History of Cancer Research

The high incidence of scrotal cancer among chimney sweeps.

The discovery that living tissues are composed of cells and all cells arise from other cells.

It reinforced the idea that cancer could be linked to identifiable and preventable causes, further driving the search for cancer-causing agents.

<p>The two conflicting views were that cancer is either an infectious disease or hereditary. The infectious disease view was based on the discovery of bacteria causing other diseases, while the hereditary view was based on observations of cancer running in families.</p> Signup and view all the answers

<p>The discovery of X-rays.</p> Signup and view all the answers

<p>The observation that exposure to X-rays could cause localized tissue damage, which could lead to cancer development, supported the idea that chronic irritation and inflammation could contribute to cancer.</p> Signup and view all the answers

<p>The confusion and lack of a definitive understanding of the origin and causes of cancer.</p> Signup and view all the answers

<p>It suggested that external factors might influence cancer development, leading scientists to investigate environmental causes.</p> Signup and view all the answers

<p>The discovery that a submicroscopic agent isolated from a chicken tumor could induce new tumors in healthy chickens.</p> Signup and view all the answers

<p>The intensive study of cancer-causing viruses focused researchers' attention on cellular genes as central players in cancer development.</p> Signup and view all the answers

<p>These investigations indicated that while visible damage sometimes occurs, something more subtle happens at the cellular level.</p> Signup and view all the answers

<p>A potential connection between X-rays' ability to promote cancer and their ability to cause genetic mutations.</p> Signup and view all the answers

<p>It provided strong support for the idea that carcinogens cause cancer by damaging genes.</p> Signup and view all the answers

<p>He proposed a genetic model explaining the origins of retinoblastoma and reconciled the view of cancer as a disease caused by external agents with the familial inheritance of some cancers.</p> Signup and view all the answers

<p>Sporadic retinoblastoma requires two somatic mutations, while familial retinoblastoma requires only one additional mutation because individuals inherit one mutation.</p> Signup and view all the answers

<p>It suggested that many cancers might be linked to the inheritance of mutated versions of growth-suppressing genes.</p> Signup and view all the answers

<p>Cancer cells are indigenous cells, abnormal cells arising from normal body tissues.</p> Signup and view all the answers

<p>It means that each malignant tumor originates from a single ancestral cell that underwent a transformation from normal to cancerous.</p> Signup and view all the answers

<p>They revealed that cancer cells are derived from the patient's own tissues, not from external sources.</p> Signup and view all the answers

<p>Tumor cells of a particular cancer patient are always of the same transplantation type as the cells of normal tissues located elsewhere in the person's body.</p> Signup and view all the answers

<p>Transplantation studies and tissue-typing tests, which show that tumor cells are of the same transplantation type as other cells in the individual's body, provide evidence for the monoclonal origin of tumors.</p> Signup and view all the answers

<p>Transplantation studies and tissue-typing tests revealed that the tumor cells of a cancer patient are always of the same transplantation type as the cells of normal tissues located elsewhere in the person's body, indicating that the tumor originated from a single ancestral cell within the individual's tissues.</p> Signup and view all the answers

<p>The two main scenarios are polyclonal tumor development, where multiple cells become cancerous, and monoclonal tumor development, where a single cancerous cell gives rise to the entire tumor.</p> Signup and view all the answers

<p>The inactivated X chromosome in female cells.</p> Signup and view all the answers

<p>X-chromosome inactivation occurs randomly during female embryonic development, with different X chromosomes being inactivated in different cells. This random inactivation allows scientists to trace the lineage of cells within a tumor, as all cells originating from the same ancestor will have the same X chromosome inactivated. This supports the idea of monoclonal tumor development.</p> Signup and view all the answers

<p>Cancer development begins with a single ancestral cell undergoing genetic transformation. This cell, and its descendants, proliferate over time, acquiring new traits and forming distinct subpopulations within the tumor. Each acquisition of a new trait represents a clonal expansion, with the successful trait driving further tumor growth.</p> Signup and view all the answers

