Circulating tumor DNA association with residual cancer burden after neoadjuvant chemotherapy in triple-negative breast cancer in TBCRC 030

BACKGROUND

We aimed to examine circulating tumor DNA (ctDNA) and its association with residual cancer burden (RCB) using an ultrasensitive assay in patients with triple-negative breast cancer (TNBC) receiving neoadjuvant chemotherapy.

PATIENTS AND METHODS

We identified responders (RCB 0/1) and matched non-responders (RCB 2/3) from the phase II TBCRC 030 prospective study of neoadjuvant paclitaxel versus cisplatin in TNBC. We collected plasma samples at baseline, 3 weeks and 12 weeks (end of therapy). We created personalized ctDNA assays utilizing MAESTRO mutation enrichment sequencing. We explored associations between ctDNA and RCB status and disease recurrence.

RESULTS

Of 139 patients, 68 had complete samples and no additional neoadjuvant chemotherapy. Twenty-two were responders and 19 of those had sufficient tissue for whole-genome sequencing. We identified an additional 19 non-responders for a matched case-control analysis of 38 patients using a MAESTRO ctDNA assay tracking 319-1000 variants (median 1000 variants) to 114 plasma samples from 3 timepoints. Overall, ctDNA positivity was 100% at baseline, 79% at week 3 and 55% at week 12. Median tumor fraction (TFx) was 3.7 × 10-4 (range 7.9 × 10-7-4.9 × 10-1). TFx decreased 285-fold from baseline to week 3 in responders and 24-fold in non-responders. Week 12 ctDNA clearance correlated with RCB: clearance was observed in 10 of 11 patients with RCB 0, 3 of 8 with RCB 1, 4 of 15 with RCB 2 and 0 of 4 with RCB 3. Among six patients with known recurrence, five had persistent ctDNA at week 12.

CONCLUSIONS

Neoadjuvant chemotherapy for TNBC reduced ctDNA TFx by 285-fold in responders and 24-fold in non-responders. In 58% (22/38) of patients, ctDNA TFx dropped below the detection level of a commercially available test, emphasizing the need for sensitive tests. Additional studies will determine whether ctDNA-guided approaches can improve outcomes.

Comment on "Soybean photosynthesis and crop yield are improved by accelerating recovery from photoprotection"

De Souza et al. (Research Articles, 19 Aug 2022, adc9831) recently claimed major soybean yield increases resulting from transformation of the nonphotochemical quenching mechanism of photosynthesis. However, there is little basis for the premise that such a transformation would result in yield increase. The field experiment was flawed and does not provide evidence for increases in crop yield.

TBCRC 030: a phase II study of preoperative cisplatin versus paclitaxel in triple-negative breast cancer: evaluating the homologous recombination deficiency (HRD) biomarker

BACKGROUND

Cisplatin and paclitaxel are active in triple-negative breast cancer (TNBC). Despite different mechanisms of action, effective predictive biomarkers to preferentially inform drug selection have not been identified. The homologous recombination deficiency (HRD) assay (Myriad Genetics, Inc.) detects impaired double-strand DNA break repair and may identify patients with BRCA1/2-proficient tumors that are sensitive to DNA-targeting therapy. The primary objective of TBCRC 030 was to detect an association of HRD with pathologic response [residual cancer burden (RCB)-0/1] to single-agent cisplatin or paclitaxel.

PATIENTS AND METHODS

This prospective phase II study enrolled patients with germline BRCA1/2 wild-type/unknown stage I-III TNBC in a 12-week randomized study of preoperative cisplatin or paclitaxel. The HRD assay was carried out on baseline tissue; positive HRD was defined as a score ≥33. Crossover to an alternative chemotherapy was offered if there was inadequate response.

RESULTS

One hundred and thirty-nine patients were evaluable for response, including 88 (63.3%) who had surgery at 12 weeks and 51 (36.7%) who crossed over to an alternative provider-selected preoperative chemotherapy regimen due to inadequate clinical response. HRD results were available for 104 tumors (74.8%) and 74 (71.1%) were HRD positive. The RCB-0/1 rate was 26.4% with cisplatin and 22.3% with paclitaxel. No significant association was observed between HRD score and RCB response to either cisplatin [odds ratio (OR) for RCB-0/1 if HRD positive 2.22 (95% CI: 0.39-23.68)] or paclitaxel [OR for RCB-0/1 if HRD positive 0.90 (95% CI: 0.19-4.95)]. There was no evidence of an interaction between HRD and pathologic response to chemotherapy.

CONCLUSIONS

In this prospective preoperative trial in TNBC, HRD was not predictive of pathologic response. Tumors were similarly responsive to preoperative paclitaxel or cisplatin chemotherapy.

Abstract PD3-14: Phase 1 study of the antibody-drug conjugate SGN-LIV1A in patients with heavily pretreated triple-negative metastatic breast cancer

Background

LIV-1, a transmembrane protein and downstream target of STAT3, is highly expressed in breast cancer cells. It is associated with lymph node involvement and metastatic progression. SGN-LIV1A is an anti-LIV-1 antibody conjugated via a protease-cleavable linker to monomethyl auristatin E (MMAE). Upon binding to cell-surface LIV-1, SGN-LIV1A is internalized and releases MMAE, which disrupts microtubulin and induces apoptosis.

Methods

This ongoing, phase 1 study evaluates safety, tolerability, pharmacokinetics, and antitumor activity of SGN-LIV1A (q3wks IV) in women with LIV-1-positive, unresectable, locally advanced or metastatic breast cancer (LA/MBC) (NCT01969643). Patients (pts) with measurable disease and ≥2 prior cytotoxic regimens for LA/MBC are eligible. Pts with ≥ Grade 2 neuropathy are excluded. Response is assessed per RECIST v1.1; pts with stable disease (SD) or better can continue treatment until disease progression or intolerable toxicity. At completion of dose escalation in hormone receptor-positive/HER2-negative (HR+/HER2–) and triple-negative (TN) pts, expansion cohorts were opened to further evaluate safety and antitumor activity of monotherapy in TN pts. Tumor biopsies are evaluated for LIV-1 expression.

