Prognostic role of platelet to lymphocyte ratio in solid tumors: a systematic review and meta-analysis

BACKGROUND

Inflammation influences cancer development and progression. An elevated platelet to lymphocyte ratio (PLR), a marker of inflammation, has been linked to poor prognosis in several malignancies. Here, we quantify the prognostic impact of this biomarker.

METHODS

A systematic review of databases was conducted to identify publications exploring the association of blood PLR and overall survival (OS) in solid tumors. Data were pooled in a meta-analysis. Pooled HRs for OS by disease group and by PLR cutoff groups were computed and weighted using generic inverse-variance and random-effect modeling.

RESULTS

Twenty studies comprising 12,754 patients were assessed. Cutoffs for PLR defining risk groups ranged from 150 to 300 and were dichotomous (12 studies; group 1) or split into three groups (<150/150-300/>300, 8 studies; group 2). Higher PLR was associated with significantly worse OS in group 1 [HR = 1.87; 95% confidence interval (CI, 1.49-2.34); P < 0.001] and with a nonsignificant association in group 2 (HR per higher category = 1.21; 95%CI, 0.97-1.50; P = 0.10). The size of effect of PLR on OS was greater for metastatic disease (HR[group 1] = 2.0; 95% CI, 1.6-2.7; HR[group 2] = 1.6; 95% CI, 1.1-2.4) than for early-stage disease (HR[group 1] = 1.5; 95% CI, 1.0-2.2; HR[group 2] = 1.0; 95% CI, 0.8-1.3). A significant association was observed for colorectal, hepatocellular, gastroesophageal, ovarian, and pancreatic carcinoma in group 1 and for colorectal cancers in group 2.

CONCLUSION

A high PLR is associated with worse OS in various solid tumors. Further research of its regulation and relevance in daily practice is warranted.

IMPACT

PLR is a readily available and inexpensive biomarker with independent prognostic value in solid tumors.

Effect of multifocality and multicentricity on outcome in early stage breast cancer: a systematic review and meta-analysis

Women with multifocal or multicentric breast tumors (multifocality henceforth) have been reported to have greater probability of nodal metastasis and relapse and worse survival than women with unifocal tumors. However, these associations have been inconsistent and multifocality is not taken into account by staging guidelines and prognostic models. A systematic review of electronic databases identified publications exploring the association between multifocality and overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), and loco-regional relapse (LRR). The hazard ratios (HRs) for OS and DFS for multifocal compared to unifocal tumors were extracted from multivariable analyses and included in a meta-analysis. For studies not reporting multivariable analyses, odds ratios (OR) were estimated from Kaplan-Meier curves for all endpoints at 5 and 10 years. Twenty-two studies comprising 67,557 women were included. Multifocality was reported in 9.5 % of patients. Classical prognostic factors were well balanced between unifocal and multifocal populations. In multivariable analyses, multifocality was associated with significantly worse OS (HR 1.65; P = 0.02), and a non-significant association with worse DFS (HR 1.96; P = 0.07). In univariable analyses, multifocality was associated with worse OS, DFS, DSS, and LRR at 5 years (OR 1.39, P = 0.02; OR 1.52, P = 0.02; OR 1.56, P = 0.03; and OR 3.23, P = 0.02, respectively). Similar estimates were observed at 10 years, but statistical significance was only reached for DSS and LRR. Mutifocality appears to be associated with a worse prognosis, however, substantial inter-study heterogeneity limits the precise determination of increased risk. Further validation of the independent prognostic impact of multifocality is warranted.

Systemic therapy for non-clear cell renal cell carcinomas: a systematic review and meta-analysis

CONTEXT

Clinical data supporting the use of targeted agents for the treatment of metastatic renal cell carcinoma (RCC) are based predominantly on patients with clear cell histology. Little is known about the efficacy of these drugs in non-clear cell variants.

OBJECTIVE

To evaluate the efficacy of different clear cell RCC (ccRCC)-approved targeted agents among patients with non-ccRCC compared with ccRCC.

EVIDENCE ACQUISITION

We conducted a systematic review of electronic databases to identify publications evaluating the outcomes of patients with non-ccRCC treated with targeted agents approved for treatment of ccRCC. Patients with sarcomatoid variant RCC were excluded from the main analysis but were evaluated as an independent cohort. End points of interest were response rate, median progression-free survival (PFS), and median overall survival (OS). Where possible, data were pooled in a meta-analysis. For studies of unselected patients with RCC, the outcomes of patients with non-ccRCC histology were compared with ccRCC. In exploratory analyses, outcomes of non-ccRCC with nonapproved agents were assessed.

EVIDENCE SYNTHESIS

A total of 49 studies comprising 7771 patients were included in the analysis. Of these, 1244 patients (16.0%) had non-ccRCC, 6300 (83.1%) had ccRCC, and 227 (2.9%) had sarcomatoid tumours. The overall response rate for non-ccRCC with targeted agents was 10.5%. In studies directly comparing non-ccRCC and ccRCC, there were significantly lower response rates for non-ccRCC (odds ratio for response: 0.52; 95% confidence interval, 0.40-0.68; p<0.001). For non-ccRCC treated with targeted agents, median PFS and OS were 7.4 and 13.4 mo, respectively; for patients with ccRCC, these were 10.5 mo and 15.7 mo, respectively (p value for difference<0.001 for both parameters).

CONCLUSIONS

Patients with non-clear cell renal cell carcinoma (non-ccRCC) have significantly lower response rates and poorer median progression-free survival and overall survival than those with ccRCC. The optimal treatment of patients with non-ccRCC remains unclear and warrants further study.

PATIENT SUMMARY

Systemic treatments for patients with renal cell carcinoma (RCC) tend to be significantly less effective for non-clear cell RCC, with lower response rates and worse progression-free survival and overall survival when compared with clear cell RCC. Optimal therapy remains unclear and warrants further study.

Prognostic role of neutrophil-to-lymphocyte ratio in solid tumors: a systematic review and meta-analysis

BACKGROUND

Inflammation may play an important role in cancer progression, and a high neutrophil-to-lymphocyte ratio (NLR) has been reported to be a poor prognostic indicator in several malignancies. Here we quantify the prognostic impact of this biomarker and assess its consistency in solid tumors.

METHODS

A systematic review of electronic databases was conducted to identify publications exploring the association of blood NLR and clinical outcome in solid tumors. Overall survival (OS) was the primary outcome, and cancer-specific survival (CSS), progression-free survival (PFS), and disease-free survival (DFS) were secondary outcomes. Data from studies reporting a hazard ratio and 95% confidence interval (CI) or a P value were pooled in a meta-analysis. Pooled hazard ratios were computed and weighted using generic inverse-variance and random-effect modeling. All statistical tests were two-sided.

RESULTS

One hundred studies comprising 40559 patients were included in the analysis, 57 of them published in 2012 or later. Median cutoff for NLR was 4. Overall, NLR greater than the cutoff was associated with a hazard ratio for OS of 1.81 (95% CI = 1.67 to 1.97; P < .001), an effect observed in all disease subgroups, sites, and stages. Hazard ratios for NLR greater than the cutoff for CSS, PFS, and DFS were 1.61, 1.63, and 2.27, respectively (all P < .001).

CONCLUSIONS

A high NLR is associated with an adverse OS in many solid tumors. The NLR is a readily available and inexpensive biomarker, and its addition to established prognostic scores for clinical decision making warrants further investigation.

Physical exercise prevents suppression of hippocampal neurogenesis and reduces cognitive impairment in chemotherapy-treated rats

RATIONALE

Chemotherapy, used for the treatment of cancer, often produces cognitive impairment that has been related to suppression of neurogenesis. Physical exercise, which promotes neurogenesis, is known to improve cognitive function in neurologically challenged animals and humans. It is unknown whether exercise similarly protects against chemotherapy-induced cognitive impairment and whether recovery of neurogenesis is a critical factor.

OBJECTIVE

The present study investigated the relationship between hippocampal neurogenesis and cognitive performance in chemotherapy-treated rats that engaged in different amounts of physical activity.

METHODS

Groups of rats, housed individually in standard cages or in specially designed cages that allowed unlimited access to a running wheel, received three injections of the chemotherapeutic drugs methotrexate and 5-fluorouracil, or equal volumes of saline. They were then administered the following cognitive tests in a water maze: (1) spatial memory (SM), (2) cued memory, (3) non-matching to sample (NMTS) rule learning; (4) delayed NMTS (DNMTS). Hippocampal neurogenesis was quantified by counting doublecortin-expressing cells in the dentate gyrus.

RESULTS

Chemotherapy administered to rats in standard cages resulted in a significant reduction in hippocampal neurogenesis and impaired performance on the SM, NMTS, and DNMTS tasks. In rats receiving chemotherapy and housed in exercise cages, neurogenesis was not suppressed and cognitive performance was similar to controls.

