logistic regression and Cox proportional hazards regression, respectively. Regression models adjusted for age, sex, margin status, tumour grade, and perioperative therapy. RESULTS: Lymph node metastases classified by AJCC 7th and 8th editions, LNR, and LODDS were associated with worse disease free-survival (DFS) and overall survival (OS) (all Ptrend<0.01). American Joint Committee on Cancer 8th edition effectively predicted DFS and OS, while minimising model complexity. Lymph node metastases had weaker prognostic value in patients with positive margins and distal resections (both Pinteraction<0.03). Lymph node metastases by AJCC 7th and 8th editions did not predict the likelihood of local disease as the first site of recurrence. CONCLUSIONS: American Joint Committee on Cancer 8th edition LN classification is an effective and practical tool to predict outcomes in patients with resected PDAC. However, the prognostic value of LN metastases is attenuated in patients with positive resection margins and distal pancreatectomies.

Less than whole uterus irradiation for patients with locally advanced cervical cancer.

INTRODUCTION: Current consensus guidelines for definitive cervical cancer intensity modulated radiation therapy (IMRT) recommend inclusion of the entire uterus within the clinical target volume, however this is debated. We aimed to evaluate outcomes of patients with cervical cancer who were treated with less than whole uterus irradiation. METHODS: We identified 109 patients with FIGO Stage IB-IVA cervical cancer treated definitively with concurrent chemoradiation, including IMRT and brachytherapy, from 2010 to 2022 at a single institution where the practice was to include the gross cervix tumor with an internal target volume with differences in bladder filing accounted for, plus additional 5 mm planning target volume (PTV) margin. Local, regional, and distant recurrences were analyzed using competing risk methods, and a Wilcoxon rank sum test was performed to assess differences in dose to organs at risk based on the proportion of the uterus included in the PTV, with the median proportion of the uterus included (75 %) used as the cut-point. RESULTS: The median follow-up time was 65 months (range 3-352 months). The 2-year cumulative incidence of LR for the entire cohort was 4.2 % (95 % confidence interval [CI] 1.3-9.7). Compared with patients who had ≥ 75 % of the uterus included in the PTV, patients who had < 75 % of the uterus included in the PTV had significantly lower bowel D200cc (p = 0.02). The cumulative incidence of local failure (LR) was not significantly different between the two groups. CONCLUSIONS: Including less than the whole uterus for definitive cervix cancer IMRT does not seem to compromise local control. Less than whole uterus irradiation could be considered for carefully selected cervix cancer patients to decrease bowel dose and possible treatment-related toxicity.

Modern Radiation Treatment Planning Parameters and Outcomes in Pediatric Tectal Gliomas.

Purpose: Pediatric low-grade tectal gliomas are rare, indolent tumors of the brain stem. We reviewed outcomes of pediatric patients who received a diagnosis of low-grade tectal gliomas and report dosimetric parameters for those receiving radiation therapy (RT). Methods and Materials: We retrospectively reviewed all pediatric patients (age <18 years) at our institution diagnosed with a low-grade glioma between 1993 and 2020 (n = 288). Twenty-three patients with tectal gliomas were identified. Patients who received RT (n = 8) had detailed dosimetric analyses performed. Doses to critical structures and any resulting toxicities were reviewed. Minimum follow-up was 2 years and complete follow-up was available for all patients. Results: Twenty-three patients, with a median age of 8.9 years, were included (range, 0.5-16.2 years). At a median follow-up of 7.4 years (range, 2-24 years), all were alive at the end of the study period. Three patients (13%) were treated with upfront RT; none of these patients developed local failure (LF) after a median follow-up of 10.6 years. One patient was treated with upfront chemotherapy with no evidence of progression afterward. Nineteen patients were initially observed after diagnosis and 26% of them (n = 5) experienced local progression. All 5 were treated with salvage RT, with 1 patient requiring further treatment with chemotherapy. Fractionation schedules for patients undergoing upfront or salvage RT included 50.4 Gy in 28 fractions (n = 4), 54 Gy in 30 fractions (n = 2), and 51 Gy in 30 fractions (n = 2). For patients treated after 2007, the gross tumor volume was delineated on a T2 magnetic resonance imaging with an average gross tumor volume-to-planning target volume expansion of 4.5 mm (range, 3-5 mm). Detailed dosimetric parameters were available for all patients treated with RT. Conclusions: Our review supports the indolent behavior for most tectal gliomas. For the subset of tumors with evidence of progression, modern photon RT results in excellent oncologic outcomes with minimal late effects.

