A hydride transfer complex reprograms NAD metabolism and bypasses senescence.

Metabolic rewiring and redox balance play pivotal roles in cancer. Cellular senescence is a barrier for tumorigenesis circumvented in cancer cells by poorly understood mechanisms. We report a multi-enzymatic complex that reprograms NAD metabolism by transferring reducing equivalents from NADH to NADP+. This hydride transfer complex (HTC) is assembled by malate dehydrogenase 1, malic enzyme 1, and cytosolic pyruvate carboxylase. HTC is found in phase-separated bodies in the cytosol of cancer or hypoxic cells and can be assembled in vitro with recombinant proteins. HTC is repressed in senescent cells but induced by p53 inactivation. HTC enzymes are highly expressed in mouse and human prostate cancer models, and their inactivation triggers senescence. Exogenous expression of HTC is sufficient to bypass senescence, rescue cells from complex I inhibitors, and cooperate with oncogenic RAS to transform primary cells. Altogether, we provide evidence for a new multi-enzymatic complex that reprograms metabolism and overcomes cellular senescence.

Clinicopathologic features of breast cancers diagnosed in women treated with prior radiation therapy for Hodgkin lymphoma: Results from a population-based cohort.

BACKGROUND: Childhood and young adult survivors of Hodgkin lymphoma (HL) are at elevated risk of developing breast cancer, yet little data exist on the tumor characteristics that develop in this high-risk patient population. METHODS: The National Cancer Institute's Surveillance, Epidemiology, and End Results database was used to identify breast cancers diagnosed between 1990 and 2016 in women who had received prior radiation therapy for HL at age 30 years or younger. Clinicopathologic features of subsequent breast cancers (breast cancer after radiation therapy for HL [BC-HL]) were examined and compared with breast cancers diagnosed in women who had no prior malignancy (breast cancer with no prior malignancy [BC-NPM]). RESULTS: In total, 321 breast cancers were identified in 257 women who had a history of radiation therapy for HL. The median age at HL diagnosis was 22 years (interquartile range, 18-26 years), and nearly all patients in the BC-HL group (97.9%) were diagnosed ≥8 years after radiation therapy. Overall, 56 patients in the BC-HL group (21.8%) developed bilateral breast cancer. Compared with women who had BC-NPM, those who had BC-HL were younger (43 vs 60 years; P < .001) and were less likely to present with ductal carcinoma in situ (8.4% vs 14.9%; P = .001). On multivariable analysis that included adjustment for age, invasive BC-HL was associated with smaller (≤2 cm) tumor size (odds ratio, 1.64; 95% CI, 1.25-2.15) and upper outer quadrant tumors (odds ratio, 1.37; 95% CI, 1.04-1.81) compared with BC-NPM. In a subset analysis of 102 women who had HER2/neu status available, the distribution of biologic subtype was not significantly different between BC-HL and BC-NPM (P = .16). CONCLUSIONS: Breast cancers in women who previously received radiation therapy for HL are characterized by earlier onset disease, although most remain estrogen receptor-positive and have early stage disease at presentation. LAY SUMMARY: Women who have had radiation therapy for Hodgkin lymphoma at a young age are at increased risk of developing early onset breast cancer; however, most of these breast cancers are sensitive to hormones (estrogen receptor-positive) and are diagnosed at early stages. Because these breast tumors are estrogen receptor-positive, medications that prevent breast cancer by blocking the effect of or lowering hormone levels (also termed endocrine prevention) may be useful in this group of high-risk women.

Surgical Management and Contralateral Breast Cancer Risk in Women with History of Radiation Therapy for Hodgkin Lymphoma: Results from a Population-Based Cohort.

