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Background: The Fragility Indexquantifies the reliability of positive trials by estimating the number of events, which would change statistically significant results to non-significant results., Methods: We identified randomized trials supporting drug approvals by the US FDA between 2009 and 2019 in lung, breast, prostate, and colon cancers and in melanoma. We reconstructed survival tablesand calculated the number of events, which would result in a non-significant result for the primary endpoint. The FI was then compared to the number of patients in each trial who withdrew consent or were lost to follow-up. Regression analyses were used to explore associations between RCT characteristics and FI and trials in which FI was lower or equal to number of participants who withdrew consent or were lost to follow-up., Results: Among 81 RCTs, the median FI was 28. The median number of patients who withdrew consent or were lost to follow up was 27. FI was equal or lower than the number of patients who withdrew consent or were lost to follow-up in 47 trials (58%). There was a modest increase in FI over time (p = 0.02). Trials with overall survival as the primary endpoint (p = 0.006) and those in the palliative setting (p < 0.001) had lower FI. There was no association with trial sample size or duration of follow-up., Findings: Statistical significance of RCTs in common solid tumours can be reversed often with a small number of additional events. Post-approval RCTs or real-world data analyses should be performed to ensure results of registration trials are robust., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Objectives: Real-world evidence (RWE) has gained increased attention in recent years as a complement to traditional clinical trials. The use of RWE to establish the efficacy of oncology drugs for Food and Drug Administration (FDA) approval has not been described. In this paper, we review 5 recent examples where RWE was submitted in support of the FDA approvals of original or supplementary indications for oncology drugs., Methods: To identify cases where RWE was used, we reviewed drug approval packages available at Drugs@FDA for oncology drugs approved between 2017 and 2019. Five cases were selected to present a broad overview of different types of RWE, different circumstances under which RWE has been used for regulatory approvals, and how FDA evaluated the data in each case. The type of RWE submitted, the indication, limitations identified by FDA reviewers, and the outcome of the submission are discussed., Results: RWE, particularly historical controls for rare or orphan indications, has been used to support both original and supplementary oncology drug approvals. Types of RWE included data from electronic health records, claims, post-marketing safety reports, retrospective medical record reviews, and expanded access studies. Small sample sizes, data quality, and methodological issues were among concerns cited by FDA reviewers., Conclusion: By bridging the gap between the constraints of the trial setting and the realities of clinical practice, RWE can add value to a regulatory submission. These early examples provide insight into how regulators evaluated RWE submitted as evidence of efficacy for oncology drugs., (Copyright © 2020 ISPOR–The Professional Society for Health Economics and Outcomes Research. Published by Elsevier Inc. All rights reserved.)

Hazardous drug is a common term used by the National Institute of Occupational Health and Safety (NIOSH) to classify medications that may induce adverse mutagenic and reproductive responses in health care personnel. NIOSH publishes a list of drugs it defines as hazardous where it may be appropriate for health care workers to take protective measures to reduce the potential for occupational exposure. Recent updates and proposed updates to this list have included large molecule biological products with oncology indications. Both NIOSH and USP <800> recommend the use of closed system transfer devices (CSTDs) during compounding. CSTDs are required for administration of prepared solution in NIOSH. However, USP has suggested that the principles of <800> are broadly applicable to hazardous drug handling activities across all facility types. USP encourages the widespread adoption and use of <800> across all health care settings, which many health care workers have interpreted beyond compounding to include administration and preparation of conventionally manufactured sterile products per approved labeling. Although the use of CSTDs may reduce exposure of health care personnel to chemotherapy agents in health care setting, the impact of CSTDs on quality of biologic drug products, including monoclonal antibodies and other proteins, is not fully understood. To complicate this issue further, there are several commercially available CSTDs in the market which have different fluid paths and material of construction that comes in contact with the drug. Testing every combination of CSTD and drug product for potential incompatibilities can be a labor intensive and impractical approach and cause delay in getting essential drugs to patients. A panel discussion was held at a recent American Association of Pharmaceutical Scientists 2018 PharmSci 360 conference to discuss the impact of CSTDs on biologics. Impact on subvisible and visible particulates and impact to other product quality attributes such as high molecular weight species formation upon contact with CSTDs were reported in American Association of Pharmaceutical Scientists meeting. Impact to deliverable dose, holdup volumes of various CSTDs, and stopper coring were also reported that has significant impact to patient safety. Given the fact that USP chapter <800> will be implemented in December 2019, feedback from health authorities regarding the use of CSTDs for biological drug products is needed to provide an appropriate risk/benefit balance to ensure patient safety and quality of the biologic drug product while also protecting the health care worker and the environment. The purpose of this commentary is to provide an industry perspective on the challenges during the use of CSTDs for biologic drug products and is intended to raise caution and awareness on the benefits and shortcomings of these devices., (Copyright © 2020 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.)