Spatially Resolved Single-Cell Assessment of Pancreatic Cancer Expression Subtypes Reveals Co-expressor Phenotypes and Extensive Intratumoral Heterogeneity.

Pancreatic ductal adenocarcinoma (PDAC) has been classified into classical and basal-like transcriptional subtypes by bulk RNA measurements. However, recent work has uncovered greater complexity to transcriptional subtypes than was initially appreciated using bulk RNA expression profiling. To provide a deeper understanding of PDAC subtypes, we developed a multiplex immunofluorescence (mIF) pipeline that quantifies protein expression of six PDAC subtype markers (CLDN18.2, TFF1, GATA6, KRT17, KRT5, and S100A2) and permits spatially resolved, single-cell interrogation of pancreatic tumors from resection specimens and core needle biopsies. Both primary and metastatic tumors displayed striking intratumoral subtype heterogeneity that was associated with patient outcomes, existed at the scale of individual glands, and was significantly reduced in patient-derived organoid cultures. Tumor cells co-expressing classical and basal markers were present in > 90% of tumors, existed on a basal-classical polarization continuum, and were enriched in tumors containing a greater admixture of basal and classical cell populations. Cell-cell neighbor analyses within tumor glands further suggested that co-expressor cells may represent an intermediate state between expression subtype poles. The extensive intratumoral heterogeneity identified through this clinically applicable mIF pipeline may inform prognosis and treatment selection for patients with PDAC. SIGNIFICANCE: A high-throughput pipeline using multiplex immunofluorescence in pancreatic cancer reveals striking expression subtype intratumoral heterogeneity with implications for therapy selection and identifies co-expressor cells that may serve as intermediates during subtype switching.

Incidence of Brain Metastases in Women Treated With Neoadjuvant Chemotherapy for Breast Cancer: Implications for Screening.

PURPOSE: Patients with metastatic breast cancer may develop brain metastases. Our study identified high-risk patients to refine selection criteria for BM screening approaches. PATIENTS: We reviewed breast cancer patients treated with neoadjuvant chemotherapy (NAC) at a single university center between 2005 and 2019. METHODS: Competing risks analysis was performed with the Fine and Gray model to analyze the cumulative incidence of BM and loco-regional recurrence. Overall survival (OS) and progression-free survival (PFS) were calculated using Kaplan-Meier and log-rank tests. Multivariable analysis was performed with Cox proportional hazards regression to identify factors predictive for development of BM. Statistical significance was determined as a 2-sided P value of <.05. RESULTS: In total, 112 patients experienced distant failure (DF) and 49 patients developed BM. Twenty patients with BM (41%) presented with symptoms requiring craniotomy +/- whole brain radiation treatment. Patients with BM were significantly more likely to have local (P < .01) and regional (P < .01) failure. On multivariable analysis, age <40 years (P = .011), presence of lung metastases (P < .0001), and residual nodal disease with >4 lymph nodes positive after NAC (P = .024) all predicted for increased likelihood of BM. Patients with these criteria had higher likelihoods of having BM (P = .013) and worse PFS (P = .044). On multivariable analysis for OS, presence of lung metastases was the most significant predictor of poor outcome (P < .0001). CONCLUSION: We propose a study of screening brain MRI for young (<40 years) patients with breast cancer receiving NAC and patients who develop metastatic disease post-NAC, especially those with lung involvement.

Initial clinical applications treating pediatric and adolescent patients using MR-guided radiotherapy.