CONCLUSIONS

Physical exercise can reduce cognitive deficits that result from chemotherapy and this effect is mediated, at least in part, by preventing suppression of drug-induced hippocampal neurogenesis. The results suggest benefits of exercise in preventing or treating cognitive impairment associated with chemotherapy.

Prognostic role of neutrophil-to-lymphocyte ratio in solid tumors: a systematic review and meta-analysis

BACKGROUND

Inflammation may play an important role in cancer progression, and a high neutrophil-to-lymphocyte ratio (NLR) has been reported to be a poor prognostic indicator in several malignancies. Here we quantify the prognostic impact of this biomarker and assess its consistency in solid tumors.

METHODS

A systematic review of electronic databases was conducted to identify publications exploring the association of blood NLR and clinical outcome in solid tumors. Overall survival (OS) was the primary outcome, and cancer-specific survival (CSS), progression-free survival (PFS), and disease-free survival (DFS) were secondary outcomes. Data from studies reporting a hazard ratio and 95% confidence interval (CI) or a P value were pooled in a meta-analysis. Pooled hazard ratios were computed and weighted using generic inverse-variance and random-effect modeling. All statistical tests were two-sided.

RESULTS

One hundred studies comprising 40559 patients were included in the analysis, 57 of them published in 2012 or later. Median cutoff for NLR was 4. Overall, NLR greater than the cutoff was associated with a hazard ratio for OS of 1.81 (95% CI = 1.67 to 1.97; P < .001), an effect observed in all disease subgroups, sites, and stages. Hazard ratios for NLR greater than the cutoff for CSS, PFS, and DFS were 1.61, 1.63, and 2.27, respectively (all P < .001).

CONCLUSIONS

A high NLR is associated with an adverse OS in many solid tumors. The NLR is a readily available and inexpensive biomarker, and its addition to established prognostic scores for clinical decision making warrants further investigation.

Prognostic role of platelet to lymphocyte ratio in solid tumors: a systematic review and meta-analysis

BACKGROUND

Inflammation influences cancer development and progression. An elevated platelet to lymphocyte ratio (PLR), a marker of inflammation, has been linked to poor prognosis in several malignancies. Here, we quantify the prognostic impact of this biomarker.

METHODS

A systematic review of databases was conducted to identify publications exploring the association of blood PLR and overall survival (OS) in solid tumors. Data were pooled in a meta-analysis. Pooled HRs for OS by disease group and by PLR cutoff groups were computed and weighted using generic inverse-variance and random-effect modeling.

RESULTS

Twenty studies comprising 12,754 patients were assessed. Cutoffs for PLR defining risk groups ranged from 150 to 300 and were dichotomous (12 studies; group 1) or split into three groups (<150/150-300/>300, 8 studies; group 2). Higher PLR was associated with significantly worse OS in group 1 [HR = 1.87; 95% confidence interval (CI, 1.49-2.34); P < 0.001] and with a nonsignificant association in group 2 (HR per higher category = 1.21; 95%CI, 0.97-1.50; P = 0.10). The size of effect of PLR on OS was greater for metastatic disease (HR[group 1] = 2.0; 95% CI, 1.6-2.7; HR[group 2] = 1.6; 95% CI, 1.1-2.4) than for early-stage disease (HR[group 1] = 1.5; 95% CI, 1.0-2.2; HR[group 2] = 1.0; 95% CI, 0.8-1.3). A significant association was observed for colorectal, hepatocellular, gastroesophageal, ovarian, and pancreatic carcinoma in group 1 and for colorectal cancers in group 2.

CONCLUSION

A high PLR is associated with worse OS in various solid tumors. Further research of its regulation and relevance in daily practice is warranted.

IMPACT

PLR is a readily available and inexpensive biomarker with independent prognostic value in solid tumors.

Perioperative chemotherapy for muscle-invasive bladder cancer: A population-based outcomes study

BACKGROUND

Practice guidelines recommend neoadjuvant chemotherapy (NACT) for bladder cancer. However, the evidence in support of adjuvant chemotherapy (ACT) is less robust. Here we describe whether the evidence of efficacy for NACT/ACT was sufficient to change clinical practice and whether the efficacy demonstrated in clinical trials was translated into effectiveness in the general population.

METHODS

Electronic records of treatment were linked to the population-based Ontario Cancer Registry to identify all patients with bladder cancer treated with cystectomy in Ontario 1994-2008. Utilization of NACT/ACT was compared across 1994-1998, 1999-2003, and 2004-2008. Logistic regression was used to analyze factors associated with NACT/ACT. Cox model and propensity score analyses were used to explore the association between ACT and survival.

RESULTS

Two thousand forty-four patients underwent cystectomy for muscle-invasive bladder cancer (MIBC). Use of NACT remained stable (mean, 4%), whereas utilization of ACT increased over time (16%, 18%, 22%; P = .001). Advanced stage (T3/T4; OR, 1.83; 95% CI, 1.38-2.46) and node-positive disease (OR, 8.10; 95% CI, 6.20-10.7) were associated with greater utilization of ACT. Five-year overall survival (OS) and cancer-specific survival (CSS) for all patients was 29% (95% CI, 28%-31%) and 33% (95% CI, 31%-35%), respectively. Utilization of ACT was associated with improved OS (HR, 0.71; 95% CI, 0.62-0.81) and CSS (HR, 0.73; 95% CI, 0.64-0.84). Results were consistent in propensity score analyses.

CONCLUSIONS

NACT remains substantially underutilized in routine clinical practice. Our results suggest that perioperative chemotherapy is associated with a substantial survival benefit in the general population. Patients who are planning to undergo cystectomy for bladder cancer should be reviewed by a multidisciplinary team.

Clinical variables associated with PSA response to abiraterone acetate in patients with metastatic castration-resistant prostate cancer

BACKGROUND

Abiraterone acetate (abiraterone) prolongs overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC). This study's objective was to retrospectively identify factors associated with prostate-specific antigen (PSA) response to abiraterone and validate them in an independent cohort. We hypothesized that the neutrophil/lymphocyte ratio (NLR), thought to be an indirect manifestation of tumor-promoting inflammation, may be associated with response to abiraterone.

PATIENTS AND METHODS

All patients receiving abiraterone at the Princess Margaret (PM) Cancer Centre up to March 2013 were reviewed. The primary end point was confirmed PSA response defined as PSA decline ≥50% below baseline maintained for ≥3 weeks. Potential factors associated with PSA response were analyzed using univariate and multivariable analyses to generate a score, which was then evaluated in an independent cohort from Royal Marsden (RM) NHS foundation.

RESULTS

A confirmed PSA response was observed in 44 out of 108 assessable patients (41%, 95% confidence interval 31%-50%). In univariate analysis, lower pre-abiraterone baseline levels of lactate dehydrogenase, an NLR ≤ 5 and restricted metastatic spread to either bone or lymph nodes were each associated with PSA response. In multivariable analysis, only low NLR and restricted metastatic spread remained statistically significant. A score derived as the sum of these two categorical variables was associated with response to abiraterone (P = 0.007). Logistic regression analysis on an independent validation cohort of 245 patients verified that this score was associated with response to abiraterone (P = 0.003). It was also associated with OS in an exploratory analysis.

CONCLUSIONS

A composite score of baseline NLR and extent of metastatic spread is associated with PSA response to abiraterone and OS. Our data may help understand the role of systemic inflammation in mCRPC and warrant further research.

Tolerability and efficacy of docetaxel in older men with metastatic castrate-resistant prostate cancer (mCRPC) in the TAX 327 trial

OBJECTIVE

Prostate cancer is a disease of older men. Weekly docetaxel (DPq1w) is often favored over the standard three-weekly regimen (DPq3w) due to concerns about safety and tolerability in this population.

MATERIALS AND METHODS

Two subgroup analyses of TAX 327 were conducted. Among patients receiving DPq3w, tolerability and efficacy were compared between three age groups: <65, 65-74 and ≥75 years. For men ≥75 years, these outcomes were compared between DPq3w, DPq1w, and mitoxantrone (MP) arms. Tolerability outcomes included dose delivery, grade 3/4 adverse events and quality of life. Efficacy outcomes included overall survival and tumor response.

RESULTS

Of 1006 men with metastatic castrate-resistant prostate cancer (mCRPC) in the trial, 335 received DPq3w. Among these, 20% were age ≥75 years. For DPq3w, there were non-significant associations of worse tolerability and efficacy with advancing age. Twenty-eight percent of men age ≥75 years had an objective pain response, compared to 38% and 34% of patients 65-74 and <65 years, respectively. There were no significant differences in prostate-specific antigen (PSA) response (43-48%, p = 0.74) or measurable tumor response (7-17%, p = 0.30) according to age. Among men ≥75 years, DPq3w resulted in more dose reductions than DPq1w (22% versus 8%, p = 0.007), but tolerability was otherwise comparable. Both were associated with more favorable efficacy than mitoxantrone.

