Selenium speciation studies in cancer patients to evaluate the responses of biomarkers of selenium status to different selenium compounds.

This work presents the first systematic comparison of selenium (Se) speciation in plasma from cancer patients treated orally with three Se compounds (sodium selenite, SS; L-selenomethionine, SeMet; or Se-methylselenocysteine, MSC) at 400 µg/day for 28 days. The primary goal was to investigate how these chemical forms of Se affect the plasma Se distribution, aiming to identify the most effective Se compound for optimal selenoprotein expression. This was achieved using methodology based on HPLC-ICP-MS after sample preparation/fractionation approaches. Measurements of total Se in plasma samples collected before and after 4 weeks of treatment showed that median total Se levels increased significantly from 89.6 to 126.4 µg kg-1 Se (p < 0.001), particularly when SeMet was administered (190.4 µg kg-1 Se). Speciation studies showed that the most critical differences between treated and baseline samples were seen for selenoprotein P (SELENOP) and selenoalbumin after administration with MSC (p = 5.8 × 10-4) and SeMet (p = 6.8 × 10-5), respectively. Notably, selenosugar-1 was detected in all low-molecular-weight plasma fractions following treatment, particularly with MSC. Two different chromatographic approaches and spiking experiments demonstrated that about 45% of that increase in SELENOP levels (to ~ 8.8 mg L-1) with SeMet is likely due to the non-specific incorporation of SeMet into the SELENOP affinity fraction. To the authors' knowledge, this has not been reported to date. Therefore, SELENOP is probably part of both the regulated (55%) and non-regulated (45%) Se pools after SeMet administration, whereas SS and MSC mainly contribute to the regulated one.

Management of rectal cancer in the era of total neoadjuvant therapy and watch and wait: A multidisciplinary team discussion at the Australasian Gastro-Intestinal Trials Group (AGITG) Annual Scientific Meeting 2022.

Rectal cancer is a common malignancy. The management of rectal cancer has recently evolved and has undergone a paradigm shift with the advent of treatment approaches such as total neoadjuvant therapy and the watch-and-wait approach. However, despite the recently available evidence, there is no consensus on the optimal management approach in the setting of locally advanced rectal cancer. To address some of the controversies, a joint multidisciplinary panel discussion was conducted at the Australasian Gastro-Intestinal Trials Group (AGITG) Annual Scientific Meeting in November 2022. Members from different subspecialties formed two panels and discussed three clinical cases in a debate format. Each case represented some of the complex issues faced by clinicians in this setting. The discussion is now presented in this manuscript, which depicts the different available management approaches and reiterates the importance of a multidisciplinary approach.

Development and Validation of a Machine Learning Approach Leveraging Real-World Clinical Narratives as a Predictor of Survival in Advanced Cancer.

PURPOSE: Predicting short-term mortality in patients with advanced cancer remains challenging. Whether digitalized clinical text can be used to build models to enhance survival prediction in this population is unclear. MATERIALS AND METHODS: We conducted a single-centered retrospective cohort study in patients with advanced solid tumors. Clinical correspondence authored by oncologists at the first patient encounter was extracted from the electronic medical records. Machine learning (ML) models were trained using narratives from the derivation cohort, before being tested on a temporal validation cohort at the same site. Performance was benchmarked against Eastern Cooperative Oncology Group performance status (PS), comparing ML models alone (comparison 1) or in combination with PS (comparison 2), assessed by areas under receiver operating characteristic curves (AUCs) for predicting vital status at 11 time points from 2 to 52 weeks. RESULTS: ML models were built on the derivation cohort (4,791 patients from 2001 to April 2017) and tested on the validation cohort of 726 patients (May 2017-June 2019). In 441 patients (61%) where clinical narratives were available and PS was documented, ML models outperformed the predictivity of PS (mean AUC improvement, 0.039, P < .001, comparison 1). Inclusion of both clinical text and PS in ML models resulted in further improvement in prediction accuracy over PS with a mean AUC improvement of 0.050 (P < .001, comparison 2); the AUC was > 0.80 at all assessed time points for models incorporating clinical text. Exploratory analysis of oncologist's narratives revealed recurring descriptors correlating with survival, including referral patterns, mobility, physical functions, and concomitant medications. CONCLUSION: Applying ML to oncologists' narratives with or without including patient's PS significantly improved survival prediction to 12 months, suggesting the utility of clinical text in building prognostic support tools.