Purpose: To demonstrate the clinical applications and feasibility of online adaptive magnetic resonance image guided radiotherapy (MRgRT) in the pediatric, adolescent and young adult (AYA) population. Methods: This is a retrospective case series of patients enrolled onto a prospective study. All pediatric (age < 18) and AYA patients (age< 30), treated on the Elekta Unity MR linear accelerator (MRL) from 2019 to 2021 were enrolled onto a prospective registry. Rationale for MRgRT included improved visualization of and alignment to the primary tumor, re-irradiation in a critical area, ability to use smaller margins, and need for daily adaptive replanning to minimize dose to adjacent critical structures. Step-and-shoot intensity-modulated radiation treatment (IMRT) plans were generated for all Unity patients with a dose grid of 3 mm and a statistical uncertainty of < 1% per plan. Results: A total of 15 pediatric and AYA patients have been treated with median age of 13 years (range: 6 mos - 27 yrs). Seven patients were <10 yo. The clinical applications of MRgRT included Wilms tumor with unresectable IVC thrombus (n=1), Ewing sarcoma (primary and metastatic, n=3), recurrent diffuse intrinsic pontine glioma (DIPG, n=2), nasopharyngeal carcinoma (n=1), clival chordoma (n=1), primitive neuroectodermal tumor of the pancreas (n=1), recurrent gluteo-sacral germ cell tumor (n=1), C-spine ependymoma (n=1), and posterior fossa ependymoma (n=1). Two children required general anesthesia. One AYA patient could not complete the MRgRT course due to tumor-related pain exacerbated by longer treatment times. Two AYA patients experienced anxiety related to treatment on the MRL, one of which required daily Ativan. No patient experienced treatment interruptions or unexpected toxicity. Conclusion: MRgRT was well-tolerated by pediatric and AYA patients. There was no increased use of anesthesia outside of our usual practice. Dosimetric advantages were seen for patients with tumors in critical locations such as adjacent to or involving optic structures, stomach, kidney, bowel, and heart.

Neoadjuvant Chemotherapy Is Associated with Altered Immune Cell Infiltration and an Anti-Tumorigenic Microenvironment in Resected Pancreatic Cancer.

PURPOSE: Neoadjuvant chemotherapy is increasingly administered to patients with resectable or borderline resectable pancreatic ductal adenocarcinoma (PDAC), yet its impact on the tumor immune microenvironment is incompletely understood. DESIGN: We employed quantitative, spatially resolved multiplex immunofluorescence and digital image analysis to identify T-cell subpopulations, macrophage polarization states, and myeloid cell subpopulations in a multi-institution cohort of up-front resected primary tumors (n = 299) and in a comparative set of resected tumors after FOLFIRINOX-based neoadjuvant therapy (n = 36) or up-front surgery (n = 30). Multivariable-adjusted Cox proportional hazards models were used to evaluate associations between the immune microenvironment and patient outcomes. RESULTS: In the multi-institutional resection cohort, immune cells exhibited substantial heterogeneity across patient tumors and were located predominantly in stromal regions. Unsupervised clustering using immune cell densities identified four main patterns of immune cell infiltration. One pattern, seen in 20% of tumors and characterized by abundant T cells (T cell-rich) and a paucity of immunosuppressive granulocytes and macrophages, was associated with improved patient survival. Neoadjuvant chemotherapy was associated with a higher CD8:CD4 ratio, greater M1:M2-polarized macrophage ratio, and reduced CD15+ARG1+ immunosuppressive granulocyte density. Within neoadjuvant-treated tumors, 72% showed a T cell-rich pattern with low immunosuppressive granulocytes and macrophages. M1-polarized macrophages were located closer to tumor cells after neoadjuvant chemotherapy, and colocalization of M1-polarized macrophages and tumor cells was associated with greater tumor pathologic response and improved patient survival. CONCLUSIONS: Neoadjuvant chemotherapy with FOLFIRINOX shifts the PDAC immune microenvironment toward an anti-tumorigenic state associated with improved patient survival.

Prospective randomized trial of email and/or telephone reminders to enhance vaginal dilator compliance in patients undergoing brachytherapy for gynecologic malignancies.

PURPOSE: To evaluate whether email survey +/- telephone reminder versus no intervention would facilitate compliance with vaginal dilator use in women undergoing brachytherapy for gynecologic malignancies and to assess changes in vaginal canal (VC) length between the groups. METHODS AND MATERIALS: A 72 patients were enrolled onto a three-arm single-institution randomized prospective clinical trial and stratified by whether they received external beam radiation treatment in addition to brachytherapy and by total radiation dose to the VC. Patients were subsequently randomized to one of three groups: email survey alone, email survey + telephone reminder, or no intervention. Change in VC length over time was measured for each patient. RESULTS: The median follow-up time was 17.3 months. There were no differences in patient-reported compliance between the 3 groups. Vaginal dilator compliance fell over the course of the study period and was 33% at 24 months. Baseline VC length and radiation dose were found to be the most important predictors of VC shortening over time. When accounting for baseline length, radiation dose, and follow-up time, type of intervention did not impact changes in VC length from baseline (p = 0.20). CONCLUSIONS: Our study is the first to show the importance of baseline VC length as it relates to VC shortening following brachytherapy for gynecologic cancers and highlights the difficulties in improving VC compliance among this patient population. Further study is required to improve the incidence of late effects in this group.