CONCLUSIONS

Tolerability and efficacy of DPq3w appear less favorable with advancing age. Compared to DPq1w, DPq3w is associated with better survival outcomes, but similar tolerability, and remains the standard first-line chemotherapy option in mCRPC. Toxicity is substantial, therefore careful patient selection, close monitoring and early management of toxicities is advised.

The role of kinin receptors in cancer and therapeutic opportunities

Kinins are generated within inflammatory tissue microenvironments, where they exert diverse functions, including cell proliferation, leukocyte activation, cell migration, endothelial cell activation and nociception. These pleiotropic functions depend on signaling through two cross talking receptors, the constitutively expressed kinin receptor 2 (B2R) and the inducible kinin receptor 1 (B1R). We have reviewed evidence, which supports the concept that kinin receptors, especially kinin receptor 1, are promising targets for cancer therapy, since (1) many tumor cells express aberrantly high levels of these receptors; (2) some cancers produce kinins and use them as autocrine factors to stimulate their growth; (3) activation of kinin receptors leads to activation of macrophages, dendritic cells and other cells from the tumor microenvironment; (4) kinins have pro-angiogenic properties; (5) kinin receptors have been implicated in cancer migration, invasion and metastasis; and (6) selective antagonists for either B1R or B2R have shown anti-proliferative, anti-inflammatory, anti-angiogenic and anti-migratory properties. The multiple cross talks between kinin receptors and renin-angiotensin system (RAS) as well as its implications for targeting KKS or RAS for the treatment of malignancies are also discussed. It is expected that B1R antagonists would interfere less with housekeeping functions and therefore would be attractive compounds to treat selected types of cancer. Reliable clinical studies are needed to establish the translatability of these data to human settings and the usefulness of kinin receptor antagonists.

Androgen receptor expression and outcomes in early breast cancer: a systematic review and meta-analysis

BACKGROUND

The androgen receptor (AR) is expressed frequently in breast cancer, but its prognostic significance is unclear. Preclinical data suggest that expression of AR may modify clinical outcomes in early breast cancer with improved prognosis in estrogen receptor (ER)-positive disease and poorer prognosis in ER-negative disease.

METHODS

A systematic review of electronic databases was conducted to identify studies published between 1946 and July 2012 and to explore the association between AR expression and overall survival (OS) and disease-free survival (DFS) in women diagnosed with early breast cancer. The odds ratios (OR) for OS and DFS at 3 and 5 years were calculated and then weighted and pooled in a meta-analysis with Mantel-Haenszel random-effect modeling. All statistical tests were two-sided.

RESULTS

Nineteen studies with a total of 7693 women were included. AR expression was documented in 60.5% of patients. ER-positive tumors were more likely to express AR- than ER-negative tumors (74.8% vs 31.8%, χ(2) P < .001). Compared with tumors without AR expression, those expressing AR were associated with improved OS at both 3 and 5 years (OR = 0.47, 95% confidence interval [CI] = 0.39 to 0.58, P < .001; and OR = 0.40, 95% CI = 0.29 to 0.56, P < .001). The absolute differences in the probability of OS at 3 and 5 years were 6.7% (95% CI = 3.5% to 9.8%) and 13.5% (95% CI = 7.5% to 19.6%), respectively. Results for 3- and 5-year DFS were similar. Coexpression of the ER did not influence OS at 3 or at 5 years.

CONCLUSIONS

Expression of AR in women with breast cancer is associated with better OS and DFS irrespective of coexpression of ER.

Use of the proton pump inhibitor pantoprazole to modify the distribution and activity of doxorubicin: a potential strategy to improve the therapy of solid tumors

PURPOSE

Limited drug distribution within solid tumors is an important cause of drug resistance. Basic drugs (e.g., doxorubicin) may be sequestered in acidic organelles, thereby limiting drug distribution to distal cells and diverting drugs from their target DNA. Here we investigate the effects of pantoprazole, a proton pump inhibitor, on doxorubicin uptake, and doxorubicin distribution and activity using in vitro and murine models.

EXPERIMENTAL DESIGN

Murine EMT-6 and human MCF-7 cells were treated with pantoprazole to evaluate changes in endosomal pH using fluorescence spectroscopy, and uptake of doxorubicin using flow cytometry. Effects of pantoprazole on tissue penetration of doxorubicin were evaluated in multilayered cell cultures (MCC), and in solid tumors using immunohistochemistry. Effects of pantoprazole to influence tumor growth delay and toxicity because of doxorubicin were evaluated in mice.

RESULTS

Pantoprazole (>200 μmol/L) increased endosomal pH in cells, and also increased nuclear uptake of doxorubicin. Pretreatment with pantoprazole increased tissue penetration of doxorubicin in MCCs. Pantoprazole improved doxorubicin distribution from blood vessels in solid tumors. Pantoprazole given before doxorubicin led to increased growth delay when given as single or multiple doses to mice bearing MCF7 xenografts.

CONCLUSIONS

Use of pantoprazole to enhance the distribution and cytotoxicity of anticancer drugs in solid tumors might be a novel treatment strategy to improve their therapeutic index.

Evolution of clinical trial design in early drug development: systematic review of expansion cohort use in single-agent phase I cancer trials

PURPOSE

To evaluate the use and objectives of expansion cohorts in phase I cancer trials and to explore trial characteristics associated with their use.

METHODS

We performed a systematic review of MEDLINE and EMBASE, limiting studies to single-agent phase I trials recruiting adults and published after 2006. Eligibility assessment and data extraction were performed by two reviewers. Data were assessed descriptively, and associations were tested by univariable and multivariable logistic regression.

RESULTS

We identified 611 unique phase I cancer trials, of which 149 (24%) included an expansion cohort. The trials were significantly more likely to use an expansion cohort if they were published more recently, were multicenter, or evaluated a noncytotoxic agent. Objectives of the expansion cohort were reported in 74% of trials. In these trials, safety (80%), efficacy (45%), pharmacokinetics (28%), pharmacodynamics (23%), and patient enrichment (14%) were cited as objectives. Among expansion cohorts with safety objectives, the recommended phase II dose was modified in 13% and new toxicities were described in 54% of trials. Among trials aimed at assessing efficacy, only 11% demonstrated antitumor activity assessed by response criteria that was not previously observed during dose escalation.

CONCLUSION

The utilization of expansion cohorts has increased with time. Safety and efficacy are common objectives, but 26% fail to report explicit aims. Expansion cohorts may provide useful supplementary data for phase I trials, particularly with regard to toxicity and definition of recommended dose for phase II studies.

Translating clinical trials to clinical practice: outcomes of men with metastatic castration resistant prostate cancer treated with docetaxel and prednisone in and out of clinical trials

BACKGROUND

Multiple factors can influence outcomes of patients receiving identical interventions in clinical trials and in routine practice. Here, we compare outcomes of men with metastatic castrate-resistant prostate cancer (mCRPC) treated with docetaxel and prednisone in routine practice and in clinical trials.

PATIENTS AND METHODS

We reviewed patients with mCRPC treated with docetaxel at Princess Margaret Cancer Centre. Primary outcomes were overall survival and PSA response rate. Secondary outcomes were reasons for discontinuation and febrile neutropenia. Outcomes were compared for men treated in routine practice and in clinical trials, and with data from the TAX 327 study.

RESULTS

From 2001 to 2011, 438 men were treated, of whom 357 received 3-weekly docetaxel as first-line chemotherapy: 314 in routine practice and 43 in clinical trials. Trial patients were younger and had better performance status. Median survival was 13.6 months [95% confidence interval (95% CI) 12.1-15.1 months] in routine practice and 20.4 months (95% CI 17.4-23.4 months, P = 0.007) within clinical trials, compared with 19.3 months (95% CI 17.6-21.3 months, P < 0.001) in the TAX 327 study. PSA response rates were 45%, 54%, and 53%, respectively (P = NS). Reasons for treatment discontinuation were similar although trial patients received more cycles (median: 6 versus 8 versus 9.5, P < 0.001). Rates of febrile neutropenia were 9.6, 0, and 3% (P < 0.001) while rates of death within 30 days of last dose were 4%, 0%, and 3%, respectively (P = NS).

CONCLUSIONS

Survival of patients with mCRPC treated with docetaxel in routine practice is shorter than for men included in trials and is associated with more toxicity.

The prognostic importance of metastatic site in men with metastatic castration-resistant prostate cancer

The presence of visceral metastases is adversely prognostic in men with metastatic castration-resistant prostate cancer (mCRPC), but the prognostic impact of the site of visceral metastasis is unclear. Men with mCRPC in the TAX 327 phase 3 trial receiving docetaxel or mitoxantrone every 3 wk or weekly docetaxel, each with prednisone, were analyzed retrospectively to study the impact of the site of visceral metastasis on overall survival (OS). Patients were assessed for OS by site of metastases: liver with or without other sites, lung with or without bone or lymph nodes, bone plus lymph nodes, bone only, and lymph nodes only. Cox proportional hazards regression, adjusted for treatment and stratification factors, was performed. Men with liver metastases with or without other metastases had shorter median OS (10.0 mo; 95% confidence interval [CI], 5.4-11.5) than men with lung metastases with or without bone or nodal metastases (median OS: 14.4 mo; 95% CI, 11.5-22.4). Men with lymph node-only disease had the best median OS (26.7 mo; 95% CI, 22.3-34.2), followed by men with bone-only metastases (median OS: 19.0 mo; 95% CI, 18.2-20.7) and bone-plus-node disease (median OS: 15.7 mo; 95% CI, 14.4-17.2). Thus, pattern of spread including site of visceral metastasis confers a differential prognostic impact. These data require validation and may inform trial design and therapy.