Results

To date, 69 pts (18 HR+/HER2–, 51 TN) have received a median of 3 cycles (range, 1–12) of SGN-LIV1A at doses of 0.5–2.8 mg/kg. Median age was 56 yrs. Pts had a median of 3 prior cytotoxic regimens for LA/MBC; 58 had visceral disease and 37 had bone metastases. No dose-limiting toxicities (DLTs) occurred in 19 DLT-evaluable pts; maximum tolerated dose was not exceeded at 2.8 mg/kg. Expansion cohorts of TN pts were opened at 2.0 and 2.5 mg/kg. Treatment-emergent adverse events (AEs) reported in ≥25% of pts were fatigue (59%), nausea (51%), peripheral neuropathy (44%), alopecia (36%), decreased appetite (33%), constipation (30%), abdominal pain, diarrhea, and neutropenia (25% each). Most AEs were Grade 1/2; AEs ≥ Grade 3 included neutropenia (25%) and anemia (15%). Febrile neutropenia occurred in 2 pts whose total dose exceeded 200 mg per cycle, including 1 treatment-related death due to sepsis. No other treatment-related deaths occurred on-study. Seven pts discontinued treatment due to AEs. In dose escalation, activity was observed in 17 efficacy evaluable (EE) HR+/HER2- pts, with a disease control rate (DCR= CR+PR+SD) of 59% (10 SD), including 1 pt with SD ≥24 wks. Among the 44 EE TN pts (dose escalation plus expansion cohorts), the objective response rate (ORR) was 32% (14 PR) with a confirmed PR rate of 21%, DCR was 64% (14 PR, 14 SD), and clinical benefit rate (CBR=CR+PR+SD ≥24 wks) was 36% (16 pts). For TN pts, median PFS was 11.3 wks (95% CI: 6.1, 17.1); 10 pts remain on treatment.

Of 631 MBC tumor samples of all clinical subtypes evaluated for LIV-1, 91% were positive; 75% had moderate-to-high expression (H-score ≥100).

Conclusions

LIV-1 is expressed in almost all MBC tumors. SGN-LIV1A monotherapy was generally well tolerated and showed encouraging antitumor activity in heavily pretreated TN MBC, with a PR rate of 32%, confirmed PR rate of 21%, and CBR (≥24 wks) of 36%. Response duration data continue to evolve. Enrollment continues in the TN monotherapy expansion cohort.

Citation Format: Modi S, Pusztai L, Forero A, Mita M, Miller KD, Weise A, Krop I, Burris III H, Kalinsky K, Tsai M, Liu MC, Hurvitz SA, Wilks S, Ademuyiwa F, Diab S, Han HS, Kato G, Nanda R, O'Shaughnessy J, Kostic A, Li M, Specht J. Phase 1 study of the antibody-drug conjugate SGN-LIV1A in patients with heavily pretreated triple-negative metastatic breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD3-14.

Abstract P5-14-10: Weekly doxorubicin and daily oral cyclophosphamide followed by nab-paclitaxel for adjuvant therapy of high-risk localized breast cancer

BACKGROUND: The addition of taxanes to anthracycline-based adjuvant chemotherapy has improved disease free survival (DFS) in women with high-risk early-stage breast cancer. Many studies have sought to optimize the dose intensity and density of these agents to produce improvements in outcome and tolerability. The purpose of this study was to assess the use of metronomic doxorubicin plus daily oral cyclophosphamide (AC) for 12 weeks followed by nab-paclitaxel (nP) for 12 weeks in this population. Those patients with Her2 positive disease were also given adjuvant trastuzumab.

METHODS: A non-randomized phase II clinical trial was designed to (1) test the DFS at 2 years compared to historical controls, (2) assess dose intensity delivered, (3) assess use of nP in the adjuvant setting, and (4) evaluate toxicities associated with the regimen. Overall survival (OS) was a secondary outcome. The dosing of A was 24mg/m2 IV qweek and C was 60mg/m2 oral daily; nP, 100mg/m2 IV qweek.

RESULTS: Sixty patients were enrolled on the study with a median follow-up of 6 years and a median age of 50 (range 30-69). 58% of patients had node positive disease. Receptor categories included hormone receptor positive (ER positive or PR positive) and HER2 negative (n=24; 40%); ER negative, PR negative, and HER2 negative (triple negative; n=19; 32%); or HER2 positive (n=17; 28%). DFS at 2 years was 93% (1 death, 3 recurrence) and at 6 years was 82%, comparable to historical controls. OS at 2 years and 6 years was 98% and 88%, respectively. Mean dose intensity was greater than 90% for AC and 88% for nP. Treatment was well-tolerated with the most common grade ≥3 toxicity being neutropenia and a 2% incidence of febrile neutropenia.

Disease-free survival and overall survival at 2 and 6 years 2 year 6 year  DFS %OS %DFS %OS %All patients93988288ER+ or PR+, HER2-921007979Triple negative89957989HER2+10010088100

CONCLUSSIONS: Patients achieved similar DFS to that seen in historical controls with similar rates of adverse events. Since nP dosing was 100 mg/m2, even with 88% dose intensity, the delivered taxane dose is greater than standard weekly paclitaxel. Notably disease control was particularly impressive in the triple negative subtype, which has been shown to benefit from nP over standard paclitaxel in the neoadjuvant setting in the GeparSepto (GBG 69) trial. Metronomic AC followed by nP is a safe, effective option for delivery of adjuvant chemotherapy for high-risk patients.

Citation Format: Cho E, Wu Q, Rubinstein L, Linden H, Gralow J, Specht J, Gadi V, Ellis G. Weekly doxorubicin and daily oral cyclophosphamide followed by nab-paclitaxel for adjuvant therapy of high-risk localized breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-14-10.

