Introduction
Early diagnosis provides the best hope many have in beating cancer. Unfortunately, this is not the end of the fight for many cancer patients. Primary tumors may be successfully treated early, only to later discover they have metastasized to other areas of the body.
The common medical definition of metastasis is:
The spread of cancer from one part of the body to another.
Tumors formed from cells that have spread are called “secondary
tumors” and contain cells that are like those in the original (primary)
tumor.
This definition could be the reason why early treatment of a primary tumor is ineffective against metastatic tumor cells. As the definition suggests, the accepted model for the metastasis of tumor cells is through clonal evolution, where secondary tumors have similar genomes to the primary tumor. Recent studies suggest, however, that this may not be accurate.
Significant divergence between primary and secondary tumors in renal cell metastases and breast metastases has been discovered in recent studies. An alternative model, one of a parallel evolution, would explain why therapies aimed at primary tumors are unsuccessful against metastatic cells.
Further research on this alternative model could lead to therapies that not only target the properties of the primary tumor but also those of the secondary tumor and save many from the burden of fighting cancer again.
Methods
This study took 386 breast cancer patients and split them into two groups. M0, patients showing cells with no metastasis, and M1 patients, those that showed metastasis and performed a genomic analysis, or comparative genomic hybridization (CGH) of the Cytokeratin...
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... tumor cells that could potentially disseminate, mutate, change, and grow into another tumor. More emphasis needs to be put on the development of disseminated cells because the changes in their growth cannot be reflected by the genomic data obtained from the primary tumor data; as a result, they can not be dealt with in the same manner.
The main idea of this study is to underscore: "the need to validate potential cellular targets for adjuvant and systemic therapies on disseminated cancer cells directly"( Cancer Cell: July 2003).
The paper that is being discussed is :
Gray, J.W., Evidence emerges for early metastasis and parallel evolution of primary and metastatic tumors. Cancer Cell July 2003.
Schmidt-Kittler, O. et al., From latent disseminated cells to overt metastasis: genetic analysis of systemic breast cancer progression. PNAS 100, 7734 (2003).
The concept of tumor heterogeneity being related to the course of the disease and clinical outcome in cancer patients draws additional attention in the era of personalized medicine (1). Current cancer treatment strategies are based on the site of origin of the primary tumor. However, it was shown that tumors developed from distinct cell types differ in their prognosis and response to cytotoxic therapies (2...
U.S. Congress, Office of Technology Assessment. 1990. Unconventional Cancer Treatments, OTA-H-405. Washington, D.C.: U.S. Government Printing Office.
Tumours that are treated at early stages have a higher chance to heal. Besides that, lesions that are well differentiated and that are superficial also have a better prognosis.
The acquisition of an immortalized proliferative potential is very important for human tumors because, otherwise, the tumors will not grow in number nor will they metastasize. Mutations in progenitor cells would not be transmitted too far as they have limited replication and proliferation ability. Thus, the growth of the tumors will be limited. Hence, if there is even a very small population of cells with the ability to proliferate continuously, there will be a source for productions of more cells for the tumor. Clonogenic assays have shown that, though most cells in a tumor have a limited ability to proliferate, a subset of cancer cells exist in these tumors that continuously proliferate and give rise to new tumors on transplantation.
Chemotherapy is the treatment of a tumor with chemical agents to reduce mass or eradicate a tumor completely. There are certain mechanisms by which chemotherapy inhibits cancer. The first mechanism is cell death by cytotoxicity. Some chemical agents in certain amounts are toxic to cells. The cells die due to the toxic...
..., while a cell undergoes cell cycle, when a cell comes in contact with another cell, it stops reproducing. However, cancer cells continue to duplicate repeatedly until there is a mass of cells or a tumor to form (see figure 9). Lastly, in cell division when there is a mutation or abnormality in the DNA, a normal cell stops dividing. However, a cancerous cell will continue to duplicate and form mutations (“Cell Biology and Cancer”). Also, cancer cells are harmful because they grow and duplicate with complete disregard to the functions and limitations of the body (see figure 10). Also, cancerous cells have the ability to spread through metastasis throughout parts of the body through the bloodstream. In terms of similar behavior to that of normal cells, cancerous cells also duplicate, but at a very different rate ("Cancer Cells vs. Normal Cells: What's Different?").