Objective: The purpose of this study was to assess the change in student confidence to perform oncology pharmacy competencies before and after completing oncology didactic instruction using a flipped classroom approach., Methods: First year doctor of pharmacy students completed a survey prior to the Applied Science and Therapeutics (AST) oncology module (pre-survey) and the same survey following the completion of the oncology module (post-survey). The survey consisted of questions addressing prior oncology pharmacy experience related to employment (research or patient care) and education, level of interest in oncology pharmacy, and level of confidence to perform thirteen oncology pharmacy competencies., Results: One-hundred sixteen students completed the pre-survey and 35 completed the post-survey. Students completing both surveys reported greater confidence in all oncology pharmacy competencies (p < 0.0001) after instruction. The greatest increases in student confidence were related to chemotherapy dose calculations, patient education, and drug-drug interactions., Conclusions: The delivery of oncology content using flipped classroom instruction in the AST course successfully increased student confidence in ability to perform oncology pharmacy competencies. Cancer screening, cancer risk factors, and the preparation and dispensing of chemotherapy were competencies identified as needing greater emphasis in classroom instruction. Future studies are needed to assess student's knowledge and application of oncology pharmacy competencies in both the experiential and classroom settings., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objectives: To compare US Food and Drug Administration (FDA) and European Medicines Agency (EMA) labeling for evidence based on patient-reported outcomes (PROs) of new oncology treatments approved by both agencies., Methods: Oncology drugs and indications approved between 2012 and 2016 by both the FDA and the EMA were identified. PRO-related language and analysis reported in US product labels and drug approval packages and EMA summaries of product characteristics were compared for each indication., Results: In total, 49 oncology drugs were approved for a total of 64 indications. Of the 64 indications, 45 (70.3%) included PRO data in either regulatory submission. No FDA PRO labeling was identified. PRO language was included in the summary of product characteristics for 21 (46.7%) of 45 indications. European Organisation for Research and Treatment of Cancer and Functional Assessment of Cancer Therapy measures were used frequently in submissions. FDA's comments suggest that aspects of study design (eg, open labels) or the validity of PRO measures was the primary reason for the lack of labeling based on PRO endpoints. Both agencies identified missing PRO data as problematic for interpretation., Conclusions: During this time period, the FDA and the EMA used different evidentiary standards to assess PRO data from oncology studies, with the EMA more likely to accept data from open-label studies and broad concepts such as health-related quality of life. An understanding of the key differences between the agencies may guide sponsor PRO strategy when pursuing labeling. Patient-focused proximal concepts are more likely than distal concepts to receive positive reviews., (Copyright © 2019. Published by Elsevier Inc.)

Background: Several organizations have developed frameworks to systematically assess the value of new drugs. These organizations include the American Society of Clinical Oncology (ASCO), the European Society for Medical Oncology (ESMO), the Institute for Clinical and Economic Review (ICER), and the National Comprehensive Cancer Network (NCCN)., Objectives: To understand the extent to which these four tools can facilitate value-based treatment decisions in oncology., Methods: In this pilot study, eight panelists conducted value assessments of five advanced lung cancer drugs using the ASCO, ESMO, and ICER frameworks. The panelists received instructions and published clinical data required to complete the assessments. Published NCCN framework scores were abstracted. The Kendall's W coefficient was used to measure convergent validity among the four frameworks. Intraclass correlation coefficients were used to measure inter-rater reliability among the ASCO, ESMO, and ICER frameworks. Sensitivity analyses were conducted., Results: Drugs were ranked similarly by the four frameworks, with Kendall's W of 0.703 (P = 0.006) across all the four frameworks. Pairwise, Kendall's W was the highest for ESMO-ICER (W = 0.974; P = 0.007) and ASCO-NCCN (W = 0.944; P = 0.022) and the lowest for ICER-NCCN (W = 0.647; P = 0.315) and ESMO-NCCN (W = 0.611; P = 0.360). Intraclass correlation coefficients (confidence interval [CI]) for the ASCO, ESMO, and ICER frameworks were 0.786 (95% CI 0.517-0.970), 0.804 (95% CI 0.545-0.973), and 0.281 (95% CI 0.055-0.799), respectively. When scores were rescaled to 0 to 100, the ICER framework provided the narrowest band of scores., Conclusions: The ASCO, ESMO, ICER, and NCCN frameworks demonstrated convergent validity, despite differences in conceptual approaches used. The ASCO inter-rater reliability was high, although potentially at the cost of user burden. The ICER inter-rater reliability was poor, possibly because of its failure to distinguish differential value among the sample of drugs tested. Refinements of all frameworks should continue on the basis of further testing and stakeholder feedback., (Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.)