Changes in bone mineral density in men starting androgen deprivation therapy and the protective role of vitamin D

SUMMARY

Androgen deprivation therapy in 80 men was associated with declines in bone mineral density (BMD), which were greatest in the first year, and in the lumbar spine compared to controls. Vitamin D use was associated with improved BMD in the lumbar spine and in the first year.

INTRODUCTION

Decreased BMD is a common side effect of androgen deprivation therapy (ADT), leading to increased risk of fractures. Although loss of BMD appears to be greatest within the first year of starting ADT, there are few long-term studies of change in BMD, and risk factors for bone loss are not well-characterized.

METHODS

Men aged 50+ with nonmetastatic prostate cancer starting continuous ADT were enrolled in a prospective longitudinal study. BMD was determined by dual-energy x-ray absorptiometry at baseline and yearly for 3 years. Matched controls were men with prostate cancer not receiving ADT. Multivariable regression analysis examined predictors of BMD loss.

RESULTS

Eighty ADT users and 80 controls were enrolled (mean age 69 years); 52.5 % had osteopenia and 8.1 % had osteoporosis at baseline. After 1 year, in adjusted models, ADT was associated with significant losses in lumbar spine BMD compared to controls (-2.57 %, p = 0.006), with a trend towards greater declines at the total hip (p = 0.09). BMD changes in years 2 and 3 were much smaller and not statistically different from controls. Use of vitamin D but not calcium was associated with improved BMD in the lumbar spine in year 1 (+6.19 %, p < 0.001) with smaller nonsignificant increases at other sites (+0.86 % femoral neck, +0.86 % total hip, p > 0.10) primarily in the first year.

CONCLUSIONS

Loss of BMD associated with ADT is greatest at the lumbar spine and in the first year. Vitamin D but not calcium may be protective particularly in the first year of ADT use.

Assessing adherence to oral chemotherapy using different measurement methods: Lessons learned from capecitabine

Purpose

Adherence to oral medication is important in oncology. Few studies have evaluated adherence with cancer agents such as capecitabine, which is given on a complicated schedule. Furthermore, little guidance exists regarding the best methods for monitoring adherence with oral cancer drugs. The purpose of our study was to evaluate adherence to capecitabine using several accepted measures.

Patients and methods

Patients treated with capecitabine for gastrointestinal cancers were included in this prospective cohort study. Adherence was evaluated during two consecutive cycles of capecitabine using three assessment methods: self-report, pill count, and use of a microelectronic monitoring system. The primary endpoint was proportion of patients adherent to capecitabine (>80% of adherence according to the three methods of measurement); the secondary objective was to compare the three methods of measurement.

Results

Nineteen patients were accrued to this study. Further accrual was stopped after the first planned analysis, because 18 and 19 patients were adherent by self-report and pill count, respectively. The overall adherence rates were 99, 100, and 61% with self-report, pill count, and microelectronic monitoring system cap, respectively. Ten (53%) patients were classified as nonadherent (<80% of adherence according to at least one method of measurement), but four of them transferred their pills into another medication container suggesting that measurement of adherence using microelectronic monitoring system technology may not be useful.

Conclusion

While we did not identify a major adherence issue with capecitabine in our study, it provides insight into problems associated with measurement of adherence in oncology and suggests that combining measures of adherence maximizes accuracy.

Initial biopsy Gleason score as a predictive marker for survival benefit in patients with castration-resistant prostate cancer treated with docetaxel: data from the TAX327 study

BACKGROUND

Since 2004, docetaxel has been the standard first-line systemic therapy for patients with metastatic castration-resistant prostate cancer (mCRPC). With abiraterone recently becoming available in the predocetaxel setting, it is warranted to identify subgroups of patients who may obtain the greatest benefit from docetaxel and particularly qualify for receiving docetaxel as first-line treatment for mCRPC.

OBJECTIVE

We aimed to identify factors that could characterize subgroups of patients who obtain the greatest benefit from the use of docetaxel.

DESIGN, SETTING, AND PARTICIPANTS

TAX327 was multinational, randomized, phase 3 study that was conducted from 2000 to 2002 in 1006 men with mCRPC.

INTERVENTION

Patients were randomized to receive docetaxel every 3 wk (D3), weekly docetaxel (D1), or mitoxantrone every 3 wk (M3), each with prednisone.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We investigated whether patients with poorly differentiated tumors (Gleason score ≥7) at diagnosis had greater benefit from D3 compared with M3 than patients with better differentiated tumors (Gleason score ≤6). Using a Cox model, we compared overall survival (OS) between the treatment groups within each subgroup of Gleason score.

RESULTS AND LIMITATIONS

The TAX 327 data showed that the OS benefit of D3 versus M3 was greater in patients with high-grade tumors (median OS: 18.9 vs 14.5 mo; p=0.009) than in patients with low-grade tumors (median OS: 21.6 vs 20.7 mo; p=0.674). Limitations of a retrospective analysis apply.

CONCLUSIONS

The survival benefit obtained with docetaxel is most pronounced in patients with high-Gleason-score tumors (Gleason ≥7). In a time of shifting paradigms in mCRPC, with abiraterone becoming available prior to docetaxel chemotherapy, Gleason score may help in selecting patients who obtain the greatest benefit from docetaxel as first-line treatment for mCRPC. Prospective validation of these findings is warranted.

Phase III trials of targeted anticancer therapies: redesigning the concept

Randomized phase III trials provide the gold-standard evidence for the approval of new drugs: an experimental treatment is compared with the current standard of care to identify clinically relevant differences in a predefined endpoint. However, there are several problems relating to the current role of phase III trials in drug development including the limited clinical benefit observed for some approved agents, the necessity for large trials to detect these differences, the inability of such trials to identify rare but important toxicities, and high cost. The design of phase III trials evaluating drug combinations, and those including biomarkers, presents additional challenges. Here, we review these problems and suggest that phase III trials with adaptive designs in selected prescreened populations could reduce these limitations.

Scheduling of paclitaxel and gefitinib to inhibit repopulation for optimal treatment of human cancer cells and xenografts that overexpress the epidermal growth factor receptor

PURPOSE

In clinical studies, evaluating the combination of chemotherapy and the epidermal growth factor receptor (EGFR) inhibitor gefitinib, treatments were administered concurrently, despite it being counter-intuitive to give a cytostatic agent concurrent with cycle-active chemotherapy. One strategy to enhance efficacy might be to give the agents sequentially, thus allowing selective inhibition of repopulation of cancer cells between doses of chemotherapy. Here, we evaluate the hypothesis that sequential administration might allow inhibition of repopulation by gefitinib, with tumor cells re-entering cycle to allow sensitivity to subsequent chemotherapy.

METHODS

Sequential and concurrent administration of paclitaxel and gefitinib were studied in vitro and in xenografts using EGFR over-expressing, EGFR-mutant, and EGFR wild-type human cancer cell lines. We evaluated cell cycle distribution and repopulation during treatment.

RESULTS

The sequential use of gefitinib and paclitaxel to treat EGFR over-expressing A431 cells in vitro decreased repopulation compared to chemotherapy alone, and there was greater cell kill compared to concurrent treatment. In contrast, combined treatment led to greater growth delay than use of gefitinib alone for concurrent but not for sequential treatment of mice bearing A431 xenografts; concurrent treatment had greater effects to reduce functional vasculature in the tumors. Conversely, sequential treatment led to greater growth delay than concurrent treatment of EGFR-mutant HCC-827 xenografts that are sensitive to lower doses of gefitinib.

CONCLUSIONS

These studies highlight the importance of considering effects on the cell cycle, and on the solid tumor microenvironment, including tumor vasculature, when scheduling cytostatic and cytotoxic agents in combination.

The tumor microenvironment and strategies to improve drug distribution

The microenvironment within tumors is composed of a heterogeneous mixture of cells with varying levels of nutrients and oxygen. Differences in oxygen content result in survival or compensatory mechanisms within tumors that may favor a more malignant or lethal phenotype. Cells that are rapidly proliferating are richly nourished and preferentially located close to blood vessels. Chemotherapy can target and kill cells that are adjacent to the vasculature, while cells that reside farther away are often not exposed to adequate amounts of drug and may survive and repopulate following treatment. The characteristics of the tumor microenvironment can be manipulated in order to design more effective therapies. In this review, we describe important features of the tumor microenvironment and discuss strategies whereby drug distribution and activity may be improved.