Locoregional and Distant Outcomes in Women With cT1-3N1 Breast Cancer Treated With Neoadjuvant Chemotherapy With or Without Adjuvant Radiotherapy.

BACKGROUND: We evaluated the impact of postmastectomy radiotherapy (PMRT) or supraclavicular radiation therapy (SCV RT) in women with cT1-3N1 breast cancer (BC) who became node negative (ypN0) after neoadjuvant chemotherapy (NAC). PATIENTS AND METHODS: We retrospectively reviewed 485 women treated with NAC for BC between 2005 and 2019. Radiation treatment fields were reviewed in detail. Pathologic complete response (pCR) was defined as ypT0/Tis ypN0. Patients who had residual nodal disease were defined as ypN+. Those who achieved complete response in the lymph nodes but not in the breast were defined as ypT+ypN0. RESULTS: After excluding patients with cT4 and cN0 disease at diagnosis, a total of 185 patients with cT1-3N1 BC were included. Patients were more likely to receive PMRT if they had ypN+ disease (P < .001) and/or lymphovascular invasion (P = .03). Patients who underwent lumpectomy were more likely to receive SCV RT if they did not achieve pCR (P = .04) and/or if they had ypN+ disease (P = .01). The 5-year rates of locoregional recurrence (LRR) were 15% for all patients, 14% for patients who attained ypT+ypN0, and 5% for patients who achieved pCR. Of ypT+ypN0 patients (n = 98), 53 received PMRT or SCV RT and 45 did not. For these patients, there were no differences in LRR based on whether a patient did or did not receive PMRT or SCV RT (P = .23). CONCLUSION: Recommendations for or against PMRT or SCV RT after NAC vary based on final pathologic response. We await the results of ongoing randomized clinical trials to help guide clinical decision making in this context.

Composition, Spatial Characteristics, and Prognostic Significance of Myeloid Cell Infiltration in Pancreatic Cancer.

PURPOSE: Although abundant myeloid cell populations in the pancreatic ductal adenocarcinoma (PDAC) microenvironment have been postulated to suppress antitumor immunity, the composition of these populations, their spatial locations, and how they relate to patient outcomes are poorly understood. EXPERIMENTAL DESIGN: To generate spatially resolved tumor and immune cell data at single-cell resolution, we developed two quantitative multiplex immunofluorescence assays to interrogate myeloid cells (CD15, CD14, ARG1, CD33, HLA-DR) and macrophages [CD68, CD163, CD86, IFN regulatory factor 5, MRC1 (CD206)] in the PDAC tumor microenvironment. Spatial point pattern analyses were conducted to assess the degree of colocalization between tumor cells and immune cells. Multivariable-adjusted Cox proportional hazards regression was used to assess associations with patient outcomes. RESULTS: In a multi-institutional cohort of 305 primary PDAC resection specimens, myeloid cells were abundant, enriched within stromal regions, highly heterogeneous across tumors, and differed by somatic genotype. High densities of CD15+ARG1+ immunosuppressive granulocytic cells and M2-polarized macrophages were associated with worse patient survival. Moreover, beyond cell density, closer proximity of M2-polarized macrophages to tumor cells was strongly associated with disease-free survival, revealing the clinical significance and biologic importance of immune cell localization within tumor areas. CONCLUSIONS: A diverse set of myeloid cells are present within the PDAC tumor microenvironment and are distributed heterogeneously across patient tumors. Not only the densities but also the spatial locations of myeloid immune cells are associated with patient outcomes, highlighting the potential role of spatially resolved myeloid cell subtypes as quantitative biomarkers for PDAC prognosis and therapy.

Patterns of Failure in Women Who Have Residual Nodal Disease After Neoadjuvant Chemotherapy for Breast Cancer According to Extent of Lymph Node Surgery.

