Definitive radiotherapy for vaginal recurrence of early-stage endometrial cancer: survival outcomes and effect of mismatch repair status.

OBJECTIVE: To evaluate clinical outcomes, prognostic factors, and toxicity in patients with vaginal recurrence of early-stage endometrial cancer treated with definitive radiotherapy. METHODS: Retrospective review identified 62 patients with stage I-II endometrial cancer and vaginal recurrence treated with external beam radiotherapy and image-guided brachytherapy with definitive intent from November 2004 to July 2017. All patients had prior hysterectomy without adjuvant radiotherapy and >3 months follow-up. Mismatch repair (MMR) status was determined by immunohistochemical staining of the four mismatch repair proteins (MLH1, MSH2, PMS2, and MSH6) when available in the pathology record. Rates of vaginal control, recurrence-free survival, and overall survival were calculated by Kaplan-Meier. Univariate and multivariate analyses were performed by Cox proportional hazards. RESULTS: Most patients had endometrioid histology (55, 89%), grade 1 or 2 tumor (53, 85%), and vaginal-only recurrence (55, 89%). With a median follow-up of 39 months (range, 3-167), 3- and 5-year rates of vaginal control, recurrence-free survival, and overall survival were 86% and 82%, 69% and 55%, and 80% and 61%, respectively. On multivariate analysis, non-endometrioid histology (HR 12.5, P<0.01) was associated with relapse when adjusted for chemotherapy use. Patients with non-endometrioid histology also had a 4.5-fold higher risk of death when adjusted for age (P=0.02). Twenty patients had known MMR status, all with grade 1-2 endometrioid tumors and 10 (50%) with MMR deficiency. The 3-year recurrence-free survival was 100% for MMR-proficient tumors and 52% for MMR-deficient (P=0.03). Late grade 2 and 3 gastrointestinal, genitourinary and vaginal toxicity was reported in 27% and 3%, 15% and 2%, and 16% and 2% of patients, respectively. CONCLUSION: Definitive radiotherapy with image-guided brachytherapy resulted in 5-year local control rates exceeding 80% and late severe toxicity rates were under 3%. Distant recurrence was common and highest for those with grade 3 or non-endometrioid tumors and MMR deficient grade 1-2 disease.

Low-dose adjuvant vaginal cylinder brachytherapy for early-stage non-endometrioid endometrial cancer: recurrence risk and survival outcomes.

OBJECTIVE: The aim of this study was to evaluate recurrence patterns and survival outcomes for patients with early-stage non-endometrioid endometrial adenocarcinoma treated with adjuvant high-dose rate vaginal brachytherapy with a low-dose scheme. METHODS: A retrospective review was performed of patients with International Federation of Gynecology and Obstetrics (FIGO) stage I-II non-endometrioid endometrial cancer who received adjuvant vaginal brachytherapy with a low-dose regimen of 24 Gy in six fractions from November 2005 to May 2017. All patients had >6 months of follow-up. Rates of recurrence-free survival, overall survival, vaginal, pelvic, and distant recurrence were calculated by the Kaplan-Meier method. Prognostic factors for recurrence and survival were evaluated by Cox proportional hazards modeling. RESULTS: A total of 106 patients were analyzed. Median follow-up was 49 months (range 9-119). Histologic subtypes were serous (47%, n=50), clear cell (10%, n=11), mixed (27%, n=29), and carcinosarcoma (15%, n=16). Most patients (79%) had stage IA disease, 94% had surgical nodal assessment, and 13% had lymphovascular invasion. Adjuvant chemotherapy was delivered to 75%. The 5-year recurrence-free and overall survival rates were 74% and 83%, respectively. By histology, 5-year recurrence-free/overall survival rates were: serous 73%/78%, clear cell 68%/88%, mixed 88%/100%, and carcinosarcoma 56%/60% (p=0.046 and p<0.01). On multivariate analysis, lymphovascular invasion was significantly associated with recurrence (HR 3.3, p<0.01). The 5-year vaginal, pelvic, and distant recurrence rates were 7%, 8%, and 21%, respectively. Vaginal and pelvic recurrence rates were highest for patients with carcinosarcoma, lymphovascular invasion and/or FIGO stage IB/II disease. At 5 years, vaginal and pelvic recurrence rates for patients with lymphovascular invasion were 33% and 40%, respectively. Patients with stage IA disease or no lymphovascular invasion had 5-year vaginal recurrence rates of 4% and pelvic recurrence rates of 6% and 3%, respectively. CONCLUSIONS: Adjuvant high-dose rate brachytherapy with a low-dose scheme is effective for most patients with early-stage non-endometrioid endometrial cancer, particularly stage IA disease and no lymphovascular invasion. Pelvic radiation therapy should be considered for those with carcinosarcoma, lymphovascular invasion and/or stage IB/II disease.