Abstract P4-02-05: Test-retest fidelity of FDG SUVmax in bone and non-boney metastatic breast cancer lesions in local area network PET/CT scanners

Background: Metabolic activity in lesions, measured by FDG-PET, is often used for assessing tumor aggressiveness and response to therapy. Patients may be scanned on different machines, so quantitative measurements should be reproducible. Reducing SUV variability in PET machines throughout a local network can aid in monitoring patient response to therapy and increase access to clinical trials.

Methods: Eighteen female patients with advanced or metastatic breast cancer underwent paired FDG PET/CT test-retest studies with 1-15 days between scans, and without interim change in treatment. Ten patients were studied in the same scanner and 8 patients were studied in 2 different scanners. Five different PET/CT scanners were used (2 GE DSTE, 2 Siemens (BioGraph 6 and mCT), 1 Philips Ingenuity TF). Each PET/CT scanner was calibrated using NIST-traceable reference sources to characterize and reduce variability. All of the images were interpreted by two separate reviewers. SUVmax values in lesions, corresponding normal tissue, and normal liver were collected. Linear mixed models with random intercept (patient effects) were fitted to compare differences in log(|SUVmax % difference|+.01) in multiple lesions per patient.

Results: SUVmax was assessed in a total of 130 lesions (75 bone). The median number of lesions per patient was 5 (range 1-17). Average SUVmax ranged from 1.0 to 18.2 (mean±SD = 6.0±3.2). The median SUVmax difference was 0.4 (8%) for 47 lesions imaged twice in the same scanner, and was 0.6 (13%) for 83 lesions imaged in two different scanners. In a multivariable linear mixed effects model, SUVmax for different scanners within the same institution did not differ more than for the same scanner (p=0.39), but repeat scans with different scanners and site personnel at had an average of 78% greater percentage difference in SUVmax than for the same scanner (p=0.009). In the same model, the average percent difference in SUVmax for bone lesions was estimated as 30% lower than for other sites (p=0.06, 95% confidence interval 0-50%). Examining normal liver uptake, the median SUVmean was 2.5 (range 1.9-3.1) with an median 6.5% difference between measurements (range 1.1%-23.7%) that did not appear to differ based on scanners used for repeat measurements (p=0.47).

Conclusions: The variability in quantitative FDG SUVmax between scans is modest, suggesting reliable reproducibility in appropriately calibrated settings. In our study, bone lesions had somewhat higher fidelity than other tumor sites. Additional studies will address variability in other cancer types. Careful calibration and monitoring of PET/CT scanners, and consistent imaging protocols are necessary in clinical trials that utilize quantitative PET/CT imaging in order to confidently interpret results.

Research Support: NIH grant U01-CA148131 and NCI-SAIC Contract 24XS036-004.

Citation Format: Linden HM, Peterson LM, Kurland B, Roberts T, Specht J, Shields AT, Novakova A, Christopfel R, Byrd D, Muzi M, Mankoff DA, Kinahan P. Test-retest fidelity of FDG SUVmax in bone and non-boney metastatic breast cancer lesions in local area network PET/CT scanners [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-02-05.

Abstract P6-12-04: Phase 1 study of the antibody-drug conjugate (ADC) SGN-LIV1A in patients with heavily pretreated metastatic breast cancer

Background

LIV-1, a transmembrane protein and downstream target of STAT3, is highly expressed in breast cancer cells. It is associated with lymph node involvement and metastatic progression. SGN-LIV1A is an anti-LIV-1 antibody conjugated via a protease-cleavable linker to monomethyl auristatin E (MMAE). Upon binding to cell-surface LIV-1, SGN-LIV1A is internalized and releases MMAE, which binds to tubulin and induces G2/M arrest and apoptosis.

Methods

This is an ongoing, phase 1 dose-escalation study evaluating safety, tolerability, pharmacokinetics, and antitumor activity of SGN-LIV1A (q3 wks IV) in women with LIV-1-positive, unresectable, locally advanced or metastatic breast cancer (LA/MBC) (NCT01969643). Patients (pts) with measurable disease and ≥2 prior cytotoxic regimens for LA/MBC were eligible. Pts with ≥Grade 2 neuropathy were excluded. Response was assessed per RECIST v1.1; pts with stable disease (SD) or better could continue treatment until disease progression or intolerable toxicity. At completion of dose escalation in hormone receptor-positive/HER2-negative (HR+/HER2–) and triple-negative (TN) pts, expansion cohorts were opened to further evaluate safety and antitumor activity of monotherapy in TN pts and combination therapy with trastuzumab (Tz) in HER2-positive (HER2+) pts. Pre- and post-treatment tumor biopsies were done to evaluate LIV-1 expression and other correlative endpoints.

Results

To date, 39 pts (18 HR+/HER2–, 21 TN) have received a median of 3 cycles (range, 1–10) of SGN-LIV1A monotherapy at doses of 0.5–2.8 mg/kg. Median age was 57 yrs (range, 33–79). At baseline, pts had a median of 4 prior cytotoxic regimens for LA/MBC (range, 2–8); 36 had visceral disease and 25 had bone involvement. No dose-limiting toxicities (DLT) occurred in 19 DLT-evaluable pts; maximum tolerated dose was not exceeded at 2.8 mg/kg. Treatment-emergent adverse events (AEs) reported in ≥30% of pts were: fatigue (64%), nausea (54%), alopecia (46%), decreased appetite (41%), constipation (39%), neutropenia (33%), and vomiting (31%). Peripheral neuropathy was reported in 9 pts (23%). Most AEs were Grade 1/2, except neutropenia (all ≥Grade 3). Four pts discontinued treatment due to AEs (acute respiratory distress syndrome, nausea, pneumonia, tachycardia). In dose escalation, modest activity was observed in 17 efficacy evaluable (EE) HR+/HER2- pts, with a disease control rate (DCR) of 59% (10 SD), including 1 pt with SD≥24 wks. Among the 17 EE TN pts (dose escalation plus cohort expansion), the overall response rate (ORR) was 41% (7 PR), DCR was 82% (7 PR, 7 SD) and clinical benefit rate (CBR=OR+SD≥24 wks) was 53% (9 pts). For TN pts, median PFS was 17.1 wks (95% CI: 6.0, 18.4); 6 pts remain on treatment.

