The PARTNER trial of neoadjuvant olaparib with chemotherapy in triple-negative breast cancer.

PARTNER is a prospective, phase II-III, randomized controlled clinical trial that recruited patients with triple-negative breast cancer1,2, who were germline BRCA1 and BRCA2 wild type3. Here we report the results of the trial. Patients (n = 559) were randomized on a 1:1 basis to receive neoadjuvant carboplatin-paclitaxel with or without 150 mg olaparib twice daily, on days 3 to 14, of each of four cycles (gap schedule olaparib, research arm) followed by three cycles of anthracycline-based chemotherapy before surgery. The primary end point was pathologic complete response (pCR)4, and secondary end points included event-free survival (EFS) and overall survival (OS)5. pCR was achieved in 51% of patients in the research arm and 52% in the control arm (P = 0.753). Estimated EFS at 36 months in the research and control arms was 80% and 79% (log-rank P > 0.9), respectively; OS was 90% and 87.2% (log-rank P = 0.8), respectively. In patients with pCR, estimated EFS at 36 months was 90%, and in those with non-pCR it was 70% (log-rank P < 0.001), and OS was 96% and 83% (log-rank P < 0.001), respectively. Neoadjuvant olaparib did not improve pCR rates, EFS or OS when added to carboplatin-paclitaxel and anthracycline-based chemotherapy in patients with triple-negative breast cancer who were germline BRCA1 and BRCA2 wild type. ClinicalTrials.gov ID: NCT03150576 .

Circulating tumour DNA analysis to direct therapy in advanced breast cancer (plasmaMATCH): a multicentre, multicohort, phase 2a, platform trial.

BACKGROUND: Circulating tumour DNA (ctDNA) testing might provide a current assessment of the genomic profile of advanced cancer, without the need to repeat tumour biopsy. We aimed to assess the accuracy of ctDNA testing in advanced breast cancer and the ability of ctDNA testing to select patients for mutation-directed therapy. METHODS: We did an open-label, multicohort, phase 2a, platform trial of ctDNA testing in 18 UK hospitals. Participants were women (aged ≥18 years) with histologically confirmed advanced breast cancer and an Eastern Cooperative Oncology Group performance status 0-2. Patients had completed at least one previous line of treatment for advanced breast cancer or relapsed within 12 months of neoadjuvant or adjuvant chemotherapy. Patients were recruited into four parallel treatment cohorts matched to mutations identified in ctDNA: cohort A comprised patients with ESR1 mutations (treated with intramuscular extended-dose fulvestrant 500 mg); cohort B comprised patients with HER2 mutations (treated with oral neratinib 240 mg, and if oestrogen receptor-positive with intramuscular standard-dose fulvestrant); cohort C comprised patients with AKT1 mutations and oestrogen receptor-positive cancer (treated with oral capivasertib 400 mg plus intramuscular standard-dose fulvestrant); and cohort D comprised patients with AKT1 mutations and oestrogen receptor-negative cancer or PTEN mutation (treated with oral capivasertib 480 mg). Each cohort had a primary endpoint of confirmed objective response rate. For cohort A, 13 or more responses among 78 evaluable patients were required to infer activity and three or more among 16 were required for cohorts B, C, and D. Recruitment to all cohorts is complete and long-term follow-up is ongoing. This trial is registered with ClinicalTrials.gov, NCT03182634; the European Clinical Trials database, EudraCT2015-003735-36; and the ISRCTN registry, ISRCTN16945804. FINDINGS: Between Dec 21, 2016, and April 26, 2019, 1051 patients registered for the study, with ctDNA results available for 1034 patients. Agreement between ctDNA digital PCR and targeted sequencing was 96-99% (n=800, kappa 0·89-0·93). Sensitivity of digital PCR ctDNA testing for mutations identified in tissue sequencing was 93% (95% CI 83-98) overall and 98% (87-100) with contemporaneous biopsies. In all cohorts, combined median follow-up was 14·4 months (IQR 7·0-23·7). Cohorts B and C met or exceeded the target number of responses, with five (25% [95% CI 9-49]) of 20 patients in cohort B and four (22% [6-48]) of 18 patients in cohort C having a response. Cohorts A and D did not reach the target number of responses, with six (8% [95% CI 3-17]) of 74 in cohort A and two (11% [1-33]) of 19 patients in cohort D having a response. The most common grade 3-4 adverse events were raised gamma-glutamyltransferase (13 [16%] of 80 patients; cohort A); diarrhoea (four [25%] of 20; cohort B); fatigue (four [22%] of 18; cohort C); and rash (five [26%] of 19; cohort D). 17 serious adverse reactions occurred in 11 patients, and there was one treatment-related death caused by grade 4 dyspnoea (in cohort C). INTERPRETATION: ctDNA testing offers accurate, rapid genotyping that enables the selection of mutation-directed therapies for patients with breast cancer, with sufficient clinical validity for adoption into routine clinical practice. Our results demonstrate clinically relevant activity of targeted therapies against rare HER2 and AKT1 mutations, confirming these mutations could be targetable for breast cancer treatment. FUNDING: Cancer Research UK, AstraZeneca, and Puma Biotechnology.

