Explanation: This statement describes malignant tumors. Benign tumors are defined by their inability to invade surrounding tissues or spread to other parts of the body.

Explanation: The source confirms that oncology is the medical specialty dedicated to the comprehensive management of cancer.

Explanation: The defining characteristic of malignant tumors, as opposed to benign tumors, is their ability to invade surrounding tissues and metastasize, or spread, to other parts of the body.

Explanation: Cancer is also referred to as a malignant tumor or malignant neoplasm, reflecting its nature as a group of cells that have undergone unregulated, invasive growth.

Explanation: In 2019, there were an estimated 23.6 million new cancer cases worldwide, representing a 26% increase over the previous decade.

Explanation: The avoidance of apoptosis is one of the six essential characteristics that all tumor cells display to facilitate malignant tumor production.

Explanation: Metastasis is the spread of cancer from a primary tumor to other locations, and it is the cause of most cancer-related fatalities.

Explanation: The source defines cancer as a disease of tissue growth regulation, where the genes that control cell growth and differentiation must be altered for a normal cell to become cancerous.

Explanation: The roles are reversed: oncogenes promote cell growth and reproduction, while tumor suppressor genes inhibit cell division and survival.

Explanation: The Warburg effect describes the opposite phenomenon: most cancer cells rely heavily on glycolysis for energy production, unlike normal cells which primarily use oxidative phosphorylation.

Explanation: One of the six hallmarks of cancer is the ability to undergo limitless cell divisions. Limited cell divisions are characteristic of normal, non-cancerous cells.

Explanation: The two main classes of genes affected in cancer are oncogenes, which promote cell growth, and tumor suppressor genes, which inhibit cell division and survival.

Explanation: Clonal evolution describes the process where initial genetic errors in a cell lead to further, more severe errors, allowing the cell to escape normal growth controls and progress towards a more invasive state.

Explanation: Epigenetic alterations, such as DNA methylation, modify how genes are expressed without altering the DNA sequence itself. These changes can be passed down through cell divisions and are frequently observed in cancers.

Explanation: Once a cancer has metastasized, the prognosis worsens significantly. The majority of cancer-related deaths are due to the spread of the primary tumor to other parts of the body.

Explanation: The vast majority of cancers (90-95%) are attributed to environmental and lifestyle factors, while only 5-10% are caused by inherited genetic defects.

Explanation: The term 'environmental' is used broadly to refer to any non-inherited factor, including lifestyle choices, diet, behavior, and exposure to infectious agents, not just pollution.

Explanation: Current evidence does not support psychological stress as a risk factor for the initial onset of cancer, although it may worsen outcomes for those already diagnosed.

Explanation: Cancer is generally not a transmissible disease, with very rare exceptions. However, certain transmissible infectious agents can contribute to cancer development.

Explanation: Tobacco smoke is responsible for a higher percentage, accounting for 90% of all lung cancer cases.

Explanation: Alcohol consumption is a known risk factor for several cancers, including those of the breast, throat, liver, esophagus, mouth, larynx, and colon.

Explanation: Exposure to PFOA is known to cause at least two kinds of cancer, one of which is kidney cancer.

Explanation: Some chemotherapy agents and immunosuppressive drugs are themselves carcinogens and can elevate the risk of developing a secondary primary cancer.

Explanation: These factors are related to a much larger proportion, approximately 30-35% of cancer deaths.

Explanation: Physical inactivity is believed to contribute to cancer risk not only through its influence on body weight but also via negative effects on the immune and endocrine systems.

Explanation: The proportion of cancer deaths related to infectious diseases is significantly higher in Africa (25%) than in the developed world (less than 10%).

Explanation: Children are twice as likely as adults to develop radiation-induced leukemia, indicating a higher susceptibility.

Explanation: While classified as a possible carcinogen, studies have not found a consistent link between mobile phone radiation and cancer risk.

Explanation: The vast majority of cancers are non-hereditary. Less than 0.3% of the population carries a genetic mutation with a large effect on cancer risk, accounting for less than 3-10% of all cancers.

Explanation: Physical trauma resulting in cancer is rare, and claims that it directly causes cancer have not been proven. It is thought that cancer may arise during the healing process rather than from the trauma itself.

Explanation: Chronic inflammation is hypothesized to directly cause mutations and can promote cancer cell proliferation, survival, and migration by influencing the tumor microenvironment.

Explanation: Age is the most significant risk factor for developing cancer, with most invasive cancer patients being over 65, due to factors like accumulated DNA errors and immunosenescence.

Explanation: Regular physical activity is associated with a reduced risk of cancer. Insufficient physical activity is a risk factor, along with carcinogen exposure, obesity, and certain infections.

Explanation: Only a small fraction, 5-10% of cancer cases, are caused by inherited genetic defects. The majority are due to environmental and lifestyle factors.

Explanation: Analyzing mutational signatures in tumor DNA can help identify the causative agents, such as distinguishing lung cancer caused by tobacco smoke from that caused by other factors.

Explanation: Tobacco smoke is the leading cause of lung cancer, responsible for 90% of cases.

Explanation: The source lists cancers of the mouth, kidney, and pancreas as being caused by tobacco use, but does not include brain cancer in this list.

Explanation: Perfluorooctanoic acid (PFOA), a chemical used in Teflon production, is a known carcinogen that causes at least two types of cancer.

Explanation: These combined lifestyle factors are related to a significant portion, approximately 30-35%, of all cancer deaths.

Explanation: A high-salt diet is specifically identified as a risk factor for developing gastric cancer.

Explanation: Globally, approximately 18% of cancer deaths are attributed to infectious diseases, with significant regional variation.

