Instruct: Given a question, retrieve relevant documents that can help answer the question.
Query: How common are basal cancerous cells?
Basal-cell cancer is a very common skin cancer. It is much more common in fair-skinned individuals with a family history of basal-cell cancer and increases in incidence closer to the equator or at higher altitude. There are approximately 800,000 new cases yearly in the United States alone. Up to 30% of Caucasians develop basal-cell carcinomas in their lifetime. In Canada, the most common skin cancer is basal-cell carcinoma (as much as one third of all cancer diagnoses), affecting 1 in 7 individuals over a lifetime.
When tumor cells metastasize, the new tumor is called a "secondary" or "metastatic" tumor, and its cells are similar to those in the original or primary tumor. This means that if breast cancer metastasizes to the lungs, the secondary tumor is made up of abnormal breast cells, not of abnormal lung cells. The tumor in the lung is then called "metastatic breast cancer", not "lung cancer". Metastasis is a key element in cancer staging systems such as the TNM staging system, where it represents the "M". In overall stage grouping, metastasis places a cancer in Stage IV. The possibilities of curative treatment are greatly reduced, or often entirely removed, when a cancer has metastasized.
Glioblastoma Multiforme is also a malignant tumor and classified as a grade IV. Glioblastomas can contain more than one cell type (i.e., astrocytes, oligodendrocytes). Also, while one cell type may die off in response to a particular treatment, the other cell types may continue to multiply. Glioblastomas are the most invasive type of glial tumors as they grow rapidly and spread to nearby tissue. Approximately 50% of astrocytomas are glioblastomas and are very difficult to treat.
Hereditary cancer syndromes underlie 5 to 10% of all cancers and there are over 50 identifiable hereditary forms of cancer. Scientific understanding of cancer susceptibility syndromes is actively expanding: additional syndromes are being found, the underlying biology is becoming clearer, and commercialization of diagnostic genetics methodology is improving clinical access. Given the prevalence of breast and colon cancer, the most widely recognized syndromes include hereditary breast-ovarian cancer syndrome (HBOC) and hereditary non-polyposis colon cancer (HNPCC, Lynch syndrome).
Neuro-oncology is the study of brain and spinal cord neoplasms, many of which are (at least eventually) very dangerous and life-threatening (astrocytoma, glioma, glioblastoma multiforme, ependymoma, pontine glioma, and brain stem tumors are among the many examples of these). Among the malignant brain cancers, gliomas of the brainstem and pons, glioblastoma multiforme, and high-grade (highly anaplastic) astrocytoma are among the worst. In these cases, untreated survival usually amounts to only a few months, and survival with current radiation and chemotherapy treatments may extend that time from around a year to a year and a half, possibly two or more, depending on the patient's condition, immune function, treatments used, and the specific type of malignant brain neoplasm. Surgery may in some cases be curative, but, as a general rule, malignant brain cancers tend to regenerate and emerge from remission easily, especially highly malignant cases. In such cases, the goal is to excise as much of the mass (tumor cells) and as much of the tumor margin as possible without endangering vital functions or other important cognitive abilities.
Fyn overexpression has been studied in relation to the following cancers: prostate cancer, glioblastoma multiform, squamous cell carcinoma of the head and neck, pancreatic cancer, chronic melogenic leukemia, and melanoma. This overexpression triggers a promotion of “anti-apoptotic activity of Akt” in prostate cancer, meaning that these cells have gained the ability to avoid the normal cell death pathways (a common hallmark of cancer). Additionally, in glioblastoma multiform, Src and Fyn have been found to be “effectors of oncogenic EGFR signaling” which has led to tumor invasion and cancer cell survival.
Since the 1940s, medical science has developed chemotherapy, radiation therapy, adjuvant therapy and the newer targeted therapies, as well as refined surgical techniques for removing cancer. Before the development of these modern, evidence-based treatments, 90% of cancer patients died within five years. With modern mainstream treatments, only 34% of cancer patients die within five years. However, while mainstream forms of cancer treatment generally prolong life or permanently cure cancer, most treatments also have side effects ranging from unpleasant to fatal, such as pain, blood clots, fatigue, and infection. These side effects and the lack of a guarantee that treatment will be successful create appeal for alternative treatments for cancer, which purport to cause fewer side effects or to increase survival rates despite evidence to suggest a 2–5 fold increase in death with alternative medicines.