Of 281 MBC tumor samples evaluated for LIV-1, 93% were positive; 81% had moderate-to-high expression (H-score ≥100).

Conclusions

LIV-1 is expressed in almost all MBC tumors. SGN-LIV1A monotherapy has been generally well tolerated and shown encouraging antitumor activity in heavily pretreated TN MBC, with a PR rate of 41% and a CBR at ≥24 wks of 53%. Response duration data continue to evolve. Enrollment continues in the TN monotherapy expansion cohort and the HER2+ combination cohort with Tz.

Citation Format: Forero-Torres A, Modi S, Specht J, Miller K, Weise A, Burris III H, Liu M, Krop I, Pusztai L, Kostic A, Li M, Mita M. Phase 1 study of the antibody-drug conjugate (ADC) SGN-LIV1A in patients with heavily pretreated metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-12-04.

Prospects of Genomic Prediction in the USDA Soybean Germplasm Collection: Historical Data Creates Robust Models for Enhancing Selection of Accessions

The identification and mobilization of useful genetic variation from germplasm banks for use in breeding programs is critical for future genetic gain and protection against crop pests. Plummeting costs of next-generation sequencing and genotyping is revolutionizing the way in which researchers and breeders interface with plant germplasm collections. An example of this is the high density genotyping of the entire USDA Soybean Germplasm Collection. We assessed the usefulness of 50K single nucleotide polymorphism data collected on 18,480 domesticated soybean (Glycine max) accessions and vast historical phenotypic data for developing genomic prediction models for protein, oil, and yield. Resulting genomic prediction models explained an appreciable amount of the variation in accession performance in independent validation trials, with correlations between predicted and observed reaching up to 0.92 for oil and protein and 0.79 for yield. The optimization of training set design was explored using a series of cross-validation schemes. It was found that the target population and environment need to be well represented in the training set. Second, genomic prediction training sets appear to be robust to the presence of data from diverse geographical locations and genetic clusters. This finding, however, depends on the influence of shattering and lodging, and may be specific to soybean with its presence of maturity groups. The distribution of 7608 nonphenotyped accessions was examined through the application of genomic prediction models. The distribution of predictions of phenotyped accessions was representative of the distribution of predictions for nonphenotyped accessions, with no nonphenotyped accessions being predicted to fall far outside the range of predictions of phenotyped accessions.

Abstract P1-03-01: Circulating CAIX as a biomarker in breast cancer

Introduction: Carbonic anhydrase-IX (CAIX) facilitates the reversible hydration of carbon dioxide to bicarbonate and protons, a process integral to maintaining pH differences across the cancer cell plasma membrane. CAIX is regulated by hypoxia inducible factor-1 alpha (HIF-1 alpha) and is essential for the elimination of acid loads generated by glycolysis. High CAIX expression is associated with poor prognosis and chemoresistance in breast cancer patients (pts) (1-3). To explore the role of CAIX as a possible biomarker for predicting breast cancer therapies, we measured plasma CAIX levels in response to various chemotherapy regimens, including anti-angiogenics, in several breast cancer clinical trials.

Methods: Circulating plasma CAIX was quantified using a commercially available enzyme-linked immunosorbent assay (ELISA) kit (R & D Systems). We evaluated the plasma stability of CAIX by quantifying levels within 1 hour as well as at 24 and 48 hours post phlebotomy in healthy controls (n = 10). We also evaluated the ideal anticoagulant for sample collection and stability of CAIX levels over time in healthy controls. For our analysis in breast cancer pts, we quantified plasma CAIX levels in two populations treated on chemotherapeutic clinical trials: 1) locally advanced breast cancer (LABC) pts treated in the neoadjuvant setting with paclitaxel in combination with sunitinib followed by anthracycline (AC) based chemotherapy (n = 63); 2) metastatic breast cancer (MBC) pts treated with systemic chemotherapy with either irinotecan + etoposide; or paclitaxel + a novel immunomodulatory agent (n = 22).

Results: In healthy control subjects, plasma levels of CAIX were stable at all time points tested (within1 hour, 24 hrs, 48 hours post phlebotomy) with no significant change on repeat testing at 6 months. Average baseline plasma CAIX levels were lowest in normal controls (20.5 pg/ml) compared to pts with LABC (34.1 pg/ml) or MBC (90.7 pg/ml) (p = <0.001). In pts with LABC, CAIX rose significantly in response to paclitaxel/sunitinib (TS) therapy (p = 0.01) but not further with anthracycline based therapy (p = 0.37). The rise in response to TS was primarily in pts with baseline levels below the median. In pts with MBC treated with cytotoxic chemotherapies (without an anti-angiogenic) CAIX levels did not change in response to therapy.

Discussion: Plasma CAIX is a robust biomarker that is stable at room temperature in plasma for at least 48hrs and over time in healthy controls. Plasma CAIX levels are elevated in pts with MBC when compared to those with LABC or normal controls. CAIX levels rise in response to anti-angiogenic therapy but not in response to cytotoxic chemotherapy. Our results suggest CAIX may be a robust and easily measured pharmacodynamic biomarker of anti-angiogenic induced hypoxia and HIF-1 alpha upregulation.

1. Potter CP and Harris AL. Br J Cancer. 89:2-7, 2003.

2. Betof AS, Rabbani ZN, Hardee ME, et al. BJ Cancer. 106:916-922, 2012.

3. Generali D, Fox Berruti A, et al. Endocrine-Related Cancer. 13:921-30, 2006.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-03-01.

