Long-term chemoprevention in patients with adenomatous polyposis coli: an observational study

Prospective short-term studies on effectiveness of non-steroidal anti-inflammatory drugs (NSAIDs) point towards a decrease in the number and size of polyps. Effectiveness and safety in the prevention of progression in familial polyposis with NSAIDs in long-term use, which is the prerequisite for therapeutic evaluation in prospective studies, is unknown. The total absolute observation period of 54 patients under sulindac was 399 patient years with a mean of 7.4 (2-19) years per patient. 36 patients (66.7%) showed a fast decrease of polyp burden, 8 (14.8%) were slow responders, and 9 (16.7%) had stable disease; one patient had a slow progression. Upper gastrointestinal (GI) polyp burden remained stable in 47% patients, increased in 31%, and improved in 22%. Advanced adenomas were found in 8 patients only within the first 5 years of chemoprevention, no patient developed desmoid disease, anamnestically evaluated on every follow-up. There were no life-threatening side-effects. Dosage and delivery pattern were essential for effectiveness. This study provides evidence that chemoprevention with sulindac is effective and safe and can, either alone or in combination with other drugs, become a long-term management option in cases of adenomatous polyposis. These results justify further long-term prospective chemoprevention studies to elaborate treatment protocols and guidelines.

Dietary Intervention for Preventing Colorectal Cancer: A Practical Guide for Physicians

Colorectal cancer (CRC) is a disease with high prevalence and mortality. Estimated preventability for CRC is approximately 50%, indicating that altering modifiable factors, including diet and body weight, can reduce CRC risk. There is strong evidence that dietary factors including whole grains, high-fiber, red and processed meat, and alcohol can affect the risk of CRC. An alternative strategy for preventing CRC is use of a chemopreventive supplement that provides higher individual exposure to nutrients than what can be obtained from the diet. These include calcium, vitamin D, folate, n-3 polyunsaturated fatty acids, and phytochemicals. Several intervention trials have shown that these dietary chemopreventives have positive protective effects on development and progression CRC. Research on chemoprevention with phytochemicals that possess anti-inflammatory and/or, anti-oxidative properties is still in the preclinical phase. Intentional weight loss by bariatric surgery has not been effective in decreasing long-term CRC risk. Physicians should perform dietary education for patients who are at high risk of cancer for changing their dietary habits and behaviour. An increased understanding of the role of individual nutrients linked to the intestinal micro-environment and stages of carcinogenesis would facilitate the development of the best nutritional formulations for preventing CRC.

Black tea extract prevents inorganic arsenic induced uncontrolled proliferation, epithelial to mesenchymal transition and induction of metastatic properties in HaCaT keratinocytes - an in vitro study

A major global problem is chronic exposure to inorganic arsenic (iAs) which causes various health hazards including cancer. Escalation of reactive oxygen species (ROS) generation by chronic iAs exposure promotes Epithelial to Mesenchymal transition (EMT) which is followed by metastatic progression. In the present study, skin keratinocyte cells (HaCaT) were divided into three groups: (i) untreated, (ii) chronically iAs exposed, (iii) black tea extract (BTE) along with iAs treated. ROS was estimated by flowcytometry, expression of EMT markers were assessed by flowcytometry, western-blotting and Immunofluorescence. For metastatic studies, wound-healing assay, gelatin zymography, western-blot, transwell migration/invasion assay had been performed. Long term exposure of HaCaT cells to iAs causes excess generation of ROS. Morphological transformation and EMT were apparent at 210 days of exposure. Development of metastatic characteristics were observed at 240 days. Alterations in the parameters induced by iAs were found to be ameliorated by BTE. BTE was found to quench excess generation of ROS by iAs, subsequently inhibiting the chain of events like EMT and metastasis. Therefore, BTE may be considered as a potential phytochemical to prevent the deleterious effect of iAs. Skin carcinogenesis induced by iAs may thus be prevented by BTE via inhibition of EMT.

Renal cell carcinoma management: A step to nano-chemoprevention

Renal cell carcinoma (RCC) is one of the most common kidney cancers, responsible for nearly 90 % of all renal malignancies. Despite the availability of many treatment strategies, RCC still remains to be an incurable disease due to its resistivity towards conventional therapies. Nanotechnology is an emerging field of science that offers newer possibilities in therapeutics including cancer medicine, specifically by targeted delivery of anticancer drugs. Several phytochemicals are known for their anti-cancer properties and have been regarded as chemopreventive agents. However, the hydrophobic nature of many phytochemicals decreases its bioavailability and distribution, thus showing limited therapeutic effect. Application of nanotechnology to enhance chemoprevention is an effective strategy to increase the bioavailability of phytochemicals and thereby its therapeutic efficacy. The present review focuses on the utility of nanotechnology in RCC treatment and chemopreventive agents of RCC. We have also visualized the future prospects of nanomolecules in the prevention and cure of RCC.

