Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
Dr. Balentine received his undergraduate degree from McDaniel College in Westminster, Maryland. He attended medical school at the Philadelphia College of Osteopathic Medicine graduating in1983. He completed his internship at St. Joseph's Hospital in Philadelphia and his Emergency Medicine residency at Lincoln Medical and Mental Health Center in the Bronx, where he served as chief resident.
Cancer is the uncontrolled growth of abnormal cells anywhere
in a body. The abnormal cells are termed cancer cells, malignant cells, or tumor
cells. Many cancers and the abnormal cells that compose the cancer tissue are
further identified by the name of the tissue that the abnormal cells originated
from (for example, breast cancer, lung cancer, colon cancer). Cancer is not
confined to humans; animals and other living organisms can get cancer. Below is
a schematic that shows normal cell division and how when a cell is damaged or
altered without repair to its system, the cell usually dies. Also shown is what
can occur when such damaged or unrepaired cells do not die and become cancer
cells and proliferate with uncontrolled growth; a mass of cancer cells develop.
Frequently, cancer cells can break away from this original mass of cells, travel
through the blood and lymph systems, and lodge in other organs where they can
again repeat the uncontrolled growth cycle. This process of cancer cells leaving
an area and growing in another body area is termed metastatic spread or
metastatic disease. For example, if breast cancer cells spread to a bone (or
anywhere else), it means that the individual has metastatic breast cancer.
There are over 200 types of cancers; most can fit into the following
categories according to the National Cancer Institute:
Carcinoma: Cancer that begins in the skin or in tissues that line or
cover internal organs
Sarcoma: Cancer that begins in bone, cartilage, fat, muscle, blood
vessels, or other connective or supportive tissue
Leukemia: Cancer that starts in blood-forming tissue such as the
bone marrow and causes large numbers of abnormal blood cells to be produced and
enter the blood
The incidence of
cancer and cancer types are influenced by many factors such as age, sex, race,
local environmental factors, diet, and genetics. Consequently, the incidence of
cancer and cancer types vary depending on these variable factors. For example,
the World Health Organization (WHO) provides the following general information
about cancer worldwide:
Cancer is a leading cause of death worldwide. It
accounted for 7.4 million deaths (around 13% of all deaths) in 2004 (statistics
published in 2009).
Lung, stomach, liver, colon, and breast cancer cause the
most cancer deaths each year.
Deaths from cancer worldwide are projected to
continue rising, with an estimated 12 million deaths in 2030.
Different areas of
the world may have cancers that are either more or less predominant then those
found in the U.S. One example is that stomach cancer is often found in Japan,
while it is rarely found in the U.S.
The objective of this article is to introduce
the reader to general aspects of cancers. It is designed to be an overview of
cancer and cannot cover every cancer type. This article will also attempt to
help guide the reader to more detailed sources about specific cancer types.
Questions to Ask Your Doctor After a Cancer Diagnosis
Medical Author: Melissa Conrad Stöppler, MD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR
1. What type of cancer do I have? How was the diagnosis established? Are
there any other diagnostic tests that could provide useful information?
2. What is the extent of spread (stage) of the cancer? To what extent does
the stage of the cancer influence treatment?
3. Should I get a second opinion? Can you recommend someone who could provide
a second opinion?
4. What are the treatment options? How do you decide among the different
options? Are there investigational treatments or clinical trialsavailable for
this type of cancer?
5. How much is known about the type of cancer that I have? How common is this
cancer and the type of treatment I am to receive? Would I be better off being
treated in a more specialized center?
6. What is your experience in treating this type of cancer? What have been
the results of this treatment, in your experience?
7. How much time should I take to make a decision about treatment?
8. What is the goal of treatment (for example, to completely eradicate the
tumor, to reduce the size of the tumor, to alleviate symptoms)?
9. How often must I receive treatment? How will I feel after treatment? If
there will be side effects of treatment, are there any medications that can help
prevent or lessen the severity of these? How soon can I return to normal
activities after treatment?
Flexible sigmoidoscopy is a procedure that allows your doctor to examine the rectum and the lower (sigmoid) colon. The flexible sigmoidoscope is a flexible tube 60 cm long and about the thickness of your "...