Aflibercept versus placebo in combination with docetaxel and prednisone for treatment of men with metastatic castration-resistant prostate cancer (VENICE): a phase 3, double-blind randomised trial

BACKGROUND

Docetaxel plus prednisone is standard first-line chemotherapy for men with metastatic castrate-resistant prostate cancer. Aflibercept is a recombinant human fusion protein that binds A and B isoforms of VEGF and placental growth factor, thereby inhibiting angiogenesis. We assessed whether the addition of aflibercept to docetaxel and prednisone would improve overall survival in men with metastatic castrate-resistant prostate cancer compared with the addition of placebo to docetaxel and prednisone.

METHODS

VENICE was a phase 3, multicentre, randomised double-blind placebo-controlled parallel group study done in 31 countries (187 sites). Men with metastatic castrate-resistant prostate cancer, adequate organ function, and no prior chemotherapy were treated with docetaxel (75 mg/m(2) intravenously every 3 weeks) and oral prednisone (5 mg twice daily) and randomly allocated (1:1) to receive aflibercept (6 mg/kg) or placebo, intravenously, every 3 weeks. Treatment allocation was done centrally via an interactive voice response system, using a computer-generated sequence with a permuted-block size of four and stratified according Eastern Co-operative Group performance status (0-1 vs 2). Patients, investigators, and other individuals responsible for study conduct and data analysis were masked to treatment assignment. Aflibercept or placebo vials were supplied in identical boxes. The primary endpoint was overall survival using intention-to-treat analysis. This is the primary analysis of the completed trial. The study is registered with ClinicalTrials.gov, number NCT00519285 FINDINGS: Between Aug 17, 2007, and Feb 11, 2010, 1224 men were randomly allocated to treatment: 612 to each group. At final analysis, median follow-up was 35 months (IQR 29-41) and 873 men had died. Median overall survival was 22·1 months (95·6% CI 20·3-24·1) in the aflibercept group and 21·2 months (19·6-23·8) in the placebo group (stratified hazard ratio 0·94, 95·6% CI 0·82-1·08; p=0·38). We recorded a higher incidence of grade 3-4 gastrointestinal disorders (182 [30%] vs 48 [8·0%]), haemorrhagic events (32 [5·2%] vs ten [1·7%]), hypertension (81 [13%] vs 20 [3·3%]), fatigue (97 [16%] vs 46 [7·7%]), infections (123 [20%] vs 60 [10%]) and treatment-related fatal adverse events (21 [3·4%] vs nine [1·5%]) in the aflibercept group than in the placebo group.

INTERPRETATION

Aflibercept in combination with docetaxel and prednisone given as first-line chemotherapy for men with metastatic castrate-resistant prostate cancer resulted in no improvement in overall survival and added toxicity compared with placebo. Docetaxel plus prednisone remains the standard treatment for such men who need first-line chemotherapy.

FUNDING

Sanofi and Regeneron Pharmaceuticals Inc.

Influence of concurrent medications on outcomes of men with prostate cancer included in the TAX 327 study

OBJECTIVES

The TAX 327 trial was pivotal in establishing docetaxel in castration refractory metastatic prostate cancer. Various commonly prescribed and over-the-counter co-administered medications are thought to exhibit anti-neoplastic properties and/or could potentially have pharmacokinectic interactions with docetaxel lessening the effectiveness of chemotherapy.

METHODS

To examine the effect of on prostate cancer outcomes within this trial, we examined overall survival, prostate-specific antigen (PSA) response, percent PSA reduction, pain response and QOL responses for 14 families of medications including metformin, digoxin, verapamil, proton pump inhibitors, nitrates, statins, cox-2 inhibitors, warfarin, heparins, ascorbic acid, selenium, tocopherol, antidepressants and erythropoietin.

RESULTS

Our findings did not reveal any medication that had a significant additive or synergistic effect with docetaxel. We did note, however, that patients on digoxin or verapamil had poorer overall survival, possibly due to a trend of fewer cycles of administered chemotherapy being administered to the verapamil group, consistent with a pharmacokinectic interaction.

CONCLUSIONS

These data are only hypothesis-generating given the statistical limitations, but may form a basis for similar future analysis in other malignancies. The data suggest the need to be aware of pharmacokinectic interactions with medications that may interact with docetaxel.

Treatment of prostate cancer with intermittent versus continuous androgen deprivation: a systematic review of randomized trials

PURPOSE

Uncertainty exists regarding benefits of intermittent androgen deprivation (IAD) compared with continuous androgen deprivation (CAD) for treatment of prostate cancer. On the basis of a systematic review of evidence, our aim was to formulate a recommendation for either IAD or CAD to treat relapsing, locally advanced, or metastatic prostate cancer.

METHODS

We searched literature published up to September 2012 from MEDLINE, EMBASE, the Cochrane Library, and major conference proceedings. We included randomized controlled trials comparing IAD and CAD if they reported overall survival (OS) or biochemical/radiologic time to disease progression.

RESULTS

Nine studies with 5,508 patients met our criteria. There were no significant differences in time-to-event outcomes between the groups in any studies. The pooled hazard ratio (HR) for OS was 1.02 (95% CI, 0.94 to 1.11) for IAD compared with CAD, and the HR for progression-free survival was 0.96 (95% CI, 0.76 to 1.20). More prostate cancer-related deaths with IAD tended to be balanced by more deaths not related to prostate cancer with CAD. Superiority of IAD for sexual function, physical activity, and general well-being was observed in some trials. Median cost savings with IAD was estimated to be 48%.

CONCLUSION

There is fair evidence to recommend use of IAD instead of CAD for the treatment of men with relapsing, locally advanced, or metastatic prostate cancer who achieve a good initial response to androgen deprivation. This recommendation is based on evidence against superiority of either strategy for time-to-event outcomes and substantial decrease with IAD in exposure to androgen deprivation, resulting in less cost, inconvenience, and potential toxicity.

Enhanced drug delivery in rabbit VX2 tumours using thermosensitive liposomes and MRI-controlled focused ultrasound hyperthermia

PURPOSE

The efficacy of anticancer drugs in solid tumours is impaired by their inability to reach all cancer cells in sufficient concentration to cause cytotoxicity. Hyperthermia-triggered release of drugs from thermosensitive liposomes can increase tumour drug concentration, but tumour-specific drug delivery requires precise temperature control, and effects on microregional distribution of anticancer drugs in tumours are unknown. Here we evaluate thermally triggered release of doxorubicin in a rabbit tumour model by comparing free versus thermosensitive liposomal doxorubicin administered systemically during magnetic resonance imaging (MRI)-controlled focused ultrasound hyperthermia.

MATERIALS AND METHODS

Twelve rabbits with a transplanted VX2 tumour in each thigh had a 10 mm diameter region in one tumour heated to 43°C using focused ultrasound with temperature control by MRI thermometry. Delivery of doxorubicin to tumours and normal tissues was quantified by fluorescence in tissue homogenates, and by fluorescence microscopy.

RESULTS

Using thermosensitive liposomal doxorubicin (2.5 mg/kg), doxorubicin concentrations in heated tumours were 26.7 times higher than in unheated tumours (n = 7, p = 0.017, two-sided Wilcoxon signed-rank test). There was no significant enhancement with free doxorubicin in heated versus unheated tumours (n = 3, p = 0.5). With thermosensitive liposomes (8.3 mg/kg), fluorescence microscopy demonstrated increased doxorubicin fluorescence in heated versus unheated tumours, co-localised with nuclear staining throughout the tumour.

CONCLUSIONS

Localised image-guided delivery of high concentrations of doxorubicin to cancer cells was achieved non-invasively in implanted tumours with temperature-sensitive drug carriers and a preclinical MRI-controlled focused ultrasound hyperthermia system.