Cancer presents a major healthcare challenge worldwide, with several millions new cases a year, and represents a therapeutic area with a high need for new drugs. To respond to this, the parties of the International Conference for Harmonization agreed in 2007 to develop a guideline on nonclinical requirements for oncology therapeutics' development (ICH S9), which came into effect in early 2010. This guideline includes recommendations to facilitate and accelerate the development and marketing of cancer therapeutic agents for serious and life threatening malignancies and aims to address this need through a refinement and a reduction in the use of experimental animals, following the 3Rs principles. To assess the impact of ICH S9 on drug development and reduction of animal use, we performed an analysis of Marketing Authorization Applications at the European Medicines Agency relevant to the period in which the development of the guideline was approaching the final steps and its early implementation period. From the analysis performed, a consistent trend towards a decrease in the average number of non-clinical studies performed (-40.7%) and number of animals used per development program (-58.1%) for new chemical entities has been detected, highlighting increasing compliance by companies to the recommendations of ICH S9., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Although clear and validated recommendations exist concerning the evaluation of cancer treatments at the international level, the criteria retained to obtain the marketing authorization (MA) are multiple and heterogeneous. This qualitative survey explores the opinion related to the assessment of cancer treatment among the several concerned population. By the way of semi-structured interviews, our aim was to elicit perceptions toward the criteria which should be retained during the process of MA, by patients, oncologists, members of the pharmaceutical industry, health decision-makers and general population. Our survey emphasizes the variability of the significations associated with the criteria of efficiency of cancer treatments according to the characteristics of the respondents. We also have observed some common expectations from patients and oncologists toward the economic and political aspect, but also from the whole respondents toward the importance of the comfort of the patients. Lastly, the necessity to define specific criteria related to clinical cases emerges.

Introduction: Response-assessment metrics play an important role in clinical trials and routine patient management. For patients with malignant pleural mesothelioma (MPM), the standard for response assessment is image-based measurements of tumor thickness made according to the modified RECIST (Response Evaluation Criteria in Solid Tumors) protocol. To classify tumor response, changes in tumor thickness are compared with the standard RECIST -30% and +20% cutoffs for partial response (PR) and progressive disease (PD), respectively, which are not specific to MPM. The purpose of this work is to optimize the correlation between tumor response and patient survival by assessing the validity of existing response criteria in MPM and proposing alternative criteria., Methods: Computed tomography measurements of tumor thickness were acquired at baseline and throughout treatment for 78 patients undergoing standard-of-care chemotherapy. Overall survival was correlated with best response and first follow-up response using Harrell's C statistic. The response criteria for PD and PR were each varied in 1% increments to obtain optimized classification criteria. The performance was cross-validated using a leave-one-out approach., Results: Median survival was 14.9 months. The performance of the standard RECIST criteria in correlating response with survival was C=0.778, whereas the optimized performance of C=0.855 was obtained with criteria of -64% for PR and +50% for PD. After cross-validation, this performance was slightly reduced to C=0.829., Conclusions: Optimized tumor-response classification criteria were obtained for patients with MPM. These criteria improve the correlation between image-based response and patient survival.