Report on computational assessment of Tumor Infiltrating Lymphocytes from the International Immuno-Oncology Biomarker Working Group.

Assessment of tumor-infiltrating lymphocytes (TILs) is increasingly recognized as an integral part of the prognostic workflow in triple-negative (TNBC) and HER2-positive breast cancer, as well as many other solid tumors. This recognition has come about thanks to standardized visual reporting guidelines, which helped to reduce inter-reader variability. Now, there are ripe opportunities to employ computational methods that extract spatio-morphologic predictive features, enabling computer-aided diagnostics. We detail the benefits of computational TILs assessment, the readiness of TILs scoring for computational assessment, and outline considerations for overcoming key barriers to clinical translation in this arena. Specifically, we discuss: 1. ensuring computational workflows closely capture visual guidelines and standards; 2. challenges and thoughts standards for assessment of algorithms including training, preanalytical, analytical, and clinical validation; 3. perspectives on how to realize the potential of machine learning models and to overcome the perceptual and practical limits of visual scoring.

18F-Fluorodeoxyglucose PET/CT and dynamic contrast-enhanced MRI as imaging biomarkers in malignant pleural mesothelioma.

PURPOSE: The purpose of this study was to compare the use of fluorine-18-fluorodeoxyglucose (F-FDG) PET with computed tomography (CT) and dynamic contrast-enhanced (DCE) MRI to predict prognosis and monitor treatment in malignant pleural mesothelioma. PATIENTS AND METHODS: F-FDG PET/CT and DCE-MRI studies carried out as part of the South West Area Mesothelioma Pemetrexed trial were used. F-FDG PET/CT and DCE-MRI studies were carried out before treatment, and after two cycles of chemotherapy, on patients treated with pemetrexed and cisplatin. A total of 73 patients were recruited, of whom 65 had PET/CT and DCE-MRI scans. Baseline measurements from F-FDG PET/CT (maximum standardized uptake value, metabolic tumour volume and total lesion glycolysis) and DCE-MRI (integrated area under the first 90s of the curve and washout slope) were compared with overall survival (OS) using Kaplan-Meier and Cox regression analyses, and changes in imaging measurements were compared with disease progression. RESULTS: PET/CT and DCE-MRI measurements were not correlated with each other. Maximum standardized uptake value, metabolic tumour volume and total lesion glycolysis were significantly related to OS with Cox regression analysis and Kaplan-Meir analysis, and DCE-MRI washout curve shape was significantly related to OS. DCE-MRI curve shape can be combined with F-FDG PET/CT to give additional prognostic information. Changes in measurements were not related to progression-free survival. CONCLUSIONS: F-FDG PET/CT and DCE-MRI give prognostic information in malignant pleural mesothelioma. Neither PET/CT nor DCE-MRI is useful for monitoring disease progression.

The impact of the 21-gene assay on adjuvant treatment decisions in oestrogen receptor-positive early breast cancer: a prospective study.