<p>Genetic instability in cancer cells leads to rearrangements, duplications, and deletions of chromosomes, giving rise to diverse characteristics within the tumor. This contributes to the heterogeneity of cancerous cells within a single tumor.</p> Signup and view all the answers

<p>Cancer cells have larger nuclei that often occupy most of the cell's volume, unlike normal cells where the nucleus is only about one-fifth the size of the cell.</p> Signup and view all the answers

<p>Cancer cells have lost the growth restraints that characterize normal cells. They divide uncontrollably, show no contact inhibition, and have a reduced reliance on growth factors, whereas normal cells exhibit controlled growth and dependence on growth factors.</p> Signup and view all the answers

<p>This ability enables tumors to continuously grow without the constraints that normally limit cell growth, leading to uncontrolled proliferation and tumor expansion.</p> Signup and view all the answers

<p>They established a relationship between mutagenicity and carcinogenicity, providing support for the idea that chemical carcinogens directly induce mutations in cellular genes, leading to abnormal cell growth and potentially cancer.</p> Signup and view all the answers

<p>Carcinogens damage cellular genes, leading to mutations in critical genes. These mutations trigger abnormal cell growth in the affected cell and its descendants, ultimately resulting in tumor formation years later.</p> Signup and view all the answers

<p>If inherited mutations in critical genes predispose individuals to cancer, then family members who share these mutations are more likely to develop cancerous cells, explaining the increased risk of cancer in families with a history of the disease.</p> Signup and view all the answers

<p>Cancer cells are genetically unstable, have larger nuclei than normal cells, and have lost their normal growth restraints.</p> Signup and view all the answers

<p>Normal cells exhibit contact inhibition, meaning they stop dividing upon contact with other cells. However, cancer cells lack this inhibition, leading to uncontrolled proliferation despite contact with other cells.</p> Signup and view all the answers

<p>Cancer was understood to be initiated by mutations in critical genes, triggered by carcinogens or inherited mutations. These mutations lead to abnormal cell growth and ultimately tumor formation.</p> Signup and view all the answers

<p>The early explanation lacked knowledge of the specific genes involved in causing cancer and their roles in the cell.</p> Signup and view all the answers

<p>The two categories are proto-oncogenes and tumor suppressor genes.</p> Signup and view all the answers

<p>Proto-oncogenes encourage cell division, while tumor suppressor genes inhibit it.</p> Signup and view all the answers

<p>They become oncogenes which stimulate excessive cell division.</p> Signup and view all the answers

<p>Mutations inactivate tumor suppressor genes, eliminating the inhibition of cell division.</p> Signup and view all the answers

<p>They code for proteins involved in receiving and processing growth-stimulating signals from other cells.</p> Signup and view all the answers

<p>Oncogenes cause the proteins in growth-promoting pathways to become overactive, leading to faster cell proliferation.</p> Signup and view all the answers

<p>Growth factors stimulate cell division by binding to specific receptor proteins on the surfaces of neighboring cells.</p> Signup and view all the answers

<p>Some oncogenes cause cells to produce excessive amounts of growth factors, stimulating both the growth of neighboring cells and their own excessive division.</p> Signup and view all the answers

<p>They can cause aberrant receptor proteins to release stimulatory signals even without the presence of growth factors or disrupt signal transmission within the cytoplasm, leading to continuous stimulatory messages.</p> Signup and view all the answers

<p>They produce proteins that operate in inhibitory pathways, counterbalancing the growth-stimulating pathways.</p> Signup and view all the answers

<p>When inactivated, these genes prevent the flow of inhibitory messages to the nucleus, allowing cells to ignore normal growth restrictions.</p> Signup and view all the answers

<p>This system detects and corrects errors in DNA, safeguarding against mutations caused by carcinogens or DNA replication errors.</p> Signup and view all the answers

<p>If the system fails, errors become permanent mutations, potentially contributing to the development of cancer.</p> Signup and view all the answers

<p>This knowledge allows targeted efforts in prevention, detection, and treatment by focusing on the specific genes that are driving the disease.</p> Signup and view all the answers