Localized Adult Ewing Sarcoma: Favorable Outcomes with Alternating Vincristine, Doxorubicin, Cyclophosphamide, and Ifosfamide, Etoposide (VDC/IE)-Based Multimodality Therapy.

BACKGROUND: In children with localized Ewing sarcoma (ES), addition of ifosfamide and etoposide to cyclophosphamide, doxorubicin, and vincristine (VDC/IE) improved 5-year overall survival (OS) to 70%-80%. Prior to delivery of VDC/IE in adults, 5-year OS was <50%. We reviewed our institutional outcomes for adults with ES who received VDC/IE-based treatment. MATERIALS AND METHODS: Between 1997-2013, 67 adults with localized ES were treated with curative intent. Local recurrence-free survival (LRFS), progression-free survival (PFS), and OS were determined using Kaplan-Meier method; comparisons were assessed with log-rank. Proportional hazard models were used to determine predictive factors. RESULTS: All patients received VDC/IE (median 14 cycles.) Local therapy was surgery for 33, radiation therapy for 17, or both for 17. Median follow-up for living patients was 5.2 years. Six patients had disease progression on therapy. Site of first failure was local for three, local and distant for two, and distant for ten. Five-year LRFS was 91%; 5-year LRFS was 96% for nonpelvic disease and 64% for pelvic disease (p = .003). Five-year PFS was 66%, and 5-year OS was 79%. On multivariate analysis, pelvic site had a 3.3 times increased risk of progression (p = .01). CONCLUSION: Survival for adults with localized ES treated with VDC/IE-based multimodality therapy appears to be better than historical data and similar to excellent outcomes in children. Pelvic site of disease remains a predictor of worse outcome. Given the paucity of literature for adult ES, these data help validate VDC/IE-based therapy as an appropriate treatment approach for this rare disease in adults. IMPLICATIONS FOR PRACTICE: Ewing sarcoma (ES) is rare in adults. Treatment approaches for adults have been extrapolated from the pediatric experience, and there is a sense that adults fare less well than children. We reviewed treatment outcomes in adults with localized ES treated with cyclophosphamide, doxorubicin, and vincristine in alternation with ifosfamide and etoposide (VDC/IE) as part of multimodality therapy. Survival outcomes appear to be better than historical data for adults and similar to the excellent outcomes for children. These data help validate VDC/IE-based therapy as an appropriate treatment approach for this rare disease in adults.

Integrated genomic analysis illustrates the central role of JAK-STAT pathway activation in myeloproliferative neoplasm pathogenesis.

Genomic studies have identified somatic alterations in the majority of myeloproliferative neoplasms (MPN) patients, including JAK2 mutations in the majority of MPN patients and CALR mutations in JAK2-negative MPN patients. However, the role of JAK-STAT pathway activation in different MPNs, and in patients without JAK2 mutations, has not been definitively delineated. We used expression profiling, single nucleotide polymorphism arrays, and mutational profiling to investigate a well-characterized cohort of MPN patients. MPN patients with homozygous JAK2V617F mutations were characterized by a distinctive transcriptional profile. Notably, a transcriptional signature consistent with activated JAK2 signaling is seen in all MPN patients regardless of clinical phenotype or mutational status. In addition, the activated JAK2 signature was present in patients with somatic CALR mutations. Conversely, we identified a gene expression signature of CALR mutations; this signature was significantly enriched in JAK2-mutant MPN patients consistent with a shared mechanism of transformation by JAK2 and CALR mutations. We also identified a transcriptional signature of TET2 mutations in MPN patent samples. Our data indicate that MPN patients, regardless of diagnosis or JAK2 mutational status, are characterized by a distinct gene expression signature with upregulation of JAK-STAT target genes, demonstrating the central importance of the JAK-STAT pathway in MPN pathogenesis.