Ent-abietane diterpenoid lactone glycosides and a phenolic glycoside from Phlogacanthus pulcherrimus T. Anderson with cytotoxic and cancer chemopreventive activities

Nine undescribed ent-abietane diterpenoid lactone glycosides, pulcherrimosides A-I, and a phenolic glycoside, phlogoside A, together with ten known compounds were isolated from the aerial parts of Phlogacanthus pulcherrimus T. Anderson. Their structures were established through spectral methods, especially 2D NMR and HRESIMS analyses, and by acid hydrolysis. The absolute configurations of pulcherrimosides A-I were determined through the interpretation of electronic circular dichroism (ECD) data. Some of the isolates were evaluated for their in vitro cytotoxic and cancer chemopreventive properties. Helioscopinolide A and 17-hydroxyhelioscopinolide A showed good cytotoxic activity against HeLa cells with IC₅₀ values of 18.16 ± 0.58 and 16.60 ± 0.23 μM, respectively. Pulcherrimoside D inhibited superoxide anion radical formation in the xanthine/xanthine oxidase (XXO) assay with an IC₅₀ value of 59.5 μM. Helioscopinolide A and pulcherrimoside D were strong aromatase inhibitors with IC₅₀ values of 9.0 and 11.9 μM, respectively. Among the tested compounds, pulcherrimoside D was considered an interesting cancer chemopreventive agent for further study as it provided good activity in several in vitro cancer preventive assays and was not toxic to normal cells.

The efficacy of chemopreventive agents on the incidence of colorectal adenomas: A systematic review and network meta-analysis

Colorectal cancer (CRC) is the fourth most common cancer and third leading cause of cancer-related death worldwide. Use of chemopreventive agents (CPAs) to reduce the incidence of precursor colorectal adenomas could lower the future burden of CRC. Many classes of potential CPAs have been investigated. To identify the most effective CPAs, we conducted a systematic review and a network meta-analysis (NMA). An electronic search was performed through August 2020 to identify all randomized controlled trials (RCTs) assessing the efficacy of CPAs in reducing the incidence of colorectal adenomas at the time of surveillance colonoscopy among patients who had previously undergone polypectomy during an index colonoscopy. In total, 33 RCTs were included in the NMA, which was conducted under a Bayesian inference framework. Random effects models were used with adjustment for follow-up length and control group event rates to yield relative risks (RRs) and 95% credible intervals (CrIs). Our full network consisted of 13 interventions in addition to a placebo arm. Of 20,925 included patients, 7766 had an adenoma. Compared to placebo, the combination of difluoromethylornithine (DFMO) + Sulindac (RR 0.24, CrI 0.10-0.55) demonstrated a protective effect, while aspirin had a RR of 0.77 (CrI 0.60-1.00), celecoxib 800 mg had a RR of 0.56 (CrI 0.31-1.01) and metformin had a RR of 0.56 (CrI 0.22-1.39). Our results suggest that select CPAs may be efficacious in preventing the development of adenomas. Further studies are needed to identify those patients most likely to benefit and the minimum effective dosages of CPAs.

Aromatase inhibitors and contralateral breast cancer in BRCA mutation carriers

BACKGROUND

Deleterious BRCA mutations confer a significant lifetime risk of breast cancer (BC) as well as contralateral BC (CBC) in patients who do not undergo prophylactic mastectomy. Prior reports have suggested that tamoxifen reduces the risk of CBC in BRCA mutation carriers. Whether aromatase inhibitors (AI) have the same effect is unknown.

METHODS

This is a retrospective review of patients diagnosed with non-metastatic ER+ BC between 2004 and 2014 with known BRCA mutation status. Patients were followed from primary diagnosis until CBC diagnosis or death. Median follow-up was 11.5 years. Risk of CBC was evaluated as time to event.

RESULTS

935 subjects were included in this analysis, with 53 BRCA1 mutation carriers, and 94 BRCA2 mutation carriers. Median age at diagnosis was 42.7 years. Seventy-two percent (676) received tamoxifen and 43% (405) received AI. A total of 66 CBCs occurred, of which 10% (15/147) occurred in BRCA mutation carriers vs 6.5% (51/788) in BRCA wild type. Multivariate analyses indicated that BRCA status and AI use were significantly associated with CBC risk. AI use resulted in a significant reduction in risk of CBC (HR 0.44, p = 0.004) regardless of the BRCA mutation status. Tamoxifen use was not associated with reduced risk of CBC.

CONCLUSIONS

This is the first report showing that AIs reduce the risk of CBC in BRCA mutation carriers. The potential role of AIs as chemoprevention should be validated in larger independent cohorts.

Barriers and facilitators to using aspirin for preventive therapy: a qualitative study exploring the views and experiences of people with Lynch syndrome and healthcare providers

BACKGROUND

The National Institute for Health and Care Excellence (NG151) recommends considering daily aspirin for people with Lynch syndrome to reduce colorectal cancer risk. However, deciding whether to initiate aspirin could be a complex decision for patients and their healthcare providers, as both the potential benefits and harms need to be considered.