Cancer is the term used to describe a group of diseases consisting of hundreds of ailments and although there exists so many different types of cancer, they all begin in a similar way. The body is made up of over a trillion cells, and cancer is the uncontrolled growth of malfunctioning cells in the body (Dawson, 1996). “Normal body cells grow, divide, and die in an orderly fashion. During the early years of a person’s life, normal cells divide faster to allow the person to grow. After the person becomes an adult, most cells divide only to replace worn-out or dying cells or to repair injuries” (American Cancer Society, 2012).
This statement is very true. When someone is diagnosed with cancer it starts a journey down a road that no one wants to travel on. In recent years, there have been countless trials and tests to find a cure for this terrible disease but none have been entirely successful. There are treatments on the market that can help and slow down the process, but they have various side effects that aren’t quite appealing. The best treatments in todays world include; Rituxan, Avastin, Revlimid, and Gleevec. They all have a different tasks and developments that take affects in the body but each remarkable in its own way.
According to the American Cancer Society, Each year, more than 200,000 women are diagnosed with breast cancer; furthermore Twelve percent of all women will contract the disease, and 3.5% of them will die from breast cancer (American Cancer Society, 2005). There are risk factors that may lead to breast cancer. There are 4 stages of breast cancer and several treatments, although treatments vary from types and stages of breast cancer. Breast cancer is the leading cause of death among women who are 40 to 55 years old (Breast Cancer, 2009).Cancer occurs when cells divide uncontrollably. It changes from a normal cell to cancerous cells that require gene alterations. Therefore the altered genes and the uncontrolled growth may lead to tumors. Tumors can be benign or malignant, benign tumors are not cancerous whereas malignant are cancerous. Benign tumors will not spread, but it can damage the tissues around it. Malignant tumors invade, damage, and destroy tissues that are nearby and can spread. When cancer cells break away from a malignant tumor and enter into the bloodstream, cancer can spread throughout the body. The cancer cells from breast cancer can be found in the lymph nodes under the arm. Cancer that spreads into other parts of the body; its still has the same name as the original cancer. So basically if you are diagnosed with breast cancer and it goes into your lungs, you still have breast cancer.
Healthy cells grow and divide in a way to keep your body functioning properly. But when a cell is damaged and becomes cancerous, cells continue to divide, even when new cells aren't...
According to Essentials of Human Disease and Conditions textbook, “The most important prognostic factors are age at diagnosis, size of the primary tumor, and the presence of tissue invasion or metastases. (American Cancer Society, 2012)
...of not only them but also other things. (Schulz 2005). Finally, in conclusion, gene mutations and alterations affect the body’s ability to control the rate of cell division, which therefore defines cancer the direct result of gene mutation. Cells affected by mutations are exposed to the reproduction into a tumour. Once the tumour expands in growth, more and more mutations occur in subsequent cell divisions and eventually become a dysplasia and instigates invasion into surrounding tissues. In simpler terms, the cancer is spread to other organs and parts of the body. Following this, metastasis occurs resulting in the cancer spreading through the person and/or animals blood stream and/or lymphatic systems and forms other colonies which thus secretes other harmful organelles, and also disrupts normal bodily function, and possibly leading to and eventuating in death.
Cancer develops when cells in a part of the body begin to grow out of
By harnessing this normal cell process, scientists hope to have found an effective way to combat cancer. Cancer is a disease that affects human somatic cells. It causes the cells to divide uncontrollably and form masses known as tumors. There are two different types of cancer tumors. Some tumors are benign, and other tumors are malignant.
For most, the primary fears associated with cancer are connected to the effects of treatments. If the patient is diagnosed when the cancer is still in the early stages, more than likely surgery is the appropriate treatment. However if the cancer has developed into an advanced stage, a more drastic treatment is necessary.