Globally, , liver cancer resulted in 754,000 deaths, up from 460,000 in 1990, making it the third leading cause of cancer death after lung and stomach. In 2012, it represented 7% of cancer diagnoses in men, the 5th most diagnosed cancer that year. Of these deaths 340,000 were secondary to hepatitis B, 196,000 were secondary to hepatitis C, and 150,000 were secondary to alcohol. HCC, the most common form of liver cancer, shows a striking geographical distribution. China has 50% of HCC cases globally, and more than 80% of total cases occur in sub-Saharan Africa or in East-Asia due to hepatitis B virus. Cholangiocarcinoma also has a significant geographical distribution, with Thailand showing the highest rates worldwide due to the presence of liver fluke.
People get liver cancer (also called "hepatocellular carcinoma, HCC" or "hepatoma)" typically from a prolonged Hepatitis B or C infection or as a result of cirrhosis from chronic alcoholism. Liver cancer may bring about yellowing of the skin and eyes (jaundice), itching (pruritus), or cause a buildup of fluid in the abdomen (ascites). A person may feel an enlarging mass, or the cancer might be revealed by abnormal liver function tests.
The prognosis for lymphangioma circumscriptum and cavernous lymphangioma is generally excellent. This condition is associated with minor bleeding, recurrent cellulitis, and lymph fluid leakage. Two cases of lymphangiosarcoma arising from lymphangioma circumscriptum have been reported; however, in both of the patients, the preexisting lesion was exposed to extensive radiation therapy.
The somatic mutation theory of metastasis development has not been substantiated in human cancers. Rather, it seems that the genetic state of the primary tumor reflects the ability of that cancer to metastasize. Research comparing gene expression between primary and metastatic adenocarcinomas identified a subset of genes whose expression could distinguish primary tumors from metastatic tumors, dubbed a "metastatic signature." Up-regulated genes in the signature include: SNRPF, HNRPAB, DHPS and securin. Actin, myosin and MHC class II down-regulation was also associated with the signature. Additionally, the metastatic-associated expression of these genes was also observed in some primary tumors, indicating that cells with the potential to metastasize could be identified concurrently with diagnosis of the primary tumor. Recent work identified a form of genetic instability in cancer called chromosome instability (CIN) as a driver of metastasis. In aggressive cancer cells, loose DNA fragments from unstable chromosomes spill in the cytosol leading to the chronic activation of innate immune pathways, which are hijacked by cancer cells to spread to distant organs.
Uncommon risk factors include genetic disorders such as neurofibromatosis, Li–Fraumeni syndrome, tuberous sclerosis, or Turcot syndrome. Previous radiation therapy is also a risk. For unknown reasons, GBM occurs more commonly in males.
Because cancer is a class of diseases, it is unlikely that there will ever be a single "cure for cancer" any more than there will be a single treatment for all infectious diseases. Angiogenesis inhibitors were once incorrectly thought to have potential as a "silver bullet" treatment applicable to many types of cancer. Angiogenesis inhibitors and other cancer therapeutics are used in combination to reduce cancer morbidity and mortality.
Herpes has been used in research with HeLa cells to determine its ability to assist in the treatment of malignant tumors. A study conducted using suicide gene transfer by a cytotoxic approach examined a way to eradicate malignant tumors. Gene therapy is based on the cytotoxic genes that directly or indirectly kill tumor cells regardless of its gene expression. In this case the study uses the transfer of the Herpes simplex virus type I thymidine kinase (HSVtk) as the cytotoxic gene. Hela cells were used in these studies because they have very little ability to communicate through gap junctions. The Hela cells involved were grown in a monolayer culture and then infected with the HSV virus. The HSV mRNA was chosen because it is known to share characteristics with normal eukaryotic mRNA.
When diagnosing osteoblastoma, the preliminary radiologic workup should consist of radiography of the site of the patient's pain. However, computed tomography (CT) is often necessary to support clinical and plain radiographic findings suggestive of osteoblastoma and to better define the margins of the lesion for potential surgery. CT scans are best used for the further characterization of the lesion with regard to the presence of a nidus and matrix mineralization. MRI aids in detection of nonspecific reactive marrow and soft tissue edema, and MRI best defines soft tissue extension, although this finding is not typical of osteoblastoma. Bone scintigraphy (bone scan) demonstrates abnormal radiotracer accumulation at the affected site, substantiating clinical suspicion, but this finding is not specific for osteoblastoma. In many patients, biopsy is necessary for confirmation.
