Cancer etiology: Variation in cancer risk among tissues is poorly explained by the number of gene mutations

"I am in a Fight with My Brain": A Qualitative Study on Cancer-Related Ruminations of Individuals with Cancer

OBJECTIVE

This study aimed to determine the cancer-related ruminations from the subjective perspectives of individuals with cancer.

DATA SOURCES

The study adopted a qualitative design, and participants (N = 16) were individuals with cancer. The analysis and interpretation of data were carried out according to the phenomenological-hermeneutical method.

CONCLUSION

The following four themes emerged as a result of the analysis of qualitative data revealing the experiences of individuals with cancer: (1) attributed meanings to cancer-related ruminations, (2) perceived ruminations toward an uncertain future, (3) losing against intrusive ruminations, and (4) fighting with ruminations. The results underline the negative impact of ruminative thoughts on the disease process and social life of individuals with cancer. Individuals with cancer struggle with intense thoughts about the cause, treatment, and future of the disease from the moment they are diagnosed with cancer. In order to stop ruminative thoughts, individuals with cancer have tried solutions such as distracting activities and avoiding thoughts.

IMPLICATIONS FOR NURSING PRACTICE

Nurses have an important role in catching verbal and nonverbal cues for rumination, as they are constantly together with individuals with cancer and make observations. Therefore, nurses can raise awareness about their ruminative thoughts and teach coping skills to individuals with cancer.

Quantifying substantial carcinogenesis of genetic and environmental factors from measurement error in the number of stem cell divisions

Background

The relative contributions of genetic and environmental factors versus unavoidable stochastic risk factors to the variation in cancer risk among tissues have become a widely-discussed topic. Some claim that the stochastic effects of DNA replication are mainly responsible, others believe that cancer risk is heavily affected by environmental and hereditary factors. Some of these studies made evidence from the correlation analysis between the lifetime number of stem cell divisions within each tissue and tissue-specific lifetime cancer risk. However, they did not consider the measurement error in the estimated number of stem cell divisions, which is caused by the exposure to different levels of genetic and environmental factors. This will obscure the authentic contribution of environmental or inherited factors.

Methods

In this study, we proposed two distinct modeling strategies, which integrate the measurement error model with the prevailing model of carcinogenesis to quantitatively evaluate the contribution of hereditary and environmental factors to cancer development. Then, we applied the proposed strategies to cancer data from 423 registries in 68 different countries (global-wide), 125 registries across China (national-wide of China), and 139 counties in Shandong province (Shandong provincial, China), respectively.

Results

The results suggest that the contribution of genetic and environmental factors is at least 92% to the variation in cancer risk among 17 tissues. Moreover, mutations occurring in progenitor cells and differentiated cells are less likely to be accumulated enough for cancer to occur, and the carcinogenesis is more likely to originate from stem cells. Except for medulloblastoma, the contribution of genetic and environmental factors to the risk of other 16 organ-specific cancers are all more than 60%.

Conclusions

This work provides additional evidence that genetic and environmental factors play leading roles in cancer development. Therefore, the identification of modifiable environmental and hereditary risk factors for each cancer is highly recommended, and primary prevention in early life-course should be the major focus of cancer prevention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10219-w.

Origin of Cancer: Cell work is the Key to Understanding Cancer Initiation and Progression

The cell is the smallest unit of life. It is a structure that maintains order through self-organization, characterized by a high level of dynamism, which in turn is characterized by work. For this work to take place, a continuous high flow of energy is necessary. However, a focused view of the physical relationship between energy and work is inadequate for describing complex biological/medical mechanisms or systems. In this review, we try to make a connection between the fundamental laws of physics and the mechanisms and functions of biology, which are characterized by self-organization. Many different physical work processes (work) in human cells are called cell work and can be grouped into five forms: synthetic, mechanical, electrical, concentration, and heat generation cell work. In addition to the flow of energy, these cell functions are based on fundamental processes of self-organization that we summarize with the term Entirety of molecular interaction (EoMI). This illustrates that cell work is caused by numerous molecular reactions, flow equilibrium, and mechanisms. Their number and interactions are so complex that they elude our perception in their entirety. To be able to describe cell functions in a biological/medical context, the parameters influencing cell work should be summarized in overarching influencing variables. These are “biological” energy, information, matter, and cell mechanics (EMIM). This makes it possible to describe and characterize the cell work involved in cell systems (e.g., respiratory chain, signal transmission, cell structure, or inheritance processes) and to demonstrate changes. If cell work and the different influencing parameters (EMIM influencing variables) are taken as the central property of the cell, specific gene mutations cannot be regarded as the sole cause for the initiation and progression of cancer. This reductionistic monocausal view does not do justice to the dynamic and highly complex system of a cell. Therefore, we postulate that each of the EMIM influencing variables described above is capable of changing the cell work and thus the order of a cell in such a way that it can develop into a cancer cell.