Abstract 3801A: Reoxygenation and repopulation of hypoxic cells in a solid tumor after chemotherapy: a cause of treatment failure

Background: Hypoxia occurs in solid tumors: chronic diffusion-limited hypoxia occurs distal from functional blood vessels, while acute hypoxia may occur because of interruptions in blood flow. Well-nourished tumor cells close to blood vessels tend to be rapidly proliferating but hypoxic cells located farther away are slowly-proliferating. Chemotherapy may spare hypoxic cells because of poor drug distribution to them and because most drugs are selectively toxic to proliferating cells. Intervals between administration of chemotherapy allow for recovery of normal tissues (e.g. repopulation of bone marrow) but might allow re-oxygenation and resumed proliferation of formerly hypoxic cells due to better supply of nutrients to them, as is observed during radiotherapy. Here we evaluate these processes in human tumor xenografts Methods: Two specific markers of hypoxic cells (pimonidazole [pimo] and EF5) were injected into mice bearing MCF7 tumor xenografts, and tumor cells labeled with one or both markers were recognized in tumor sections (in relation to DioC7+ve functional tumor blood vessels) using appropriate fluorescence-labeled antibodies and imunohistochemistry. Proliferating cells were identified by an antibody to Ki67. Mice were treated with pimo and then either doxorubicin or saline one hour later; EF5 was given after a variable interval of 24, 48, 72, 96 or 120 hours; mice were killed two hours after the second injection. Changes in the location, proliferation and oxygen status of formerly hypoxic (pimo+ve) cells were quantified by their distance from hypoxia, Ki67 status and uptake of EF5 as a function of time. Results: Following treatment with doxorubicin, the proportion of hypoxic cells in the entire tumor decreased from 1.5% (pimo+ve) prior to injection to 0.7% (EF5+ve) at 24 hours. The percentage of pimo+ve formerly hypoxic cells that are no longer hypoxic (i.e. EF5 - ve) at 24 hours was 90% after docxorubicin compared to 27% in controls, indicating rescue of previous hypoxic cells that would have died in the absence of treatment. Proliferation of these pimo+ve cells that were cycling (Ki67+ve) increased from 7% to 15.0% at 24 Hours and then slowly decreased. Conclusions: Formerly hypoxic cells in MCF7 xenografts undergo re-oxygenation and increase their proliferation following treatment with doxorubicin. Originally hypoxic cells (that may have died in the absence of treatment) can move closer to blood vessels, re-oxygenate and repopulate a tumor. Treatment directed to killing hypoxic cells (e.g. with hypoxia activated pro-drugs) has potential to improve the outcome of chemotherapy.

Supported by a research grant from the Canadian Institutes for Health Research.

Citation Format: Jasdeep K. Saggar, Ian F. Tannock. Reoxygenation and repopulation of hypoxic cells in a solid tumor after chemotherapy: a cause of treatment failure. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3801A. doi:10.1158/1538-7445.AM2013-3801A

Abstract 3829A: Pantoprazole enhances the activity of chemotherapy for solid tumors by inhibition of autophagy

Purpose: Resistance to anti-tumour agents is a major cause of treatment failure in patients with cancer. Luciani have shown that PPIs can augment the effects of chemotherapy in vitro and in vivo, most likely by modifying the acid-base balance across the cell membrane and/or of intracellular organelles such as lysosomes and endososmes. Endosomes are important intermediaries of the process of autophagy, a survival mechanism for stressed cells and a possible target for anticancer therapy. Here we evaluated the effect of pantoprazole (PTP) to modify cytotoxic effects of the commonly-used anticancer drug docetaxel (DOC) for cultured cells and for human tumour xenografts, to modify the distribution of biomarkers of activity of docetaxel in relation to tumour blood vessels and inhibit autophagy.

Methods: Endosomal pH of cells was measured by fluorescence spectroscopy following exposure to the endosomal probe Lysosensor. Levels of autophagy were evaluated by quantifying the level of the LC3B protein in Western blots. Human prostate cancer PC3 cells were transfected with a construct where LC3B was linked to red (RFP) and green (GFP) fluorescent protein (mRFP-GFP-LC3) such that cells with high levels of autophagy stained red while those with low levels stained green. Cytotoxicity of DOC +/-PTP was evaluated in vitro by a colony-forming assay for PC3 parental cells, and for cells transfected with shRNAs to inhibit autophagy. Growth delay of three human xenografts in nude mice was evaluated following treatment with single or multiple doses of DOC+/- PTP. The distribution of drug effects in tumour sections in relation to blood vessels was quantified (at early intervals of ∼30 minutes) by γH2AX, a marker of DNA damage, and (at 24 hours) by cleaved caspase 3, a marker of apoptosis.

Results: PTP increased endosomal pH and inhibited autophagy in a dose and time dependent manner. PTP was not cytotoxic when used alone but increased the cytotoxicity of DOC for cultured PC3 cells; the effects of PTP were reduced against genetically-modified cells that have reduced ability to undergo autophagy. Pre-treatment with PTP increased markedly the growth delay due to DOC of three different xengografts, especially after three treatments at weekly intervals, with minimal effects on DOC toxicity. Cellular effects of DOC evaluated by γH2AX and by cleaved caspase 3 decreased with increasing distance from tumour blood vessels, but were enhanced substantially by pre-treatment with PTP. There is less cell proliferation and marked reduction in hypoxia in xenografts generated from autophagy-deficient PC3 cells compared to PC3 wild type xenografts.

Conclusions: Pantoprazole increases the therapeutic effectiveness of docetaxel in vitro and in vivo, and a potential mechanism is inhibition of autophagy. Docetaxel is the primary chemotherapy for men with metastatic castration resistant prostate cancer, and we plan a phase II study of PTP + DOC in such patients.

Citation Format: Qian Tan, Anthony Joshua, Jasdeep Saggar, Man Yu, Carol M Lee, Marianne Koritzinsky, Bradly R Wouters, Ian F Tannock. Pantoprazole enhances the activity of chemotherapy for solid tumors by inhibition of autophagy. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3829A. doi:10.1158/1538-7445.AM2013-3829A

A phase II study of cediranib (AZD 2171) in treatment naive patients with progressive unresectable recurrent or metastatic renal cell carcinoma. A trial of the PMH phase 2 consortium

BACKGROUND

Inhibition of angiogenesis has emerged as an effective therapeutic strategy in metastatic renal cell cancer (mRCC). In this single arm phase 2 study, we evaluated the efficacy and tolerability of cediranib (AZD2171) a potent angiogenesis inhibitor in first line mRCC.

METHODS

Eligible patients who had no prior systemic therapy received cediranib 45 mg orally once daily continuously. The primary endpoint was objective response rate (ORR). Secondary endpoints were clinical benefit rate (ORR plus stable disease (SD) ≥ 4 months), duration of response, progression free survival (PFS), median overall survival (OS), safety and tolerability.

RESULTS

Between January 2006 and April 2008, 44 patients were accrued. The median age was 62 (range 44-83) and performance status was either 0 (22 patients) or 1 (22 patients). Of the 39 evaluable patients there were 15 (38 %) partial responses (95 % CI: 23-55 %); 18 stable disease (SD) for a clinical benefit rate of 33/39 = 85 % (95 % CI: 69-94 %) and 6 progressive disease. Median PFS was 8.9 months (95 % CI: 5.1-12.9); and median OS was 28.6 months (95 % CI: 18.2-37.3 months). The most frequent grade 3 or higher AEs included hypertension, fatigue, hand-foot syndrome and diarrhea.

CONCLUSIONS

Cediranib demonstrated significant anti-tumour activity in first line, treatment-naive mRCC, with efficacy parameters comparable to the other approved agents (sunitinib and pazopanib) in this setting. The main toxicities were fatigue, diarrhea and hypertension. Based on these encouraging results, further evaluation of cediranib in mRCC at a more tolerable dose of 30 mg daily appears warranted.

Use of molecular biomarkers to quantify the spatial distribution of effects of anticancer drugs in solid tumors

Poor distribution of anticancer drugs within solid tumors may limit their effectiveness. Here, we characterize the distribution within solid tumors of biomarkers of drug effect. γ-H2AX, cleaved-caspase-3 or -6, and Ki67 were quantified in tumor sections in relation to blood vessels (recognized by CD31) using monoclonal antibodies and immunohistochemistry. To validate their use, we compared their time-dependent distribution with that of (i) fluorescent doxorubicin and (ii) a monoclonal antibody that detects melphalan-induced DNA adducts. The biomarkers were then used to quantify the distribution of docetaxel in relation to tumor blood vessels. Activation of γ-H2AX was evaluated following in vitro exposure of tumor cells to multiple drugs. Distributions of doxorubicin in MDA-MB-231 and MCF-7 xenografts and of melphalan-induced DNA adducts in MCF-7 and EMT-6 tumors decreased with distance from blood vessels, similar to the distributions of (i) γ-H2AX at 10 minutes, (ii) cleaved caspase-3 or -6, and (iii) change in Ki67 at 24 hours following treatment. The distribution of these biomarkers following treatment with docetaxel also decreased with increasing distance from tumor blood vessels. Activation of γ-H2AX occurred within 1 hour after exposure to several drugs in culture. Multiple anticancer drugs show a decrease in activity with increasing distance from tumor blood vessels; poor drug distribution is an important cause of drug resistance. The above biomarkers may be used in designing strategies to overcome therapeutic resistance by modifying or complementing the limited spatial distribution of drug activity in solid tumors.

Abstract P6-09-02: Pre-treatment cognitive function (CF) in women with locally advanced breast cancer (LABC) and in healthy controls

Background: Several studies have reported that women with breast cancer may have cognitive dysfunction prior to chemotherapy (ChT), and that cognitive dysfunction may be related to the cancer itself or to the psychological impact of a cancer diagnosis. Previous studies assessing CF in breast cancer patients pre-ChT have done so after surgery. Women with LABC receive ChT prior to surgery, and therefore provide a unique opportunity to assess CF without the confounding factor of surgery. This study reports CF in women with newly diagnosed LABC compared to healthy controls.

