Open Questions: Cancer
See also: Cell biology --
Molecular biology and genetics
Cancer is getting broken down into more and more separate diseases as
we're able to subdivide the diagnostics and the genes associated with
them, but we're starting to take a different view of viewing cancer as
an overall disease, and we're looking at gene space where we think it
can be targeted to deal with cancer as a whole.
J. Craig Venter
Even though there is just one name, "cancer", it is sometimes helpful
to think of the name as referring
to a number of different diseases. Or, perhaps, if you wish,
it may be useful to think of "cancer" as a type of disease, and there are
a number of different varieties of the disease within the type.
In fact, there are about 200 anatomically different types of cancer. And
if further distinctions are made based on the underlying molecular
causes, it is estimated there may be 250,000 different types.
Indeed, each individual case of cancer may arise through a slightly different
sequence of cellular changes.
There are certainly many similarities among the diseases of this type.
- A cancer generally involves the unchecked and harmful proliferation
of cells of a particular kind, such as cells in the skin, lungs, breast,
or prostate gland.
- This unchecked proliferation always results from damage to cellular
DNA, which becomes unable to keep normal control over cell division.
- Cells that have become cancerous usually cease to be able to perform
their normal function in the body as a part of some specific organ type.
- Cancer becomes fatal either when the organ where it occurs ceases to
be able to perform its normal function, or when cancer cells "metastasize"
and spread their uncontrolled proliferation to other parts of the body.
At the same time, it is helpful to regard different types of cancer as
distinct diseases for various reasons:
- There are a number of different reasons that cellular DNA can be
damaged and hence lead to cancer. Different reasons usually apply to
different types of cells. In other words, there are different causes for
different types of cancer.
- The best available treatment for a partiuclar type of cancer usually
varies from one type to another, and depends on the specific way in which
cellular DNA has been damaged, as well as on physiological differences
between affected organs.
- Different types of cancer vary greatly in their propensity to
metastasize and hence in their degree of lethality.
- The physiological effects of cancer in different organs vary greatly,
and so lethality or other indirect effects can also vary greatly.
There are various ways to classify the different diseases which
are types of cancer. The most common way,
and perhaps the most useful to begin with, is simply by the part of
the body or the organ which is affected.
Here is a table of the most common types of cancer, further broken down
by estimated new cases and estimated deaths (in 2004), and even further
by sex. (The percentages refer to relative frequency in a particular
|Estimated new cases
|Prostate - 33%
||Breast - 32%
||Lung & bronchus - 32%
||Lung & bronchus - 25%
|Lung & bronchus - 13%
||Lung & bronchus - 12%
||Prostate - 10%
||Breast - 15%
|Colon & rectum - 11%
||Colon & rectum - 11%
||Colon & rectum - 10%
||Colon & rectum - 10%
|Urinary bladder - 6%
||Uterine corpus - 6%
||Pancreas - 5%
||Ovary - 6%
|Melanoma - 4%
||Ovary - 4%
||Leukemia - 5%
||Pancreas - 6%
|Non-Hodgkin lymphoma - 4%
||Non-Hodgkin lymphoma - 4%
||Non-Hodgkin lymphoma - 4%
||Leukemia - 4%
|Kidney - 3%
||Melanoma - 4%
||Esophagus - 4%
||Non-Hodgkin lymphoma - 3%
|Leukemia - 3%
||Thyroid - 3%
||Liver - 3%
||Uterine corpus - 3%
|Oral caviity - 3%
||Pancreas - 2%
||Urinary bladder - 3%
||Multiple myeloma - 2%
|Pancreas - 2%
||Urinary bladder - 2%
||Kidney - 3%
||Brain - 2%
|All other - 18%
||All other - 20%
||All other - 21%
||All other - 24%
American Cancer Society - Cancer Statistics Presentation 2004
Causes of cancer:
- Ionizing radiation
- UV radiation
- Genetic predispositions (oncogenes)
- Reactive oxygen species
- Environmental/dietary carcinogens
- Errors in DNA replication
- Failures in DNA damage detection and repair
- Problems with mitochondria and apoptosis
- (Onco)viruses, e. g. Rous sarcoma, HBV, HPV
- Bacteria (H. pylori)
- What makes environmental and dietary substances carcinogenic?
