Cancer characteristics and its causes
Department of Biotechnology, Vellore Instititu of technology, Tamil Nadu,600032, India
- Corresponding Author:
- Gopinadh G
Vellore Institute of technology
Tamil Nadu,600032, India
Received: 07/01/2015; Revised: 07/02/2015; Accepted: 17/02/2015
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Cancer is a state of an abnormal growth of cells which tend to proliferate in an uncontrolled way. Cancer is not just one disease, it is group of more than 100 different and distinctive diseases characterized by uncontrollable cell growth, body’s cells begin to divide without stopping and spread into surrounding tissues. Cancer is ultimately the result of cells that uncontrollably grow and do not die. Usually, Normal cells in body follow an orderly path of growth, division, and death. Programmed cell death is called apoptosis [1,2], and when cell death process breaks down, cancer begins to form. Unlike regular cells, cancer cells do not experience apoptosis and instead continue to grow and divide, as cells become more and more abnormal, old or damaged cells survive when they should die, and new cells  form when they are not needed. These extra cells can divide without stopping and may form growths called tumors (masses of tissue).
Cancerous tumors are malignant, which means they can spread or invade into nearby tissues, as these tumors grow, some cancer cells can break off and travel to distant places in the body through the blood or the lymph system  and form new tumors far from the original tumor .
Differences between Cancer Cells and Normal Cells
Cancer cells differ from normal cells in many ways, are as follows:
1. Growth: Normal cells stop growing (reproducing) when enough cells are present, but in the case of cancer cells, these cells don’t stop growing when there are enough cells present, thus forming a tumor.
2. Communication: Cancer cells don’t interact with other cells (as normal cells). Normal cells respond to signals sent from other nearby cells and they stop growing. Cancer cells do not respond to these signals.
3. Cell repair and cell death: Normal cells are either repaired or die (apoptosis) when they are damaged or get old. Cancer cells are either not repaired or do not undergo apoptosis.
4. Stickiness: Normal cells secrete substances that make them stick (in group). Cancer cells fail to make these substances, and can travel to locations nearby or to distant regions in the body (through the bloodstream or lymph channels).
5. Ability to Metastasize (Spread): Normal cells stay in the area of the body where they belong. Cancer cells (as they lack the adhesion molecules that cause stickiness) are able to travel to other regions of the body. Once they reach a new region they begin to grow (forming tumors far removed from the original tumor) [6-8].
6. Appearance (Under microscope): Normal cells and cancer cells may look differently. Cancer cells often exhibit much more variability in cell size, larger or smaller than normal. In addition, cancer cells often have an abnormal shape, both of the cell and nucleus. The nucleus (contains excess DNA) appears larger and darker. Cancer cells often have an abnormal number of chromosomes that are arranged in a disorganized manner.
7. Rate of growth: Normal cells reproduce themselves and then stop when required cells are produced. Cancer cells reproduce rapidly before the cells have a chance to mature.
8. Maturation: Normal cells mature. Cancer remain immature.
9. Evading the immune system: When normal cells become damaged, the immune system (via lymphocytes) identifies and removes those damaged cells. Cancer cells can trick the immune system to grow into a tumor (by escaping detection or by secreting chemicals that inactivate immune cells).
10. Functioning: Normal cells perform their respective function that they are meant to perform, whereas cancer cells may not be functional.
11. Blood supply: Normal cells undergo a process called angiogenesis (cells attract blood vessels to grow and feed the tissue) as part of normal growth and development and when new tissue is needed to repair damaged tissue. Cancer cells undergo angiogenesis even when growth is not necessary.
Causes of Cancer
Tobacco: 80% to 90% of lung cancer cases occur in smokers. Smoking has been a contributory factor in cancers of upper respiratory tract , esophagus , larynx, bladder, pancreas and as well as liver , stomach, breast, and kidney .
Alcohol: Excessive consumption of alcohol , in combination with tobacco significantly increases the chances of liver , mouth, pharynx, larynx, and esophageal  cancers.
Diet: Excessive intake of fat (leading to obesity) has been associated with cancers of the breast, colon, rectum, pancreas, prostate, gall bladder, ovaries, and uterus.