BACKGROUND: International guidelines, including NICE, recommend using the 21-gene Recurrence Score assay for guiding adjuvant treatment decisions in ER+, HER2-negative early breast cancer (BC). We investigated the impact of adding this assay to standard pathological tests on clinicians'/patients' treatment decisions and on patients' decisional conflict in the United Kingdom. METHODS: In this prospective multicentre study, eligibility criteria included: ER+ HER2-negative BC (N0/Nmic for patients ⩽50 years; ⩽3 positive lymph nodes for patients >50 years) and being fit for chemotherapy. Physicians'/patients' treatment choices and patients' decisional conflict were recorded pre- and post testing. RESULTS: The analysis included 137 patients. Overall, adjuvant treatment recommendations changed in 40.7% of patients, with the direction of the change consistent with the Recurrence Score results (net decrease in chemotherapy recommendation rate in low Recurrence Score patients and net increase in high Recurrence Score patients). Patients' choices were generally consistent with physicians' recommendations. Post-testing, patients' decisional conflict decreased significantly (P<0.0001). In the 67 patients meeting the NICE criteria for testing, the recommendation change rate was 49.3%. CONCLUSIONS: Recurrence Score testing significantly influenced treatment recommendations overall and in the subgroup of patients meeting the NICE criteria, suggesting that this test could substantially alter treatment patterns in the United Kingdom.

Medical and oncological management of malignant mesothelioma.

Mesothelioma is an aggressive cancer, for which no curative oncological treatment currently exists. This article outlines the options for managing malignant pleural effusions, describes the developments in chemotherapy over the past 10 years and summarizes the evidence for prophylactic and palliative radiotherapy.

Paraneoplastic tumefactive demyelination with underlying combined germ cell cancer.

Paraneoplastic demyelination is a rare disorder of the central nervous system. We describe a 60-year-old man with tumefactive demyelination who had an underlying retroperitoneal germ cell cancer. He presented with visuospatial problems and memory loss and had a visual field defect. His MRI was interpreted as a glioma but stereotactic biopsy showed active demyelination. Investigation for multiple sclerosis was negative but CT imaging showed retroperitoneal lymphadenopathy, and nodal biopsy confirmed a combined germ cell cancer. He responded poorly to corticosteroid treatment, and his visual field defect progressed. However, 6 months after plasma exchange and successful chemotherapy, he has partially improved clinically and radiographically. Tumefactive demyelination is typically associated with multiple sclerosis but may be paraneoplastic. It is important to recognise paraneoplastic tumefactive demyelination early, as the neurological outcome relies on treating the associated malignancy.

A randomised controlled trial of intravenous zoledronic acid in malignant pleural disease: a proof of principle pilot study.

INTRODUCTION: Animal studies have shown Zoledronic Acid (ZA) may diminish pleural fluid accumulation and tumour bulk in malignant pleural disease (MPD). We performed a pilot study to evaluate its effects in humans. METHODS: We undertook a single centre, double-blind, placebo-controlled trial in adults with MPD. Patients were randomised (1:1) to receive 2 doses of intravenous ZA or placebo, 3 weeks apart and were followed-up for 6 weeks. The co-primary outcomes were change in Visual Analogue Scale (VAS) score measured breathlessness during trial follow-up and change in the initial area under the curve (iAUC) on thoracic Dynamic Contrast Enhanced Magnetic Resonance Imaging (DCE-MRI) from randomisation to week 5. Multiple secondary endpoints were also evaluated. RESULTS: Between January 2010 and May 2013, 30 patients were enrolled, 24 randomised and 4 withdrew after randomisation (1 withdrew consent; 3 had a clinical decline). At baseline, the ZA group were more breathless, had more advanced disease on radiology and worse quality of life than the placebo group. There was no significant difference between the groups with regards change in breathlessness (Adjusted mean difference (AMD) 4.16 (95%CI -4.7 to 13.0)) or change in DCE-MRI iAUC (AMD -15.4 (95%CI -58.1 to 27.3). Two of nine (22%) in the ZA arm had a >10% improvement by modified RECIST (vs 0/11 who received placebo). There was no significant difference in quality of life measured by the QLQ-C30 score (global QOL: AMD -4.1 (-13.0 to 4.9)), side effects or serious adverse event rates. CONCLUSIONS: This is the first human study to evaluate ZA in MPD. The study is limited by small numbers and imbalanced baseline characteristics. Although no convincing treatment effect was identified, potential benefits for specific subgroups of patients cannot be excluded. This study provides important information regarding the feasibility of future trials to evaluate the effects of ZA further. TRIAL REGISTRATION: UK Clinical Research Network ID 8877 ISRCTN17030426 www.isrctn.com.