METHODS

We conducted semi-structured interviews to explore the barriers and facilitators to using aspirin for preventive therapy. We recruited 15 people with Lynch syndrome, and 23 healthcare providers across multiple professions in primary, and specialist care (e.g. clinical genetics) in the United Kingdom. Interview schedules were informed by the Theoretical Domains Framework.

RESULTS

There were three themes: 1) Considering potential harms and benefits; 2) Healthcare pathway; 3) Patients' level of interest in aspirin. All healthcare providers, across primary and specialist care, viewed general practitioners (GPs) as being responsible for prescribing and overseeing the use of aspirin. However, GPs were unfamiliar with aspirin for preventive therapy, and concerned about prescribing at higher doses (300-600 mg). To support decision-making, GPs wanted clarification from specialist clinicians on the evidence and dose to prescribe. Not all participants with Lynch syndrome received information on aspirin from their healthcare provider, and several were unsure who to discuss aspirin with. GPs were more inclined to prescribe aspirin for patients with expressed preferences for the medication, however several patients were uncertain and wanted further guidance.

CONCLUSIONS

Coordinated and multilevel strategies are needed, addressing the needs of both GPs and people with Lynch syndrome, to ensure consistent implementation of national guidance on aspirin for preventive therapy.

Dose-dependent relation between metformin and the risk of hormone receptor-positive, her2-negative breast cancer among postmenopausal women with type-2 diabetes

PURPOSE

Metformin has demonstrated a chemoprotective effect in breast cancer but there is limited evidence on the effect of cumulative exposure to metformin and the risk of hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR + /HER2-) breast cancer. This study assessed this risk with dose and intensity of metformin in postmenopausal women with type-2 diabetes mellitus (T2DM).

METHODS

This nested case-control study used the Surveillance, Epidemiology, and End Results-Medicare data (2008-2015). Cohort entry was the date of incident T2DM diagnosis. Cases were those diagnosed with HR + /HER2- breast cancer (event date) as their first/only cancer. Non-cancer T2DM controls were matched using variable-ratio-matching. Cumulative dose and average intensity of metformin were measured during the 1-year lookback period. Dose(mg) was categorized as: (1)0, (2)0-30,000, (3)30,001-136,000, (4)136,001-293,000, and (5) > 293,000, and intensity(mg/day) as: 0, 1-500, and > 500. Covariates were conceptualized using the Andersen Behavioral Model. Conditional logistic regression was used to assess the risk of HR + /HER2- breast cancer with metformin-use.

RESULTS

There were 690 cases and 2747 controls. The median duration of T2DM was 1178 days in controls and 1180 days in cases. Higher cumulative dose categories: 4 (adjusted odds ratio(aOR) = 0.72, 95% CI 0.55-0.95,p = 0.02), and 5 (OR = 0.60, 95% CI 0.42-0.85,p < 0.01) had significantly lower odds of HR + /HER2- breast cancer compared to category 0. The highest intensity category of metformin had 39% lower odds of HR + /HER2- breast cancer (OR = 0.61, 95% CI 0.46-0.82,p < 0.01) compared to the 0 mg/day group.

CONCLUSIONS

Higher metformin exposure was associated with reduced risk of HR + /HER2- breast cancer, adding to the evidence supporting metformin's chemoprotective effect.

Immunologic and dose dependent effects of rapamycin and its evolving role in chemoprevention

Rapamycin inhibits the mechanistic (formally mammalian) target of rapamycin (mTOR), an evolutionarily conserved intracellular kinase that influences activation of growth signaling pathways and immune responses to malignancy. Rapamycin has been found to have both immunosuppressant and immunostimulatory effects throughout the innate and adaptive responses based on the inhibition of mTOR signaling. While the immunosuppressant properties of rapamycin and mTOR inhibition explain rapamycin's success in the prevention of transplant rejection, the immunostimulatory characteristics are likely partially responsible for rapamycin's anti-neoplastic effects. The immunologic response to rapamycin is at least partially dependent on the dose and administration schedule, with lower doses inducing immunostimulation and intermittent dosing promoting immune function while limiting metabolic and immunosuppressant toxicities. In addition to its FDA-approved application in advanced malignancies, rapamycin may be effective as a chemopreventive agent, suspending progression of low-grade cancers, preventing invasive conversion of in situ malignancy, or delaying malignant transformation of established pre-malignant conditions.