Sexual and reproductive behavior: Having too many sex partners and becoming sexually active early has been shown to increase chances of contracting human papillomavirus (which is sexually transmitted) cause cancer of the cervix. In addition, women who don't have children or have children late in life have an increased risk for ovarian and breast cancer.
Infectious agents: approximately 15% of the world's cancer deaths are caused by viruses [16-19], bacteria  and parasites. The most common cancer-causing pathogens and the cancers associated with them are shown in table below.
Family history: cancers like breast, colon, ovarian [21,22] and uterine recur generation after generation in some families (linked to certain genes).
Occupational hazards: certain occupational hazards account for 4% of overall cancer deaths. (Leukemia [23-25] with glue and varnish workers; liver cancer with PVC manufacturers; and lung, bone and bone marrow cancer [26-28] with radiologists and uranium miners)
Environment: Radiation [29,30] (sources are x rays, radon gas, and ionizing radiation [31,32] from nuclear material) causes 1-2% of all cancer deaths. Ultra-violet radiation from the sun is responsible for the majority of melanoma [33-35] deaths
Pollution: 1% of cancer deaths are due to air, land, and water pollution. Chlorination [36,37] of water may have small rise in cancer risk . The main danger from pollution  occurs when dangerous chemicals from the industries escape into the environment  (surrounding to them).
Approximately 40% of cancer deaths [41-46] were due to tobacco and excessive alcohol use and in addition to that one-third of the deaths were related to diet and nutrition . Many of the one million skin [48,49] cancers were due to over-exposure to ultraviolet radiation from the sun rays.
- Jayakiran M (2015) Apoptosis-Biochemistry: A Mini Review. J Clin Exp Pathol 5:205.
- Shirakami Y, Sakai H, Kubota M, Kochi T, Shimizu M (2015) Dietary Phytochemicals as Cancer Preventive Agents: Efficacy and Mechanisms. J Bioanal Biomed 7: 040-049.
- Sukhotnik I, Rofe A (2014) Germ Cell Apoptosis: Clinical Implications. Andrology 3:122.
- Zaini R, Small SLH, Cross NA, Le Maitre CL (2015) Differential Interactions of Falcarinol Combined with Anti-Tumour Agents on Cellular Proliferation and Apoptosis in Human Lymphoid Leukaemia Cell Lines. J Blood Disorders Transf 6:258.
- Luo LG, Luo JZQ (2015) Anti-apoptotic Effects of Bone Marrow on Human Islets: A Preliminary Report. J Stem Cell Res Ther 5:274.
- Klerkx WM, Sie-Go DMDS, Daan NMP, Witteveen PO, Verheijen RHM (2013) A Lymphatically Metastasized Perivascular Epithelioid Cell Tumor from the Uterus. Gynecol Obstet 3:170.
- Aoyagi K, Kouhuji K, Kizaki J, Isobe T, Hashimoto K, et al. (2013) A Study of Gastric Cancer Cases with Liver Metastasis. J Gastroint Dig Syst S12:017
- Fukui A, Ushijima K, Nishio S, Fujiyoshi K, Kage M (2013) Long Survival in a Rare Case of Hepatocellular Carcinoma that Metastasized to the Ovary: A Case Report. J Clin Case Rep 3:249.
- Evans SD, Sheffer CE, Bickel WK, Cottoms N, Olson M, et al. (2015) The Process of Adapting the Evidence-Based Treatment for Tobacco Dependence for Smokers of Lower Socioeconomic Status. J Addict Res Ther 6:219.
- Twarozek AM, Eggert T, Puca ZG, DuPont N, Erwin DO, et al. (2015) Promoting Tobacco Cessation in a Community-Based Women’s Health Centre. J Women’s Health Care 4:225.
- Bertani AL, Garcia T, Minamoto SET, Godoy I (2015) Tobacco in Adolescence: Importance to Knowledge the Health Hazards and Preventive Measures. J Addict Res Ther 6:218.