<p>The overall survival rate for all cancer sites increased from 49.3 percent to 53.9 percent.</p> Signup and view all the answers

<p>Children age 15 and younger have shown particularly dramatic increases in survival rates.</p> Signup and view all the answers

<p>Improvements in cancer detection through new imaging techniques and tests are a key factor.</p> Signup and view all the answers

<p>By the time symptoms occur, many tumors may have grown large and metastasized.</p> Signup and view all the answers

<p>Cancer treatments are now more specific to the type of cancer involved, leading to better outcomes.</p> Signup and view all the answers

<p>They compare cancer research to a</p> Signup and view all the answers

<p>Molecular fingerprinting can be used to differentiate among tumors at the molecular level, enhancing the specificity of cancer diagnosis. It can also help identify which cancers are most likely to progress, allowing patients to avoid unnecessary treatment.</p> Signup and view all the answers

<p>The main components of the overall cost of cancer are direct medical costs, morbidity costs (lost productivity), and mortality costs.</p> Signup and view all the answers

<p>The time lag refers to the extended period between exposure to cancer-causing agents and the actual appearance of the disease. This delay makes it challenging to identify a direct link between specific habits and cancer development in individuals.</p> Signup and view all the answers

<p>The four levels of focus are the individual, health care providers, the national level, and the international level.</p> Signup and view all the answers

<p>The ethical concern is ensuring that interventions aimed at preventing or treating cancer are implemented and used in a way that respects individual autonomy and choices, while prioritizing the overall well-being of the population.</p> Signup and view all the answers

<p>'Interest' in this context refers to a participant's stake or involvement in a situation, particularly as it relates to their well-being and the potential impact of actions or decisions.</p> Signup and view all the answers

<p>Actions or qualities that impair the interests of individuals, families, communities, institutions, or society are considered 'wrong' or 'bad' in ethical terms.</p> Signup and view all the answers

<p>The monoclonal origin of most cancers indicates that they arise from a single mutated cell that undergoes uncontrolled proliferation. Understanding this origin helps explain the clonal expansion and genetic instability observed in cancer development.</p> Signup and view all the answers

<p>Tissue damage can create an environment that promotes the development of cancer by stimulating rapid cell division and increasing the likelihood of mutations. This connection highlights the importance of minimizing exposure to carcinogens and other factors that can cause tissue damage.</p> Signup and view all the answers

<p>X-rays are a form of ionizing radiation that can cause significant tissue damage. The observation that long-term exposure to X-rays can lead to cancer supports the idea that chronic irritation of tissues can trigger the development of the disease.</p> Signup and view all the answers

<p>The discovery of X-rays, and their ability to cause tissue damage, provided further evidence that cancer could be linked to external agents and chronic irritation, rather than solely being a product of genetic predisposition</p> Signup and view all the answers

<p>Understanding that cancer development is a multi-step process involving multiple genetic changes and clonal expansions allows researchers to identify potential targets for therapy at different stages of the disease. This approach could lead to more personalized and effective treatments for different types of cancer.</p> Signup and view all the answers

<p>Studying genetic instabilities in cancerous cells helps shed light on the mechanisms that drive tumor growth and spread. Understanding these instabilities is crucial for developing new treatments that target the underlying genetic defects and suppress the growth of cancer cells.</p> Signup and view all the answers

<p>They damage a cell's ability to repair DNA errors, leading to more frequent mutations.</p> Signup and view all the answers

<p>The discovery that certain viruses can cause cancer by inserting their DNA into the host cell's genome, leading to mutations, provided strong evidence that genetic alterations play a key role in cancer development.</p> Signup and view all the answers

<p>The p53 protein halts cell division and induces apoptosis in abnormal cells.</p> Signup and view all the answers

<p>Despite the evidence suggesting a link between unhealthful habits and cancer risk, many people continue to engage in those habits, making it difficult to prevent cancer through public health initiatives. This is partly due to the long time lag between exposure to cancer-causing factors and the development of the disease, making it hard to see the direct consequences of unhealthy lifestyle choices.</p> Signup and view all the answers