BACKGROUND: Women with history of chest irradiation for Hodgkin lymphoma are at increased risk of developing bilateral breast cancer, although contralateral breast cancer risk estimates in this population remain undefined. METHODS: We queried the SEER database for women treated with radiation therapy for Hodgkin lymphoma prior to age 30 years and were diagnosed with a subsequent breast cancer between 1990-2016. Trends in surgical management and the 5- and 10-year cumulative incidence of contralateral breast cancer were evaluated. RESULTS: The cohort included 295 women with a median age of 22 years (range 8-30 years) at Hodgkin lymphoma diagnosis, and 42 years (range 22-65 years) at breast cancer diagnosis. Overall, 263 (89.2%) presented with unilateral breast cancer, while 32 (10.8%) presented with synchronous bilateral breast cancer. Breast-conserving surgery was performed in 17.3% of patients, while mastectomy was performed in 82.7%. In 263 patients presenting with unilateral breast cancer, 50 (19.0%) underwent breast-conserving surgery and 213 (81.0%) underwent mastectomy. Subgroup analysis of mastectomy patients demonstrated a 40.5% bilateral mastectomy rate. The 5-year incidence of contralateral breast cancer in women who underwent unilateral surgery was 9.4% [95% confidence interval (CI), 5.6-15.4%], increasing to 20.2% (95% CI, 13.7-29.2%) at 10-year and 29.9% (95% CI, 20.8-41.9%) at 15-year follow-up. CONCLUSIONS: Women with a history of prior chest radiation for Hodgkin lymphoma with a diagnosis of breast cancer have a 10-year contralateral breast cancer risk of 20%. These findings support consideration of contralateral prophylactic mastectomy during surgical decision-making for management of this high-risk patient population.

Transcriptomic analysis of human primary breast cancer identifies fatty acid oxidation as a target for metformin.

BACKGROUND: Epidemiological studies suggest that metformin may reduce the incidence of cancer in patients with diabetes and multiple late phase clinical trials assessing the potential of repurposing this drug are underway. Transcriptomic profiling of tumour samples is an excellent tool to understand drug bioactivity, identify candidate biomarkers and assess for mechanisms of resistance to therapy. METHODS: Thirty-six patients with untreated primary breast cancer were recruited to a window study and transcriptomic profiling of tumour samples carried out before and after metformin treatment. RESULTS: Multiple genes that regulate fatty acid oxidation were upregulated at the transcriptomic level and there was a differential change in expression between two previously identified cohorts of patients with distinct metabolic responses. Increase in expression of a mitochondrial fatty oxidation gene composite signature correlated with change in a proliferation gene signature. In vitro assays showed that, in contrast to previous studies in models of normal cells, metformin reduces fatty acid oxidation with a subsequent accumulation of intracellular triglyceride, independent of AMPK activation. CONCLUSIONS: We propose that metformin at clinical doses targets fatty acid oxidation in cancer cells with implications for patient selection and drug combinations. CLINICAL TRIAL REGISTRATION: NCT01266486.

Study protocol of a phase II clinical trial of oral metformin for the intravesical treatment of non-muscle invasive bladder cancer.

BACKGROUND: Non-muscle-invasive bladder cancer (NMIBC) is the most common neoplasm of the urinary tract and requires life-long invasive surveillance to detect disease recurrence. Currently, there are no effective oral therapies that delay disease recurrence or progression. We recently demonstrated that in mice, metformin accumulates unchanged in the urine. Urothelial cells are exposed to metformin concentrations ~ 240-fold higher than in serum. This was effective in the treatment of mouse bladder cancer models. METHODS: We describe the protocol of a multi-centre, open-label, phase II clinical trial of metformin in up to 49 evaluable patients with intermediate-risk NMIBC with the aim to determine the overall response to administration of oral metformin for 3 months on a marker tumour deliberately left following transurethral resection of multiple, papillary NMIBC tumours. All patients will receive metformin orally at doses up to 3000 mg per day. Metformin treatment will start within 2 weeks following transurethral resection of all tumours except one marker lesion. After 3 months of metformin treatment, the effect of metformin on the marker lesion is evaluated by cystoscopy and biopsy under anaesthesia. Residual tumour, if present at this evaluation, will be resected. In case of complete disappearance of the marker lesion, the former tumour area will be biopsied. The primary outcome is the complete response rate of the marker lesion, as determined by decentralised scoring of pre- and post-treatment cystoscopy images by expert independent urologists. Secondary outcomes are the partial response rate, overall safety of metformin and the duration of the time to recurrence. DISCUSSION: Preclinical studies show the potential role of oral metformin treatment in the management of NMIBC. It could offer an alternative to current adjuvant intravesical treatment. If positive, the reported results of this study could warrant further phase III trials to compare the efficacy of metformin against current treatments of intravesical installations with chemotherapy or Bacillus Calmette-Guérin (BCG). TRIAL REGISTRATION: This trial is registered in ClinicalTrials.gov under NCT03379909.

Simultaneous Extraction of RNA and Metabolites from Single Kidney Tissue Specimens for Combined Transcriptomic and Metabolomic Profiling.