Identification of RPS14 as a 5q- syndrome gene by RNA interference screen.

Somatic chromosomal deletions in cancer are thought to indicate the location of tumour suppressor genes, by which a complete loss of gene function occurs through biallelic deletion, point mutation or epigenetic silencing, thus fulfilling Knudson's two-hit hypothesis. In many recurrent deletions, however, such biallelic inactivation has not been found. One prominent example is the 5q- syndrome, a subtype of myelodysplastic syndrome characterized by a defect in erythroid differentiation. Here we describe an RNA-mediated interference (RNAi)-based approach to discovery of the 5q- disease gene. We found that partial loss of function of the ribosomal subunit protein RPS14 phenocopies the disease in normal haematopoietic progenitor cells, and also that forced expression of RPS14 rescues the disease phenotype in patient-derived bone marrow cells. In addition, we identified a block in the processing of pre-ribosomal RNA in RPS14-deficient cells that is functionally equivalent to the defect in Diamond-Blackfan anaemia, linking the molecular pathophysiology of the 5q- syndrome to a congenital syndrome causing bone marrow failure. These results indicate that the 5q- syndrome is caused by a defect in ribosomal protein function and suggest that RNAi screening is an effective strategy for identifying causal haploinsufficiency disease genes.

Clinical outcomes and dosimetric predictors of toxicity for re-irradiation of vaginal recurrence of endometrial cancer.

OBJECTIVE: To report clinical outcomes and dosimetric predictors of late toxicity for patients with vaginal recurrence of endometrial cancer treated with brachytherapy in the re-irradiation setting. METHODS: On retrospective review, 32 patients with vaginal recurrence of endometrial cancer received salvage brachytherapy with or without pelvic radiotherapy (RT) from 06/2003-12/2017. Prior RT modalities were vaginal brachytherapy (19, 59%), pelvic RT (7, 22%) or both (6, 19%). Image-guided brachytherapy was performed with CT- (25, 78%) or MR-guidance (7, 22%). Vaginal control, recurrence-free survival (RFS) and overall survival (OS) were estimated by Kaplan-Meier method. Late toxicity was graded by Common Toxicity Criteria for Adverse Events. RESULTS: Median time from prior RT to re-irradiation was 22 months (range, 4-140). Salvage RT modalities were pelvic RT and brachytherapy (25, 78%) or brachytherapy alone (7, 22%). With median follow-up of 47 months, 3/5-year vaginal control, RFS and OS rates were 64/56%, 47/41% and 68/42%, respectively. Six patients (19%) had no evidence of disease at 85-155 months. Late grade 2/3 GI, GU and vaginal toxicity rates were 13%/16%, 19%/13%, and 9%/16%. Cumulative D2cc rectum (sum of prior and salvage RT courses) was predictive of grade 2+ and grade 3 GI toxicity. Cumulative D2cc rectum for an estimated 10% risk of late grade 2+ and 3 GI toxicity was 86 Gy and 92 Gy, respectively. CONCLUSIONS: Salvage image-guided brachytherapy in the re-irradiation setting results in modest local control and increased late toxicity for localized recurrent endometrial cancer. With long-term disease control, cumulative D2cc rectum may be used to reduce late GI complication risk.

Adjuvant Radiation Field Extent and Sites of Failure in Node Positive Endometrioid Endometrial Cancer.

