Cancer Development
Art & Research: Grace Noonan
Further Reading Literature: Grace Noonan
Cancer Development
What is cancer?
Cancer is the result of increased cell division, often following a mutation in DNA. Tumors have a multi-step development pathway that may or may not affect the surrounding tissue depending on whether it’s benign or malignant (CancerQuest).
Benign tumors, like the occasional skin wart, stays within the area it initially grew, not posing a great threat to your immediate health.
However, malignant tumors are much more dangerous because they can invade the tissues surrounding it and travel throughout the body (this is termed as a “metastasized tumor”) (NCBI).
Where do tumors come from?
There are “initiators” that “initiate” tumor development by altering the DNA through mutations. For example, the correlation between smoking and lung cancer is linked to benzopyrene, which is an initiator of tumors.
In addition, certain bacteria and viruses can initiate mutations in DNA, such as HPV. Once the DNA has been tampered with, it’s possible for the cell to proliferate without the barriers that stop normal cells from dividing. This is the “promotion” phase and there are non-mutagenic agents/”Promoters” that aid in proliferation such as mitogens, cytotoxins, and the inflammatory response (Potter).
Where do tumors come from?
There are “initiators” that “initiate” tumor development by altering the DNA through mutations. For example, the correlation between smoking and lung cancer is linked to benzopyrene, which is an initiator of tumors.
In addition, certain bacteria and viruses can initiate mutations in DNA, such as HPV. Once the DNA has been tampered with, it’s possible for the cell to proliferate without the barriers that stop normal cells from dividing. This is the “promotion” phase and there are non-mutagenic agents/”Promoters” that aid in proliferation such as mitogens, cytotoxins, and the inflammatory response (Potter).
Step 1 of cancer development: hypertrophy
The size of normal cells increase while maintaining their normal organization.
Step 2 of cancer development: hyperplasia
The altered cells increase in number and start to look more abnormal compared to the original tissue. The organization of cells begins to fall apart here.
Step 3 of cancer development: dysplasia/carcinoma in situ
At this point in development, the cells are distinctly abnormal, less differentiated, and more proliferative. This is due to the initiators that created mutations in the DNA and promoters who are beginning to allow tumor growth.
Cells in this stage are not considered to be malignant (cancerous) because they have not crossed the basal lamina/basement membrane and invaded surrounding tissue. The term “Carcinoma in situ ”(Cancer cells in place) refers to dysplastic tissue that is one step further to becoming invasive so it is considered malignant although it has not crossed the basal lamina (CancerQuest).
Step 4 of cancer development: neoplasia
These tumors are officially cancerous and have invaded the outside tissue and/or metastasized to other areas by utilizing the bloodstream.