Tissue analysis represents a powerful tool for the investigation of disease pathophysiology. However, the heterogeneous nature of tissue samples, in particular of neoplastic, may affect the outcome of such analysis and hence obscure interpretation of results. Thus, comprehensive isolation and extraction of transcripts and metabolites from an identical tissue specimen would minimize variations and enable the economic use of biopsy material which is usually available in limited amounts. Here we demonstrate a fast and simple protocol for combined transcriptomics and metabolomics analysis in homogenates prepared from one single tissue sample. Metabolites were recovered by protein precipitation from lysates originally prepared for RNA isolation and were analyzed by LC-QTOF-MS after HILIC and RPLC separation, respectively. Strikingly, although ion suppression was observed, over 80% of the 2885 detected metabolic features could be extracted and analyzed with high reproducibility (CV ≤ 20%). Moreover fold changes of different tumor and nontumor kidney tissues were correlated to an established metabolomics protocol and revealed a strong correlation ( rp ≥ 0.75). In order to demonstrate the feasibility of the combined analysis of RNA and metabolites, the protocol was applied to kidney tissue of metformin treated mice to investigate drug induced alterations.

Incretin-based Drugs and the Incidence of Colorectal Cancer in Patients with Type 2 Diabetes.

BACKGROUND: Evidence on the safety of the incretin-based drugs (glucagon-like peptide-1 [GLP-1] analogues and dipeptidyl peptidase-4 [DPP-4] inhibitors) with respect to colorectal cancer is contradictory. The objective of this study was to determine whether use of incretin-based drugs is associated with risk of incident colorectal cancer in patients with type 2 diabetes. METHODS: Using data from the UK Clinical Practice Research Datalink, we identified a cohort of 112,040 patients newly treated with antidiabetic drugs between 1 January 2007 and 31 March 2015. We modeled use of GLP-1 analogues and DPP-4 inhibitors as time-varying variables and compared them with use of sulfonylureas. We lagged exposures by 1 year for latency and to reduce reverse causality and detection bias. We used time-dependent Cox proportional hazards models to estimate hazard ratios with 95% confidence intervals of incident colorectal cancer associated with the use of GLP-1 analogues and DPP-4 inhibitors overall, by cumulative duration of use and by time since initiation. RESULTS: During 388,619 person-years of follow-up, there were 733 incident colorectal cancer events (incidence rate: 1.9 per 1,000 person-years). Use of GLP-1 analogues was not associated with colorectal cancer incidence (hazard ratio: 1.0; 95% confidence interval = 0.7, 1.6), nor was use of DPP-4 inhibitors (hazard ratio: 1.2; 95% confidence interval = 1.0, 1.5). There was no evidence of a duration-response relation for either drug. CONCLUSIONS: The results of this large population-based study indicate that use of incretin-based drugs is not associated with colorectal cancer incidence among patients with type 2 diabetes.

Circulating resistin levels and risk of multiple myeloma in three prospective cohorts.

BACKGROUND: Resistin is a polypeptide hormone secreted by adipose tissue. A prior hospital-based case-control study reported serum resistin levels to be inversely associated with risk of multiple myeloma (MM). To date, this association has not been investigated prospectively. METHODS: We measured resistin concentrations for pre-diagnosis peripheral blood samples from 178 MM cases and 358 individually matched controls from three cohorts participating in the MM cohort consortium. RESULTS: In overall analyses, higher resistin levels were weakly associated with reduced MM risk. For men, we observed a statistically significant inverse association between resistin levels and MM (odds ratio, 0.44; 95% confidence interval (CI) 0.24-0.83 and 0.54; 95% CI 0.29-0.99, for the third and fourth quartiles, respectively, vs the lowest quartile; Ptrend=0.03). No association was observed for women. CONCLUSIONS: This study provides the first prospective evidence that low circulating resistin levels may be associated with an increased risk of MM, particularly for men.

Circulating levels of obesity-related markers and risk of renal cell carcinoma in the PLCO cancer screening trial.