Fulvestrant plus anastrozole or placebo versus exemestane alone after progression on non-steroidal aromatase inhibitors in postmenopausal patients with hormone-receptor-positive locally advanced or metastatic breast cancer (SoFEA): a composite, multicentre, phase 3 randomised trial.

BACKGROUND: The optimum endocrine treatment for postmenopausal women with advanced hormone-receptor-positive breast cancer that has progressed on non-steroidal aromatase inhibitors (NSAIs) is unclear. The aim of the SoFEA trial was to assess a maximum double endocrine targeting approach with the steroidal anti-oestrogen fulvestrant in combination with continued oestrogen deprivation. METHODS: In a composite, multicentre, phase 3 randomised controlled trial done in the UK and South Korea, postmenopausal women with hormone-receptor-positive breast cancer (oestrogen receptor [ER] positive, progesterone receptor [PR] positive, or both) were eligible if they had relapsed or progressed with locally advanced or metastatic disease on an NSAI (given as adjuvant for at least 12 months or as first-line treatment for at least 6 months). Additionally, patients had to have adequate organ function and a WHO performance status of 0-2. Participants were randomly assigned (1:1:1) to receive fulvestrant (500 mg intramuscular injection on day 1, followed by 250 mg doses on days 15 and 29, and then every 28 days) plus daily oral anastrozole (1 mg); fulvestrant plus anastrozole-matched placebo; or daily oral exemestane (25 mg). Randomisation was done with computer-generated permuted blocks, and stratification was by centre and previous use of an NSAI as adjuvant treatment or for locally advanced or metastatic disease. Participants and investigators were aware of assignment to fulvestrant or exemestane, but not of assignment to anastrozole or placebo. The primary endpoint was progression-free survival (PFS). Analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, numbers NCT00253422 (UK) and NCT00944918 (South Korea). FINDINGS: Between March 26, 2004, and Aug 6, 2010, 723 patients underwent randomisation: 243 were assigned to receive fulvestrant plus anastrozole, 231 to fulvestrant plus placebo, and 249 to exemestane. Median PFS was 4·4 months (95% CI 3·4-5·4) in patients assigned to fulvestrant plus anastrozole, 4·8 months (3·6-5·5) in those assigned to fulvestrant plus placebo, and 3·4 months (3·0-4·6) in those assigned to exemestane. No difference was recorded between the patients assigned to fulvestrant plus anastrozole and fulvestrant plus placebo (hazard ratio 1·00, 95% CI 0·83-1·21; log-rank p=0·98), or between those assigned to fulvestrant plus placebo and exemestane (0·95, 0·79-1·14; log-rank p=0·56). 87 serious adverse events were reported: 36 in patients assigned to fulvestrant plus anastrozole, 22 in those assigned to fulvestrant plus placebo, and 29 in those assigned to exemestane. Grade 3-4 adverse events were rare; the most frequent were arthralgia (three in the group assigned to fulvestrant plus anastrozole; seven in that assigned to fulvestrant plus placebo; eight in that assigned to exemestane), lethargy (three; 11; 11), and nausea or vomiting (five; two; eight). INTERPRETATION: After loss of response to NSAIs in postmenopausal women with hormone-receptor-positive advanced breast cancer, maximum double endocrine treatment with 250 mg fulvestrant combined with oestrogen deprivation is no better than either fulvestrant alone or exemestane.

Coherent ultrasonic Doppler tomography.

Ultrasonic imaging based on the pulse-echo principle is widely used throughout the world, particularly in medical applications. However, its spatial resolution is poor (around 2 times the wavelength, or 200 µm at 15 MHz), limiting its ability to detect small but clinically important lesions (such as microcalcifications in breast cancer). The work presented here is different from the traditional approach. Continuous-wave ultrasound is transmitted to insonate a rotating object, then the amplitude and phase of the returned signals are coherently processed to reconstruct a Doppler tomographic image of the object's backscatter field. It is demonstrated numerically that the spatial resolution is up to 0.19 wavelengths and the sampling requirement and image formation method are given. To show the performance of the method, we present the results obtained by applying the new technique in simulation and experiment. A string phantom consisting of very thin copper wires and two cylindrical phantoms constructed by tissue-mimicking-material were scanned. It is demonstrated that the copper wires were located very accurately with very high spatial resolution, and good shape approximation for the cylindrical phantoms was achieved.