Ethnic Differences in Cancer Rates Among Adults With Type 2 Diabetes in New Zealand From 1994 to 2018.

Importance: People with type 2 diabetes have greater risk for some site-specific cancers, and risks of cancers differ among racial and ethnic groups in the general population of Aotearoa New Zealand. The extent of ethnic disparities in cancer risks among people with type 2 diabetes in New Zealand is unclear. Objective: To compare the risks of 21 common adult cancers among Maori, Pasifika, and New Zealand European individuals with type 2 diabetes in New Zealand from 1994 to 2018. Design, Setting, and Participants: This population-based, matched cohort study used data from the primary care audit program in Auckland, New Zealand, linked with national cancer, death, and hospitalization registration databases, collected from January 1, 1994, to July 31, 2018, with follow-up data obtained through December 31, 2019. Using a tapered matching method to balance potential confounders (sociodemographic characteristics, lifestyle, anthropometric and clinical measurements, treatments [antidiabetes, antihypertensive, lipid-lowering, and anticoagulant], period effects, and recorded duration of diabetes), comparative cohorts were formed between New Zealand European and Maori and New Zealand European and Pasifika individuals aged 18 years or older with type 2 diabetes. Sex-specific matched cohorts were formed for sex-specific cancers. Exposures: Maori, Pasifika, and New Zealand European (reference group) ethnicity. Main Outcomes and Measures: The incidence rates of 21 common cancers recorded in nationally linked databases between 1994 and 2018 were the main outcomes. Weighted Cox proportional hazards regression was used to assess ethnic differences in risk of each cancer. Results: A total of 33 524 adults were included: 15 469 New Zealand European (mean [SD] age, 61.6 [13.2] years; 8522 [55.1%] male), 6656 Maori (mean [SD] age, 51.2 [12.4] years; 3345 [50.3%] female), and 11 399 Pasifika (mean [SD] age, 52.8 [12.7] years; 5994 [52.6%] female) individuals. In the matched New Zealand European and Maori cohort (New Zealand European: 8361 individuals; mean [SD] age, 58.9 [12.9] years; 4595 [55.0%] male; Maori: 5039 individuals; mean [SD] age, 51.4 [12.3] years; 2542 [50.5%] male), significant differences between New Zealand European and Maori individuals were identified in the risk for 7 cancers. Compared with New Zealand European individuals, the hazard ratios (HRs) among Maori individuals were 15.36 (95% CI, 4.50-52.34) for thyroid cancer, 7.94 (95% CI, 1.57-40.24) for gallbladder cancer, 4.81 (95% CI, 1.08-21.42) for cervical cancer (females only), 1.97 (95% CI, 1.30-2.99) for lung cancer, 1.81 (95% CI, 1.08-3.03) for liver cancer, 0.56 (95% CI, 0.35-0.90) for colon cancer, and 0.11 (95% CI, 0.04-0.27) for malignant melanoma. In the matched New Zealand European and Pasifika cohort (New Zealand European: 9340 individuals; mean [SD] age, 60.6 [13.1] years; 4885 [52.3%] male; Pasifika: 8828 individuals; mean [SD] age, 53.1 [12.6] years; 4612 [52.2%] female), significant differences between New Zealand European and Pasifika individuals were identified for 6 cancers. Compared with New Zealand European individuals, HRs among Pasifika individuals were 25.10 (95% CI, 3.14-200.63) for gallbladder cancer, 4.47 (95% CI, 1.25-16.03) for thyroid cancer, 0.48 (95% CI, 0.30-0.78) for colon cancer, 0.21 (95% CI, 0.09-0.48) for rectal cancer, 0.21 (95% CI, 0.07-0.65) for malignant melanoma, and 0.01 (95% CI, 0.01-0.10) for bladder cancer. Conclusions and Relevance: In this cohort study, differences in the risk of 21 common cancers were found between New Zealand European, Maori, and Pasifika groups of adults with type 2 diabetes in New Zealand from 1994 to 2018. Research into the mechanisms underlying these differences as well as additional screening strategies (eg, for thyroid and gallbladder cancers) appear to be warranted.