Methods: Baseline information including participant demographics, smoking/alcohol history, co-morbidities, and medications were collected. Women with LABC underwent a 2-hour battery of CF tests prior to neoadjuvant ChT. Six cognitive domains using standardized, validated, and reliable neuropsychological tests were assessed: verbal, visual-spatial, memory, attention, processing speed, and executive function. Performance on each test was transformed to z-scores using normative data (average range z-score = −1 to 1). Participants also completed self-report questionnaires for CF (FACT-COG3 and PAOFI), fatigue (FACIT-F subscale) and affect (HADS). Data obtained were compared to those for age-matched healthy women who were administered the same battery of tests and measures.

Results: Forty-seven women with LABC and 22 controls were assessed. All women completed the CF tests and questionnaires within 2 hours. There were no significant differences between patients and controls in age (pts median age=49; controls=48), education (median years in school=16 for both), smoking or alcohol history, co-morbidities, mood disorders (anxiety, depression), previous history of concussion, or current medication for mood or sleep problems. Objective CF testing demonstrated no significant difference in the mean performance of women with LABC vs that of controls in any objective domain, nor were there statistically significant differences in the frequency of deficits (e.g., 96% of pts had &lt; 2 deficits; 86% of controls had &lt; 2 deficits). Women with LABC did not report worse CF, fatigue, or depressive symptoms compared to controls. Anxiety was the only self-reported measure where patients had more symptoms (mean HADS 7.6 vs 5.4, p &lt; .036). Consistent with the literature, only weak to no association was observed between any of the objective measures of CF and the self-reported measures. Multivariate regression analyses found for both patients and controls, low education level (≤12 years), smoking history (≥10 pack year), alcohol intake (≥10 drinks/week), and currently taking medication for anxiety, depression, or sleep to be associated with poorer CF as measured on at least one objective domain.

Conclusion: When assessed prior to ChT and surgery, no significant difference in objectively assessed or self-reported CF was observed between women with LABC and healthy controls. The effects of cancer treatment will be evaluated as part of a longitudinal study.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-09-02.

Comparison of absolute benefits of anticancer therapies determined by snapshot and area methods

BACKGROUND

Reporting of relative risk reduction as the measure of treatment effect in randomized clinical trials (RCTs) may be difficult to understand. Here, we compare two methods for assessing absolute benefits of anticancer therapies.

MATERIALS AND METHODS

We searched PubMed for RCTs comparing therapies for breast and colorectal cancers published 1975-2009 (adjuvant setting) and 2000-2010 (metastatic setting). Eligible trials reported statistically significant differences. Kaplan-Meier curves were assessed for absolute differences in time-to-event end points at a single point (snapshot method) and as the area between curves (area method). Pooled absolute benefits determined by both methods were compared by the Pitman-Morgan test.

RESULTS

Eighty-three and 39 paired curves were assessed in the adjuvant and metastatic settings, respectively. In trials of adjuvant therapy, absolute benefits were larger and more variable when assessed at different time points by the snapshot compared with the area method (median and ranges for 60-month difference in overall survival: 7.6% [2.5%-28.4%] and 4.5% [1.8%-13.6%]; P = 0.002, respectively). For metastatic disease, both methods were within 0.5 month of each other in 62% of trials.

CONCLUSIONS

The area method provides an alternative measure of absolute treatment effect, which uses all of the available data and is less dependent on the shape of survival curves.

Reversal of ATP-binding cassette drug transporter activity to modulate chemoresistance: why has it failed to provide clinical benefit?

Enhanced drug extrusion from cells due to the overexpression of the ATP-binding cassette (ABC) drug transporters inhibits the cytotoxic effects of structurally diverse and mechanistically unrelated anticancer agents and is a major cause of multidrug resistance (MDR) of human malignancies. Multiple compounds can suppress the activity of these efflux transporters and sensitize resistant tumor cells, but despite promising preclinical and early clinical data, they have yet to find a role in oncologic practice. Based on the knowledge of the structure, function, and distribution of MDR-related ABC transporters and the results of their preclinical and clinical evaluation, we discuss probable reasons why these inhibitors have not improved the outcome of therapy for cancer patients. We also outline new MDR-reversing strategies that directly target ABC transporters or circumvent relevant signaling pathways.

A randomized double-blind placebo-controlled cross-over trial of the impact on quality of life of continuing dexamethasone beyond 24 h following adjuvant chemotherapy for breast cancer

Uncertainty remains about the optimal anti-emetic regimen for control of delayed nausea and vomiting after adjuvant chemotherapy for breast cancer. Many patients receive dexamethasone but complain of insomnia, anxiety/agitation, and indigestion. The aim was to determine if patients receiving chemotherapy for breast cancer prefer treatment with dexamethasone or placebo for prophylaxis against delayed nausea and vomiting, and to compare quality of life (QOL) between the two treatments. In this randomized, double-blind, cross-over trial, we compared oral dexamethasone (4 mg twice daily for 2 days) versus placebo for chemotherapy-naïve patients with breast cancer. All patients received intravenous granisetron and dexamethasone pre-chemotherapy and oral granisetron on day 2. Primary endpoints were: (i) patient preference; (ii) difference between cycles in change of QOL from days 1 to 8. Median age of the 94 women was 51 years (range 27-76): 79 received fluorouracil/epirubicin/cyclophosphamide and 15 received doxorubicin/cyclophosphamide. Thirteen withdrew pre-cycle 2 with no differences between arms. Of 80 patients stating a preference, 31 preferred placebo (39 %, 95 % CI: 28-50 %) and 37 (46 %, 95 % CI: 35-58 %) preferred dexamethasone; 12 had no preference. There were no differences in intensity of vomiting, nausea, or time to onset of vomiting. There was greater decrease in global QOL (p = 0.06) when patients received dexamethasone. No other symptom/QOL domains differed significantly. In conclusion, no significant difference was found in patient preference, QOL, or symptoms regardless of whether dexamethasone or placebo was used after adjuvant chemotherapy.

How valid are claims for synergy in published clinical studies?

BACKGROUND

Clinical trials evaluating drug combinations are often stimulated by claims of synergistic interactions in preclinical models. Overuse or misuse of the term synergy could lead to poorly designed clinical studies.

METHODS

We searched PubMed using the terms 'synergy' or 'synergistic' and 'cancer' to select articles published between 2006 and 2010. Eligible studies were those that referred to synergy in preclinical studies to justify a drug combination evaluated in a clinical trial.

RESULTS

Eighty-six clinical articles met eligibility criteria and 132 preclinical articles were cited in them. Most of the clinical studies were phase I (43%) or phase II trials (56%). Appropriate methods to evaluate synergy in preclinical studies included isobologram analysis in 18 studies (13.6%) and median effect in 10 studies (7.6%). Only 26 studies using animal models (39%) attempted to evaluate therapeutic index. There was no association between the result of the clinical trial and the use of an appropriate method to evaluate synergy (P=0.25, chi-squared test).

CONCLUSIONS

Synergy is cited frequently in phase I and phase II studies to justify the evaluation of a specific drug combination. Inappropriate methods for evaluation of synergy and poor assessment of therapeutic index have been used in most preclinical articles.

The price we pay for progress: a meta-analysis of harms of newly approved anticancer drugs

PURPOSE

Registration of new anticancer drugs is usually based on results of randomized controlled trials (RCTs) showing improved efficacy when compared with standard therapy. There is relatively less emphasis on toxicity. In our study, we analyze serious toxicities of newly approved anticancer drugs reported in pivotal RCTs used for drug registration.

PATIENTS AND METHODS

We identified RCTs evaluating agents for the treatment of solid tumors approved by the US Food and Drug Administration between 2000 and 2010. Odds ratios (OR) and 95% CI were computed for three end points of safety and tolerability: treatment-related death, treatment-discontinuation related to toxicity, and grade 3 or 4 adverse events (AEs). These were then pooled in a meta-analysis. Correlations between these end points and the hazard ratios for overall survival (OS) and progression-free survival (PFS) were also assessed.

RESULTS

Thirty-eight RCTs were analyzed. Compared with control groups, the odds of toxic death was greater for new agents (OR, 1.40; 95% CI, 1.15 to 1.70; P < .001) as were the odds of treatment-discontinuation (OR, 1.33; 95% CI, 1.22 to 1.45, P < .001). Grade 3 or 4 AEs (OR, 1.52; 95% CI, 1.35 to 1. 71; P < .001) were also more common with new agents, especially nonhematologic AEs such as diarrhea, skin reactions, and neuropathy. There were no significant correlations between safety end points and OS or PFS.

CONCLUSION

New anticancer agents that lead to improvements in time-to-event end points also increase morbidity and treatment-related mortality. The balance between efficacy and toxicity may be less favorable in clinical practice because of selection of fewer patients with good performance status and limited comorbidities. Patients' baseline health characteristics should be considered when choosing therapy.