Background: Published chemotherapy utilization rates for rectal cancer show considerable variation. Optimal chemotherapy utilization rates can serve as benchmarks to assess the quality of cancer care. The purpose of this study was to determine the optimal proportion of patients with rectal cancer who should receive chemotherapy at least once., Patients and Methods: An optimal chemotherapy utilization tree was constructed using indications for chemotherapy identified from evidence-based treatment guidelines. Epidemiologic data were merged with treatment indications to calculate an optimal chemotherapy utilization rate; this rate was compared with reported actual rates of chemotherapy utilization., Results: Chemotherapy is indicated at least once in 64% of patients with rectal cancer. Although the actual (Australian and United States data) and optimal utilization rates are comparable for patients presenting in stages II or III rectal cancer, actual utilization rates are higher than the optimal for stage I and lower than optimal for patients presenting in stage IV rectal cancer., Conclusion: Chemotherapy may be under-utilized in the initial management of patients presenting with metastatic rectal cancer., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Objectives: A randomised controlled trial was performed to compare the symptomatic effects on patients with benign prostatic hyperplasia (BPH) treated by two therapeutic approaches - the Western medicine (WM) and traditional Chinese medicine (TCM)., Methods: Four primary outcome measures, namely the quality of life (QOL), maximum urine flow ratio (UFR), International Prostate Symptom Score (IPSS) and prostate volumes, as well as four urethra-related and 35 non-urethra-related symptoms, were investigated to evaluate the effects on 31 BPH patients subjected to WM (Terazosin Hydrochloride Hytrin, THH) and 30 cases to TCM (herbal Saxifrage tablet, HST). The effects of both treatments are compared by the two-sample Kolmogorov-Smirnov test. The contributions of symptoms for four assessments are analysed by the logistic regression model and the Chow test., Results: The effect of TCM is weaker than that of WM in the assessment of the IPSS score (p<0.05), and both treatments are similar in the prostate volumes, the maximum UFR and the QOL assessments (p>0.05), as well as in the effective number of urethra-related or non-urethra-related symptoms before and after treatment (p>0.05). By comparing the linear regression models, different urethra-related and non-urethra-related symptom patterns associated with TCM and WM therapies are detected for four assessments, especially for the prostate volume assessment (p<0.01)., Conclusion: TCM (HST) is a potentially effective treatment in improving the QOL, prostate volumes and maximum UFR for patients with BPH, though it is less effective in ameliorating the IPSS score when compared with WM (THH). The non-urethra-related symptoms experienced by BPH patients might be one of the parameters to further achieve the tailored diagnosis and treatment for BPH., (Copyright 2009 Elsevier Ltd. All rights reserved.)

Purpose: This paper summarizes the role of external advisors in oncology drug development and regulation from a global perspective., Design: Recently, representatives from the United States Food and Drug Administration, European Medicines Agency, the Japanese Pharmaceuticals and Medical Devices Agency, the Australian Therapeutic Goods Administration and Health Canada held a meeting in conjunction with the American Society of Clinical Oncology meeting. The role of external advisors in oncology drug development and regulation in each of these jurisdictions was presented and discussed., Results: All regulatory bodies described have experience with two forms of outside expertise: advice from individual experts and advice from a group of experts assembled as an advisory group. Regulatory jurisdictions use individual experts variably. In some regions, individual experts provide advice based on knowledge and experience during the drug development phase or in the planning phase for the submission of a drug registration package. In other regions, these individuals serve as external evaluators with the primary responsibility for the review of a clinical trials package submitted for drug registration. Advisory boards have been formalized in all jurisdictions discussed. Advisory boards have a role in discussing specific applications as well as broad policy issues. A common theme is a composition of a core panel of experts with augmentation by additional expertise as needed for consideration of specific scientific questions. In all jurisdictions, advisory board recommendations are not binding on the regulatory body., Conclusions: Global oncology drug development and registration involves the use of experts by regulatory authorities. The types of experts needed, the expert's role and the transparency of the advisory process reflect the individual needs in different regions.

The translocation (9;22) gives rise to the p190(Bcr-Abl) and p210(Bcr-Abl) tyrosine kinase proteins, considered sufficient for leukemic transformation. Philadelphia-positive (Ph(+)) acute leukemia patients failing to respond to initial induction therapy have a poor prognosis with few effective treatment options. Imatinib is an orally administered, potent inhibitor of the Bcr-Abl tyrosine kinase. We conducted a clinical trial in 56 patients with relapsed or refractory Ph(+) acute lymphoblastic leukemia (ALL; 48 patients) or chronic myelogenous leukemia in lymphoid blast crisis (LyBC; 8 patients). Imatinib was given once daily at 400 mg or 600 mg. Imatinib induced complete hematologic responses (CHRs) and complete marrow responses (marrow-CRs) in 29% of ALL patients (CHR, 19%; marrow-CR, 10%), which were sustained for at least 4 weeks in 6% of patients. Median estimated time to progression and overall survival for ALL patients were 2.2 and 4.9 months, respectively. CHRs were reported for 3 (38%) of the patients with LyBC (one sustained CHR). Grade 3 or 4 treatment-related nonhematologic toxicity was reported for 9% of patients; none of the patients discontinued therapy because of nonhematologic adverse reactions. Grade 4 neutropenia and thrombocytopenia occurred in 54% and 27% of patients, respectively. Imatinib therapy resulted in a clinically relevant hematologic response rate in relapsed or refractory Ph(+) acute lymphoid leukemia patients, but development of resistance and subsequent disease progression were rapid. Further studies are warranted to test the effects of imatinib in combination with other agents and to define the mechanisms of resistance to imatinib.

