Oncologists, in turn, are physicians who treat people with cancer.
Unlike benign conditions or tumors, there are several factors that make a cancer cell a cancer cell.
There are hallmarks of cancer that differentiate it from benign conditions.
Andrei Orlov / Istockphoto.com / Stock
Cancer cellsoften lack sticky substances known as adhesion molecules that keep the cells in place.
This allows the cells to spread (metastasize) to other regions of the body.
Types
There are many types of cancer as well as health professionals who treat the disease.
Oncologists
There are three primary types ofoncologistsor physicians who treat people with cancer.
There are also many subspecialties of oncology.
One term that confuses many people is “invasive cancer.”
Many epithelial tumors begin as an area of abnormal tissue (dysplasia).
This can progress tocarcinoma-in-situor CIN.
When cells spread beyond the basement membrane, the abnormality is then considered invasive cancer.
Mutations can arise due to exposures tocarcinogensin the environment or due to byproducts of the normal metabolism of cells.
Hereditary mutations (such as BRCA mutations) can also predispose a person to develop cancer.
It’s important to distinguish hereditary (germline) mutations from acquired (somatic) mutations.
Most mutations responsible for cancer arise after birth.
The fact that these mutations accumulate over time is the reason why cancer becomes more common as we age.
In some cases, however, a combination of hereditary and acquired mutations is responsible.
Epigenetics, or non-permanent changes to genes, is also important in the initiation of cancer.
Some of these include:
Risk Factors
There are a number of risk factors for cancer.
These risk factors do not necessarily cause cancer, but are associated with an increased risk.
Fortunately, several of these are avoidable, at least to some degree.
In fact, some cancers may even be preventable with vaccinations.
Risk factors for cancer include:
Age
For many types of cancer, the risk increases with age.
This makes sense when considering the causes above and the accumulation of mutations.
Environmental Exposures
A number of environmental exposures have been linked to cancer.
Examples include:
Immunization against hepatitis B and HPV is now available.
Genetics
Genetics are important in many cancer types.
A number of medications, especially immunosuppressive medications, have been associated with a higher risk of cancer.
Blood Tests
Depending on the jot down of cancer, blood tests may raise suspicion.
For example, a very high white blood cell count may raise suspicion about possible leukemia.
There are also a number of tumor markers that may be increased with different cancers.
Imaging
Imaging tests are frequently used in the diagnosis of cancer.
This includes tests such as:
Procedures
Procedures are also frequently used when diagnosing cancer.
Staging
Once a cancer is diagnosed, in many cases staging is done.
Staging is a critical step with many tumors for define the best treatment options.
Screening
We currently havecancer screening testsfor a number of different cancers.
Some of these include:
Genetic screening may also be done to look for a hereditary predisposition to cancer.
One of the most important factors when talking about treatment is to look at the goal of treatment.
In some cases, treatments are used in attempt to cure a cancer.
In other cases, it’s hoped that treatment will extend life.
It is the mainstay of treatments for tumors such as breast cancer.
This therapy used high doses of radiation concentrated in a small area of tissue.
It is also being used more frequently to treat areas of metastases from a number of tumors.
Chemotherapy
Chemotherapyuses cytotoxic drugs that kill cells that are rapidly dividing.
Targeted Therapy
Targeted therapies are treatments that target specific pathways in the growth of a cancer.
The growth ofprecision medicinehas come with learning about these pathways and finding ways to intervene.
Unfortunately, cancers often become resistant to these treatments in time.
Supportive Care
Supportive treatments are also extremely important in treating cancer.
The other major area is that of survivorship.
Miller KD, Nogueira L, Mariotto AB, et al.Cancer treatment and survivorship statistics.
CA: A Cancer Journal for Clinicians.
National Cancer Institute.Risk factors.
American Cancer Society.Cancer facts and figures.
Niederhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE.Abeloff’s clinical oncology.
Philadelphia, PA: Elsevier.
Schiller JT, Lowy DR.Virus infection and human cancer: an overview.Recent Results Cancer Res.2014;193:1-10. doi:10.1007/978-3-642-38965-8_1