Supportive Care Needs Assessment for Cancer Survivors at a Comprehensive Cancer Center in the Middle East: Mending the Gap

BACKGROUND

Cancer survivors are often underprepared for what to expect post-treatment, and there are knowledge gaps regarding cancer survivors' supportive care needs in Jordan and neighboring Arab countries. This study aimed to identify gaps in supportive care needs among adult cancer survivors seen at King Hussein Cancer Center in Amman, Jordan, and explore predictors of unmet needs.

METHODS

This was an observational cross-sectional study using a modified version of the Supportive Care Needs Survey 34 item short form (SCNS-SF34).

RESULTS

Two hundred and forty adult cancer survivors completed the study questionnaire. The assessed needs were highest in the financial domain, including covering living expenses, managing cancer treatment adverse effects and co-morbidities. The least prevalent reported needs were in sexuality and reproductive consultations. Late-stage diagnosis was independently associated with higher physical, psychological, health system/information, financial and overall need scores, with p-values of 0.032, 0.027, 0.052, 0.002 and 0.024, respectively. The overall quality of life score was independently and inversely associated with physical, psychological, health system/information, financial and overall need domains, with p-values of 0.015, <0.0001, 0.015, 0.004 and 0.0003, respectively.

CONCLUSIONS

This needs assessment identified problem areas for targeting interventions across the Jordanian cancer survivor population, and understanding these findings highlights opportunities for intervention to address gaps in care.

Nanoparticles: Promising Auxiliary Agents for Diagnosis and Therapy of Thyroid Cancers

Simple Summary

Thyroid cancer (TC) is rare relative to cancers of many other organs (breast, prostate, lung, and colon). The majority of TCs are differentiated tumors that are relatively easy to treat and have a good prognosis. However, for anaplastic TC, a rapidly growing and aggressive tumor, treatment is suboptimal because the effective drugs cause severe adverse effects. Drug delivery by nanocarriers can improve treatment by reducing side effects. This can either be mediated through better retention in the tumor tissue due to size (passive targeting) or through the attachment of specific molecules that zero in on the cancer cells (active targeting). Nanoparticles are already used for diagnosis and imaging of TC. For unresectable anaplastic TC, nanoparticle-based treatments, less suitable for deeply located cancers, could be useful, based on low-intensity focused ultrasound and near-infrared irradiation. All potential applications of nanoparticles in TC are still in the preclinical phase.

Abstract

Cancers of the endocrine system are rare. The majority are not highly malignant tumors. Thyroid cancer (TC) is the most common endocrine cancer, with differentiated papillary and follicular tumors occurring more frequently than the more aggressive poorly differentiated and anaplastic TC. Nanoparticles (NP) (mainly mesoporous silica, gold, carbon, or liposomes) have been developed to improve the detection of biomarkers and routine laboratory parameters (e.g., thyroid stimulating hormone, thyroglobulin, and calcitonin), tumor imaging, and drug delivery in TC. The majority of drug-loaded nanocarriers to be used for treatment was developed for anaplastic tumors because current treatments are suboptimal. Further, doxorubicin, sorafenib, and gemcitabine treatment can be improved by nanotherapy due to decreased adverse effects. Selective delivery of retinoic acid to TC cells might improve the re-differentiation of de-differentiated TC. The use of carbon NPs for the prevention of parathyroid damage during TC surgery does not show a clear benefit. Certain technologies less suitable for the treatment of deeply located cancers may have some potential for unresectable anaplastic carcinomas, namely those based on low-intensity focused ultrasound and near-infrared irradiation. Although some of these approaches yielded promising results in animal studies, results from clinical trials are currently lacking.

High percentage of cancer stem cells in metastatic locations; a comment on a claim "variation in cancer risk among tissues can be explained by the number of stem cell divisions"

Metastasis is the major cause of cancer-related deaths. Cancer relapse and metastasis are associated with a part of cancer cells with stem cell properties. These cancer stem cells (CSCs) are resistant to treatments. In a recent survey, we observed that the population of cancer stem-like cells among metastatic tumor cells was significantly higher than that among the primary tumor cells. This high percentage can partly explain the reasons for chemoresistance and relapse in metastatic cancers. Analysis of the role of CSCs in metastasis has been mainly conceptual and speculative, and the reasons for a higher number of CSCs in the metastatic loci are questionable. Tomasetti and Vogelstein's claim can partly answer the question. They postulated that the proliferation rate of normal stem cells in some tissue is greater than that of other tissues, and accordingly, the incidence of cancer in these tissues is high. In compliance with CSCs paradigm, resident normal stem cells of tissues are the most probable source of CSCs. After homing of metastatic cancer cells in a tissue with high rate of normal stem cell proliferation, there is a big opportunity for cancer cells to convert normal stem cells to cancer stem cells. This is the powerful effect of cancerous microenvironment on resident stem cells of tissue. Therefore, in metastatic cancers, the number of CSCs in primary tumor or in each metastatic location is relevant to the proliferation rate of resident normal stem cells of the location. This concept is a confirmation of Tomasetti and Vogelstein's claim and can answer some fundamental questions about metastasis process.