Asparaginase is an enzyme used in the treatment of acute lymphoblastic leukemia and lymphoblastic lymphoma in children. It has minimal bone marrow toxicity. Its major side effects are anaphylaxis, pancreatitis, diabetes, coagulation abnormalities, and thrombosis, especially intracranial. It is derived from 2 different sources: Escherichia coli and Erwinia chrysanthemi. Nonrandomized clinical studies have suggested a similar efficacy of these 2 types of asparaginases and a lower toxicity for Erwinia-asparaginase. The European Organisation for Research and Treatment of Cancer-Children's Leukemia Group (EORTC-CLG) 58881 trial randomized 700 children with acute lymphoblastic leukemia or lymphoblastic lymphoma to either E coli- or Erwinia-asparaginase at the same dosage of 10 000 IU/m(2) twice weekly to compare toxicity and efficacy. Coagulation abnormalities were more frequent in the E coli-asparaginase than in the Erwinia-asparaginase arm of the study (30.2% versus 11.9%, P <.0001). The incidence of other toxicity was not significantly different. In the Erwinia-asparaginase arm, more patients failed to achieve complete remission (4.9% versus 2.0%; P =.038) and the relapse rate was higher, leading to shorter event-free survival (hazard ratio,1.59; 95% CI, 1.23-2.06; P =.0004). The estimate of event-free survival rate (SE) at 6 years was 59.8% (2.6%) versus 73.4% (2.4%). Overall survival rate at 6 years was also lower in the Erwinia-asparaginase arm at 75.1% (2.3%) versus 83.9% (2.0%), P =.002. With the dose scheduling used in this protocol, E coli-asparaginase induced more coagulation abnormalities but was superior to Erwinia-asparaginase for the treatment of childhood lymphoid malignancies.

Inositol hexaphosphate (InsP6, phytic acid) is ubiquitous in the plant kingdom and is abundant in cereals and legumes. In much smaller amounts InsP6 and its lower phosphorylated forms (InsP1-5) are contained in most mammalian cells, where they are important in regulating vital cellular functions. Both in vivo and in vitro experiments have suggested striking anticancer potential (preventive as well as therapeutic) for InsP6 with and without inositol. In addition to reduce cell proliferation, InsP6 increases differentiation of malignant cells often resulting in reversion to the normal phenotype. InsP6 is quickly absorbed from the rat stomach and upper intestine and distributed as inositol and InsP1. In vitro it is instantaneously taken up by malignant cells undergoing variable dephosphorylation to inositol and InsP1-5, pointing toward their role in mediating the action of InsP6. Because InsP6 is high in high-fiber diets, our studies also may explain, at least in part, the epidemiologic observation showing high-fiber diets are associated with a lower incidence of certain cancers. Although further studies are needed to elucidate the mechanism(s) of this action, inclusion of InsP6 in our strategies for cancer prevention and therapy is warranted.

Cancer prevention aims to halt or reverse the development and progression of precancerous cells through the use of noncytotoxic nutrients and/or pharmacologic agents during the lengthy time period between tumor initiation and frank malignancy. This paper reviews cancer chemoprevention studies and focuses on Phase III trials, which are large, randomized, placebo-controlled studies that usually last several years. Studies may include multiple agents and dose levels, long-term toxicity evaluations or the modulation of surrogate endpoint biomarkers. Sample sizes of individual studies vary depending on statistical concerns and the demographics of the subject population. Recent Phase III trials include several promising agents: retinol; the retinoids 13-cis retinoic acid, all-trans-retinoic acid and 4-hydroxyphenyl retinamide; beta-carotene; finasteride and tamoxifen. Because one of the many actions of retinoids is the induction of epidermal differentiation, clinical trials with this class of agents have largely been conducted in epithelial or squamous cell tumor types. Several Phase III studies that have targeted the reversal of premalignant lesions or the prevention of second primary tumors have shown promising positive results. In contrast, some studies have shown that chemopreventive agents may have limited activity against the recurrence or progression of cells that have already undergone malignant transformation. Thus, the role of chemoprevention appears to lie in reversal of the premalignant process rather than suppression of malignant growth.