Two cycles of adjuvant carboplatin for clinical stage 1 testicular seminoma in New Zealand centres: A retrospective analysis of efficacy and long-term events.

BACKGROUND: Adjuvant carboplatin reduces relapse risk in clinical stage 1 (CS1) seminoma, though there is a paucity of long-term safety data. AIM: Our objective was to report long-term outcomes of two cycles of adjuvant carboplatin dosed at area under the time-concentration curve (AUC) of 7. METHODS AND RESULTS: We performed a retrospective analysis on treatment and outcomes of patients with CS1 seminoma who received adjuvant carboplatin from 2000 to 2016 at our centres in the Midland Region, New Zealand. Of 159 patients, median age 39 years, 153 received two cycles of carboplatin: 147 dosed at AUC7 and 6 at AUC6. Six patients had one cycle of carboplatin AUC7. One patient relapsed at 22 months and died of bleomycin pneumonitis 2 months after achieving a complete response with BEP chemotherapy. Neither RTI (present in 21.3%) nor tumor size >4 cm (in 43.3%) was predictive of relapse. Median follow-up was 106 months. At 15 years, outcomes were: relapse-free survival 99.4%, overall survival 91.4%, disease-specific survival 100%, subsequent malignant neoplasm rate 7.6%, and second testicular germ cell tumor rate 3.85%. One patient had persistent grade 1 thrombocytopenia at 46 months. CONCLUSIONS: These data add to the body of evidence that two cycles of carboplatin AUC7 is safe and effective adjuvant treatment for CS1 seminoma.

Long-term Follow-up of Standard-Dose Pembrolizumab Plus Reduced-Dose Ipilimumab in Patients with Advanced Melanoma: KEYNOTE-029 Part 1B.

PURPOSE: Combination therapy with reduced-dose programmed death 1 inhibitor plus standard-dose cytotoxic T-lymphocyte-associated antigen 4 inhibitor demonstrated efficacy, but substantial toxicity, in melanoma. We present long-term results of part 1B of KEYNOTE-029, which assessed safety and efficacy of standard-dose pembrolizumab plus reduced-dose ipilimumab in advanced melanoma. PATIENTS AND METHODS: Part 1B was an expansion cohort of the open-label, phase Ib portion of KEYNOTE-029. Eligible patients had advanced melanoma and no previous immune checkpoint inhibitor therapy. Patients received pembrolizumab 2 mg/kg (amended to 200 mg) every 3 weeks plus ipilimumab 1 mg/kg every 3 weeks (four cycles), then pembrolizumab alone for up to 2 years. Primary end point was safety; secondary end points included objective response rate (ORR), progression-free survival (PFS), duration of response (DOR), and overall survival (OS). RESULTS: A total of 153 patients received at least one dose of pembrolizumab plus ipilimumab. At a median follow-up of 36.8 months, 71.9% had received four doses of ipilimumab and 30.7% had completed 2 years of pembrolizumab; 26.1% completed both treatments. Treatment-related adverse events occurred in 96.1% (47.1% grade 3/4; no deaths), leading to discontinuation of one or both study drugs in 35.9%. ORR was 62.1% with 42 (27.5%) complete and 53 (34.6%) partial responses. Median DOR was not reached; 36-month ongoing response rate was 84.2%. Median PFS and OS were not reached; 36-month rates were 59.1% and 73.4%, respectively. CONCLUSIONS: Standard-dose pembrolizumab plus reduced-dose ipilimumab demonstrated robust antitumor activity, durable response, and favorable long-term survival with manageable toxicity.