Extended survival in women with brain metastases from HER2 overexpressing breast cancer.

OBJECTIVES: Brain metastases (BM) are a significant complication of metastatic breast cancer (MBC). The high incidence of BM in HER2 overexpressing MBC is now well recognized, however, the optimal management of such patients is not yet clearly defined. We aimed to analyze factors affecting survival after diagnosis of BM in patients treated in our center. MATERIALS AND METHODS: Retrospective analysis of survival in all patients treated with antineoplastic therapy for BM from MBC in our institution between May 1st 2002 and April 30th 2005, according to HER2 expression and use of trastuzumab after diagnosis of BM. RESULTS: The median survival of the 26 patients with HER2 overexpressing disease after diagnosis of BM was significantly longer than that of the 60 patients with HER2 nonoverexpressing disease (6.2 vs. 3.8 months, P = 0.027). Further analysis revealed that this seems to be due to the favorable outcome of the 70% (n = 18) of HER2 overexpressing patients who received trastuzumab after BM were diagnosed. Median survival of this group was 11.9 months, compared with 3.8 months (HER2 nonoverexpressing disease, P = 0.002) and 3.0 months (HER2 overexpressing disease not treated with trastuzumab after development of BM, P = 0.05). CONCLUSION: Patients with HER2 overexpressing MBC who received trastuzumab after diagnosis of BM survived longer than expected. This finding justifies an active therapeutic approach: disease progression within central nervous system does not preclude benefit from trastuzumab treatment.

Study of etanercept, a tumor necrosis factor-alpha inhibitor, in recurrent ovarian cancer.

PURPOSE: Convincing data support the link between inflammation and ovarian cancer. Tumor necrosis factor-alpha (TNF-alpha), a major mediator of inflammation, is chronically produced in the ovarian tumor microenvironment and may enhance tumor growth and invasion by inducing the secretion of cytokines, proangiogenic factors, and metalloproteinases. Etanercept is a recombinant human soluble p75 TNF receptor that binds to TNF-alpha and renders it biologically unavailable. In the current study, we sought to determine the toxicity, biologic activity, and therapeutic efficacy of etanercept in recurrent ovarian cancer. PATIENTS AND METHODS: We initiated a phase I-B, nonrandomized, open-label study in patients with recurrent ovarian cancer. Etanercept was administered subcutaneously at a dose of 25 mg twice weekly (cohort one) and 25 mg thrice weekly (cohort two) until disease progression. RESULTS: Thirty patients were recruited (cohort one, 17 patients; cohort two, 13 patients). Eighteen of the 30 patients (cohort one, 11 patients; cohort two, seven patients) completed > or = 12 weeks of treatment. Six patients achieved prolonged disease stabilization (cohort one, two patients [40 and 25 weeks]; cohort two, four patients [34, 24, 22, and 24 weeks]). A significant rise in immunoreactive TNF was seen in all patients (pretreatment compared with end of treatment). A phytohemagglutinin-stimulated whole-blood cytokine assay showed a significant fall in interleukin-6 (cohort one [11 of 17]) and CCL2 (cohort one [13 of 17]) levels. Common adverse effects were injection-site reactions and fatigue. CONCLUSION: We provide evidence for the biologic activity and safety of etanercept in recurrent ovarian cancer. Our data suggest possible clinical activity that must be confirmed in future studies.

Phase I study of MetXia-P450 gene therapy and oral cyclophosphamide for patients with advanced breast cancer or melanoma.