The CHAMP-study: the CHemopreventive effect of lithium in familial AdenoMatous Polyposis; study protocol of a phase II trial

BACKGROUND

Familial adenomatous polyposis (FAP) is a rare autosomal dominant disease characterized by germline mutations in the Adenomatous Polyposis Coli (APC) gene, resulting in the development of numerous colorectal adenomas. As these patients have a high risk of developing colorectal cancer (CRC), guidelines suggest prophylactic colectomy during early adulthood, however, adenoma development is still observed in the remaining intestinal tract. Therefore, FAP patients would benefit from chemoprevention strategies reducing the development of adenomas. Recent work in mice reveals a chemopreventive effect of lithium on the development of adenomas by inhibiting the expansion of Apc mutated intestinal stem cells (ISCs) within the crypts of normal intestinal mucosa. Here, we aim to investigate the effect of lithium on the spread of APC mutant cells within the human intestinal epithelium.

METHODS

This prospective phase II single arm trial has a duration of 18 months. FAP patients (18-35 years) with a genetically confirmed APC mutation who did not undergo colectomy will be treated with lithium carbonate orally achieving a serum level of 0.2-0.4 mmol/l between month 6 and 12. Colonoscopy with biopsies of normal intestinal mucosa will be performed at baseline and every six months. The primary endpoint is the effect of lithium on the spread of APC mutant cells within intestinal crypts over time by using APC specific marker NOTUM in situ hybridization. Secondary endpoints include change in adenoma burden, patient reported side effects and safety-outcomes. Total sample size is 12 patients and recruitment will take place in the Amsterdam UMC, location AMC in the Netherlands.

DISCUSSION

The outcome of this study will function as a proof-of-concept for the development of novel chemoprevention approaches that interfere with the competition between normal and mutant ISCs.

TRIAL REGISTRATION

ClinicalTrials.gov ( https://clinicaltrials.gov/ ): NCT05402891 (June 1, 2022) and the EU Clinical Trials Register: EuraCT 2022-000240-30 (January 1, 2022).

Targeting Ras-ERK cascade by bioactive natural products for potential treatment of cancer: an updated overview

MAPK (mitogen-activated protein kinase) or ERK (extracellular-signal-regulated kinase) pathway is an important link in the transition from extracellular signals to intracellular responses. Because of genetic and epigenetic changes, signaling cascades are altered in a variety of diseases, including cancer. Extant studies on the homeostatic and pathologic behavior of MAPK signaling have been conducted; however, much remains to be explored in preclinical and clinical research in terms of regulation and action models. MAPK has implications for cancer therapy response, more specifically in response to experimental MAPK suppression, compensatory mechanisms are activated. The current study investigates MAPK as a very complex cell signaling pathway that plays roles in cancer treatment response, cellular normal conduit maintenance, and compensatory pathway activation. Most MAPK inhibitors, unfortunately, cause resistance by activating compensatory feedback loops in tumor cells and tumor microenvironment components. As a result, innovative combinatorial treatments for cancer management must be applied to limit the likelihood of alternate pathway initiation as a possibility for generating novel therapeutics based on incorporation in translational research. We summarize current knowledge about the implications of ERK (MAPK) in cancer, as well as bioactive products from plants, microbial organisms or marine organisms, as well as the correlation with their chemical structures, which modulate this pathway for the treatment of different types of cancer.

Qualitative analysis of shared decision-making for chemoprevention in the primary care setting: provider-related barriers

Background

Chemoprevention with anti-estrogens, such as tamoxifen, raloxifene or aromatase inhibitors, have been shown to reduce breast cancer risk in randomized controlled trials; however, uptake among women at high-risk for developing breast cancer remains low. The aim of this study is to identify provider-related barriers to shared decision-making (SDM) for chemoprevention in the primary care setting.

Methods

Primary care providers (PCPs) and high-risk women eligible for chemoprevention were enrolled in a pilot study and a randomized clinical trial of web-based decision support tools to increase chemoprevention uptake. PCPs included internists, family practitioners, and gynecologists, whereas patients were high-risk women, age 35–75 years, who had a 5-year invasive breast cancer risk ≥ 1.67%, according to the Gail model. Seven clinical encounters of high-risk women and their PCPs who were given access to these decision support tools were included in this study. Audio-recordings of the clinical encounters were transcribed verbatim and analyzed using grounded theory methodology.

Results

Six primary care providers, of which four were males (mean age 36 [SD 6.5]) and two were females (mean age 39, [SD 11.5]) and seven racially/ethnically diverse high-risk female patients participated in this study. Qualitative analysis revealed three themes: (1) Competing demands during clinical encounters; (2) lack of knowledge among providers about chemoprevention; and (3) limited risk communication during clinical encounters.

Conclusions

Critical barriers to SDM about chemoprevention were identified among PCPs. Providers need education and resources through decision support tools to engage in risk communication and SDM with their high-risk patients, and to gain confidence in prescribing chemoprevention in the primary care setting.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12911-022-01954-y.

Association between hypertension and cutaneous melanoma, and the effect of aspirin: extended follow-up of a large randomised controlled trial

BACKGROUND

The association between hypertension and melanoma is unclear, and previous analyses of data from the ASPirin in Reducing Events in the Elderly (ASPREE) study demonstrated a reduced number of invasive melanoma events amongst aspirin-exposed hypertensive individuals.