PURPOSE: Obesity is an established risk factor for renal cell carcinoma (RCC). It is unclear what biologic mechanisms underlie this association, although recent evidence suggests that the effects of circulating hormones such as insulin-like growth factors (IGF) and adipokines may play a role. METHODS: To address this question, we conducted a nested case-control study of RCC (252 cases, 252 controls) within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial investigating associations with pre-diagnostic serum levels of total adiponectin, high-molecular-weight (HMW) adiponectin, IGF-1, IGF-binding protein-3 (IGFBP-3), and C-peptide. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated using conditional logistic regression. RESULTS: After adjustment for potential confounders, non-significant associations with RCC were observed for total adiponectin (OR for highest vs. lowest quartile = 0.65, 95% CI 0.37-1.14; p trend = 0.35), HMW adiponectin (0.67, 0.38-1.17; p trend = 0.36), IGF-1 (1.35, 0.77-2.39; p trend = 0.17), IGFBP-3 (1.47, 0.83-2.62; p trend = 0.53), and C-peptide (1.52, 0.86-2.70; p trend = 0.15). In a joint analysis with body mass index (BMI, kg/m2), obese individuals (BMI ≥30) with above-median levels of IGFBP-3 had a significantly higher risk versus those with BMI <25 and below-median IGFBP-3 (OR 2.42, 1.11-5.26), whereas obese individuals with low IGFBP-3 did not (1.18, 0.53-2.64) (p interaction = 0.35). CONCLUSIONS: The results of this study, while not clearly supporting associations with these obesity-related hormones, suggest that the association between obesity and RCC may be partially modified through mechanisms related to elevated IGFBP-3.

Menstrual cycle characteristics and steroid hormone, prolactin, and growth factor levels in premenopausal women.

PURPOSE: Menstrual cycle characteristics are markers of endocrine milieu. However, associations between age at menarche and adulthood sex steroid hormone levels have been inconsistent, and data on menstrual characteristics and non-sex steroid hormones are sparse. METHODS: We assessed the relations of menstrual characteristics with premenopausal plasma sex steroid hormones, sex hormone binding globulin (SHBG), prolactin, and growth factors among 2,745 premenopausal women (age 32-52) from the Nurses' Health Study II. Geometric means and tests for trend were calculated using multivariable general linear models. RESULTS: Early age at menarche was associated with higher premenopausal early-follicular free estradiol (percent difference < 12 vs. > 13 years = 11%), early-follicular estrone (7%), luteal estrone (7%), and free testosterone (8%) (all p trend < 0.05). Short menstrual cycle length at age 18-22 was associated with higher early-follicular total (< 26 vs. > 39 days = 18%) and free estradiol (16%), early-follicular estrone (9%), SHBG (7%), lower luteal free estradiol (- 14%), total (- 6%), and free testosterone (- 15%) (all p trend < 0.05). Short adult menstrual length was associated with higher early-follicular total estradiol (< 26 vs. > 31 days = 14%), SHBG (10%), lower luteal estrone (- 8%), progesterone (- 9%), total (- 11%) and free testosterone (- 25%), and androstenedione (- 14%) (all p trend < 0.05). Irregularity of menses at 18-22 was associated with lower early-follicular total (irregular vs. very regular = - 14%) and free estradiol (- 14%), and early-follicular estrone (- 8%) (All p trend < 0.05). Irregularity of adult menstrual cycle was associated with lower luteal total estradiol (irregular vs. very regular = - 8%), SHBG (- 3%), higher total (8%), and free testosterone (11%) (all p trend < 0.05). CONCLUSIONS: Early-life and adulthood menstrual characteristics are moderately associated with mid-to-late reproductive year's hormone concentrations. These relations of menstrual characteristics with endogenous hormone levels could partially account for associations between menstrual characteristics and reproductive cancers or other chronic diseases.

Relapse-free survival of statistically standardized continuous RT-PCR estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2): NCIC CTG MA.14.

Recent ASCO/CAP guidelines focus on decision making associated with the presence/absence of continuous breast biomarkers. Statistical standardization (SS) is demonstrated as a method to evaluate the effects of continuous RT-PCR biomarker expression levels on breast cancer outcomes. MA.14 allocated 667 postmenopausal patients to tamoxifen based on locally determined ER/PR. Of 299 available patient tumor samples, 292 passed internal quality control. All tumors were centrally assessed by RT-PCR ER/PR/HER2 with each biomarker's z-scores categorized: ≥1.0 standard deviation (SD) below mean; <1.0 SD below mean; ≤1.0 SD above mean; >1.0 SD above mean. Log-rank statistics tested univariate differences in breast cancer relapse-free survival (RFS). Continuous SS-ER/PR/HER2 were assessed in multivariate Cox step-wise forward regression, adding a factor if p ≤ 0.05. Sensitivity analyses examined an external HER2+ cut-point of 1.32. Patients whose tumors were tested were representative of the MA.14 population (p values = 0.18-0.90). At 9.8 years median follow-up, SS-ER did not univariately impact RFS (p = 0.31). SS-PR values above the mean (z ≥ 0.0) had the best univariate RFS (p = 0.03). SS-HER2 also univariately impacted RFS (p = 0.004) with lowest (z-scores ≤ -1.0) and highest (z-scores > 1.0) having shortest RFS. Multivariate stratified/unstratified Cox models indicated patients with T1 tumors (p = 0.02/p = 0.0002) and higher SS-PR (p = 0.02/p = 0.01) had longer RFS; node-negative patients had better RFS (in unstratified analysis, p < 0.0001). Local ER/PR status did not impact RFS (p > 0.05). Patients with SS HER2+ ≥ 1.32 had worse RFS (univariate, p = 0.05; multivariate, p = 0.06). We demonstrated that higher SS-PR, and SS HER2 levels, measured by RT-PCR impacted breast cancer RFS outcomes. Evaluation in other trials may provide support for this methodology.