<p>Telomeres shorten with each cell division, limiting the number of divisions; cancer cells often evade this limitation.</p> Signup and view all the answers

<p>Cancer develops over time as multiple mutations accumulate, leading to a malignant state.</p> Signup and view all the answers

<p>Cancer incidence increases with age due to the accumulation of mutations over time.</p> Signup and view all the answers

<p>Exposures to carcinogens increase the likelihood of harmful mutations occurring.</p> Signup and view all the answers

<p>It means critical mutations are already present in all cells, advancing the tumor formation process.</p> Signup and view all the answers

<p>There can be years or decades between exposure and cancer development as multiple mutations accumulate.</p> Signup and view all the answers

<p>Apoptosis eliminates damaged cells, preventing cancer development when functioning correctly.</p> Signup and view all the answers

<p>Cancer is now understood as a complex, multistep process rather than a result of single mutations.</p> Signup and view all the answers

<p>Cancer cells can proliferate indefinitely due to disruptions in normal division limits.</p> Signup and view all the answers

<p>Incidence rate, mortality rate, and survival rate are the three key metrics.</p> Signup and view all the answers

<p>Cancer cells that evade apoptosis are less responsive to treatments that rely on cell death.</p> Signup and view all the answers

<p>Telomerase enables cancer cells to maintain telomere length, allowing endless division.</p> Signup and view all the answers

<p>SEER aims to estimate cancer incidence and patient survival in the United States.</p> Signup and view all the answers

<p>The incidence rate was 14.1 cases per 100,000 children.</p> Signup and view all the answers

<p>Men have a 1 in 2 lifetime risk, while women have a 1 in 3 risk.</p> Signup and view all the answers

<p>Relative risk compares the likelihood of developing cancer between individuals with a certain exposure and those without it.</p> Signup and view all the answers

<p>Cancer is the second leading cause of childhood death after accidents.</p> Signup and view all the answers

<p>Hereditary mutations account for less than 5 percent of fatal cancer cases.</p> Signup and view all the answers

<p>Exposure to carcinogens increases the likelihood of cancer development depending on individual susceptibility.</p> Signup and view all the answers

<p>It means that exposure to the factor significantly increases the probability of developing cancer.</p> Signup and view all the answers

<p>There was the first sustained decline in the cancer death rate after decades of increase.</p> Signup and view all the answers

<p>Leukemias and brain cancers were the most common, accounting for over half of childhood cancers.</p> Signup and view all the answers

<p>Cancer incidence can differ based on factors like race, sex, age, and environmental exposures.</p> Signup and view all the answers

<p>Epidemiology helps identify factors associated with cancer development and informs prevention strategies.</p> Signup and view all the answers

<p>'Hard core' cancers are those that would occur even without external environmental influences or mutations.</p> Signup and view all the answers

<p>Individuals with fair skin are more susceptible to developing skin cancer than those with darker complexions.</p> Signup and view all the answers

<p>Tumor suppressor genes function to suppress or block the development of cancer by regulating cell division and maintaining genomic stability.</p> Signup and view all the answers

<p>UV radiation can damage the DNA in skin cells, leading to mutations that may result in melanoma and other types of skin cancer.</p> Signup and view all the answers

<p>X-chromosome inactivation is the process where one of the two X chromosomes in female mammals is condensed and inactivated to ensure equal gene expression with males.</p> Signup and view all the answers

<p>Xeroderma pigmentosum is a hereditary condition that causes extreme sensitivity to sunlight and an increased risk of skin cancers due to inadequate DNA repair mechanisms.</p> Signup and view all the answers

<p>Dermatologists recommend this to provide comprehensive protection against skin damage that can lead to various forms of skin cancer, including melanoma.</p> Signup and view all the answers

<p>De facto public policy.</p> Signup and view all the answers

<p>Science assists individuals in making informed choices to enhance welfare.</p> Signup and view all the answers

<p>The relationship is not linear; individuals can choose against sound knowledge.</p> Signup and view all the answers