Doxorubicin and cyclophosphamide-induced parotitis: A case report.

WHAT IS KNOWN AND OBJECTIVE: Drug-induced parotitis is a rare adverse drug reaction (ADR). A comprehensive literature review identified only three clearly associated medications: L-asparaginase, clozapine and phenylbutazone. CASE DESCRIPTION: We describe a novel case of drug-induced parotitis attributed to doxorubicin and cyclophosphamide chemotherapy for breast cancer. WHAT IS NEW AND CONCLUSION: Using general and parotitis-specific tools for assessing the probability of an ADR, we estimate the association of doxorubicin and cyclophosphamide with parotitis in this case as 'probable'. To our knowledge, this represents the first reported case of parotitis attributable to these medications and provides a valuable learning tool for the assessment of previously unrecognized ADRs.

Comparison of three oral selenium compounds in cancer patients: Evaluation of differential pharmacodynamic effects in normal and malignant cells.

BACKGROUND: Selenium (Se) compounds have demonstrated therapeutic synergism in combination with anticancer treatments whilst reducing normal tissue toxicities in a range of experimental models. While reduction in some toxicities of chemotherapy and radiation has been confirmed in randomised clinical trials, they have not been powered to evaluate improved anticancer efficacy. A lack of data on the clinical potencies of the main nutritionally-relevant forms of Se and the relationship between their pharmacokinetic (PK) profiles and pharmacodynamic (PD) effects in cancer patients has hampered progress to date. The primary objective of this study was to determine the dose and form of Se that can be most safely and effectively used in clinical trials in combination with anti-cancer therapies. STUDY METHODS: In a phase I randomised double-blinded study, the PD profile of sodium selenite (SS), Se-methylselenocysteine (MSC) and seleno-l-methionine (SLM) were compared in two cohorts of 12 patients, one cohort with chronic lymphocytic leukaemia (CLL) and the other with solid malignancies. All 24 patients were randomised to receive 400 µg of elemental Se as either SS, MSC or SLM, taken orally daily for 8 weeks. PD parameters were assessed before, during and 4 weeks after Se compound exposure in plasma and peripheral blood mononuclear cells (PBMCs). RESULTS: No significant sustained changes were observed in plasma concentrations of vascular endothelial growth factor-α (VEGF-α), expression of proteins associated with endoplasmic reticulum stress (the unfolded protein response) or in intracellular total glutathione in PBMCs, in either disease cohort or when grouped by Se compound. CONCLUSIONS: At the 400 µg dose level no substantial changes in PD parameters were noted. Extrapolating from pre-clinical data, the dose examined in this cohort was too low to achieve the Se plasma concentration (≥ 5 µM) expected to elicit significant PD effects. Recruitment of a subsequent cohort at higher doses to exceed this PK threshold is planned.

SPAR - a randomised, placebo-controlled phase II trial of simvastatin in addition to standard chemotherapy and radiation in preoperative treatment for rectal cancer: an AGITG clinical trial.