Genome sequence of the palaeopolyploid soybean

Soybean (Glycine max) is one of the most important crop plants for seed protein and oil content, and for its capacity to fix atmospheric nitrogen through symbioses with soil-borne microorganisms. We sequenced the 1.1-gigabase genome by a whole-genome shotgun approach and integrated it with physical and high-density genetic maps to create a chromosome-scale draft sequence assembly. We predict 46,430 protein-coding genes, 70% more than Arabidopsis and similar to the poplar genome which, like soybean, is an ancient polyploid (palaeopolyploid). About 78% of the predicted genes occur in chromosome ends, which comprise less than one-half of the genome but account for nearly all of the genetic recombination. Genome duplications occurred at approximately 59 and 13 million years ago, resulting in a highly duplicated genome with nearly 75% of the genes present in multiple copies. The two duplication events were followed by gene diversification and loss, and numerous chromosome rearrangements. An accurate soybean genome sequence will facilitate the identification of the genetic basis of many soybean traits, and accelerate the creation of improved soybean varieties.

Dasatinib Plus Capecitabine for Advanced Breast Cancer: Safety and Efficacy Data from Phase 1 Study CA180-004

Background: SRC is a potential therapeutic target in breast cancer and has a central role in hormone therapy resistance and in osteoclast activity. Dasatinib is a potent SRC inhibitor that inhibits breast cancer cell proliferation and migration in vitro, including synergy with 5FU in some cell lines, and inhibits osteoclast activity in clinical trials. CA180-004 is a phase 1 study designed to identify dose-limiting toxicities (DLT) and recommended phase 2 doses of dasatinib plus capecitabine in women with advanced breast cancer (ABC). Safety and efficacy data are now reported with additional follow-up.Methods: Cohorts of pts with ABC were treated at four dose levels (DL) with capecitabine (mg/m2 twice daily [BID] on D1-14 of 21-day cycles) and dasatinib (mg daily): DL1: capecitabine 825 + dasatinib 50 BID; DL2: capecitabine 825 + dasatinib 70 BID; DL3: capecitabine 1000 + dasatinib 70 BID; DL3a: capecitabine 1000 + dasatinib 100 once daily (QD). All pts had performance status 0-1, prior taxane and/or anthracycline and ≤2 prior chemotherapy-containing regimens for advanced disease. Disease assessments were performed every 6 weeks. DL3a was expanded for further safety and efficacy estimate using best objective response and progression-free survival (PFS) rates.Results: To date, 47 pts with ABC have been treated, 31 in escalation phase plus 16 in expansion (5 too early). Median age was 52 years (range 35-77). Tumor subtypes: 14% were Her2-amplified, 57% ER+ or PR+, 29% triple-negative. Safety was previously reported (ASCO 2009) for escalation phase; no MTD was defined based on DLTs. Of 20 evaluable pts in DL3a, 2 DLTs have been observed: 1 pneumonia, pain and pleural effusion plus 1 diarrhea, neutropenia, vomiting, mucositis and anemia. The most common drug-related adverse events (AEs, any grade) were headache, fatigue/asthenia, nausea/vomiting, diarrhea, hand-foot syndrome (HFS) and pleural effusion. The most common grade 3/4 AEs were fatigue/asthenia, HFS, vomiting and diarrhea. To date, 19 have remained on treatment ≥4 months, including 3 for >1 year. Median duration of treatment (n=42) was 13 weeks; 23 pts have discontinued for progression and 7 for toxicity. Of 38 pts with on-study assessment, 6 had confirmed partial response (treatment durations 17+, 23, 25, 36+, 71, 73 wks), 6 had unconfirmed partial or clinical response (5, 11, 13, 18, 23+, 24 wks), and 9 had prolonged stable disease (16+, 17, 23+, 24+, 25+, 29, 39+, 48+, 63+ wks). Updated efficacy data, including PFS by hormone receptor status, will be presented.Conclusions: Dasatinib and capecitabine combination treatment was well tolerated and encouraging efficacy was observed. Further assessment of this combination is warranted.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3092.

Dasatinib plus capecitabine (Cap) for progressive advanced breast cancer (ABC): Phase I study CA180004

1012

Background: SRC family kinases (SFK) mediate numerous signal-transduction pathways relevant to breast cancer as well as osteoclast function. Dasatinib, a potent oral inhibitor of SFK and other kinases has preclinical activity in breast models and in vitro synergy with Cap in some breast cancer cell lines (KPL-4 and HCC-70). A phase I trial of dasatinib plus Cap was conducted to define dose-limiting toxicities (DLT), maximum tolerated (MTD), and recommended phase II (RP2D) doses. Methods: Sequential cohorts of pts with ABC were treated with Cap twice daily (BID) on days 1–14 and dasatinib daily in 21-day cycles using dose levels (DL) for Cap (mg/m2) and dasatinib (mg): DL1: Cap 825 + dasatinib 50 BID; DL2: Cap 825 + dasatinib 70 BID; DL3: Cap 1000 + dasatinib 70 BID; DL3a: Cap 1000 + dasatinib 100 once daily (QD). All pts had ECOG performance status 0–1, had prior anthracycline and/or taxane, and received ≤2 regimens in advanced setting. MTD was based on DLT in first cycle and RP2D also based on tolerability of additional cycles. Results: 31 pts with ABC, median age 53 years (range 36–78) were treated. Number of pts treated/evaluable for DLT/reported DLT (event) were DL1: 7/6/1 (headache, grade 3); DL2: 9/7/0; DL3: 6/6/1 (diarrhea, grade 3), and DL3a: 9/9/1 (pneumonia, grade 3). Most frequent AEs related to either drug and occurring at any time on study (n pts) were nausea (12), vomiting (7), diarrhea (6), abdominal pain (2), fatigue (8), headache (7), musculoskeletal pain (1), and pleural effusion (4); hand-foot syndrome (5) was as expected for Cap alone. 11 patients experienced a Grade 3–4 non-hematologic AE at some point during the study. Laboratory abnormalities were uncommon. To date, 20 pts have continued treatment for ≥6 weeks and 9 pts for ≥12 weeks. Number of pts who (at any time) reduced dasatinib/reduced Cap/discontinued for toxicity were DL1: 2/2/1; DL2 2/2/3; DL3: 2/1/2; DL3a: 0/1/1. Updated safety and efficacy data will be presented. Conclusions: Dasatinib + Cap was tolerated without unexpected combined-treatment toxicity; few pts required dose reduction in later cycles. The recommended phase II dose, Cap 1000 plus dasatinib 100 QD, is well tolerated and will be studied for efficacy in an expanded patient cohort.