Explanation: Human papillomavirus (HPV) is the oncovirus most directly linked to the development of cervical cancer.

Explanation: The bacterial infection Helicobacter pylori is a known cause of gastric carcinoma.

Explanation: Ionizing radiation can act synergistically with other carcinogens, becoming a more potent cancer-causing agent when combined with them, such as radon gas exposure combined with tobacco smoke.

Explanation: Taller individuals have a greater number of cells in their bodies, which statistically increases the probability of a cancerous transformation occurring in one of those cells.

Explanation: Asbestos causes cancer, particularly mesothelioma, primarily through the physical effects of its mineral fibers in tissues, rather than through a chemical reaction.

Explanation: While these symptoms can indicate cancer, they are not definitive and may be caused by various other medical conditions.

Explanation: Early-stage cancer often produces no symptoms. When symptoms do appear, they are frequently non-specific and can be attributed to other conditions, making early diagnosis challenging.

Explanation: Cachexia is a systemic symptom, not a local one. It is an inflammatory state that causes ongoing muscle loss and weakness throughout the body.

Explanation: While signs, symptoms, or screening may suggest cancer, a definitive diagnosis requires a pathologist to examine a tissue sample (biopsy).

Explanation: Carcinoma originates from epithelial cells. Cancer originating from connective tissue is known as a sarcoma.

Explanation: Local symptoms arise directly from the tumor's mass or ulceration. Difficulty swallowing due to esophageal cancer is a direct physical effect, whereas weight loss, fatigue, and hypercalcemia are systemic symptoms.

Explanation: Paraneoplastic syndromes are systemic symptoms caused by hormones or other molecules produced by the tumor itself, which then circulate and affect distant parts of the body.

Explanation: While other methods are used for detection and assessment, a definitive diagnosis of cancer typically requires a pathologist to examine a tissue sample (biopsy).

Explanation: Cancers are typically named using the Latin or Greek word for the organ of origin combined with a suffix indicating the cell type, such as '-carcinoma' for epithelial cells or '-sarcoma' for connective tissue.

Explanation: Vitamin supplementation does not appear to be effective at preventing cancer, and some supplements, like beta-carotene, have been shown to increase cancer rates in high-risk groups.

Explanation: The USPSTF does not routinely recommend screening for prostate cancer, along with several other types like bladder, testicular, ovarian, and pancreatic cancer.

Explanation: A large majority, between 70% and 90% of common cancers, are attributed to environmental factors and are therefore considered potentially preventable.

Explanation: The Human Papillomavirus (HPV) vaccine is designed to prevent infection by HPV, which is a primary cause of cervical cancer.

Explanation: Cancer screening aims to detect cancer in its early, asymptomatic stages, which can lead to better treatment outcomes.

Explanation: The USPSTF does not routinely recommend screening for ovarian cancer, along with bladder, testicular, pancreatic, and prostate cancers.

Explanation: The average five-year survival rate for all cancer types in the United States is higher, at approximately 66%.

Explanation: Unlike traditional chemotherapy, targeted therapy specifically targets molecular differences between cancer cells and normal cells, rather than broadly attacking all rapidly dividing cells.

Explanation: Palliative care can be combined with cancer-treating therapies and does not require patients to cease treatments aimed at the cancer itself. This distinguishes it from hospice care.

Explanation: Traditional chemotherapy uses cytotoxic drugs that primarily work by killing cells that divide rapidly, a key characteristic of most cancer cells.

Explanation: Surgery is the primary treatment for most solid cancers, aiming to remove the tumor mass. It is also crucial for obtaining a biopsy for definitive diagnosis and staging.

Explanation: A key distinction is that palliative care can be administered alongside curative treatments, whereas hospice care is typically for patients who have ceased treatments aimed at the cancer itself.

Explanation: Ancient Greek physicians, such as Hippocrates, named the disease 'karkinos' because the appearance of a solid malignant tumor with swollen veins resembled a crab.

Explanation: The earliest known written record of cancer is much older, found in the Egyptian Edwin Smith Papyrus from approximately 1600 BC.

Explanation: This theory, a popular alternative treatment in the 1970s, posited that a 'cancer personality' caused the disease, leading to victim-blaming and increased patient anxiety.

Explanation: Although absolute spending has increased, the share of total health expenditure for cancer treatment has remained relatively stable, around 5% in the US and 6% in Europe.

Explanation: The EEOC includes cancer as a protected condition to prevent discriminatory effects on workers and provides guidelines for accommodating employees with cancer.

Explanation: This is unlikely because cancer is not a single disease but a class of many distinct diseases, each with different biological characteristics requiring varied treatment approaches.

Explanation: The earliest known written record of cancer is found in the Egyptian Edwin Smith Papyrus, dating to about 1600 BC, which describes breast cancer.

Explanation: The physician John Hill was the first to describe tobacco sniffing as a cause of nose cancer in 1761.

Explanation: The 'just-world fallacy' posits that people blame patients for their illness to regain a sense of control, stemming from the belief that bad things (like cancer) must be a punishment for bad choices.

Explanation: In 2015, the total healthcare expenditure on cancer in the United States was estimated to be $80.2 billion.

Explanation: A single cure is unlikely because 'cancer' is a term for a class of many distinct diseases, each with unique biological characteristics that require different treatment approaches.

Explanation: The three most prevalent cancers in children are leukemia (34%), brain tumors (23%), and lymphomas (12%).

Explanation: Diagnosing cancer during pregnancy is difficult because its symptoms can be mistaken for normal discomforts associated with pregnancy, often leading to a diagnosis at a later stage.

Explanation: Canine transmissible venereal tumor, also known as Sticker's sarcoma, is a type of cancer that spreads between dogs through the transmission of the tumor cells themselves.