BACKGROUND: Retrospective studies show improved outcomes in colorectal cancer patients if taking statins, including overall survival, pathological response of rectal cancer to preoperative chemoradiotherapy (pCRT), and reduced acute and late toxicities of pelvic radiation. Major tumour regression following pCRT has strong prognostic significance and can be assessed in vivo using MRI-based tumour regression grading (mrTRG) or after surgery using pathological TRG (pathTRG). METHODS: A double-blind phase 2 trial will randomise 222 patients planned to receive long-course fluoropyrimidine-based pCRT for rectal adenocarcinoma at 18+ sites in New Zealand and Australia. Patients will receive simvastatin 40 mg or placebo daily for 90 days starting 1 week prior to standard pCRT. Pelvic MRI 6 weeks after pCRT will assess mrTRG grading prior to surgery. The primary objective is rates of favourable (grades 1-2) mrTRG following pCRT with simvastatin compared to placebo, considering mrTRG in 4 ordered categories (1, 2, 3, 4-5). Secondary objectives include comparison of: rates of favourable pathTRG in resected tumours; incidence of toxicity; compliance with intended pCRT and trial medication; proportion of patients undergoing surgical resection; cancer outcomes and pathological scores for radiation colitis. Tertiary objectives include: association between mrTRG and pathTRG grouping; inter-observer agreement on mrTRG scoring and pathTRG scoring; studies of T-cell infiltrates in diagnostic biopsies and irradiated resected normal and malignant tissue; and the effect of simvastatin on markers of systemic inflammation (modified Glasgow prognostic score and the neutrophil-lymphocyte ratio). Trial recruitment commenced April 2018. DISCUSSION: When completed this study will be able to observe meaningful differences in measurable tumour outcome parameters and/or toxicity from simvastatin. A positive result will require a larger RCT to confirm and validate the merit of statins in the preoperative management of rectal cancer. Such a finding could also lead to studies of statins in conjunction with chemoradiation in a range of other malignancies, as well as further exploration of possible mechanisms of action and interaction of statins with both radiation and chemotherapy. The translational substudies undertaken with this trial will provisionally explore some of these possible mechanisms, and the tissue and data can be made available for further investigations. TRIAL REGISTRATION: ANZ Clinical Trials Register ACTRN12617001087347. (www.anzctr.org.au, registered 26/7/2017) Protocol Version: 1.1 (June 2017).

Comparative Safety and Pharmacokinetic Evaluation of Three Oral Selenium Compounds in Cancer Patients.

Selenium (Se) compounds have demonstrated anticancer properties in both preclinical and clinical studies, with particular promise in combination therapy where the optimal form and dose of selenium has yet to be established. In a phase I randomised double-blinded study, the safety, tolerability and pharmacokinetic (PK) profiles of sodium selenite (SS), Se-methylselenocysteine (MSC) and seleno-l-methionine (SLM) were compared in patients with chronic lymphocytic leukaemia and a cohort of patients with solid malignancies. Twenty-four patients received 400 µg of elemental Se as either SS, MSC or SLM for 8 weeks. None of the Se compounds were associated with any significant toxicities, and the total plasma Se AUC of SLM was markedly raised in comparison to MSC and SS. DNA damage assessment revealed negligible genotoxicity, and some minor reductions in lymphocyte counts were observed. At the dose level used, all three Se compounds are well-tolerated and non-genotoxic. Further analyses of the pharmacodynamic effects of Se on healthy and malignant peripheral blood mononuclear cells will inform the future evaluation of higher doses of these Se compounds. The study is registered under the Australian and New Zealand Clinical Trials Registry No: ACTRN12613000118707.

The Interaction of Selenium with Chemotherapy and Radiation on Normal and Malignant Human Mononuclear Blood Cells.

Selenium, a trace element with anticancer properties, can reduce harmful toxicities of chemotherapy and radiotherapy without compromising efficacy. However, the dose-response relationship in normal versus malignant human cells is unclear. We evaluated how methylseleninic acid (MSA) modulates the toxicity and efficacy of chemotherapy and radiation on malignant and non-malignant human mononuclear blood cells in vitro. We specifically investigated its effects on endoplasmic reticulum stress induction, intracellular glutathione concentration, DNA damage and viability of peripheral blood mononuclear cells and THP1 monocytic leukaemia cells in response to radiation, cytosine arabinoside or doxorubicin chemotherapy. MSA, at lower concentrations, induced protective responses in normal cells but cytotoxic effects in malignant cells, alone and in conjunction with chemotherapy or radiation. However, in normal cells higher concentrations of MSA were directly toxic and increased the cytotoxicity of radiation but not chemotherapy. In malignant cells higher MSA concentrations were generally more effective in combination with cancer treatments. Thus, optimal MSA concentrations differed between normal and malignant cells and treatments. This work supports clinical reports that selenium can significantly reduce dose-limiting toxicities of anticancer therapies and potentially improve efficacy of anticancer treatments. The optimal selenium compound and dose is not yet determined.