[Table: see text]

A single U/C nucleotide substitution changing alanine to valine in the beet necrotic yellow vein virus P25 protein promotes increased virus accumulation in roots of mechanically inoculated, partially resistant sugar beet seedlings

Beet necrotic yellow vein virus (BNYVV) A type isolates E12 and S8, originating from areas where resistance-breaking had or had not been observed, respectively, served as starting material for studying the influence of sequence variations in BNYVV RNA 3 on virus accumulation in partially resistant sugar beet varieties. Sub-isolates containing only RNAs 1 and 2 were obtained by serial local lesion passages; biologically active cDNA clones were prepared for RNAs 3 which differed in their coding sequences for P25 aa 67, 68 and 129. Sugar beet seedlings were mechanically inoculated with RNA 1+2/RNA 3 pseudorecombinants. The origin of RNAs 1+2 had little influence on virus accumulation in rootlets. E12 RNA 3 coding for V(67)C(68)Y(129) P25, however, enabled a much higher virus accumulation than S8 RNA 3 coding for A(67)H(68)H(129) P25. Mutants revealed that this was due only to the V(67) 'GUU' codon as opposed to the A(67) 'GCU' codon.

Use of changes in blood flow PET measurements to predict post-therapy lymph node status among locally advanced breast cancer patients

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Background: Response to neoadjuvant therapy in the primary tumor and nodal metastasis predicts benefit to patients as shown in several large clinical trials. We have previously shown that changes in tumor blood flow (BF) measured by [15O]-water PET predict pathologic primary tumor response. We now test whether primary tumor blood flow changes also predict axillary nodal metastases response and post-therapy lymph node status among women with locally advanced breast cancer (LABC) receiving neoadjuvant chemotherapy. Methds: Fifty-five women with a primary diagnosis of LABC underwent dynamic [15O]-water PET scans prior to and at midpoint of neoadjuvant chemotherapy. We evaluated associations between tumor BF changes and pathologic primary tumor response: categorized as complete (CR), partial (PR) or no response (NR). We also assessed the relationship between primary tumor BF changes and post-therapy axillary lymph node status, categorizing the high risk (HR) group as 4+ nodes with extracapsular extension (ECE, n=12) versus the lower risk (LR) group with either fewer than 4+ nodes or without ECE (n=43). Results: The median changes in BF versus tumor response were: CR = -77%, PR = -40%, and, NR = +20% (P = <0.001). For axillary node response, the median BF change among HR patients was +20% versus - 49% among LR patients (P = 0.004). Eight of 17 patients with an increase in tumor blood flow were HR whereas 4/38 patients with decreased tumor blood flow were HR (P = 0.002). Conclusions: Change in primary tumor blood flow over the course of neoadjuvant chemotherapy predicts pathologic response to treatment with a substantial decrease observed among CRs. An increase in primary tumor BF with treatment portends significant residual primary tumor and a nearly 50% chance of very high-risk nodal disease post-therapy.

No significant financial relationships to disclose.

Tumor metabolism, blood flow changes, and prognosis by positron emission tomography: A prospective cohort of locally advanced breast cancer patients

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Background: Breast cancer patients with locally advanced tumors receive preoperative chemotherapy to provide early systemic treatment and assess in-vivo tumor response. Positron emission tomography (PET) has been used to follow tumor response to therapy, as pathologic response is predictive of patient outcome. We evaluated the prognostic utility of serial quantitative PET tumor blood flow (BF) and metabolism measurements. Methods: Fifty-five women with a primary diagnosis of locally advanced breast carcinoma (LABC) underwent dynamic [18F]-FDG and [15O]-water PET scans prior to and at midpoint of neoadjuvant chemotherapy. The FDG metabolic rate (MRFDG), transport (K1), and flux (Ki) parameters were calculated, and tumor blood flow was estimated from the [15O]-water study. Associations between tumor BF and MRFDG measurements and disease-free survival (DFS) and overall survival (OS) were evaluated using the Cox proportional hazards model. Results: Patients that had an increase in BF and K1, from baseline to mid-therapy measurements, had elevated recurrence and mortality risks compared to patients that had reductions in BF and MRFDG values. In multivariate analysis, changes in BF and K1 remained independent prognostic indicators of DFS and OS survival. Conclusions: PET measurements of tumor response prior to completion of neoadjuvant chemotherapy were predictive of patient outcome. Patients that failed to have a decline in BF and K1 experienced higher risks of recurrence and mortality that was largely independent of clinical tumor characteristics assessed in this study. These results suggest that tumor perfusion, measured directly by [15O]-water or indirectly by dynamic FDG PET, is highly predictive of outcome in neoadjuvantly treated breast cancer.

No significant financial relationships to disclose.

Abnormal leaf formation in soybean: genetic and environmental effects

Soybean is trifoliolate, but 4-, 5-, or 6-foliolate leaves have been reported and expression of such multi-foliolate (MF) leaf forms has been shown to be heritable. Here we analyze the genetic complexity of the MF phenotype and the dependence of its expression on the environment. Recombinant inbred (RI) segregants of soybean were grown in different environments. The frequency of plants expressing the MF phenotype as well as the frequency of nodes exhibiting MF leaves varied with both the environment and the RI segregant genotype. Growth chamber experiments supported field observations suggesting that environment (day length, temperature, etc.) at emergence influenced expression of MF during subsequent growth. Marker facilitated analyses of three RI segregant populations identified quantitative trait loci (QTLs) in 17 regions of the soybean genome. These either directly regulated MF phenotype expression, or were involved in interactions with such loci. Loci, identified in one RI population also were identifiable in another, different, RI population. Most of the loci affected both the frequency of plants expressing MF, and the number of nodes on MF plants that expressed the phenotype. However, a few loci differentiated between these two effects. Many loci affected plants in both field experiments, however, a few differentiated between the two environments. Similar patterns were observed for interactions between loci. QTLs regulating the MF phenotype were located in genome regions that also contained QTLs regulating major agronomic traits-e.g. yield, lodging, etc. This suggests that the loci involved regulate plant growth at some over-arching level, controlling multiple phenotypes or traits.