Tumour Initiation: a Discussion on Evidence for a "Load-Trigger" Mechanism

Appropriate mechanical forces on cells are vital for normal cell behaviour and this review discusses the possibility that tumour initiation depends partly on the disruption of the normal physical architecture of the extracellular matrix (ECM) around a cell. The alterations that occur thence promote oncogene expression. Some questions, that are not answered with certainty by current consensus mechanisms of tumourigenesis, are elegantly explained by the triggering of tumours being a property of the physical characteristics of the ECM, which is operative following loading of the tumour initiation process with a relevant gene variant. Clinical observations are consistent with this alternative hypothesis which is derived from studies that have, together, accumulated an extensive variety of data incorporating biochemical, genetic and clinical findings. Thus, this review provides support for the view that the ECM may have an executive function in induction of a tumour. Overall, reported observations suggest that either restoring an ECM associated with homeostasis or targeting the related signal transduction mechanisms may possibly be utilised to modify or control the early progression of cancers. The review provides a coherent template for discussing the notion, in the context of contemporary knowledge, that tumourigenesis is an alliance of biochemistry, genetics and biophysics, in which the physical architecture of the ECM may be a fundamental component. For more definitive clarification of the concept there needs to be a phalanx of experiments conceived around direct questions that are raised by this paper.

Circulating Tumor Cells as a Tool for Assessing Tumor Heterogeneity

Tumor heterogeneity is the major cause of failure in cancer prognosis and prediction. Accurately detecting heterogeneity for the development of biomarkers and the detection of the clones resistant to therapy is one of the main goals of contemporary medicine. Metastases belong to the natural history of cancer. The present review gives an overview on the origin of tumor heterogeneity. Recent progress has made it possible to isolate and characterize circulating tumor cells (CTCs), which are the drivers of the disease between the primary sites and metastatic foci. The most recent methods for characterizing CTCs are summarized and we discuss the power of CTC profiling for analyzing tumor heterogeneity in early and advanced diseases.

Multi-stage models for the failure of complex systems, cascading disasters, and the onset of disease

Complex systems can fail through different routes, often progressing through a series of (rate-limiting) steps and modified by environmental exposures. The onset of disease, cancer in particular, is no different. Multi-stage models provide a simple but very general mathematical framework for studying the failure of complex systems, or equivalently, the onset of disease. They include the Armitage-Doll multi-stage cancer model as a particular case, and have potential to provide new insights into how failures and disease, arise and progress. A method described by E.T. Jaynes is developed to provide an analytical solution for a large class of these models, and highlights connections between the convolution of Laplace transforms, sums of random variables, and Schwinger/Feynman parameterisations. Examples include: exact solutions to the Armitage-Doll model, the sum of Gamma-distributed variables with integer-valued shape parameters, a clonal-growth cancer model, and a model for cascading disasters. Applications and limitations of the approach are discussed in the context of recent cancer research. The model is sufficiently general to be used in many contexts, such as engineering, project management, disease progression, and disaster risk for example, allowing the estimation of failure rates in complex systems and projects. The intended result is a mathematical toolkit for applying multi-stage models to the study of failure rates in complex systems and to the onset of disease, cancer in particular.

A 30-s exposure to ethanol 20% is cytotoxic to human keratinocytes: possible mechanistic link between alcohol-containing mouthwashes and oral cancer

OBJECTIVES

To provide mechanistic evidence for the epidemiological link between long-term use of alcohol-containing mouthwashes and oral cancer.

MATERIAL AND METHODS

Human epithelial keratinocytes were exposed for 30 s to concentrations of ethanol commonly present in mouthwashes. After a recovery period, cell viability was assessed with the MTT assay.

RESULTS

A marked cytotoxic effect was observed for ethanol concentrations of 20% and above.

CONCLUSIONS

The cytotoxicity of ethanol may explain the epidemiological association between mouthwash use and oral cancer. Evidence suggests that the risk of developing cancer in a tissue is strongly determined by the number of stem cell divisions accumulated by the tissue during a person's lifetime; cell division is a major source of mutations and other cancer-promoting errors. Since cell death activates the division of stem cells, the possible cytotoxicity of ethanol on the cells lining the oral mucosa will promote the division of the stem cells located in deeper layers to produce new cells to regenerate the damaged epithelium. If we regularly use mouthwashes containing cytotoxic concentrations of ethanol, the stem cells of the oral cavity may need to divide more often than usual and our risk of developing oral cancer may increase.

CLINICAL RELEVANCE

Many mouthwashes contain percentages of ethanol above 20%. Because ethanol is not crucial to prevent and reduce gingivitis and plaque, members of the dental team should consider the potential risk of oral cancer associated with frequent use of alcohol-containing mouthwashes when advising their patients.