- At what points in the development of a cancer is the process
most easily interrupted?
- How do very large animals like elephants and whales avoid
- Are there blood tests which can detect cancer at an early
- What is the role of the immune system in dealing with cancer?
- Why is it so hard to develop therapeutic drugs to treat
cancer, even though we know so much about the signaling
pathways that facilitate cancer?
Open Directory Project: Cancer
- Categorized and annotated links. A version of this
list is at
Google, with entries sorted in "page rank" order. May also be
- Categorized site directory. Entries usually include
Sites with general resources
MedlinePlus: Cancers Topics
- MelinePlus provides links to many types of information on
almost every medical topic -- news, overviews, symptoms and
diagnosis, genetics, research, etc.
This page gives links to pages on specific types of cancer.
- A general portal for cancer-related information. Many links are
types of cancer. Other features include
news, discussion forums,
FAQs, and other services for patients and medical specialists.
National Cancer Institute
- This U. S. government site provides a huge mine of resources
on cancer, including
many overview articles,
information on clinical trials, and
general cancer information.
Plans and Priorities for Cancer Research
- This is the budget proposal of the U. S.
National Cancer Institute
for 2004. It has special emphasis on important areas of cancer
research. Similar but more recent information can be found in
the budget proposals for
New Scientist Special Report on Cancer
- Primarily offers links to many news articles from the past
several years of New Scientist magazine. But there are
also other features, including facts and figures, external links,
frequently-asked questions, and a short bibliography.
Nature Cancer Update
- Excellent portal/gateway for cancer research. Provides general
and specialist news on cancer research, and other services for
- "The Web resource for biologic oncology". Sponsored by
Compute Against Cancer
- Cooperative distributed computing project to assist in cancer
Intel-United Devices Cancer Research Project
- Another Cooperative distributed computing project to assist in
The Cancer Genome Atlas
- Web site of TCGA project of the U. S.
National Cancer Institue.
"The Cancer Genome Atlas (TCGA) is a comprehensive and
coordinated effort to accelerate our understanding of the
molecular basis of cancer through the application of genome
analysis technologies, including large-scale genome sequencing."
The Cancer Genome Project
- "The Cancer Genome Project is using the human genome
sequence and high throughput mutation detection techniques
to identify somatically acquired sequence variants/mutations
and hence identify genes critical in the development of
human cancers." Web site includes news, external links, lists
of publications, and databases of accumulated data, such as
Cancer Gene Census,
Catalog of Somatic Mutations in Cancer (COSMIC), and the
CGP Copy Number Analysis.
Cancer Prevention and Control
- Site maintained by the U. S.
Centers for Disease Control and
Prevention. Provides information on different types of cancer,
fact sheets, and some scientific articles.
Cancer Research UK - Science and Research
- Web pages of a UK organization that helps coordinate and
fund cancer research, part of the
Cancer Research UK site.
National Toxicology Program Report on Carcinogens
- This is the U. S. government's official list of known
carcinogens. See in particular the
10th Report on Carcinogens, which lists details of 228
substances "known" or "reasonably anticipated" to pose a
cancer risk. (Individual sections are in PDF format.)
American Institute for Cancer Research
- Home page of an organization which "supports
research into the role of diet and nutrition in the prevention
and treatment of cancer". It advocates a predominantly
plant-based diet and consuming more vegetables, fruits,
whole grains and beans. Further explanation of this position
is provided in the section of
general information on diet & cancer.
Memorial Sloan-Kettering Cancer Center
- Web site of a major cancer research and treatment center.
The site provides extensive information on all types of cancer,
genetics of cancer, and cancer risk reduction.
The Oral Cancer Foundation
- "The Oral Cancer Foundation is a national public service,
non-profit entity designed to reduce suffering and save lives
through prevention, education, research, advocacy, and support."
The site contains a lot of information pertaining to oral
and other cancers, especially
Surveys, overviews, tutorials
- Topic category from
- Article from
- Overview in several parts by Richard Conan-Davies.
Understanding Cancer Series
- A series of tutorials in slide format
on topics related to cancer, such as
molecular diagnostics, and
DNA's repair system studied in hopes of better cancer treatments
- July 2009 article about how problems in the cell's natural
systems for detecting and repairing damage to DNA can lead to
Can you catch cancer?