Linkage mapping of powdery mildew and greenbug resistance genes on recombinant 1RS from 'Amigo' and 'Kavkaz' wheat-rye translocations of chromosome 1RS.1AL

Cultivated rye (Secale cereale L., 2n = 2x = 14, RR) is an important source of genes for insect and disease resistance in wheat (Triticum aestivum L., 2n = 6x = 42). Rye chromosome arm 1RS of S. cereale 'Kavkaz' originally found as a 1BL.1RS translocation, carries genes for disease resistance (e.g., Lr26, Sr31, Yr9, and Pm8), while 1RS of the S. cereale 'Amigo' translocation (1RSA) carries a single resistance gene for greenbug (Schizaphis graminum Rondani) biotypes B and C and also carries additional disease-resistance genes. The purpose of this research was to identify individual plants that were recombinant in the homologous region of.1AL.1RSV and 1AL.1RSA using both molecular and phenotypic markers. Secale cereale 'Nekota' (1AL.1RSA) and S. cereale 'Pavon 76' (1AL.1RSV) were mated and the F1 was backcrossed to 'Nekota' (1AL.1AS) to generate eighty BC1F2:3 families (i.e., ('Nekota' 1AL.1RSA x 'Pavon 76' 1AL.1RSV) x 'Nekota' 1AL.1AS). These families were genotyped using the secalin-gliadin grain storage protein banding pattern generated with polyacrylamide gel electrophoresis to discriminate 1AL.1AS/1AL.1RS heterozygotes from the 1AL.1RSA+V and 1AL.1AS homozygotes. Segregation of the secalin locus and PCR markers based on the R173 family of rye specific repeated DNA sequences demonstrated the presence of recombinant 1AL.1RSA+V families. Powdery mildew (Blumeria graminis) and greenbug resistance genes on the recombinant 1RSA+V arm were mapped in relation to the Sec-1 locus, 2 additional protein bands, 3 SSRs, and 13 RFLP markers. The resultant linkage map of 1RS spanned 82.4 cM with marker order and spacing showing reasonable agreement with previous maps of 1RS. Fifteen markers lie within a region of 29.7 cM next to the centromere, yet corresponded to just 36% of the overall map length. The map position of the RFLP marker probe mwg68 was 10.9 cM distal to the Sec-1 locus and 7.8 cM proximal to the powdery mildew resistance locus. The greenbug resistance gene was located 2.7 cM proximal to the Sec-1 locus.

Early experience with 'new federalism' in health insurance regulation

The authors monitored the implementation of the Health Insurance Portability and Accountability Act (HIPAA) from 1997 to 1999. Regulators in all states and relevant federal agencies were interviewed and applicable laws and regulations studied. The authors found that HIPAA changed legal protections for consumers' health coverage in several ways. They examine how the process of regulating such coverage was affected at the state and federal levels and under an emerging partnership of the two. Despite some early implementation challenges, HIPAA's successes have been significant, although limited by the law's incremental nature.

[Structure and quality of German-language gastroscopy information forms from the patients' viewpoint]

Information about procedure and risks is prerequisite for obtaining informed consent for endoscopy. This prospective and randomized investigation evaluated (i) the extent of patients' information needs and (ii) the formal quality (language, ease of understanding, length, figures etc.) of three information forms concerning upper CI-endoscopy issued in 1995 by DIOmed (1), perimed compliance (2), and PERIMED-spitta (3) as judged by the patients. (iii) Outcome quality was investigated as the influence of these forms on understanding why and how endoscopy was performed as well as the influence on feeling threatened. Furthermore patients' anxiety was assessed by using Spielberger's state-trait anxiety inventory (STAI). 218 patients completed the investigation (n = 73; 70; 75, respectively). 60% claimed the need for a detailed explanation of the planned endoscopy and 48% said they wanted exhaustive informations about potential complications and risks. The three forms (length 819, 771, 1,245 words) were entirely read by 87%, 89% and 82% of the patients. Positive language, adequate length (69%, 69%, 71%) and adequate layout were evenly attributed to the three forms. A high impact of the figures for understanding was found more frequently (48%, 46%, 35%) with (1) and (2) and language war regarded easy by 57%, 54% and 44%, respectively. Flesh's reading ease score, however, proved a sophisticated niveau of language with all three forms. The indication for endoscopy (37%, 49%, 56%) and explanation of performance (43%, 43%, 63%) was superior with (3). This form also reduced anxiety as judged by STAI-means, overall STAI-changes, and relevant changes (> or = 5 points). Form (2) increased patients' anxiety.

CONCLUSION

While the formal quality of all information forms is appreciated by patients both their reading ease score and figures should be improved. A significant reduction of anxiety can be achieved by appropriate selection of the information material.

Caregiving: concept analysis and outcomes

More than ever before, caregiving has become a salient public policy issue. A number of recent and anticipated demographic, economic and social changes have occurred that make it imperative for researchers to critically examine the impact of caregiving on family caregivers' health, behavior, emotions, and social status. Researchers at the University of Iowa College of Nursing are working to classify standardized nursing-sensitive patient outcomes for use in language development, practice, research, and education to evaluate the effectiveness of nursing interventions and clinical nursing services. This article focuses on family caregiving and the analysis of caregiver role performance in both direct and indirect care, linking outcomes and indicators, to enable nurses to promote the health of caregivers.

Genome duplication in soybean (Glycine subgenus soja)

Restriction fragment length polymorphism mapping data from nine populations (Glycine max x G. soja and G. max x G. max) of the Glycine subgenus soja genome led to the identification of many duplicated segments of the genome. Linkage groups contained up to 33 markers that were duplicated on other linkage groups. The size of homoeologous regions ranged from 1.5 to 106.4 cM, with an average size of 45.3 cM. We observed segments in the soybean genome that were present in as many as six copies with an average of 2.55 duplications per segment. The presence of nested duplications suggests that at least one of the original genomes may have undergone an additional round of tetraploidization. Tetraploidization, along with large internal duplications, accounts for the highly duplicated nature of the genome of the subgenus. Quantitative trait loci for seed protein and oil showed correspondence across homoeologous regions, suggesting that the genes or gene families contributing to seed composition have retained similar functions throughout the evolution of the chromosomes.