BACKGROUND: Optimal surgical management of limited axillary nodal disease following neoadjuvant chemotherapy (NAC) for breast cancer is evolving. Concerns exist with respect to leaving residual disease in the axilla when omitting axillary lymph node dissection (ALND) in this setting. We sought to determine whether extent of nodal surgery altered patterns of failure and patient outcomes. PATIENTS AND METHODS: We identified 70 patients with breast cancer who were confirmed cN0 after NAC yet had residual nodal disease (ypN1) on sentinel lymph node biopsy (SLNB). Twenty-eight patients underwent SLNB alone and 42 underwent SLNB+completion (c)ALND in a non-randomized fashion. Most (n = 65) patients underwent adjuvant regional nodal irradiation (RNI). Detailed patterns of failure data were obtained for each patient. RESULTS: The median follow-up was 43.5 months. There were 30 (43%) recurrences. Of these, 5 were isolated locoregional failures, and 24 were distant failures. There were no significant differences in local (P = .13), regional (P = .62), or distant (P = .47) failure between patients who underwent SLNB alone versus SLNB+cALND. Seventeen (24%) patients died. Overall survival was similar in both groups with median overall survival not reached for those who underwent SLNB and 109 months for those who underwent SLNB+cALND (P = .45). CONCLUSIONS: There were no differences in patterns of recurrence among patients with 1 to 3 involved lymph nodes after NAC who underwent SLNB alone versus SLNB+cALND in the setting of RNI. We await the results of ongoing, prospective clinical trials to confirm the relative merits of RNI in lieu of cALND in these patients.

Stereotactic Body Radiation Therapy for Cholangiocarcinoma: Optimizing Locoregional Control With Elective Nodal Irradiation.

PURPOSE: To review our institutional experience of treating cholangiocarcinoma using stereotactic body radiation therapy (SBRT). METHODS AND MATERIALS: A total of 40 patients with intrahepatic (n = 25) or perihilar (n = 15) cholangiocarcinoma treated with SBRT were retrospectively reviewed. SBRT was delivered in 1 to 5 fractions with median dose of 40 Gy. Competing risk analysis was used to estimate cumulative incidence of local in-field, local out-of-field, regional, and distant failure. Kaplan-Meier and log-rank tests were used to calculate overall survival (OS). Toxicity was scored using Common Terminology Criteria for Adverse Events, version 4.0. RESULTS: The median follow-up time was 18 months. The 1-year incidence of local in-field, local out-of-field, regional, and distant failure was 8%, 23%, 13%, and 22%, respectively. Median OS was 23 months and 1- and 2-year OS rates were 69% and 39%, respectively. Patients with perihilar tumors had a 1-year incidence of regional failure of 24% and worse OS (P = .013). Patients with regional failure were more likely to develop distant metastases, 32% versus 19% at 1 year (P = .11). Acute grade 3 + hepatobiliary toxicity developed in 15 patients (36%). CONCLUSIONS: In this series of cholangiocarcinoma patients treated with definitive SBRT, patterns of failure reveal that regional failures are not insignificant, particularly for perihilar tumors. Elective nodal irradiation of regional lymphatics should be considered when using SBRT. A prospective study of elective nodal irradiation in patients with perihilar tumors would further clarify whether this approach improves outcomes without increasing hepatobiliary toxicity.

Central Nervous System Relapse After Stem Cell Transplantation in Adolescents and Young Adults with Acute Lymphoblastic Leukemia: A Single-Institution Experience.

Purpose: To evaluate outcomes and central nervous system (CNS) relapse in adolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL), who underwent total body irradiation (TBI) before allogeneic hematopoietic stem cell transplantation (allo-SCT). Methods: A total of 136 AYA patients with ALL who received TBI before allo-SCT between 1998 and 2018 were reviewed. Twenty patients received cranial radiation in their initial treatment before conditioning for transplant and were excluded. Competing risk analysis was used to estimate the cumulative incidence of relapse. Kaplan-Meier and log-rank tests were used to calculate overall survival (OS) and to identify factors predictive of relapse. OS and time to relapse were calculated from date of allo-SCT. Results: One hundred sixteen patients were included in the analysis. Median age was 27 years and median follow-up time was 42 months. Twenty-six patients suffered a disease relapse and 49 died, 26 of posttransplantation complications. The median time to relapse was 7 months and the 5-year OS was 60%. Seven patients had a CNS relapse: 4 of 20 patients (25%) with pre-SCT CNS disease had a post-allo-SCT CNS relapse compared to 3 of 97 (3.1%) without pre-SCT CNS disease. Median time to CNS relapse was 7 months. Patients with post-SCT CNS relapse had median OS of 19 months. Conclusions: AYA patients with CNS disease who undergo an allo-SCT have a high rate of CNS relapse. The addition of additional CNS-directed therapy to transplant protocols warrants further investigation.