Cancer chemoprevention refers to the reduction of cancer incidence by administration of agents or drugs that inhibit, reverse or retard the cancer process. Genistein has demonstrated a wide variety of biological activities that make it a good candidate for a chemopreventive agent. Many agents, such as genistein, are currently being tested with the goal of developing safe and effective chemopreventive drugs for human use. Genistein was investigated as a potential chemopreventive agent in an azoxymethane-induced colon carcinogenesis model. Genistein was tested for its ability to inhibit aberrant colon crypts in the colon of F344 rats that had been treated with azoxymethane. Genistein was administered in the diet from 1 wk before the carcinogen to 4 wk after the first carcinogen dose for a total of 5 wk. At both doses, 75 and 150 mg/kg, the mean number of foci per colon was significantly reduced. Further development of this agent includes demonstration of the preventive efficacy in an in vivo tumorigenesis model, followed by preclinical pharmacology and toxicology testing. Phase 1, 2 and 3 clinical chemoprevention trials would be then performed to determine pharmacokinetics, safe doses, and effectiveness for New Drug Approval.

Saponins, which are present in plants, have been suggested as possible anticarcinogens. They possess surface-active characteristics that are due to the amphiphilic nature of their chemical structure. The proposed mechanisms of anticarcinogenic properties of saponins include direct cytotoxicity, immune-modulatory effects, bile acid binding and normalization of carcinogen-induced cell proliferation. However, the anticarcinogenic effects of saponins from commonly consumed plant foods have not been studied. Soybeans are one of the most important sources of dietary saponins. They are the main protein supplier in many vegetarian diets. Our results showed that soybean saponins at the concentration of 150-600 ppm had a dose-dependent growth inhibitory effect on human carcinoma cells (HCT-15). Viability was also significantly reduced. Soybean saponins did not increase cell membrane permeability in a dose-dependent fashion, whereas gypsophilla saponin, a nondietary saponin, increased permeability with increasing concentrations. Electron microscopy indicated that soybean and gysophilla saponins alter cell morphology and interact with the cell membrane in different ways.

There is much evidence suggesting that compounds present in soybeans can prevent cancer in many different organ systems. The evidence for specific soybean-derived compounds having a suppressive effect on carcinogenesis in animal model systems is limited, however. There is evidence that the following isolated soybean derived products suppress carcinogenesis in vivo: a protease inhibitor, the Bowman-Birk inhibitor, inositol hexaphosphate (phytic acid) and the sterol beta-sitosterol. Other compounds that may be able to suppress carcinogenesis in animals are the soybean isoflavones. Soybean compounds reported to have other types of anticarcinogenic activity include soybean trypsin inhibitor, saponins and genistein. There is much evidence to suggest that diets containing large amounts of soybean products are associated with overall low cancer mortality rates, particularly for cancers of the colon, breast and prostate. It is believed that supplementation of human diets with certain soybean products shown to suppress carcinogenesis in animals could markedly reduce human cancer mortality rates.

Because many Western diseases are hormone-dependent cancers, we have postulated that the Western diet, compared with a vegetarian or semi-vegetarian diet, may alter hormone production, metabolism or action at the cellular level. Recently, our interest has been focused on the cancer-protective role of some hormone-like diphenolic phytoestrogens of dietary origin, the lignans and isoflavonoids. The precursors of the biologically active compounds originate in soybean products (mainly isoflavonoids but also lignans), as well as whole grain cereals, seeds, probably berries and nuts (mainly lignans). The plant lignan and isoflavonoid glycosides are converted by intestinal bacteria to hormone-like compounds with weak estrogenic and antioxidative activity; they have now been shown to influence not only sex hormone metabolism and biological activity but also intracellular enzymes, protein synthesis, growth factor action, malignant cell proliferation, differentiation and angiogenesis, making them strong candidates for a role as natural cancer protective compounds. Epidemiological investigations support this hypothesis, because the highest levels of these compounds are found in countries or regions with low cancer incidence. This report is a review of results that suggest that the diphenolic isoflavonoids and lignans are natural cancer-protective compounds.