Outcomes after primary intensity-modulated radiation therapy for oropharyngeal squamous cell carcinoma at a New Zealand regional cancer centre: Impact of p16 status.

INTRODUCTION: The rising incidence of oropharyngeal squamous cell carcinoma (OPSCC) in New Zealand is due to an increase in the numbers of human papilloma virus (HPV)-associated OPSCC. We evaluated the impact of positive p16 immunohistochemistry, as a surrogate for HPV positivity, on OPSCC outcomes after primary intensity-modulated radiotherapy (IMRT) with or without concurrent chemotherapy. METHODS: Retrospective review was undertaken of electronic medical records of 90 patients with OPSCC who received primary IMRT with or without chemotherapy between 2008 and mid-2015 at the Regional Cancer Centre, Waikato Hospital, Hamilton, New Zealand. RESULTS: Median age was 57.5 years. Immunohistochemistry for p16 was positive in 53 (59%) OPSCC while 37 (41%) had negative or unknown p16 status. Median radiotherapy dose was 70 Gy. Chemotherapy was administered to 78 (87%) patients, most receiving high-dose cisplatin. Nine patients had residual disease following treatment completion. Seven patients relapsed, and 26 died during the study period. Five patients with p16-positive OPSCC had persistent or recurrent disease. Actuarial 3-year locoregional control, disease-free survival, and overall survival for all patients were 80.7%, 74.7%, and 77.1%, respectively. Among p16-positive OPSCC patients, 3-year locoregional control, disease-free survival, and overall survival were 89.5%, 80.8%, and 90.9%, respectively. CONCLUSION: Outcomes after IMRT for OPSCC at Waikato Hospital are in line with the reported literature. Human papilloma virus-related OPSCC has better outcomes compared with patients with unknown or HPV-unrelated OPSCC. Trials are underway evaluating reduced intensity of treatment for HPV-related OPSCC.

Phase IB Trial of the Anti-Cancer Stem Cell DLL4-Binding Agent Demcizumab with Pemetrexed and Carboplatin as First-Line Treatment of Metastatic Non-Squamous NSCLC.

BACKGROUND: Delta-like ligand 4-Notch (DLL4-Notch) signaling contributes to the maintenance of chemotherapy-resistant cancer stem cells and tumor vasculature. OBJECTIVE: This phase IB trial of demcizumab, an IgG2 humanized monoclonal antibody directed against DLL4, was undertaken to determine its maximum tolerated dose, safety, immunogenicity, preliminary efficacy, pharmacokinetics, and pharmacodynamics, combined with standard chemotherapy. PATIENTS AND METHODS: Forty-six treatment-naive patients with metastatic non-squamous non-small cell lung cancer (NSCLC) were enrolled in this open-label, dose-escalation study using a standard 6 + 6 design. Demcizumab (2.5, 5.0, and 7.5 mg/kg) was given once every 3 weeks with standard doses of pemetrexed and carboplatin using a continuous (six cycles followed by demcizumab maintenance) or a truncated demcizumab regimen (four cycles followed by pemetrexed maintenance). RESULTS: Initially, continuous demcizumab was given until progression but two patients developed grade 3 pulmonary hypertension and congestive heart failure after eight or more infusions. Thereafter, 23 patients were treated with a truncated regimen of demcizumab, which was not associated with any grade 3 or greater cardiopulmonary toxicity. Common adverse events were hypertension, raised brain natriuretic peptide, and those expected from carboplatin and pemetrexed alone. Twenty of 40 evaluable patients (50%) had objective tumor responses. In peripheral blood, demcizumab treatment modulated the expression of genes regulating Notch signaling and angiogenesis, and achieved concentrations exceeding those saturating DLL4 binding. CONCLUSIONS: This study has identified a truncated dosing regimen and recommended phase II dose of demcizumab (5 mg/kg q3-weekly ×4) for subsequent clinical evaluation in combination with standard carboplatin and pemetrexed chemotherapy. NCT01189968.