METHODS

Data from the ASPREE study which included (1) the intervention period with a median follow-up of 4.7 years, and (2) the observational period with an additional 2 years follow-up, were combined for this analysis. Logistic regression analyses examined the association between baseline hypertension and treatment status and past melanoma history. Survival analyses examined the association between hypertension and melanoma risk, and the effect of aspirin across hypertension groups. Cox proportional hazards models were used to compare incidence across groups.

RESULTS

19,114 participants (median age of 74 years) were randomised to daily 100 mg aspirin or placebo. At baseline, hypertension and past melanoma history were recorded in 14,195 and 685 individuals, respectively. After adjustment for confounders, hypertension was significantly associated with past melanoma history (OR=1.34, 95%CI: 1.11-1.62). In a prospective analysis, baseline hypertension was not associated with melanoma risk. However, aspirin was associated with a reduced risk of incident melanoma amongst individuals with uncontrolled hypertension (blood pressure ≥140/90 mmHg; HR=0.63, 95%CI 0.44-0.89), but not in those with controlled hypertension (HR=1.04, 95%CI 0.74-1.46).

CONCLUSION

Our results support a reduced melanoma incidence amongst individuals with uncontrolled hypertension exposed to aspirin. Additional studies are required to confirm these findings.

Metformin use is not associated with colorectal cancer incidence in type-2 diabetes patients: evidence from methods that avoid immortal time bias

PURPOSE

Immortal time bias (ITB) continues to distort many observational studies on metformin use and cancer risk. Our objective was to employ three statistical methods proven to avoid ITB and compare their results to that of a naïve time-fixed analysis in order to provide further evidence of metformin's association, or none thereof, with colorectal cancer (CRC) incidence.

METHODS

A total of 41,533 Korean subjects with newly diagnosed type-2 diabetes in 2005-2015 were selected from a prospectively maintained cohort (median follow-up of 6.3 years). Time-to-CRC incidence was regressed upon metformin use (yes/no, average prescription days/year) using time-dependent Cox, landmark, nested case-control, and time-fixed Cox analyses. Other CRC risk factors were included to adjust for possible confounding.

RESULTS

Neither metformin ever-use nor average metformin prescription days/year was associated with incident CRC hazard in time-dependent Cox, landmark, and nested case-control analyses with HR (95% CI) of 0.88 (0.68-1.13), 0.86 (0.65-1.12), and 1.10 (0.86-1.40) for metformin ever-use, and 0.97 (0.90-1.04), 0.95 (0.88-1.04), and 1.02 (0.95-1.10) for average metformin prescription days/year, respectively. In contrast, time-fixed Cox regression showed a falsely exaggerated protective effect of metformin on CRC incidence.

CONCLUSION

The association between metformin use and subsequent CRC incidence was statistically nonsignificant after accounting for time-related biases such as ITB. Previous studies that avoided these biases and meta-analyses of RCTs on metformin and cancer incidence were in agreement with our results. A definitive, large-scale RCT is needed to clarify this topic, and future observational studies should be explicit in avoiding ITB and other time-related biases.

Plant-derived bioactive compounds in colon cancer treatment: An updated review

Colon cancer is the third most predominant cancer caused by genetic, environmental and nutritional factors. Plant-based compounds are very well known to regress colon cancer in many ways, like delaying tumor growth, managing chemotherapy and radiation therapy side-effects, and working at the molecular levels. Medicinal plants contain many bioactive phytochemicals such as flavonoids, polyphenol compounds, caffeic acid, catechins, saponins, polysaccharides, triterpenoids, alkaloids, glycosides, phenols, quercetin, luteolin, kaempferol and luteolin glycosides, carnosic acid, oleanolic acid, rosmarinic acid, emodin, and eugenol and anthricin. These bioactive compounds can reduce tumor cell proliferation via several mechanisms, such as blocking cell cycle checkpoints and promoting apoptosis through activating initiator and executioner caspase. Traditional medicines have been used globally to treat cancers because of their anti-cancer effects, antioxidant properties, anti-inflammatory properties, anti-mutagenic effects, and anti-angiogenic effects. In addition, these medicines effectively suppress early and intermediate stages of carcinogenesis when administered in their active and pure form. However, traditional medicine is not very popular due to some critical challenges. These include poor solubility and absorption of these compounds, intellectual property-related issues, involvement of drug synergism, absence of drug-likeness, and unsure protocols for their extraction from the plant source. Using bioactive compounds in colon cancer has equal advantages and limitations. This review highlights the benefits and challenges of using bioactive compounds derived from plants for colon cancer. We have also discussed using these compounds to target cancer stem cell self-renewal, its effects on cancer cell metabolism, safety parameters, easy modulation, and their bioavailability.

4-nitroquinoline-1-oxide (4NQO) induced oral carcinogenesis: A systematic literature review

OBJECTIVE

Based on a critical review of published studies, we aimed to develop a good practice guide for using 4-nitroquinoline-1-oxide (4NQO) as an inducer of oral carcinogenesis in Wistar rats.