Metformin in patients with advanced pancreatic cancer: a double-blind, randomised, placebo-controlled phase 2 trial.

BACKGROUND: In preclinical work and retrospective population studies, the anti-diabetic drug metformin has been associated with antineoplastic activity and decreased burden of many cancers, including pancreatic cancer. There is therefore interest in the hypothesis that this drug might be repurposed for indications in oncology. We aimed to assess the efficacy of the addition of metformin to a standard systemic therapy in patients with advanced pancreatic cancer, and provide the first report of a clinical trial with a survival endpoint of metformin for an oncological indication. METHODS: We did this double-blind, randomised, placebo-controlled phase 2 trial at four centres in the Netherlands. Patients aged 18 years or older with advanced pancreatic cancer were randomly assigned (1:1), via a permutated computer-generated block allocation scheme (block size of six) to receive intravenous gemcitabine (1000 mg/m(2)) on days 1, 8, and 15 every 4 weeks and oral erlotinib (100mg) once daily in combination with either oral metformin or placebo twice daily. Metformin dose was escalated from 500 mg (in the first week) to 1000 mg twice daily in the second week. Randomisation was stratified by hospital, diabetes status, and tumour stage. The primary endpoint was overall survival at 6 months in the intention-to-treat population. This trial is complete and is registered with ClinicalTrials.gov, number NCT01210911. FINDINGS: Between May 31, 2010, and Jan 3, 2014, we randomly assigned 121 patients to receive gemcitabine and erlotinib with either placebo (n=61) or metformin (n=60). Overall survival at 6 months was 63·9% (95% CI 51·9-75·9) in the placebo group and 56·7% (44·1-69·2) in the metformin group (p=0·41). There was no difference in overall survival between groups (median 7·6 months [95% CI 6·1-9·1] vs 6·8 months [95% CI 5·1-8·5] in the metformin group; hazard ratio [HR] 1·056 [95% CI 0·72-1·55]; log-rank p=0·78). The most frequent grade 3-4 toxic effects were neutropenia (15 [25%] patients in placebo group vs 15 [25%] in metformin group), skin rash (six [10%] vs four [7%]), diarrhoea (three [5%] vs six [10%]), and fatigue (two [3%] vs six [10%]). INTERPRETATION: Addition of a conventional anti-diabetic dose of metformin does not improve outcome in patients with advanced pancreatic cancer treated with gemcitabine and erlotinib. Future research should include studies of more potent biguanides, and should focus on patients with hyperinsulinaemia and patients with tumours showing markers of sensitivity to energetic stress, such as loss of function of AMP kinase, a key regulator of cellular energy homoeostasis. FUNDING: Academic Medical Centre, Amsterdam, and The Terry Fox Foundation, Vancouver, Canada.

Prediagnostic plasma IGFBP-1, IGF-1 and risk of prostate cancer.