<p>Improved general education and cultivating an anti-smoking ethos.</p> Signup and view all the answers

<p>Autonomy and protecting others from harm are two core values.</p> Signup and view all the answers

<p>It has been offset by a rapid increase in cigarette consumption elsewhere.</p> Signup and view all the answers

<p>It helps to explore diverse solutions rather than relying on one single strategy.</p> Signup and view all the answers

<p>Ethical inquiry requires posing clear questions and seeking well-reasoned answers.</p> Signup and view all the answers

<p>Pluralism introduces diverse cultural approaches and ethical values, leading to varied interpretations.</p> Signup and view all the answers

<p>It is increasingly difficult to deny the claims of science.</p> Signup and view all the answers

<p>To encourage critical thinking about these relationships in daily life.</p> Signup and view all the answers

<p>The costs of implementation and the urgency of the situation are two crucial considerations.</p> Signup and view all the answers

<p>Overwhelming evidence links cigarette smoking to lung cancer, supporting the need for policy restrictions.</p> Signup and view all the answers

<p>It may encourage better choices related to health and wellness.</p> Signup and view all the answers

<p>Public funds may be diverted from beneficial societal programs to cancer treatments.</p> Signup and view all the answers

<p>It refers to a cultural mindset that actively discourages smoking.</p> Signup and view all the answers

<p>De jure public policy, which encompasses laws and regulations.</p> Signup and view all the answers

<p>De jure public policy can struggle against the addictive nature of nicotine and tobacco marketing.</p> Signup and view all the answers

<p>The complex interplay between knowledge, choice, and behavior.</p> Signup and view all the answers

<p>Individual freedom can conflict with public health interests, such as tobacco use.</p> Signup and view all the answers

<p>Personal behaviors and societal influences.</p> Signup and view all the answers

<p>Competing well-reasoned answers often exist due to the complex nature of ethical tradeoffs.</p> Signup and view all the answers

<p>It raises awareness about the risks of smoking and promotes healthier choices.</p> Signup and view all the answers

<p>A solid foundation of information and rigorous interpretation is crucial for ethical decision-making.</p> Signup and view all the answers

<p>Cultural approaches lead to differing standards for marketing and using tobacco.</p> Signup and view all the answers

<p>Social, cultural, and political factors can complicate the formulation of effective regulations.</p> Signup and view all the answers

<p>It reveals varying priorities that individuals assign to ethical considerations.</p> Signup and view all the answers

<p>De jure public policy refers to rules and regulations enforced by government entities.</p> Signup and view all the answers

<p>People aged 15 to 34 and those over 55 are at the highest risk for Hodgkin lymphoma.</p> Signup and view all the answers

<p>Basal cell cancer and squamous cell cancer are classified as nonmelanoma skin cancers.</p> Signup and view all the answers

<p>An oncogene is a gene that, when mutated, can promote uncontrolled cell growth, leading to cancer.</p> Signup and view all the answers

<p>Palliative treatment aims to improve the quality of life without altering the disease's course.</p> Signup and view all the answers

<p>A precancerous polyp is a growth in the colon that often has the potential to become cancerous.</p> Signup and view all the answers

<p>Remission refers to the disappearance of signs and symptoms of cancer.</p> Signup and view all the answers

<p>Radon is a radioactive gas that can damage lung cells when inhaled, increasing lung cancer risk.</p> Signup and view all the answers

<p>Relative risk compares the likelihood of developing cancer in those with a certain exposure to those without.</p> Signup and view all the answers

<p>The SEER Program collects cancer incidence data to inform epidemiological studies and public health policies.</p> Signup and view all the answers

<p>Proto-oncogenes are normal genes that regulate cell growth, while oncogenes are mutated forms that promote cancer.</p> Signup and view all the answers

<p>A sarcoma is a malignant tumor that originates in connective or supportive tissues.</p> Signup and view all the answers

<p>Staging refers to the process of determining the extent of cancer and whether it has spread.</p> Signup and view all the answers