Skin lesions suspicious for melanoma: New Zealand excision margin guidelines in practice.

INTRODUCTION New Zealand guidelines for cutaneous melanoma management recommend excision biopsy specimens of suspected lesions have a 2 mm horizontal margin, and a deep margin into upper subcutis. AIM To assess guideline compliance of suspicious lesion biopsies taken in the community and in a hospital. METHODS Patients admitted to Waikato Hospital, Hamilton, for diagnostic or treatment melanoma surgery during the year ending February 2016 were retrospectively identified, and their demographic and biopsy characteristics examined. RESULTS In total, 140 patients had excision biopsies: 61.4% were performed outside the hospital. Biopsy data were available for 126 specimens. Mean horizontal margin was greater (P = 0.001) in hospital biopsies (4.8 mm, standard deviation (s.d.) 3.7 mm) than biopsies performed elsewhere (2.8 mm; s.d. 1.8 mm). Horizontal margins >2.0 mm occurred in 70.6% of specimens; 21.6% of ≤2.0 mm specimens had a tumour-positive margin. Subsequent wide local excision identified residual melanoma in 9.6% of specimens, which was not associated (P = 0.3) with primary horizontal margin ≤2.0 mm. Mean deep margin of hospital biopsies (6.5 mm; s.d. 2.7 mm) was greater (P < 0.001) than in other biopsies (4.1 mm; s.d. 2.7 mm). Horizontal margin >2.0 mm specimens had greater (P < 0.001) mean deep margin (5.9 mm; s.d. 2.7 mm) than specimens with horizontal margin ≤2.0 mm (mean deep margin 3.3 mm; s.d. 2.7 mm). Deep margin ≤2.0 mm (19.0%) was independently associated with the facility where biopsy was performed (P = 0.001) and horizontal margin (P < 0.001). DISCUSSION The New Zealand biopsy deep margin recommendation does not lend itself to meaningful audit. Compliance with the horizontal margin recommendation was low, but of uncertain clinical significance.

Optimising Selenium for Modulation of Cancer Treatments.

Selenium is an essential trace element involved in many biological processes that are mediated through, at least, 25 selenoproteins expressed in humans. Extensive study of selenium compounds has demonstrated growth inhibition of malignant cells in a vast array of experimental models. Moreover combining selenium with conventional cancer therapy has yielded promising results in both preclinical studies and a cohort of human trials. The aim of this review is to highlight the current research evaluating the role of selenium compounds in combination with chemotherapy and radiation. Pharmacodymanic mechanisms responsible for the differential effects of the commonly studied compounds on healthy and malignant cells are presented and the pertinent in vitro and in vivo data summarised. The clinical utility of this approach is discussed both in terms of anti-tumour efficacy and toxicity prevention. Finally a case is made for novel trial designs to facilitate rapid progression into pivotal studies.

Standard-dose pembrolizumab in combination with reduced-dose ipilimumab for patients with advanced melanoma (KEYNOTE-029): an open-label, phase 1b trial.