PURPOSE: In patients with node-positive endometrial cancer, adjuvant radiation therapy with chemotherapy decreases local-regional recurrence compared with chemotherapy alone. However, the optimal radiation field borders and extent of nodal coverage have not been well studied. In a multi-institutional cohort, survival outcomes and sites of failure were analyzed for patients with International Federation of Gynaecology and Obstetrics (FIGO) stage IIIC endometrioid endometrial cancer treated with pelvic radiation therapy (PRT) versus extended-field radiation therapy (EFRT), which encompassed high para-aortic lymph nodes. METHODS AND MATERIALS: In a multi-institutional retrospective study, 143 patients with FIGO stage IIIC1 or IIIC2 endometrioid endometrial cancer treated with adjuvant radiation therapy from 2000 to 2016 were identified. Patient subgroups were classified by substage and radiation field extent: stage IIIC1 received EFRT, stage IIIC1 received PRT, and stage IIIC2 received EFRT. Recurrence-free survival (RFS), overall survival (OS), and out-of-field recurrence were calculated by the Kaplan-Meier method. Multivariate analysis was performed using the Cox proportional hazards model. Sites of failure were categorized as within or outside the radiation field. RESULTS: The median follow-up was 59 months; 87% of patients received chemotherapy. The 5-year RFS and OS rates were 73% and 87%, respectively. By subgroup, 5-year RFS rates were 79% for stage IIIC1 EFRT, 73% for stage IIIC1 PRT, and 69% for stage IIIC2 EFRT (P = .4). On multivariate analysis, the recurrence risk was highest for stage IIIC2 EFRT, although this result was not statistically significant (adjusted hazard ratio, 2.0; P = .4). In-field vaginal and nodal recurrences were observed in 2 patients (1%) and 4 patients (3%), respectively. Of 78 patients with stage IIIC1 cancer treated with PRT, 5 (6%) had isolated para-aortic nodal relapse outside the radiation field; 3 were long-term survivors (more than 6 years after salvage therapy). For patients with para-aortic recurrence, 86% had lymphovascular invasion, 71% had myometrial invasion of ≥50%, and 57% had grade 3 disease. CONCLUSIONS: Adjuvant chemoradiation therapy resulted in excellent survival outcomes for patients with FIGO stage IIIC endometrioid endometrial cancer. For patients with positive pelvic nodes, isolated para-aortic relapse outside the PRT field was uncommon and amenable to salvage therapy.

A Phase 1 Dose-Escalation Trial of Radiation Therapy and Concurrent Cisplatin for Stage II and III Triple-Negative Breast Cancer.

PURPOSE: Patients with triple-negative breast cancer (TNBC) experience higher local-regional recurrence rates than those with luminal or HER2-positive tumors. This prospective, phase 1B trial was designed to assess the safety and to establish the maximum tolerated dose (MTD) of cisplatin with radiation therapy for women with early-stage TNBC. METHODS AND MATERIALS: Eligible patients had stage II or III TNBC. Cisplatin was initiated at 10 mg/m2 intravenously once weekly during radiation and then escalated in a 3 + 3 design by 10 mg/m2 at each dose level until 40 mg/m2, or the MTD, was reached. Patients undergoing breast-conserving therapy (BCT) or mastectomy were accrued in separate parallel cohorts during dose escalation, followed by a 10-patient expansion at the MTD. RESULTS: During 2013 to 2018, 55 patients were accrued. Four patients developed dose-limiting toxicity. In the BCT cohort, 1 patient receiving 40 mg/m2 developed tinnitus resulting in a cisplatin delay; therefore, this was the BCT cohort MTD. In the mastectomy cohort, 1 patient receiving 20 mg/m2 developed a grade 3 urinary infection, and 2 additional patients had dose-limiting toxicities at 40 mg/m2 (grade 3 neutropenia and grade 2 tinnitus), both resulting in cisplatin delay. Thus, 30 mg/m2 was the mastectomy cohort MTD. Median follow-up was 48.5 months. Three-year disease-free survival was 74.7% for the BCT cohort and 64.4% for the mastectomy cohort. CONCLUSIONS: Adjuvant radiation therapy with concurrent cisplatin is feasible with a recommended phase 2 dose of 30 mg/m2 and 40 mg/m2 intravenously weekly in mastectomy and BCT cohorts, respectively.

Identification of an evolutionarily conserved transcriptional signature of CD8 memory differentiation that is shared by T and B cells.