PURPOSE: MetXia-P450 is a novel recombinant retroviral vector that encodes the human cytochrome P450 type 2B6 gene (CYP2B6), Escherichia coli lacZ, and neomycin resistance marker genes. Cytochrome P450 enzymes are primarily expressed in the liver and convert the prodrug cyclophosphamide to an active phosphoramide mustard and acrolein. Gene-based delivery of CYP2B6 to the tumor site leads to local prodrug activation and higher concentrations of the active metabolites at the target site. EXPERIMENTAL DESIGN: MetXia-P450 was directly injected into metastatic cutaneous tumor nodules on days 1 and 2 and nodules biopsied on day 7. Oral cyclophosphamide (100 mg/m(2)) was administered between days 8 and 22. Subsequent cycles of oral cyclophosphamide were repeated for 2 of 4 weeks. Gene transfer levels in biopsy samples were measured by histologic and quantitative PCR analyses. Safety assessments were made using PCR for vector dissemination to the blood after injection and using PCR and serologic analyses to detect replicating virus. Secondary end points included clinical response, toxicity, and evaluation of antitumor immune responses by measurement of carcinoembryonic antigen and 5T4 antibodies. RESULTS: Twelve patients with breast cancer (n = 9) and melanoma (n = 3) received three dose levels of MetXia-P450 ( approximately 8 x 10(5), approximately 8 x 10(6), and approximately 8 x 10(7) lacZ transferring units/mL). The product was safe and well tolerated. The lacZ transgene was detected in biopsy material by immunohistochemistry in 10 of 12 patients and integrated viral sequences by PCR in 3 of 6 patients. One (8%) patient with breast cancer had a partial response and received 7 months of oral cyclophosphamide. Four (33%) patients had stable disease for > or =3 months and the rest had progressive disease. Preliminary immunologic analyses were suggestive of an antitumor response in two patients (partial response in one patient and stable disease in one patient). CONCLUSION: MetXia was safe and well tolerated. Gene transfer was detected at all dose levels, and the initial suggestion of an antitumor response indicates that MetXia-P450 should undergo further clinical assessment.

A phase II study of etanercept (Enbrel), a tumor necrosis factor alpha inhibitor in patients with metastatic breast cancer.

PURPOSE: Tumor necrosis factor (TNF) alpha is a key player in the tumor microenvironment and is involved in the pathogenesis of breast cancer. Etanercept is a recombinant human soluble p75 TNF receptor that binds to TNF-alpha and renders it biologically unavailable. In the current study, we sought to determine the toxicity, biological activity, and therapeutic efficacy of Etanercept in metastatic breast cancer. EXPERIMENTAL DESIGN: We initiated a Phase II, nonrandomized, open-labeled study in patients with progressive metastatic breast cancer refractory to conventional therapy (Phase I toxicity data were available in patients with rheumatoid arthritis). Etanercept was administered subcutaneously at a dose of 25 mg twice weekly until disease progression. RESULTS: Sixteen patients were recruited [median age 53 years (range, 34 to 74)]. A total of 141.6 weeks of therapy was administered (median of 8.1 weeks). Seven patients received > or =12 weeks of therapy. The most common side effects were injection site reactions (6), fatigue (5), loss of appetite (2), nausea (1), headache (1), and dizziness (1). Brief period of disease stabilization was seen in 1 patient lasting for 16.4 weeks. Immunoreactive TNF-alpha was elevated within 24 hours of therapy and persisted until the end of treatment (days 7, 28, 56, and 84). Phytohemagglutinin stimulates the production of interleukin-6 and CCL2 in peripheral blood cells, and the ability of Etanercept to modulate this response was assessed in a cytokine release assay. A consistent decrease in interleukin-6 and CCL2 level was seen compared with pretreatment values in serial blood samples (days 1, 7, 28, 56, and 84). CONCLUSIONS: Our study shows the safety and biological activity of Etanercept in breast cancer and provides data to assess pharmacodynamic endpoints of different schedules of Etanercept and combinations with chemotherapy or other biological therapies.

Pharmacokinetic study of cisplatin and infusional etoposide phosphate in advanced breast cancer with correlation of response to topoisomerase IIalpha expression.

PURPOSE: There is substantial interpatient variability in etoposide pharmacokinetics. Pharmacokinetic adjustment to specific plasma concentrations may make it possible to define a therapeutic plasma concentration and relate drug target expression in the tumor to response. This study evaluated the combination of cisplatin with a prolonged infusion of etoposide phosphate (EP) in advanced breast cancer and correlated response to topoisomerase II expression. EXPERIMENTAL DESIGN: Eligible patients, previously treated with an anthracycline, received 60 mg/m(2) cisplatin, followed by a 5-day infusion of EP. Plasma etoposide levels were measured on days 2 and 4 of each cycle with adjustment of the infusion rate to achieve an initial target etoposide concentration of 2 micro g/ml or 1.5 micro g/ml. Primary tumor blocks were stained by immunohistochemistry for topoisomerase IIalpha and beta. RESULTS: Thirty-six patients, treated in three consecutive cohorts, received 145 cycles of chemotherapy. Targeting plasma etoposide concentration reduced interpatient pharmacokinetic variability (32% and 62% of patients, respectively, within 10% of target concentration on days 2 and 4; cycle 1). Significant hematological toxicity (89% of patients with at least one episode of grade III/IV neutropenia, 64% of patients with at least one episode of grade III/IV thrombocytopenia) was observed. Thirty-nine percent of patients achieved a partial response, and 19% had stable disease for at least 3 months. The median time to tumor progression was 4 months, with a median survival of 11 months. Topoisomerase IIalpha expression was significantly higher (P < 0.001) in responding patients compared with those with stable or progressive disease. There was no difference in topoisomerase IIbeta expression between groups. CONCLUSION: Cisplatin and infusional EP is an active, but intensive, schedule in heavily pretreated patients with breast cancer. Clinical response correlates with tumor topoisomerase IIalpha expression.