BACKGROUND: Reduced-dose nivolumab in combination with standard-dose ipilimumab improves objective response and progression-free survival compared with standard-dose ipilimumab alone, but increases toxicity. We assessed the safety and anti-tumour activity of standard-dose pembrolizumab in combination with reduced-dose ipilimumab. METHODS: In this open-label, phase 1b trial, we recruited patients from 12 medical centres in Australia, New Zealand, and the USA. Eligible patients were aged at least 18 years, had advanced melanoma, had an Eastern Coooperative Oncology Group performance status of 0 or 1, had measurable disease according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, had adequate organ function, had resolution of toxic effects of the most recent previous chemotherapy to grade 1 or less, had no active autoimmune disease requiring systemic steroids or immunosuppressive agents, had no active non-infectious pneumonitis, had no uncontrolled thyroid dysfunction or diabetes, had no active brain metastases, and had not received previous immune checkpoint inhibitor therapy. Patients received intravenous pembrolizumab 2 mg/kg plus intravenous ipilimumab 1 mg/kg every 3 weeks for four doses, followed by intravenous pembrolizumab 2 mg/kg every 3 weeks for up to 2 years or disease progression, intolerable toxicity, withdrawal of consent, or investigator decision. The primary endpoint was safety and tolerability. The proportion of patients achieving an objective response assessed per RECIST version 1.1 by independent central review and overall survival were secondary endpoints. We also assessed progression-free survival. The primary endpoint was assessed in all patients who received at least one dose of combination therapy. Activity was assessed in all enrolled patients. This trial is registered with ClinicalTrials.gov, number NCT02089685. Enrolment into this cohort is closed, but patients are still being monitored for safety and anti-tumour activity. FINDINGS: Between Jan 13, 2015, and Sept 17, 2015, we enrolled and treated 153 patients. As of the Oct 17, 2016, cutoff date, median follow-up was 17·0 months (IQR 14·8-18·8). 110 (72%) of 153 patients received all four pembrolizumab plus ipilimumab doses; 64 (42%) remained on pembrolizumab monotherapy. 110 grade 3-4 treatment-related adverse events occurred in 69 (45%) patients. No treatment-related deaths occurred. Treatment-related adverse events led to discontinuation of pembrolizumab and ipilimumab in 22 (14%) patients, including 17 (11%) who discontinued both treatments for the same event and five (3%) who discontinued ipilimumab for one event and later discontinued pembrolizumab for another. 12 (8%) patients discontinued ipilimumab only and 14 (9%) discontinued pembrolizumab only because of treatment-related adverse events. 158 immune-mediated adverse events of any grade occurred in 92 (60%) patients, and 50 immune-mediated adverse events of grade 3-4 occurred in 42 (27%) patients; the most common immune-mediated adverse events were hypothyroidism (25 [16%]) and hyperthyroidism (17 [11%]). 93 (61% [95% CI 53-69]) patients achieved an objective response. Estimated 1 year progression-free survival was 69% (95% CI 60-75), and estimated 1 year overall survival was 89% (95% CI 83-93). INTERPRETATION: Standard-dose pembrolizumab given in combination with four doses of reduced-dose ipilimumab followed by standard-dose pembrolizumab has a manageable toxicity profile and provides robust anti-tumour activity in patients with advanced melanoma. These data suggest that standard-dose pembrolizumab plus reduced-dose ipilimumab might be a tolerable, efficacious treatment option for patients with advanced melanoma. A randomised phase 2 trial of alternative dosing strategies of this combination is underway. FUNDING: Merck & Co, Inc.

Development of a qPCR Method to Measure Mitochondrial and Genomic DNA Damage with Application to Chemotherapy-Induced DNA Damage and Cryopreserved Cells.

DNA damage quantitation assays such as the comet assay have focused on the measurement of total nuclear damage per cell. The adoption of PCR-based techniques to quantify DNA damage has enabled sequence- and organelle-specific assessment of DNA lesions. Here we report on an adaptation of a qPCR technique to assess DNA damage in nuclear and mitochondrial targets relative to control. Novel aspects of this assay include application of the assay to the Rotor-Gene platform with optimized DNA polymerase/fluorophore/primer set combination in a touchdown PCR protocol. Assay validation was performed using ultraviolet C radiation in A549 and THP1 cancer cell lines. A comparison was made to the comet assay applied to peripheral blood mononuclear cells, and an estimation of the effects of cryopreservation on ultraviolet C-induced DNA damage was carried out. Finally, dose responses for DNA damage were measured in peripheral blood mononuclear cells following exposure to the cytotoxic agents bleomycin and cisplatin. We show reproducible experimental outputs across the tested conditions and concordance with published findings with respect to mitochondrial and nuclear genotoxic susceptibilities. The application of this DNA damage assay to a wide range of clinical and laboratory-derived samples is both feasible and resource-efficient.