After Ag encounter, naive lymphocytes differentiate into populations of memory cells that share a common set of functions including faster response to Ag re-exposure and the ability to self-renew. However, memory lymphocytes in different lymphocyte lineages are functionally and phenotypically diverse. It is not known whether discrete populations of T and B cells use similar transcriptional programs during differentiation into the memory state. We used cross-species genomic analysis to examine the pattern of genes up-regulated during the differentiation of naive lymphocytes into memory cells in multiple populations of human CD4, CD8, and B cell lymphocytes as well as two mouse models of memory development. We identified and validated a signature of genes that was up-regulated in memory cells compared with naive cells in both human and mouse CD8 memory differentiation, suggesting marked evolutionary conservation of this transcriptional program. Surprisingly, this conserved CD8 differentiation signature was also up-regulated during memory differentiation in CD4 and B cell lineages. To validate the biologic significance of this signature, we showed that alterations in this signature of genes could distinguish between functional and exhausted CD8 T cells from a mouse model of chronic viral infection. Finally, we generated genome-wide microarray data from tetramer-sorted human T cells and showed profound differences in this differentiation signature between T cells specific for HIV and those specific for influenza. Thus, our data suggest that in addition to lineage-specific differentiation programs, T and B lymphocytes use a common transcriptional program during memory development that is disrupted in chronic viral infection.

Low-Dose Adjuvant Cylinder Brachytherapy for Endometrioid Endometrial Cancer.

PURPOSE: Our purpose was to evaluate outcomes and sites of failure for women with early stage endometrial adenocarcinoma treated with adjuvant high-dose-rate (HDR) vaginal brachytherapy (VB) with a low dose scheme. METHODS AND MATERIALS: Retrospective review identified 318 patients with International Federation of Gynecology and Obstetrics (FIGO) stage I-II endometrioid endometrial cancer who received adjuvant HDR VB to a dose of 24 Gray (Gy) in 6 fractions from 2005 to 2017. Patients with <6 months follow-up were excluded. Dose was prescribed to cylinder surface and computerized tomography (CT) imaging was performed before each fraction to assess cylinder placement. Rates of vaginal relapse (VR), pelvic nodal relapse, distant metastasis, recurrence-free survival, and overall survival were calculated by Kaplan-Meier method. Univariate analysis was performed by log rank test or Cox proportional hazards. Pretreatment CT images were analyzed for patients with VR. RESULTS: Median follow-up was 42 months for 243 patients. The 3-year rates of VR, pelvic nodal relapse, distant metastasis, recurrence-free survival, and overall survival were 1.9%, 1.5%, 4.3%, 94.1%, and 98.9%, respectively. The 3-year VR rates by Gynecologic Oncology (GOG)-99 risk groups were 0%, 1.4%, and 3.2% for low risk, low-intermediate risk, and high-intermediate risk (HIR) disease (P = .5). By Post-operative Radiation Therapy in Endometrial Carcinoma (PORTEC) risk stratification, 3-year VR rate was 1.3% for HIR disease. On review of pretreatment CT images of the 6 patients with VR, 3 patients had relapse at the introitus outside of the treated vaginal length, and 3 had in-field recurrence at the vaginal apex. Higher body mass index (BMI) was associated with VR, with a 14% increase in risk per BMI unit (kg/m2, P = .02). There were no reported grade 2 GI or any grade 3 toxicities. CONCLUSIONS: Adjuvant HDR VB with a low-dose regimen results in excellent clinical outcomes for patients with early stage endometrioid endometrial cancer. Patients with higher BMI may be at increased risk of VR, and additional study is needed to optimize brachytherapy treatment parameters.

Emergency innovation: implications for the trauma surgeon.

BACKGROUND: Experimentation involving human subjects requires careful attention to the protection of their rights. Beginning with the Belmont Report in 1979, the United States has developed various sets of rules and regulations that identify the requirements for performing human subject research. In addition, these standards attempt to define the fundamental difference between what constitutes research versus clinical treatment versus innovation. We explore the intersection between two areas of independent bioethics, surgical innovation and emergency research; the point we refer to as emergency innovation. METHODS: A systematic literature review in each of the fields of emergency research and surgical innovation was completed. The ethical principles involved in each field were identified. In addition, a recent case of surgical innovation within the context of emergency treatment is evaluated for the ethics invoked. RESULTS: One of the great challenges in emergency innovation is that the main protection offered in innovation (heightened informed consent) is not possible in the emergency context where in fact informed consent is waived. Interestingly, the rest of the protections outlined for each field are not mutually exclusive. They can and should be utilized in any project that takes place at this intersection. However, as there are no strict regulations in place for the collision of these two fields, the possibility of having the majority of the involved ethical principles misinterpreted or ignored is very real. CONCLUSIONS: For emergency innovation, where it is unclear what ethical principles and regulatory powers apply, it is imperative to be unambiguous about the purpose of the investigation, to adhere to all applicable ethical principles, and to have utmost consideration for protection of the research subject. To determine intent, the goals of the study must be outlined precisely - and if those include the prospect of publication, institutional review board (IRB) approval should be involved early. If, however, the innovation is subtle and the goal geared toward improved patient care, a small feasibility trial would be an appropriate first step before transitioning to a formal larger study approved by an IRB. In either case, the degree of the change in practice must be carefully evaluated and the vulnerability of the research subjects respected. With careful attention paid to all applicable ethical principles at the emergency innovation intersection, medical progress can continue at minimized risk to the human subject participants.