Lymphangiosarcoma is a malignant soft tissue tumour, whereas lymphangioma is a benign tumour occurring frequently in association with Turner syndrome. Lymphangioleiomyomatosis is a benign tumour of the smooth muscles of the lymphatics that occurs in the lungs.
The American Cancer Society reported that "[t]here is no reliable scientific evidence that Gerson therapy is effective in treating cancer, and the principles behind it are not widely accepted by the medical community. It is not approved for use in the United States." In 1947, the National Cancer Institute reviewed 10 claimed cures submitted by Gerson; however, all of the patients were receiving standard anticancer treatment simultaneously, making it impossible to determine what effect, if any, was due to Gerson's therapy. A review of the Gerson Therapy by Memorial Sloan-Kettering Cancer Center concluded: "If proponents of such therapies wish them to be evaluated scientifically and considered valid adjuvant treatments, they must provide extensive records (more than simple survival rates) and conduct controlled, prospective studies as evidence". In 1959, the National Cancer Institute (NCI) again reviewed cases of patients treated by Gerson. The NCI found that the available information did not prove the regimen had benefit. Cancer Research UK states that "Available scientific evidence does not support any claims that Gerson therapy can treat cancer [...] Gerson therapy can be very harmful to your health."
Treatment options vary and depend on the type and stage of cancer. Common treatments include surgery, chemotherapy, radiation therapy, amputation, and immunotherapy. A combination of therapies may be used. Knowledge and treatment of cancer have increased significantly in the past three decades. Survival rates have also increased due to the increase prevalence of canine cancer treatment centers and breakthroughs in targeted drug development. Canine cancer treatment has become an accepted clinical practice and access to treatment for owners has widely expanded recently. Cancer-targeting drugs most commonly function to inhibit excessive cell proliferation by attacking the replicating cells. However, there is still a prevalent pharmacy gap in veterinary oncology.
Following a three-hour hearing on August 5, the Commission concluded that Chenar's finding had been in error. They found that the tumor had features of a glioblastoma multiforme, with widespread areas of necrosis, palisading of cells, and a "remarkable vascular component" described as having "the nature of a small congenital vascular malformation." Psychiatric contributors to the report concluded that "the relationship between the brain tumor and [...] Whitman's actions [...] cannot be established with clarity. However, the [...] tumor conceivably could have contributed to his inability to control his emotions and actions," while the neurologists and neuropathologists concluded: "The application of existing knowledge of organic brain function does not enable us to explain the actions of Whitman on August first."
Singer and Grismaijer argue that bra-wearing may cause breast cancer because of a purported effect on lymphatic circulation. Their interpretation is that constriction from tightly worn bras inhibits the proper functioning of the lymphatic system and leads to a buildup of fluid within the breast tissue. According to the authors, bra-induced constriction of the breast lymphatic vessels concentrates toxins within the breast tissue, which may ultimately lead to cancer.
Most adult stem cells are lineage-restricted (multipotent) and are generally referred to by their tissue origin (mesenchymal stem cell, adipose-derived stem cell, endothelial stem cell, dental pulp stem cell, etc.). Muse cells (multi-lineage differentiating stress enduring cells) are a recently discovered pluripotent stem cell type found in multiple adult tissues, including adipose, dermal fibroblasts, and bone marrow. While rare, muse cells are identifiable by their expression of SSEA-3, a marker for undifferentiated stem cells, and general mesenchymal stem cells markers such as CD105. When subjected to single cell suspension culture, the cells will generate clusters that are similar to embryoid bodies in morphology as well as gene expression, including canonical pluripotency markers Oct4, Sox2, and Nanog.
Nevoid basal-cell carcinoma syndrome (NBCCS), also known as basal-cell nevus syndrome, multiple basal-cell carcinoma syndrome, Gorlin syndrome, and Gorlin–Goltz syndrome, is an inherited medical condition involving defects within multiple body systems such as the skin, nervous system, eyes, endocrine system, and bones. People with this syndrome are particularly prone to developing a common and usually non-life-threatening form of non-melanoma skin cancer. About 10% of people with the condition do not develop basal-cell carcinomas (BCCs).