Penetration of anticancer drugs through tumour tissue as a function of cellular packing density and interstitial fluid pressure and its modification by bortezomib

Background

Limited penetration of anticancer drugs in solid tumours is a probable cause of drug resistance. Our previous results indicate that drug penetration depends on cellular packing density and adhesion between cancer cells.

Methods

We used epithelioid and round cell variants of the HCT-8 human colon carcinoma cell lines to generate tightly and loosely packed xenografts in nude mice. We measured packing density and interstitial fluid pressure (IFP) and studied the penetration of anti-cancer drugs through multilayered cell cultures (MCC) derived from epithelioid HCT-8 variants, and the distribution of doxorubicin in xenografts with and without pre-treatment with bortezomib.

Results

We show lower packing density in xenografts established from round cell than epithelioid cell lines, with lower IFP in xenografts. There was better distribution of doxorubicin in xenografts grown from round cell variants, consistent with previous data in MCC. Bortezomib pre-treatment reduced cellular packing density, improved penetration, and enhanced cytotoxcity of several anticancer drugs in MCC derived from epithelioid cell lines. Pre-treatment of xenografts with bortezomib enhanced the distribution of doxorubicin within them.

Conclusions

Our results provide a rationale for further investigation of agents that enhance the distribution of chemotherapeutic drugs in combination with conventional chemotherapy in solid tumours.

Abstract 5247: Use of two markers of hypoxia to study migration, re-oxygenation and repopulation of originally hypoxic cells in MCF-7 tumor xenografts following chemotherapy

Background: Hypoxia occurs in solid tumors: chronic diffusion-limited hypoxia occurs distal from functional blood vessels, while acute hypoxia may occur because of interruptions in blood flow. Well-nourished tumor cells close to blood vessels tend to be rapidly proliferating but hypoxic cells located farther away are slowly-proliferating. Chemotherapy may spare hypoxic cells because of poor drug distribution to them and because most drugs are selectively toxic to proliferating cells. Intervals between administration of chemotherapy allow for recovery of normal tissues (e.g. repopulation of bone marrow) but might allow re-oxygenation and resumed proliferation of formerly hypoxic cells due to better supply of nutrients to them, as is observed during radiotherapy. Therefore, it is important to establish a technique whereby hypoxia can be studied allowing for the assessment of different hypoxia-modulating therapies that can be used to prevent tumor relapse. Methods: Two specific markers of hypoxic cells (pimonidazole [pimo] and EF5) were injected into mice bearing MCF7 tumor xenografts, and tumor cells labeled with one or both markers were recognized in tumor sections (in relation to DioC7+ve functional tumor blood vessels) using appropriate fluorescence-labeled antibodies and imunohistochemistry. Proliferating cells were identified by an antibody to Ki67. Mice were treated with pimo and then either doxorubicin or saline one hour later; EF5 was given after a variable interval of 24, 48, 72, 96 or 120 hours; mice were killed two hours after the second injection. Changes in the location, proliferation and oxygen status of formerly hypoxic (pimo+ve) cells were quantified by their distance from blood vessels, Ki67 status and uptake of EF5 as a function of time. Results: Following treatment with doxorubicin, the proportion of hypoxic cells in the entire tumor decreased from1.5% (pimo+ve) prior to injection to 0.7% (EF5+ve) at 24 hours. The proportion of pimo+ve formerly hypoxic cells that are no longer hypoxic (i.e. EF5 - ve) at 24 hours was 75% after treatment compared to 18% in controls indicating rescue of previous hypoxic cells that would have died in the absence of treatment. The proportion of these pimo+ve cells that were cycling (Ki67+ve) increased from 4.7% to 15.0% at 24 Hours and then slowly decreased. Conclusions: There is a decrease in the proportion of hypoxic cells in MCF7 xenografts following treatment with doxorubicin. Originally hypoxic cells (that may have died in the absence of treatment) can move closer to blood vessels, re-oxygenate, and repopulate the tumor. Treatment directed to killing hypoxic cells (e.g. with hypoxia activated pro-drugs) has the potential to improve the outcome of chemotherapy by inhibiting tumor cell repopulation. Supported by are search grant from the Canadian Institutes for Health Research.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5247. doi:1538-7445.AM2012-5247

The effects of chemotherapy on cognitive function in a mouse model: a prospective study

PURPOSE

Clinical studies indicate that up to 70% of patients with cancer who receive chemotherapy experience cognitive impairment. The present study used a prospective longitudinal design to assess short- and long-term effects of commonly used anticancer drugs on cognitive performance in a mouse model.

EXPERIMENTAL DESIGN

Normal mice received three weekly injections of a combination of methotrexate + 5-fluorouracil (CHEMO group) or an equal volume of saline (SAL group). Cognitive tests, measuring different aspects of learning and memory, were administered before treatment, immediately after treatment, and three months later. Structural MRI scanning was conducted at each stage of cognitive testing.

RESULTS

The CHEMO group exhibited deficits on cognitive tasks acquired pretreatment [spatial memory, nonmatching-to-sample (NMTS) learning, and delayed NMTS], as well as impaired new learning on two tasks (conditional associative learning, discrimination learning) introduced posttreatment. Consistent with clinical evidence, cognitive deficits were pronounced on tests that are sensitive to hippocampal and frontal lobe dysfunction, but the CHEMO group's poor performance on the discrimination learning problem suggests that impairment is more widespread than previously thought. Cognitive deficits persisted for at least three months after treatment but some recovery was noted, particularly on tests thought to be under frontal lobe control. The MRI tests did not detect brain changes that could be attributed to treatment.

CONCLUSIONS

Chemotherapeutic agents can have adverse effects on information acquired pretreatment as well as new learning and memory and, despite some recovery, impairment is long lasting.

Targeting tumor architecture to favor drug penetration: a new weapon to combat chemoresistance in pancreatic cancer?

Pancreatic ductal adenocarcinoma (PDA) responds poorly to chemotherapy. In this issue of Cancer Cell, Provenzano et al. identify hyaluronan as a pivotal determinant of elevated interstitial fluid pressures (IFP) and vascular collapse in PDA. PEGPH20 treatment ablates stromal hyaluronan, normalizes IFP, and increases accessibility of tumor cells to anticancer drugs.

Phase II study of cytarabine in men with docetaxel-refractory, castration-resistant prostate cancer with evaluation of TMPRSS2-ERG and SPINK1 as serum biomarkers

What's known on the subject? and What does the study add? To date, there has been limited impetus to examine the use of cytarabine in prostate cancer. We presented preliminary laboratory data to suggest its utility in the castration refractory prostate cancer (CRPC) population which, combined with a previous case report, suggested it may have hitherto unrecognized utility in this setting. Embedded in this study was peripheral blood sampling for TMPRSS2-ERG and SPINK1, two genes that are believed to define prostate cancer genotypes, to assess their utility as biomarkers This study suggests that at the delivered doses, cytarabine has limited efficacy and significant myelotoxicity suggesting, it does not have a role in the treatment of docetaxel-refractory CRPC. The presence of serum TMPRSS2-ERG and SPINK1 mRNA biomarkers recovered from blood suggest that their analysis is worthy of further study.

OBJECTIVES

To run a phase II clinical trial of cytarabine in men with docetaxel-refractory, castration-resistant prostate cancer (CRPC), based on evidence that cytarabine might be effective in men with abnormalities of ERG oncogenes. To measure mRNA levels of prostate cancer-related genes in blood as biomarkers.

PATIENTS AND METHODS

Ten of a planned maximum of 30 men received i.v. cytarabine at doses of 0.25-1g/m(2) at 21-day intervals. The primary endpoint was prostate-specific antigen (PSA) response. Archival tumour samples were assessed by fluorescence in-situ hybridization for TMPRSS2:ERG translocation, and by immunohistochemistry for serine peptidase inhibitor Kazal type 1 (SPINK1). Blood was processed for mRNA quantification of TMPRSS2:ERG (exon1:exon4), SPINK1 and PSA.

RESULTS

A PSA response was not observed in any patient. The trial was stopped at the end of stage 1 of a modified Flemming design. The median number of cycles administered was 3. Grade 3-4 haematological toxicity was common. Five patients were subsequently excluded from the study for toxicity, and five for disease progression. Analysis of whole blood mRNA for T1:E4 translocation in TMPRSS2:ERG was consistent with that in the tumour in 8/9 evaluable cases (one was concordantly positive, seven were concordantly negative), SPINK1 results were concordant in 9/10 cases (two were concordantly positive, seven were concordantly negative [P = 0.047 for the predictive value]). There was no correlation between PSA or SPINK protein and their respective mRNA copy levels in blood.

CONCLUSIONS

Cytarabine at the doses used is ineffective for men with CRPC. Blood mRNA levels of prostate cancer genes may represent a novel aspect of monitoring prostate cancer and have implications for the understanding of tumour-derived mRNA.