An erythroid differentiation signature predicts response to lenalidomide in myelodysplastic syndrome.

BACKGROUND: Lenalidomide is an effective new agent for the treatment of patients with myelodysplastic syndrome (MDS), an acquired hematopoietic disorder characterized by ineffective blood cell production and a predisposition to the development of leukemia. Patients with an interstitial deletion of Chromosome 5q have a high rate of response to lenalidomide, but most MDS patients lack this deletion. Approximately 25% of patients without 5q deletions also benefit from lenalidomide therapy, but response in these patients cannot be predicted by any currently available diagnostic assays. The aim of this study was to develop a method to predict lenalidomide response in order to avoid unnecessary toxicity in patients unlikely to benefit from treatment. METHODS AND FINDINGS: Using gene expression profiling, we identified a molecular signature that predicts lenalidomide response. The signature was defined in a set of 16 pretreatment bone marrow aspirates from MDS patients without 5q deletions, and validated in an independent set of 26 samples. The response signature consisted of a cohesive set of erythroid-specific genes with decreased expression in responders, suggesting that a defect in erythroid differentiation underlies lenalidomide response. Consistent with this observation, treatment with lenalidomide promoted erythroid differentiation of primary hematopoietic progenitor cells grown in vitro. CONCLUSIONS: These studies indicate that lenalidomide-responsive patients have a defect in erythroid differentiation, and suggest a strategy for a clinical test to predict patients most likely to respond to the drug. The experiments further suggest that the efficacy of lenalidomide, whose mechanism of action in MDS is unknown, may be due to its ability to induce erythroid differentiation.

Pilot study on the impact of F18-labeled thymidine PET/CT on gross tumor volume identification and definition for pancreatic cancer.

PURPOSE: Accurate target definition for radiation therapy planning in localized pancreatic cancer is critical, particularly when using strategies that omit elective coverage. Standard imaging modalities such as computed tomography (CT), magnetic resonance imaging, and endoscopic ultrasound have limited concordance with pathologic evaluation. Biologic imaging with [F18]-fluorodeoxyglucose (FDG)-positron emission tomography (PET) can also be difficult to interpret because increased activity is indicative of increased glucose metabolism, rather than cellular proliferation. [F18]-3'-deoxy-3'-fluorothymidine labeled thymidine (FLT) is a proliferative marker which exploits the expression of pyrimidine-metabolizing enzymes. We evaluate the impact of FLT-PET on pancreatic target definition for radiation planning. METHODS AND MATERIALS: Patients with biopsy-proven, newly diagnosed, untreated pancreatic adenocarcinoma were enrolled on an institutional review board-approved prospective study. Patients were injected with FLT and scanned 20 to 30 minutes later. Two physicians (referred to as observer 1 and observer 2) independently contoured the gross tumor volume (GTV) and involved nodes on CT scan only and then again with the assistance of coregistered FLT-PET. Conformality index (CI), the ratio of the volumes of intersection and union, was used as the metric for volume comparison (where CI = 0 represents no overlap and CI = 1 represents perfect overlap). RESULTS: Nine patients were enrolled in this study. FLT-avidity was discerned in 8 of 9 patients. Average CT-GTV volume for observers 1 and 2 was 38.1 and 26.5 mL, respectively. Average FLT-GTV volume for observers 1 and 2 was 39.1 and 25.0 mL, respectively. For the 8 patients with FLT-avid tumors, addition of FLT data improved concordance of GTV definition between physicians in 6 of 8 tumors. Average CI for interobserver CT-GTV was 0.325. Addition of FLT-PET information improved the average CI to 0.400. CONCLUSIONS: FLT-PET improves interobserver concordance in GTV definition. Further studies will focus on verification of these findings, pathologic verification of the FLT-PET signal, and optimization of the FLT-PET signal threshold for autosegmentation.