- Wasim, Z. Md. and Ayya Raju, M (2012) altered-electron-transport-activities-in-the-thylakoid-membranes-of-maize-leaves-under-copper-ion,IJPAES 2: 270-275
- Razvodovsky YE (2015) The Differential Effects of Beverage Type on Alcohol Poisoning Mortality in Russia. J Alcohol Drug Depend 3:200.
- Håkansson A , Medvedeo A (2015) Role of Medication and Background Variables in Dropout from Opiate Withdrawal Treatment – A Retrospective Chart Review. J Alcohol Drug Depend 3:199.
- Yildirim AE, Ocal S, Ocal R, Altun R, Korkmaz M, et al. (2015) An Unexpected Cause of Hyperactive Delirium in Patients with Decompensated Nonalcoholic Cirrhosis. J Gastrointest Dig Syst 5: 261.
- Hanna JRA (2015) Expression of CD95 in Acute Lymphocytic Leukemia (ALL) in Egyptian Children before and after Treatment. J Blood Disorders Transf 6: 250.
- Takemoto S (2014) CD25+, CD30+Adult T-Cell Leukemia/Lymphoma cells, Virus-Infected Cells or Regulatory T-Cells?. J Hematol Thrombo Dis 2:175.
- Pandey MK, Rastogi S, Kale VP, Gowda T, Amin SG (2014) Targeting CXCL12/CXCR4 Axis in Multiple Myeloma. J Hematol Thrombo Dis 2:159.
- Achard C, Boisgerault N, Delaunay T, Tangy F, Grégoire M, et al. (2015) Induction of Immunogenic Tumor Cell Death by Attenuated Oncolytic Measles Virus. J Clin Cell Immunol 6:291.
- AlSaeedi MH (2014) 45 Years Old Male Patient with Malignant Melanoma of the Lower Lip. Pigmentary Disorders 1:i102
- Phunsawat A, Tuchinda L, Somboonviboon W (2012) Plasma Phenytoin Levels and Incidence of Seizure in Patients Undergoing Craniotomy for Supratentorial Brain Tumors. J Anesth Clin Res 3:255
- Abdelmeged A, Abdalah A, Mahran A, Gamal A, Elgendy E (2015) A Comparative Study between GnRH Antagonist and Long Agonist Protocols in Patients with Polycystic Ovarian Syndrome (PCOS) Undergoing in vitro Fertilization. JFIV Reprod Med Genet 3:137.
- Rawal R, Patel S, Shah K, Mundra A, Umrania V, et al. (2015) Genomic Sequence Analysis of Chromosomal Translocation Breakpoints in Leukemia: “A Computational Approach”. Biomedical Data Mining 3:107.
- Patriarca A, Salutari P, Di Zacomo S (2015) The Impact of Molecular Genetic in Acute Myeloid Leukemias. J Blood Disorders Transf 6:252.
- Singal R, Narang D, Dang R, Bakshish K, Garg P (2015) Awareness and Follow up of Breast Cancer in a Young Female. J Health Med Informat 6:181.
- Hashimoto R, Nakamura K, Itoh S, Daida H, Nakazato Y, et al. (2015) Bone Marrow-Derived Regenerated Smooth Muscle Cells Have Ion Channels and Properties Characteristic of Vascular Smooth Muscle Cells. J Stem Cell Res Ther 5:257.
- Baoxia Z, Jinsheng Z, Meimei Du, Xiaoya W, Wei Li (2015) Effect of PNS on Mobilizing Bone-marrow Mesenchymal Stem Cells in Rats. Nat Prod Chem Res 3:161.
- Shipounova I, Petinati N, Bigildeev A, Drize N, Sorokina T, et al. (2014) Properties of the Bone Marrow Stromal Microenvironment in Adult Patients with Acute Lymphoblastic Leukemia before and After Allogeneic Transplantation of Hematopoietic Stem Cells. J Leuk 2:153.
- Bechet D, Frochot C, Vanderesse R, Barberi-Heyob M (2012) Innovations of Photodynamic Therapy for Brain Tumors: Potential of Multifunctional Nanoparticles. J Carcinogene Mutagene S8:001.