DESIGN

A systematic search was performed on Medline Ovid, PubMed, Embase, Web of Science, and Scopus databases. The SYRCLE's risk of bias tool was used to assess the quality of the studies.

RESULTS

Thirty-five articles met the selection criteria; 22 (62.9%) of them administered 4NQO systemically in drinking water, with a mean concentration of 30.2 ppm (SD±15.9) and during a mean period of 20.8 (SD±7.8) weeks. The other 13 (37.1%) studies performed topical applications of 4NQO painting the oral mucosa of the animals three times a week (100%) with a mean period of administration of 16.8 (SD±7.0) weeks. Different 4NQO concentrations used for other periods achieved significant tumor development. Most studies didn't perform quantitative clinical analysis, and the histopathological diagnosis/grading criteria varied considerably.

CONCLUSIONS

A poor description of solution care, adverse effects, and the number of losses were observed, and the reporting of these features needs to be improved. Suggestions to guide the development of future research are provided.

Dietary phytochemicals/nutrients as promising protector of breast cancer development: a comprehensive analysis

Genetic change, particularly epigenetic alteration, is one of the imperative factors for sporadic breast cancer development in the worldwide population of women. The DNA methylation process is essential and natural for human cellular renewal and tissue homeostasis, but its dysregulation contributes to many pathological changes, including breast tumorigenesis. Chemopreventive agents mainly protect the abnormal DNA methylation either by hindering the division of pre-malignant cells or looming the DNA damage, which leads to malignancy. The present review article is about understanding the potential role of dietary phytochemicals in breast cancer prevention. Accordingly, a literature search of the published article until August 2021 has been performed. Further, we have investigated the binding affinity of different phytochemicals isolated from diverse dietary sources against the various oncogenic proteins related to breast cancer initiation to understand the common target(s) in breast cancer prevention mechanisms. Various small phytochemicals, especially dietary phytochemicals including sulforaphane, mahanine, resveratrol, linolenic acid, diallyl sulfide, benzyl/phenethyl isothiocyanate, etc. are being investigated as the chemopreventive agent to manage breast cancer development, and some of them have shown promising outcomes in the cited research. In this present review, we discuss the recent advancement in acceptance of such types of potential dietary phytochemicals as a chemopreventive agent against breast cancer development and their inner lining mechanism. The critical clinical trials and cohort studies have also been considered to understand the progress in contemporary perspectives.

Utility of Indian fruits in cancer prevention and treatment: Time to undertake translational and bedside studies

The World Health Organization predicts a 70% increase in cancer incidents in developing nations over the next decade, and it will be the second leading cause of death worldwide. Traditional plant-based medicine systems play an important role against various diseases and provide health care to a large section of the population in developing countries. Indigenous fruits and their bioactive compounds with beneficial effects like antioxidant, antiproliferative, and immunomodulatory are shown to be useful in preventing the incidence of cancer. India is one of the biodiversity regions and is native to numerous flora and fauna in the world. Of the many fruiting trees indigenous to India, Mango (Mangifera indica), Black plum (Eugenia jambolana or Syzygium jambolana), Indian gooseberry (Emblica officinalis or Phyllanthus emblica), kokum (Garcinia indica or Brindonia indica), stone apple or bael (Aegle marmelos), Jackfruit (Artocarpus heterophyllus), Karaunda (Carissa carandas) and Phalsa (Grewia asiatica), Monkey Jackfruit (Artocarpus lakoocha) and Elephant apple (Dillenia indica) have been shown to be beneficial in preventing cancer and in the treatment of cancer in validated preclinical models of study. In this review, efforts are also made to collate the fruits' anticancer effects and the important phytochemicals. Efforts are also made at emphasizing the underlying mechanism/s responsible for the beneficial effects in cancer prevention and treatment. These fruits have been a part of the diet, are non-toxic, and easily acceptable for human application. The plants and some of their phytochemicals possess diverse medicinal properties. The authors propose that future studies should be directed at detailed studies with various preclinical models of study with both composite fruit extract/juice and the individual phytochemicals. Additionally, translational studies should be planned with the highly beneficial, well-investigated and pharmacologically multifactorial amla to understand its usefulness as a cancer preventive in the high-risk population and as a supportive agent in cancer survivors. The outcome of both preclinical and clinical studies will be useful for patients, the healthcare fraternity, pharmaceutical, and agro-based sectors.