ACR Appropriateness Criteria®-Anal Cancer.

The management of anal cancer is driven by randomized and nonrandomized clinical trials. However, trials may present conflicting conclusions. Furthermore, different clinical situations may not be addressed in certain trials because of eligibility inclusion criteria. Although prospective studies point to the use of definitive 5-fluorouracil and mitomycin C-based chemoradiation as a standard, some areas remain that are not well defined. In particular, management of very early stage disease, radiation dose, and the use of intensity-modulated radiation therapy remain unaddressed by phase III studies. The American College of Radiology (ACR) Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Dosimetric consequences of interobserver variability in delineating the organs at risk in gynecologic interstitial brachytherapy.

PURPOSE: To investigate the dosimetric variability associated with interobserver organ-at-risk delineation differences on computed tomography in patients undergoing gynecologic interstitial brachytherapy. METHODS AND MATERIALS: The rectum, bladder, and sigmoid of 14 patients treated with gynecologic interstitial brachytherapy were retrospectively contoured by 13 physicians. Geometric variability was calculated using κ statistics, conformity index (CIgen), and coefficient of variation (CV) of volumes contoured across physicians. Dosimetric variability of the single-fraction D0.1cc and D2cc was assessed through CV across physicians, and the standard deviation of the total EQD2 (equivalent dose in 2 Gy per fraction) brachytherapy dose (SD(TOT)) was calculated. RESULTS: The population mean ± 1 standard deviation of κ, CIgen, and volume CV were, respectively: 0.77 ± 0.06, 0.70 ± 0.08, and 20% ± 6% for bladder; 0.74 ± 06, 0.67 ± 0.08, and 20% ± 5% for rectum; and 0.33 ± 0.20, 0.26 ± 0.17, and 82% ± 42% for sigmoid. Dosimetric variability was as follows: for bladder, CV = 31% ± 19% (SD(TOT) = 72 ± 64 Gy) for D0.1cc and CV = 16% ± 10% (SD(TOT) = 9 ± 6 Gy) for D2cc; for rectum, CV = 11% ± 5% (SD(TOT) = 16 ± 17 Gy) for D0.1cc and CV = 7% ± 2% (SD(TOT) = 4 ± 3 Gy) for D2cc; for sigmoid, CV = 39% ± 28% (SD(TOT) = 12 ± 18 Gy) for D0.1cc and CV = 34% ± 19% (SD(TOT) = 4 ± 4 Gy) for D2cc. CONCLUSIONS: Delineation of bladder and rectum by 13 physicians demonstrated substantial geometric agreement and resulted in good dosimetric agreement for all dose-volume histogram parameters except bladder D0.1cc. Small delineation differences in high-dose regions by the posterior bladder wall may explain these results. The delineation of sigmoid showed fair geometric agreement. The higher dosimetric variability for sigmoid compared with rectum and bladder did not correlate with higher variability in the total brachytherapy dose but rather may be due to the sigmoid being positioned in low-dose regions in the cases analyzed in this study.

Chemoradiation therapy: localized esophageal, gastric, and pancreatic cancer.

Chemoradiation plays an important role in management of locally advanced gastrointestinal tumors. This article reviews data regarding chemoradiation for tumors of the upper gastrointestinal tract. For esophageal and gastroesophageal junction cancers, chemoradiation is standard of care in the preoperative setting. In gastric cancer, 2 standards have emerged: definitively treating with perioperative chemotherapy alone and using chemoradiation postoperatively. For pancreatic cancer, the benefit of radiation is less well defined. The future of treatment sites lies in trials evaluating new chemotherapy regimens, alternative systemic therapies, and different radiation fractionation schema. Because care of these patients is complex, multimodality team evaluation before treatment is encouraged.

MicroRNA-mediated control of cell fate in megakaryocyte-erythrocyte progenitors.