Skin cancers are cancers that arise from the skin. They are due to the development of abnormal cells that have the ability to invade or spread to other parts of the body. There are three main types of skin cancers: basal-cell skin cancer (BCC), squamous-cell skin cancer (SCC) and melanoma. The first two, along with a number of less common skin cancers, are known as nonmelanoma skin cancer (NMSC). Basal-cell cancer grows slowly and can damage the tissue around it but is unlikely to spread to distant areas or result in death. It often appears as a painless raised area of skin, that may be shiny with small blood vessels running over it or may present as a raised area with an ulcer. Squamous-cell skin cancer is more likely to spread. It usually presents as a hard lump with a scaly top but may also form an ulcer. Melanomas are the most aggressive. Signs include a mole that has changed in size, shape, color, has irregular edges, has more than one color, is itchy or bleeds.
Greater than 90% of cases are caused by exposure to ultraviolet radiation from the Sun. This exposure increases the risk of all three main types of skin cancer. Exposure has increased partly due to a thinner ozone layer. Tanning beds are becoming another common source of ultraviolet radiation. For melanomas and basal-cell cancers exposure during childhood is particularly harmful. For squamous-cell skin cancers total exposure, irrespective of when it occurs, is more important. Between 20% and 30% of melanomas develop from moles. People with light skin are at higher risk as are those with poor immune function such as from medications or HIV/AIDS. Diagnosis is by biopsy.
Decreasing exposure to ultraviolet radiation and the use of sunscreen appear to be effective methods of preventing melanoma and squamous-cell skin cancer. It is not clear if sunscreen affects the risk of basal-cell cancer. Nonmelanoma skin cancer is usually curable. Treatment is generally by surgical removal but may less commonly involve radiation therapy or topical medications such as fluorouracil. Treatment of melanoma may involve some combination of surgery, chemotherapy, radiation therapy, and targeted therapy. In those people whose disease has spread to other areas of their bodies, palliative care may be used to improve quality of life. Melanoma has one of the higher survival rates among cancers, with over 86% of people in the UK and more than 90% in the United States surviving more than 5 years.
Skin cancer is the most common form of cancer, globally accounting for at least 40% of cases. The most common type is nonmelanoma skin cancer, which occurs in at least 2-3 million people per year. This is a rough estimate, however, as good statistics are not kept. Of nonmelanoma skin cancers, about 80% are basal-cell cancers and 20% squamous-cell skin cancers. Basal-cell and squamous-cell skin cancers rarely result in death. In the United States they were the cause of less than 0.1% of all cancer deaths. Globally in 2012 melanoma occurred in 232,000 people, and resulted in 55,000 deaths. White people in Australia, New Zealand and South Africa have the highest rates of melanoma in the world. The three main types of skin cancer have become more common in the last 20 to 40 years, especially in those areas which are mostly Caucasian.
Nevoid basal cell carcinoma syndrome (NBCCS), also known as Gorlin syndrome, is an autosomal dominant cancer syndrome in which the risk of basal cell carcinoma is very high. The disease is characterized by basal cell nevi, jaw keratocysts and skeletal abnormalities. Estimates of NBCCS prevalence varies, but is approximately 1 in 60000. The presence of basal cell carcinoma is much higher in white than black individuals; 80% and 38%, respectively. Odontogenic keratocysts are found in approximately 75% of individuals with the disease and often occur early in life. The most common skeletal abnormalities occur in the head and face, but other areas are often affected such as the rib cage. The causative genetic mutation of this disease occurs in the PTCH gene, and the product of PTCH is a tumor suppressor involved in cell signaling. Although the exact role of this protein in NBCCS is not known, it is involved in the hedgehog signaling pathway, known to control cell growth and development.
Basal-cell carcinoma is a common skin cancer and occurs mainly in fair-skinned patients with a family history of this cancer. Sunlight is a factor in about two-thirds of these cancers; therefore, doctors recommend sunscreens with at least SPF 30. However, a Cochrane review examining the effect of solar protection (sunscreen only) in preventing the development of basal-cell carcinoma or cutaneous squamous cell carcinoma found that there was insufficient evidence to demonstrate whether sunscreen was effective for the prevention of either of these keratinocyte-derived cancers. The review did ultimately state that the certainty of these results were low, so future evidence could very well alter this conclusion. One-third occur in non-sun-exposed areas; thus, the pathogenesis is more complex than UV exposure as "the" cause.