Metastasis-associated protein 1-mediated antitumor and anticancer activity of dietary stilbenes for prostate cancer chemoprevention and therapy

Dietary bioactive polyphenols that demonstrate beneficial biological functions including antioxidant, anti-inflammatory, and anticancer activity hold immense promise as effective and safe chemopreventive and chemosensitizing natural anticancer agents. The underlying molecular mechanisms of polyphenols' multiple effects are complex and these molecules are considered promising targets for chemoprevention and therapy. However, the development of novel personalized targeted chemopreventive and therapeutic strategies is essential for successful therapeutic outcomes. In this review, we highlight the potential of metastasis-associated protein 1 (MTA1)-targeted anticancer and antitumor effects of three dietary stilbenes, namely resveratrol, pterostilbene, and gnetin C, for prostate cancer management. MTA1, an epigenetic reader and master transcriptional regulator, plays a key role in all stages of prostate cancer progression and metastasis. Stilbenes inhibit MTA1 expression, disrupt the MTA1/histone deacetylase complex, modulate MTA1-associated Epi-miRNAs and reduce MTA1-dependent inflammation, cell survival, and metastasis in prostate cancer in vitro and in vivo. Overall, the MTA1-targeted strategies involving dietary stilbenes may be valuable for effective chemoprevention in selected subpopulations of early stage prostate cancer patients and for combinatorial strategies with conventional chemotherapeutic drugs against advanced metastatic prostate cancer.

Chemoprevention of Oesophageal Squamous-Cell Carcinoma and Adenocarcinoma: A Multicentre Retrospective Cohort Study

BACKGROUND

Oesophageal cancer comprises 2 different histological variants: oesophageal squamous-cell carcinoma (ESCC) and adenocarcinoma (EAC). While there are multiple therapeutic options for both types, patients with advanced or metastatic oesophageal cancer still suffer from poor prognosis.

AIMS

The study aimed to examine the association between the risk of oesophageal cancer and medications and to estimate the chemopreventive effects of commonly used drugs.

METHODS

A multicentre retrospective cohort study was conducted using data from 9 hospital databases of hospitalized patients between 2014 and 2019. The primary outcomes were ESCC and EAC. The association of oesophageal cancer with drug use and clinical factors was evaluated. Odds ratios (ORs) were adjusted for age, sex, Charlson comorbidity index scores, and smoking with/without gastro-oesophageal reflux disease.

RESULTS

The use of proton pump inhibitors (PPIs) (adjusted OR [aOR] 0.48, p < 0.0001), aspirin (aOR 0.32, p < 0.0001), cyclooxygenase-2 inhibitor (COX2I) (aOR 0.70, p = 0.0005), steroid (aOR 0.19, p < 0.0001), statin (aOR 0.43, p < 0.0001), and metformin (aOR 0.42, p < 0.0001) was associated with a lower risk of ESCC than that in non-use. The use of aspirin (aOR 0.33, p = 0.0006) and steroids (aOR 0.54, p = 0.022) was associated with a lower risk of EAC than that in non-use.

CONCLUSION

COX2Is, statins, metformin, and PPIs could help in prevention of ESCC, and aspirin and steroids may be chemopreventive for both types of oesophageal cancer.

The use of ace inhibitors influences the risk of progression of BD-IPMNs under follow-up

BACKGROUND

Chemoprevention's ability to slow down or prevent the progression of BD-IPMNs is extremely appealing. Aspirin (ASA), Ace Inhibitors/Angiotensin Receptor Blockers (ACEIs/ARBs) and Statins (STATs) are frequently prescribed drugs with a possible beneficial effect on different cancer types. Their effect on IPMNs is largely unknown.

AIM

To evaluate the association between the use of ASA, ACEIs/ARBs and STATs and the risk of progression of BD-IPMNs in follow-up.

MATERIALS AND METHODS

multicenter, retrospective cohort study on patients with presumed BD-IPMNs without relative or absolute indication for surgery. Pharmacological exposures and risk factors were collected. We identified clinically relevant progression (occurrence of radiological absolute or relative indication for surgery) and any progression (occurrence of clinically relevant progression OR any dimension increase OR the occurrence of new cysts).

RESULTS

Overall 594 patients were included. ACEIs were associated with a lower occurrence of any progression (HR = 0.70; 95% CI 0.49-0.98, p = 0.04) and clinically relevant progression, HR = 0.42 (95% CI 0.20-0.88; p = 0.02). No significant effect was shown for factors associated with the occurrence of pancreas cancer such as smoking, alcohol consumption and 1st degree family history of pancreas cancer. Among pharmacological exposures, no convincing effect was shown for the chronic use of ASA, ARB and STAT.

CONCLUSIONS

ACEIs might have an effect in slowing the progression of BD-IPMNs. ASA, STAT and ARBs show no convincing effect on the progression of BD-IPMNs. Further, prospective, and long-term multicenter studies are needed to verify such association and to define the potential underlying mechanisms.

Hydroxychloroquine as pre-exposure prophylaxis against COVID-19 infection among healthcare workers: a prospective cohort study

BACKGROUND

Hydroxychloroquine had attracted significant attention in the initial phases of the COVID-19 pandemic but current recommendations do not support its use. However, the evidence against its use as pre-exposure prophylaxis have been of low to moderate quality and have been limited by high risk of bias.