Lineage specification is a critical issue in developmental and regenerative biology. We hypothesized that microRNAs (miRNAs) are important participants in those processes and used the poorly understood regulation of megakaryocyte-erythrocyte progenitors (MEPs) in hematopoiesis as a model system. We report here that miR-150 modulates lineage fate in MEPs. Using a novel methodology capable of profiling miRNA expression in small numbers of primary cells, we identify miR-150 as preferentially expressed in the megakaryocytic lineage. Through gain- and loss-of-function experiments, we demonstrate that miR-150 drives MEP differentiation toward megakaryocytes at the expense of erythroid cells in vitro and in vivo. Moreover, we identify the transcription factor MYB as a critical target of miR-150 in this regulation. These experiments show that miR-150 regulates MEP fate, and thus establish a role for miRNAs in lineage specification of mammalian multipotent cells.

An RNA interference model of RPS19 deficiency in Diamond-Blackfan anemia recapitulates defective hematopoiesis and rescue by dexamethasone: identification of dexamethasone-responsive genes by microarray.

Diamond-Blackfan anemia (DBA), a congenital erythroblastopenia, is a model disease for the study of erythroid differentiation but is poorly understood. RPS19 is the only gene yet to have been associated with DBA, but its relevance to erythroid differentiation is unclear. The molecular basis for the stimulation of erythropoiesis by glucocorticoids in patients with DBA has not been identified. We demonstrate that targeted degradation of the RPS19 transcript, through retroviral expression of short hairpin RNAs (shRNAs), blocks the proliferation and differentiation of erythroid progenitor cells in cultured human CD34(+) cells. Treatment of RPS19-deficient cells with dexamethasone restores erythroid differentiation to normal levels. We investigated the molecular basis of pharmacologic therapies for DBA using oligonucleotide microarrays to survey gene expression in CD34(+) cells treated with combinations of dexamethasone, erythropoietin, stem cell factor, and interleukin-3. Dexamethasone did not alter expression of RPS19 but activated a genetic program that includes a set of key hematopoietic regulatory genes. Genes specific to erythroid progenitor cells were up-regulated by dexamethasone, while genes specific to nonerythroid lineages were down-regulated. Deficiency of RPS19 therefore blocks proliferation of immature erythroid progenitor cells, and dexamethasone activates proliferation of the same cell population through mechanisms independent of RPS19.

A universal nucleic acid sequence biosensor with nanomolar detection limits.

A quantitative universal biosensor was developed on the basis of olignucleotide sandwich hybridization for the rapid (30 min total assay time) and highly sensitive (1 nM) detection of specific nucleic acid sequences. The biosensor consists of a universal membrane and a universal dye-entrapping liposomal nanovesicle. Two oligonucleotides, a reporter and a capture probe that can hybridize specifically with the target nucleic acid sequence, can be coupled to the universal biosensor components within a 10-min incubation period, thus converting it into a specific assay. The liposomal nanovesicles bear a generic oligonucleotide sequence on their outer surface. The reporter probes consist of two parts: the 3' end is complementary to the generic liposomal oligonucleotide, and the 5' end is complementary to the target sequence. Streptavidin is immobilized in the detection zone of the universal membranes. The capture probes are biotinylated at the 5' end and are complementary to another segment in the target sequence. Thus, by incubating the liposomal nanovesicles with the reporter probes, the target sequence, and the capture probes in a hybridization buffer for 20 min, a sandwich complex is formed. The mixture is applied to the membrane, migrates along the strip, and is captured in the detection zone via streptavidin-biotin binding. The biosensor assay was optimized with respect to hybridization conditions, concentrations of all components, and length of the generic probe. It was tested using synthetic DNA sequences and authentic RNA sequences isolated and amplified using nucleic acid sequence-based amplification (NASBA) from Escherichia coli, Bacillus anthracis, and Cryptosporidium parvum. Dose-response curves were carried out using a portable reflectometer for the instantaneous quantification of liposomal nanovesicles in the detection zone. Limits of detection of 1 fmol per assay (1 nM) and dynamic ranges between 1 fmol and at least 750 fmol (1-750 nM) were obtained. The universal biosensors were compared to specific RNA biosensors developed earlier and were found to match or exceed their performance characteristics. In addition, no changes to hybridization conditions were required when switching to the detection of a new target sequence or when using actual nucleic acid sequence-based amplified RNA sequences. Therefore, the universal biosensor described is an excellent tool for use in laboratories or at test sites for rapidly investigating and quantifying any nucleic acid sequence of interest.