Insulin-like growth factor (IGF)-1 is associated with a higher risk of prostate cancer. IGF-binding protein (IGFBP)-1, a marker for insulin activity, also binds IGF-1 and inhibits its action. Data on IGFBP-1 and prostate cancer risk are sparse and whether the IGF and insulin axes interact to affect prostate cancer carcinogenesis is unknown. We evaluated the independent and joint influence of prediagnostic plasma levels of IGFBP-1 (fasting) and IGF-1 on risk of prostate cancer among 957 cases and 1,021 controls with fasting levels of IGFBP-1 and 1,709 cases and 1,778 controls with IGF-1 nested within the Health Professionals Follow-up Study. Unconditional logistic regression adjusting for matching factors was used to estimate the odds ratio (OR) and 95% confidence interval (CI). Higher prediagnostic fasting IGFBP-1 levels were associated with lower risk of prostate cancer (highest vs. lowest quartile OR = 0.67, 95% CI 0.52-0.86, p(trend) = 0.003), which remained similar after adjusting for IGF-1. Prediagnostic IGF-1 was associated with increased risk of prostate cancer (highest vs. lowest quartile OR = 1.28, 95% CI = 1.05-1.56, p(trend) = 0.01). The associations with each marker were primarily driven by lower-grade and non-advanced prostate cancer. Being low in IGFBP-1 and high in IGF-1 did not confer appreciable additional risk (p(interaction) = 0.42). In summary, prediagnostic fasting IGFBP-1 may influence prostate cancer carcinogenesis. Being low in IGFBP-1 or high in IGF-1 is sufficient to elevate the risk of prostate cancer.

A prospective study of insulin-like growth factor 1, its binding protein 3, and risk of endometriosis.

Several retrospective case-control studies suggested that insulin-like growth factor 1 (IGF-1) or insulin-like growth factor binding protein 3 (IGFBP-3) was associated with endometriosis. However, results are inconsistent and no prospective study exists. We prospectively evaluated associations between plasma levels of IGF-1 and IGFBP-3 and laparoscopically confirmed endometriosis in a case-control study nested within the Nurses' Health Study II. Between blood collections in 1996-1999 and 2007, we ascertained 310 premenopausal women with incident endometriosis and 615 matched controls. We estimated incidence rate ratios and 95% confidence intervals using multivariable conditional logistic regression. We observed no statistically significant associations between endometriosis and IGF-1 (incidence rate ratio (IRR) = 0.88, 95% confidence interval (CI): 0.61, 1.27; Ptrend = 0.48), IGFBP-3 (IRR = 1.12, 95% CI: 0.80, 1.57; Ptrend = 0.51), and the IGF-1:IGFBP-3 molar ratio (IRR = 0.94, 95% CI: 0.66, 1.34; Ptrend = 0.64), comparing the top with the bottom tertile. IGF-1, IGFBP-3, and the molar ratio appeared to be positively associated with endometriosis risk among women aged <40 years at blood draw (IGF-1: IRR = 1.60, 95% CI: 0.86, 2.98; IGFBP-3: IRR = 1.85, 95% CI: 1.08, 3.16; IGF-1:IGFBP-3: IRR = 1.57, 95% CI: 0.85, 2.88) but not among women aged ≥40 years at blood draw (all Pheterogeneity ≤ 0.05). Overall, these data suggest that, if IGF-1 or IGFBP-3 plays a role in the etiology of endometriosis, it is minimal and perhaps only among younger women.

Octreotide LAR and tamoxifen versus tamoxifen in phase III randomize early breast cancer trials: NCIC CTG MA.14 and NSABP B-29.

NCIC CTG MA.14 and NSABP B-29 trials examined the addition of Octreotide LAR (OCT) to 5 years of tamoxifen (TAM). Gallbladder toxicity led to B-29 discontinuation of OCT, and MA.14 OCT administration shortened to 2 years. Median follow-up was 9.8 years for 667 MA.14 patients and 6.8 years for 893 B-29 patients. The primary endpoint was disease-free survival (DFS), defined as time from randomization to time of breast cancer recurrence; second primary cancer other than squamous or basal cell skin carcinoma, cervical carcinoma in situ, or lobular breast carcinoma in situ; or death. The primary statistical test was a univariable pooled stratified log-rank test; multivariable assessment was with Cox regression. For MA.14, 97% of patients were ≥50 years; for B-29, 62%. MA.14 patients were 53% lymph node negative (LN-) while B-29 were 100% LN-; 33% of MA.14 patients received adjuvant chemotherapy, 2% concurrently, while B-29 had 53% concurrent chemotherapy. MA.14 patients were 90% hormone receptor positive; B-29, 100%. MA.14 patients experienced 5-year DFS of 80% with TAM, 76% with TAM + OCT; B-29 patients had 5-year DFS of 88% for both arms. Pooled univariable TAM + OCT to TAM hazard ratio (HR) was 0.99 (95% CI 0.81-1.20; p = 0.69): for MA.14, HR = 0.94 (0.73-1.20; p = 0.50); for B-29, HR = 1.09 (0.80-1.50; p = 0.59). Multivariable pooled HR = 0.98 (0.81-1.20; p = 0.84). Older patients (p < 0.001), with higher T stage (p < 0.001), and LN + (p < 0.001) had shorter DFS. Addition of OCT to TAM did not significantly improve DFS; gallbladder toxicity shortened the additional administration of OCT. This does not negate targeting the insulin-IGF-I receptor family with less toxic therapeutics.