METHODS

Following institutional ethics committee approval, healthcare workers (n = 1294) completing their first week-long COVID in-patient duty, subsequent institutional quarantine and RT-PCR testing for COVID-19 infection were included for this prospective cohort study. Demographic data, hydroxychloroquine usage and related adverse effects were captured through a 'Caring for the Caregivers' surveillance system. A chi-Square test of independence was used to determine the effect of hydroxychloroquine prophylaxis.

RESULTS

Among the 1294 participants (age: 31 ± 7 years, 61% women), 273 (21.1%) healthcare workers used hydroxychloroquine prophylaxis as per Indian Council of Medical Research recommendations and 83/1294 (6.4%) tested positive after their duty. There was no significant difference in COVID-19 incidence between those on hydroxychloroquine prophylaxis and those not on it (5.9% vs 6.6%, χ2 = 0.177, p = 0.675; RR = 0.89, 95% CI - 0.53 to 1.52). There were no significant adverse effects to hydroxychloroquine usage.

CONCLUSION

This study demonstrated no benefit of hydroxychloroquine prophylaxis and provides quality evidence against its use in COVID-19 prevention.

Effect of docosahexaenoic acid as a chemopreventive agent on experimentally induced hamster buccal pouch carcinogenesis

PURPOSE

The current study was directed to investigate the effectiveness of docosahexaenoic acid (DHA) as a chemopreventive agent on experimentally induced hamster buccal pouch (HBP) carcinogenesis.

MATERIAL AND METHODS

In this study we used 40 Syrian male hamsters, five weeks old, were divided into 4 groups (GI, GII, GIII, and GIV) of 10 animals in each as follows, GI: Topical application of liquid paraffin alone (thrice a week for 14 weeks), GII: Topical application of 7, 12 dimethyl benz[a]anthracene (DMBA) alone (0.5% in liquid paraffin, thrice a week for 14 weeks), GIII: Topical application of DMBA (0.5% in liquid paraffin, thrice a week for 14 weeks) + Oral administration of DHA (125 mg/kg b.w. in 1 ml distilled water by oral gavage, thrice a week for 14 weeks on alternative days of DMBA application), GIV: Oral administration of DHA alone (125 mg/kg b.w. in 1 ml distilled water by oral gavage, thrice a week for 14 weeks).

RESULTS

Gross observations and histopathological findings revealed that, in GI: normal stratified squamous epithelium, in GII: well and moderately differentiated squamous cell carcinoma (SCC), in GIII: variable results ranges from hyperkeratosis, hyperkeratosis and focal hyperplasia, mild dysplasia, and well differentiated SCC with superficial invasion of tumor cells not extended to deeper areas, while in GIV: normal similar to GI. Immunohistochemical results indicated that oral DHA treatment to DMBA treated hamsters restored the normal expression of bcl-2.

CONCLUSION

Our results indicated that DHA has the potential to be a dietary chemopreventive agent due to its capacity to improve carcinogen detoxification and to block/suppress the initiation and promotion stages of experimentally produced HBP carcinogenesis.

Initiation and tolerance of chemoprevention among women with high-risk breast lesions: the potential of low-dose tamoxifen

Purpose

High-risk lesions (HRLs) of the breast are an indication for chemoprevention, yet uptake is low, largely due to concerns about side effects. In 2019, low-dose (5 mg) tamoxifen was demonstrated to reduce breast cancer risk with improved tolerance. We describe chemoprevention uptake in an academic clinic before and after the introduction of low-dose tamoxifen.

Methods

Females age ≥ 35 with HRLs who established care from April 2017 through January 2020 and eligible for chemoprevention were included. Rates of chemoprevention initiation before and after the introduction of low-dose tamoxifen (pre-2019 vs. post-2019) were compared with chi-squared tests. Logistic regression identified demographic and clinical factors associated with chemoprevention initiation. Kaplan–Meier methods determined the rates of discontinuation.

Results

Among 660 eligible females with HRLs, 22.7% initiated chemoprevention. Median time from first visit to chemoprevention initiation was 54 days (interquartile range (IQR): 0–209); 31.0% (46/150) started chemoprevention > 6 months after their initial visit. Chemoprevention uptake was not significantly different pre-2019 vs. post-2019 (21.2% vs. 26.3%, p = 0.16); however, post-2019, low-dose tamoxifen became the most popular option (41.5%, 34/82). On multivariable analyses, age and breast cancer family history were significantly associated with chemoprevention initiation. Discontinuation rates at 1 year were lowest for low-dose tamoxifen (6.7%) vs. tamoxifen 20 mg (15.0%), raloxifene (20.4%), or an aromatase inhibitor (20.0%).

Conclusion

In this modern cohort, 22.7% of females with HRLs initiated chemoprevention with 31.0% initiating chemoprevention > 6 months after their first visit. Low-dose tamoxifen is now the most popular choice for chemoprevention, with low discontinuation rates at 1 year.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-022-06577-5.