- Bond RT, Christopoulos S, Tamilia M (2015) Incidental Growth Hormone Producing Pituitary Adenoma in a Case of Recurrent Nodular Goiter and Thyroid Carcinoma. J Clin Trials 5:212.
- Gober MD, Seykora JT (2015) Characterization of the Murine K14-FynY528F Transgenic SCC Model Provides Novel Therapeutic Insights. Med chem 5: 149-151.
- Katke RD (2015) Huge Mucinous Cystadenocarcinoma with Mucocele of Appendix in a Postmenopausal Woman: Extremely Rare Case Report with Review of Literature. Gynecol Obstet (Sunnyvale) 5:279.
- Patriarca A, Salutari P, Di Zacomo S (2015) The Impact of Molecular Genetic in Acute Myeloid Leukemias. J Blood Disorders Transf 6:252.
- Wolnicka-Glubisz A (2014) Role of Mc1r in UV-Induced Melanoma in Animal Models. J Carcinog Mutagen 5:200.
- Altunay IK (2015) Promote Melanoma Prevention through Sun Protection. Pigmentary Disorders 2: 156.
- Ichihara H, Yamasaki S, Hino M, Ueoka R, Matsumoto Y (2015) Hybrid Liposomes inhibit the Growth and Angiogenesis in Human Breast Cancer Model. J Carcinog Mutagen 6:207.
- Jalbert E, DiGiovanni R, Worth R (2015) Stage-IV Kaposiâ€™s Sarcoma During Abatacept Therapy: A Case Report. Rheumatology (Sunnyvale) 5:144.
- Asensio-Sanchez VM, Cano-Suarez M (2015) Isolated Ocular Relapse in Acute Lymphoblastic Leukemia. J Clin Case Rep 5: i103.
- Zhang X (2012) Which Drinking Water Disinfection Process Generates the Least Toxic DBP Mixture: Chlorination, Chloramination, Ozonation, or Chlorine Dioxide Treatment? J Civil Environment Engg 2:e105.
- Ziaei A, Tanhaei AP, Mazrouei S, Kharaji M, Keyhanian K et al. (2015) Livin Expression by Semi-quantitative Immuno-flourecent Staining in Hodgkin Lymphoma: A Promising Marker or a Leading Role in Pathogenesis?. J Cytol Histol 6:299.
- Maraveyas A, Muazzam IA (2015) Thromboprophylaxis in Pancreatic Cancer: Why isnâ€™t Prime Time Here Compared to Multiple Myeloma?. Pancreat Disord Ther 5:e137.
- Bullard TB, Falk JL, Smith MS, Wegst A, Roseman DH et al. (2014) Cumulative Radiation Exposure from Medical Imaging in Two Hospital Systems â€“ Implications for Medical Record Portability. Emerg Med (Los Angel) 4:211.
- Aly R, Yousef A, Elbably O (2014) Association of ABO Blood Group and Risk of Breast Cancer. J Blood Disorders Transf 5:241.
- Gandhi S, Gupta N (2015) Brentuximab Vedotin and Diffuse Large B-cell Lymphoma. J Hematol Thrombo Dis 3:183.
- Thrombocythemia and Chronic Myeloid Leukemia Compared to BCR/ABL-Negative Thrombocythemia in Essential Thrombocythemia and Polycythemia Vera. J Hematol Thrombo Dis 3: 192.
- Acharya AS, Kulkarni RV, Patrikeand SB, SG Nair (2015) Proliferative Myositis: A Rare Pseudosarcoma in Children. J Clin Case Rep 5:487.
- Christelle L, Marie L, Luc M, Marie-Pierre C, Perrine M, et al. (2015) Molecular Reclassification in Pediatric Osteosarcomas at Surgical Resection is a Potential Helpful Prognostic Marker. J Mol Biomark Diagn 6:229.
- Elshimi E, Darwish HA, Abdelaal EM, Sherify ME, Morad W, et al. (2013) Switch On/Off of Hepatitis C and Major Chronic Skin Diseases in Egyptian Patients: Study of Prevalence, the Impact of, Gender, Viral Load and the Severity of Liver Disease. J Liver 2:121.