- January 2006 article at Guardian Unlimited about types of
infections that can cause cancer.
Biology of Cancer
- A ScienceWeek
"symposium" consisting of excerpts and summaries of
articles from various sources.
- Complete online textbook.
Part of the
Cancer Death -- Causes & Prevention
- Detailed survey by
Cancer: diet and physical activity's impact
- An informative article published by the
World Health Organization.
Genetic Tests May Reveal Source of Mystery Tumors
- March 2009 New York Times news feature about new
tests being developed to determine the origin of metastatic
Leukemia Cells Flash Fake Protein "ID" to Dupe the Immune System
- Short August 2009 Scientific American article
"A crucial protein on the surfaces of malignant cells shields
them from destruction, but it could also provide a new way to
Cancer Vaccine: Looking Beyond Tumor Size
- November 2008 Scientific American article.
"Proponents see hope in changing cancer vaccines' bad reputation."
What makes pancreatic cancer so deadly?
- August 2008 Scientific American "Ask the Experts" article
on the reasons why pancreatic cancer is so difficult to treat.
- December 2006 Scientific American Sidebar about the
experimental lung cancer vaccine Stimuvax.
- April 2005 Scientific American In Focus article, subtitled
"Eating vegetables seems to do little in warding off cancer."
New Light on Breast Cancer
- August 2002 Scientific American In Focus article, subtitled
"Laser light and thermal heat could help improve the accuracy
Cancer in the Crosshairs
- Brief September 2001 Scientific American article about
the new cancer drug Gleevec.
Breast Cancer: Knocking Out a Killer
- June 2001 Scientific American In Focus article, subtitled
"Test-tube studies have uncovered key facts about the breast cancer gene
BRCA1, but new animal models of the disease promise to reveal much more."
Solid Proof of Immunity against Cancer
- April 2001 Scientific American news article about how
the immune system can prevent tumor formation.
A New Skin Cancer Culprit
- February 2001 Scientific American news article about
a mutation implicated in squamous cell carcinoma.
How Breast Cancer Starts and Spreads
- February 2001 Scientific American new article about
how breast cancer starts when cells become able to avoid
New Target for Melanoma Treatment?
- January 2001 Scientific American news story about a
new gene found to be involved in the resistance of melanoma to
Do the telomeres in cancer cells shrink?
- January 2001 Scientific American "Ask the Experts" article.
Response by Jerry W. Shay.
Coffee Reduces Risk of Bladder Cancer
- December 2000 Scientific American news article about
epidemiological evidence that coffee may protect against bladder
cancer in smokers.
Clue to Cancer in Cell-Death Proteins
- October 2000 Scientific American news article about
proteins involved with apoptosis of T cells.
How close are we to developing an effective gene therapy
for treating cancer?
- October 1999 Scientific American "Ask the Experts"
Soy Estrogens: Too Much of a Good Thing
- June 2001 news article in Science News, about how
genistein, an isoflavone that is a chemical analog of
estrogen found in soy-based foods, seemed to promote cancer
Anticancer Protein Locks onto DNA
- May 2001 news article in Science News, about how
mutations of the BRCA1 gene lead to risk of breast cancer by
interfering with DNA repair function of the BRCA1 protein.
Silencing the BRCA1 gene spells trouble
- April 2000 news article in Science News about
how an epigenetic change (hypermethylation) interfers with the
promoter region for BRCA1, resulting in inhibition of BRCA1
Fused cells hold promise of cancer vaccines
- March 2000 news article in Science News about an
experimental cancer vaccine that uses tumor cells fused to
immune system cells.
Soy Slashes Cancer-fostering Hormones
- March 2001 news article in Science News, about how
large quantities of soy in a woman's diet reduces blood concentrations
of female sex hormones.
Progestin Adds to Breast Cancer Risk
- March 2000 news article in Science News, about how
hormone replacement therapy using estrogen and progestin may
raise the risk of breast cancer.
Is Your Stomach Bugging You?
- October 1999 news article in Science News, about
controversy over whether the benefits of Helicobacter pylori
outweigh the problems (stomach ulcers, cancer).