Functional interaction between the Bloom's syndrome helicase and the RAD51 paralog, RAD51L3 (RAD51D).

Bloom's syndrome (BS) is a genetic disorder associated with short stature, fertility defects, and a predisposition to the development of cancer. BS cells are characterized by genomic instability; in particular, a high rate of reciprocal exchanges between sister-chromatids and homologous chromosomes. The BS gene product, BLM, is a helicase belonging to the highly conserved RecQ family. BLM is known to form a complex with the RAD51 recombinase, and to act upon DNA intermediates that form during homologous recombination, including D-loops and Holliday junctions. Here, we show that BLM also makes a direct physical association with the RAD51L3 protein (also known as RAD51D), a so-called RAD51 paralog that shows limited sequence similarity to RAD51 itself. This interaction is mediated through the N-terminal domain of BLM. To analyze functional interactions between BLM and RAD51L3, we have purified a heteromeric complex comprising RAD51L3 and a second RAD51 paralog, XRCC2. We show that the RAD51L3-XRCC2 complex stimulates BLM to disrupt synthetic 4-way junctions that model the Holliday junction. We also show that a truncated form of BLM, which retains helicase activity but is unable to bind RAD51L3, is not stimulated by the RAD51L3-XRCC2 complex. Our data indicate that the activity of BLM is modulated through an interaction with the RAD51L3-XRCC2 complex, and that this stimulatory effect on BLM is dependent upon a direct physical association between the BLM and RAD51L3 proteins. We propose that BLM co-operates with RAD51 paralogs during the late stages of homologous recombination processes that serve to restore productive DNA replication at sites of damaged or stalled replication forks.

Low-dose IFN-gamma induces tumor MHC expression in metastatic malignant melanoma.

Specific antitumor immune responses require expression of MHC class I or II molecules on tumor cells, and MHC antigen down-regulation is a presumed tumor growth promoting mechanism. Because IFN-gamma up-regulates tumor MHC antigen expression in vitro, in this Phase II trial of an immunologically active dose and schedule we evaluated whether this was the case in vivo. Twenty-three patients with metastatic melanoma were treated with IFN-gamma 100 microg/m(2) s.c. once weekly for a maximum of 6 months. There were three complete responses, now maintained for 53, 36, and 25 months. The remainder had progressive disease. The treatment was well tolerated, with no toxicity exceeding National Cancer Institute Common Toxicity Criteria grade II. Immunohistochemical analysis of tumor biopsies during treatment was performed using monoclonal antibodies to HLA class I (W/632) and class II (CR3/43) monomorphic determinants. HLA class I was down-regulated in 2 of 19 patients pretreatment and up-regulated by IFN-gamma in both. HLA class II was down-regulated pretreatment in 14 of 18 patients and up-regulated by IFN-gamma in 6 (43%). The HLA up-regulation persisted throughout the study. IFN-gamma induced significant but short-lived up-regulation of surrogate markers of monocyte activation (serum neopterin) and class I up-regulation (serum beta-2-microglobulin) in most patients. There was no consistent relationship between surrogate marker up-regulation, tumor antigen up-regulation, and responses. The study shows that the significant immune modulation induced by IFN-gamma does not correlate with tumor responses and that the serum surrogate marker changes do not reflect tumor events. The durable and long-lived responses, clear demonstration of tumor MHC up-regulation, and low toxicity suggest that weekly IFN-gamma 100 microg/m(2) would be a useful addition to chemoimmunotherapeutic regimens.