The use of aspirin and the risk of mortality in patients with prostate cancer.

PURPOSE: The association between the use of aspirin and mortality in patients with prostate cancer remains uncertain. We determine whether the use of aspirin in patients with prostate cancer is associated with a decreased risk of prostate cancer mortality and all cause mortality. MATERIALS AND METHODS: Using the United Kingdom National Cancer Data Repository, Clinical Practice Research Datalink and associated databases, we identified a cohort of men with nonmetastatic prostate cancer between 1998 and 2009, followed until 2012. Cox proportional hazards models were used to estimate adjusted HRs with 95% CIs of mortality outcomes associated with post-diagnostic use of aspirin defined as a time-varying exposure. Effect modification by pre-diagnostic aspirin use was also assessed. RESULTS: The cohort included 11,779 men followed for 5.4 years (SD 2.9). Post-diagnostic aspirin use was associated with an increased risk of prostate cancer mortality (HR 1.46, 95% CI 1.29-1.65) and all cause mortality (HR 1.37, 95% CI 1.26-1.50). These increased risks were restricted to patients initiating aspirin after the prostate cancer diagnosis (HR 1.84, 95% CI 1.59-2.12, and HR 1.70, 95% CI 1.53-1.88, respectively), and not in patients who were already exposed to aspirin before the diagnosis (HR 0.97, 95% CI 0.81-1.16 and HR 0.98, 95% CI 0.87-1.18, respectively). CONCLUSIONS: The post-diagnostic use of aspirin is not associated with a decreased risk of prostate cancer outcomes. Increased risks were restricted to patients initiating these drugs after their diagnosis, suggesting a noncausal association.

Effects of metformin and other biguanides on oxidative phosphorylation in mitochondria.

The biguanide metformin is widely prescribed for Type II diabetes and has anti-neoplastic activity in laboratory models. Despite evidence that inhibition of mitochondrial respiratory complex I by metformin is the primary cause of its cell-lineage-specific actions and therapeutic effects, the molecular interaction(s) between metformin and complex I remain uncharacterized. In the present paper, we describe the effects of five pharmacologically relevant biguanides on oxidative phosphorylation in mammalian mitochondria. We report that biguanides inhibit complex I by inhibiting ubiquinone reduction (but not competitively) and, independently, stimulate reactive oxygen species production by the complex I flavin. Biguanides also inhibit mitochondrial ATP synthase, and two of them inhibit only ATP hydrolysis, not synthesis. Thus we identify biguanides as a new class of complex I and ATP synthase inhibitor. By comparing biguanide effects on isolated complex I and cultured cells, we distinguish three anti-diabetic and potentially anti-neoplastic biguanides (metformin, buformin and phenformin) from two anti-malarial biguanides (cycloguanil and proguanil): the former are accumulated into mammalian mitochondria and affect oxidative phosphorylation, whereas the latter are excluded so act only on the parasite. Our mechanistic and pharmacokinetic insights are relevant to understanding and developing the role of biguanides in new and existing therapeutic applications, including cancer, diabetes and malaria.

Assessment of osteopontin in early breast cancer: correlative study in a randomised clinical trial.