The cost of treating pressure ulcers following implementation of a research-based skin care protocol in a long-term care facility

Although concern for the costs associated with pressure ulcer treatments persists, studies that precisely quantify costs are limited. A retrospective research design was used to describe the costs incurred by an 830-bed, long-term care facility to treat 81 pressure ulcers over a one-year period following implementation of a research-based, skin care protocol. The total cost for the study period was $30,079 with 73% of these expenditures attributable to nursing care. Mean cost of treatment was $3.74/pressure ulcer/day, which was a reduction from the $5.35/pressure ulcer/day cost prior to implementation of the skin care protocol. These findings suggest that implementing a research-based, skin care protocol can promote a reduction in treatment costs.

Alzheimer's special care units

An overview of Alzheimer's special care units is provided, including the several models that have been used to guide their development. Philosophy and programming, physical and social environments, staff selection and training, admission and discharge criteria, family programming, and quality and cost features are described. Evaluation and research of special units and interventions for residents with Alzheimer's, their family members and staff caregivers are discussed.

Adoption of research-based practice for treatment of pressure ulcers in long-term care

Implementation of a clinical trial to evaluate the effectiveness of electrotherapy on pressure ulcer healing provided the stimulus for adoption of research-based innovations for pressure ulcer treatment in one long-term care facility. A five-year retrospective study conducted prior to introduction of the clinical trial revealed that 72 different treatments were applied to pressure ulcers. Forty-two percent of the pressure ulcers were left open to the air or covered with a dry gauze dressing and 64% were treated with some type of antiseptic solution. Since implementation of the clinical trial and the accompanying access to wound healing research knowledge it provided in this setting, the prevailing treatment for pressure ulcers has become moist physiologic dressings.

The cost of treating pressure ulcers in a long-term care facility

Although there is rising concern with the cost of pressure ulcer treatment, actual expenditures have not been quantified in many settings. A retrospective research design was used to describe the costs incurred by an 830-bed long-term care facility to treat 240 pressure ulcers over a five-year period. The total cost was $116,416 for the study period. The mean cost of treatment was $5.35/pressure ulcer/day. These costs are substantially lower than the costs of pressure ulcer treatment in acute care. Further study to compare treatment costs with prevention costs would provide useful information on the cost benefits of prevention.

Adjunct executive appointment for faculty. An innovation in nursing collaboration

The need for collaboration has never been greater. The healthcare delivery system faces unprecedented challenges arising from prospective payment, competition in the marketplace, higher patient acuity levels, and a shortage of professional nursing staff. The authors discuss a service-education collaboration model based on adjunct executive appointments of faculty members to healthcare organizations. The authors describe the model, a conceptual framework to guide its development, case studies of its implementation, and a summary of the benefits and risks associated with the initial implementation of the model.

The implementation of nursing diagnoses. The Iowa Veterans Home experience

This article has reviewed the process of implementing nursing diagnoses in one long-term care agency. Nursing diagnoses improved nursing process skills, made problem identification more accurate, and aided the identification of nursing interventions and desired outcomes. Nursing diagnoses have become the organizing framework for quality assurance, staff development, specialization and consultation, and computer applications. The presence of a professional model of nursing practice facilitated the use of nursing diagnoses. Prior to implementing nursing diagnoses, IVH nurses had defined the scope of nursing practice and formed a committee structure for decision-making by all RNs. The structure included mechanisms for collective and individual accountability. All nurses participated in the decision to use nursing diagnoses in their practice. Each nurse had the opportunity to influence the process of change. The process of implementing nursing diagnoses at IVH continues. Nurses recognize the need to establish the validity of each diagnostic statement. Skill with the diagnostic process is expected to improve. Nurses also recognize the need to test interventions for specific diagnoses. The standard nomenclature will continue to be used for the improvement of nursing practice and for nursing department programming. The use of nursing diagnoses is the basis of the continued development of a professional model of nursing practice.

Effect of beta-casomorphins and analogs on insulin release in dogs

Opioid-active substances have been isolated from bovine beta-casein peptone (beta-casomorphin). Since the ingestion of beta-casomorphin-containing foodstuff elicits an increase in postprandial insulin release, the present study was designed to determine the effect of iv infused beta-casomorphins on insulin release. The infusion of beta-casomorphin-7, -5, -4, and -3 did not alter basal insulin secretion. During prestimulation of insulin release with amino acids and glucose the infusion of beta-casomorphin-7, -5, -4, and -3 at a dose of 1 nmol/ kg . h augmented insulin release, whereas at a concentration of 100 nmol/kg . h no further stimulatory effect was observed except for the infusion of beta-casomorphin-4. In comparison, the infusion of morphine elicited a potentiation of insulin release at the lower dose, whereas no effect was observed at the higher infusion rate. Leucine-enkephalin had no effect at the lower dose but elicited an inhibitory effect at the higher rate. The infusion of opiate-active and inactive analogs of beta-casomorphin-4 resulted in a loss of its stimulatory effect, indicating that the full tetrapeptide structure of the molecule is important for its stimulatory activity on beta-cell secretion. All stimulatory and inhibitory effects of the opioid-active substances were blocked by the specific opiate-receptor antagonist naloxone. Additionally, the present data support the concept that beta-cell secretion is stimulated by mu-receptor activation and inhibited by delta-receptor activation. The K-receptor antagonist ethyl-ketocyclazocine did not alter insulin secretion. The fact that iv administered beta-casomorphins stimulate insulin release raises the possibility that ingested food-derived opioid-active substances modulate pancreatic endocrine function also after their absorption, provided the doses employed in the present study reflect physiological concentrations of circulating beta-casomorphins.