<p>Telomerase allows cancer cells to divide indefinitely by maintaining telomere length.</p> Signup and view all the answers

<p>Radiation therapy uses high-energy rays to kill cancer cells, often delivered externally or internally.</p> Signup and view all the answers

<p>A secondary tumor is a cancerous growth that develops due to metastasis from an original tumor.</p> Signup and view all the answers

<p>Angiogenesis is the formation of new blood vessels that usually occurs alongside the growth of malignant tissue.</p> Signup and view all the answers

<p>Atypical hyperplasia is a benign condition where tissues exhibit certain abnormal features.</p> Signup and view all the answers

<p>Benign tumors are noncancerous and do not invade nearby tissues, while malignant tumors can invade other parts of the body.</p> Signup and view all the answers

<p>Apoptosis is a programmed cell death process that helps maintain cellular health by removing damaged or unneeded cells.</p> Signup and view all the answers

<p>Carcinogenesis refers to the process by which normal cells are transformed into cancer cells.</p> Signup and view all the answers

<p>The BRCA1 gene helps restrain cell growth, and inheriting an altered version increases the risk for certain cancers, like breast and ovarian cancer.</p> Signup and view all the answers

<p>A biopsy involves the removal of a tissue sample to examine under a microscope for the presence of cancer cells.</p> Signup and view all the answers

<p>Bone marrow is responsible for producing white blood cells, red blood cells, and platelets.</p> Signup and view all the answers

<p>Chemotherapy uses anticancer drugs to inhibit the growth and proliferation of cancer cells.</p> Signup and view all the answers

<p>Encapsulated refers to tumors that are confined to a specific area and remain compact.</p> Signup and view all the answers

<p>ETS comes from the burning end of a cigarette and the smoke exhaled by smokers.</p> Signup and view all the answers

<p>Carcinoma in situ involves cancer cells that remain confined to their original location without spreading.</p> Signup and view all the answers

<p>Etiology studies the causes of abnormal conditions or diseases.</p> Signup and view all the answers

<p>Gene therapy aims to alter genes to improve the body's natural ability to fight cancer or to enhance tumor sensitivity to treatment.</p> Signup and view all the answers

<p>Clinical trials aim to find better ways to prevent, diagnose, treat cancer, and answer important scientific questions.</p> Signup and view all the answers

<p>Melanocytes are responsible for producing and containing the pigment called melanin.</p> Signup and view all the answers

<p>Contact inhibition causes normal cells to halt division when they come into contact with neighboring cells.</p> Signup and view all the answers

<p>In situ cancer refers to cancer that has remained within the tissue in which it originated.</p> Signup and view all the answers

<p>Combination chemotherapy involves using two or more chemotherapeutic agents to achieve more effective treatment results.</p> Signup and view all the answers

<p>Dysplasia refers to abnormal cells that are not cancerous but may indicate a higher risk of developing cancer.</p> Signup and view all the answers

<p>The fecal occult blood test is used to reveal hidden blood in feces, indicating potential colon cancer.</p> Signup and view all the answers

<p>Malignant refers to cancerous cells that can invade nearby tissues and spread to other parts of the body.</p> Signup and view all the answers

<p>Tumor suppressor genes help regulate cell division and prevent uncontrolled cell growth.</p> Signup and view all the answers

<p>Lifetime risk refers to the probability that an individual will develop cancer over their lifetime.</p> Signup and view all the answers

<p>Hyperplasia is a precancerous condition marked by an increase in the number of normal cells lining an organ.</p> Signup and view all the answers

<p>The grading system classifies cancer cells based on how closely they resemble normal cells and their probable growth rate.</p> Signup and view all the answers

<p>Familial polyposis is an inherited condition where several hundred polyps develop in the colon and rectum.</p> Signup and view all the answers

<p>Metastasis refers to the spread of cancer growth, or secondary tumors, to sites separate from the original cancer.</p> Signup and view all the answers

<p>Benign fibroids are non-cancerous uterine tumors made up of fibrous and muscular tissue.</p> Signup and view all the answers