INTRODUCTION: Osteopontin (OPN) is a malignancy-associated glycoprotein that contributes functionally to tumor aggressiveness. In metastatic breast cancer, we previously demonstrated that elevated OPN in primary tumor and blood was associated with poor prognosis. METHODS: We measured OPN in plasma by ELISA, and in tumors by immunohistochemistry, in 624 (94%) and 462 (69%), respectively, of 667 postmenopausal women with hormone responsive early breast cancer treated by surgery followed by adjuvant treatment with tamoxifen +/- octreotide in a randomized trial (NCIC CTG MA.14; National Cancer Institute of Canada Clinical Trials Group Mammary.14). RESULTS: Plasma OPN was measured in 2,540 samples; 688 at baseline and 1,852 collected during follow-up. Mean baseline plasma OPN was 46 ng/ml (range 22.6 to 290) which did not differ from normal levels. Mean percentage OPN tumor cell positivity was 33.9 (95% CI: 30.2 to 37.9). There was no correlation between plasma and tumor OPN values. In multivariate analysis, neither was associated with event-free survival (EFS), relapse-free survival (RFS), overall survival (OS), bone RFS or non-bone RFS. An exploratory analysis in patients with recurrence showed higher mean OPN plasma levels 60.7 ng/ml (23.9 to 543) in the recurrence period compared with baseline levels. CONCLUSIONS: The hypothesis that OPN tumor expression would have independent prognostic value in early breast cancer was not supported by multivariate analysis of this study population. Plasma OPN levels in women with hormone responsive early breast cancer in the MA.14 trial were not elevated and there was no evidence for prognostic value of plasma OPN in this defined group of patients. However, our finding of elevated mean OPN plasma level around the time of recurrence warrants further study. TRIAL REGISTRATION: NCT00002864, http://clinicaltrials.gov/show/NCT00002864.

Differential effects of metformin on breast cancer proliferation according to markers of insulin resistance and tumor subtype in a randomized presurgical trial.

Treatment of diabetics with metformin is associated with decreased breast cancer risk in observational studies, but it remains unclear if this drug has clinical antineoplastic activity. In a recent presurgical trial, we found a heterogeneous effect of metformin on breast cancer proliferation (ki-67) depending upon insulin resistance (HOMA index). Here, we determined the associations of additional serum biomarkers of insulin resistance, tumor subtype, and drug concentration with ki-67 response to metformin. Two-hundred non-diabetic women were randomly allocated to metformin (850 mg/bid) or placebo for 4 weeks prior to breast cancer surgery. The ki-67 response to metformin was assessed comparing data obtained from baseline biopsy (ki-67 and tumor subtype) and serum markers (HOMA index, C-peptide, IGF-I, IGFBP-1, IGFBP-3, free IGF-I, hs-CRP, adiponectin) with the same measurements at definitive surgery. For patients with a blood sample taken within 24 h from last drug intake, metformin level was measured. Compared with placebo, metformin significantly decreased ki-67 in women with HOMA > 2.8, those in the lowest IGFBP-1 quintile, those in the highest IGFBP-3 quartile, those with low free IGF-I, those in the top hs-CRP tertile, and those with HER2-positive tumors. In women with HOMA index > 2.8, drug levels were positively correlated with the ki-67 decrease, whereas no trend was noted in women with HOMA < 2.8 (p-interaction = 0.07). At conventional antidiabetic doses, the effect of metformin on tumor ki-67 of non-diabetic breast cancer patients varies with host and tumor characteristics. These findings are relevant to design breast cancer prevention and treatment trials with metformin.

Type 2 diabetes and the risk of mortality among patients with prostate cancer.

PURPOSE: The aim of this study was to determine whether type 2 diabetes is associated with the incidence of prostate cancer mortality and all-cause mortality. METHODS: This study was conducted by linking four databases from the United Kingdom: the National Cancer Data Repository, the Clinical Practice Research Datalink, the Hospital Episodes Statistics database, and the Office for National Statistics database. The cohort consisted of men newly diagnosed with non-metastatic prostate cancer between 1 April 1998 and 31 December 2009, followed until 1 October 2012. Cox proportional hazard models were used to estimate adjusted hazard ratios with 95 % confidence intervals (CIs) of prostate cancer mortality and all-cause mortality comparing patients with to without type 2 diabetes. All models were adjusted for a number of potential confounders, which included excessive alcohol use, smoking, comorbidities, and prostate cancer-related variables. RESULTS: The cohort consisted of 11,920 patients, which included 1,132 (9.5 %) with preexisting type 2 diabetes. During a mean follow-up of 4.7 (SD 3.0) years, there were 3,605 deaths (incidence rate: 6.4 %/year) including 1,792 from prostate cancer (incidence rate: 3.3 %/year). Type 2 diabetes was associated with a 23 % increased risk of prostate cancer mortality (HR 1.23, 95 % CI 1.04-1.46) and a 25 % increased risk in all-cause mortality (HR 1.25, 95 % CI 1.11-1.40). CONCLUSIONS: The results of this large population-based study indicate that type 2 diabetes is associated with an increased risk of prostate cancer mortality and all-cause mortality, which may signal an association between hyperinsulinemia or other diabetes-associated metabolic derangements and cancer aggressivity.