Nighttime illumination might elevate cancer risk
- October 1998 news article in Science News, about
a possible relationship among exposure to light, melatonin
production, and cancer.
Missing Enzyme Incites Cancer Debate
- October 1997 news article in Science News, about how
tumors can form from cells even of mice which are deficient in
Can a pineal hormone head off everything from breast cancer to aging?
- May 1995 news article in Science News, about possible
links between melatonin and various pathologies, including cancer.
Taking Aim at p53
- January 1999 news article from The Scientist.
"Researchers are targeting the tumor suppressor with vectors,
viruses, and small molecules."
Heartburn link to cancer
- April 2001 news article about how gastro-esophageal
reflux disease may be associated with esophageal cancer.
Enzyme can block tumour-feeding blood vessels
- December 2000 news article about discovery of an enzyme that
New cancer drug starves tumours
- October 2000 news article about a potential drug
(glutathionarsenoxide) to inhibit tumor angiogenesis.
New research links breast cancer to genetics
- October 2000 news article about discovery of a gene (CYP-17)
that may indicate increased risk of breast cancer.
Testicular cancer linked to male infertility
- September 2000 news article about discovery of a correlation
between infertility problems and risk for testicular cancer.
New targets to stop cancer growth
- August 2000 news article about genes in the blood vessels of
tumors that may lead to a way to inhibit tumor angiogenesis.
Drinking while smoking doubles lung troubles
- June 2000 news article about the discovery of an
association between the long term smoking and drinking habits
of lung cancer patients and mutations in the tumor-suppressing
New protein a natural defence against cancer
- April 2000 news article about a chemokine protein that can
slow tumor growth.
Skin cancer test gives early warning
- April 2000 news article about a genetic test that indicates
susceptibility to skin cancer.
Gene for testicular cancer found
- February 2000 news article about discovery of a gene on the X
chromosome that increases risk of testicular cancer.
Turning to Telomerase As Antisense Strategies Emerge,
Basic Questions Persist
- January 1999 news article in The Scientist about
the possibility of using antisense technology to reduce the
expression of telomerase in cancer cells.
More accurate test for cervical cancer
- December 1998 news article about a new test for cervical
cancer that uses antibodies to detect abnormal cells.
It's a Cell-Eat-Cell World
The Scientist, August 2011
- For more than 100 years, pathologists have observed cancer
cells engulfing other live cells, but scientists are only now
beginning to understand how it happens and what it means for
An Aspirin for your Cancer?
The Scientist, April 2011
- Can tumors - which can originate from, and often resemble,
chronically inflamed tissue - be curtailed using familiar
anti-inflammatory agents, without their side effects?
Taking Aim at Melanoma
Keith T. Flaherty
The Scientist, April 2011
- Understanding oncogenesis at the molecular level offers
the prospect of tailoring treatments much more precisely for
patients with advanced cases of this deadliest of skin cancers.
Epigenetic Changes in Cancer
The Scientist, March 2011
- The study of how covalent marks on DNA and histones
are involved in the origin and spread of cancer cells
is also leading to new therapeutic strategies.
Interfering with Cancer
Katherine Hyde; Paul Liu
The Scientist, January 2011
- MicroRNAs may drive the development of leukemia.
The Immune System vs. Cancer
Mark J. Smyth
The Scientist, November 2009
- The comeback of an old idea in immunology prompts a rethink
of cancer progression and approaches to treatment.
New Smoking Gun?
The Scientist, April 2010
- Teams come together to target the genes behind lung
cancer, but the hunt is far from over.
The Scientist, April 2009
- Breast cancer's genetic profile calls the cancer stem
cell hypothesis into question.
Do White Blood Cells Make Cancer Deadly?
Charles Q. Choi
Scientific American, January 2009
Could Our Own Proteins Be Used to Help Us Fight Cancer?
Pramod K. Srivastava
Scientific American, July 2008
New Breast Cancer Treatments Help Sufferers Gain Ground
Francisco J. Esteva; Gabriel N. Hortobagyi
Scientific American, May 2008
- Taming Vessels to Treat Cancer
Rakesh K. Jain
Scientific American, January 2008
- Restoring order to the chaotic blood vessels inside a
tumor opens a window of opportunity for attacking it.
Surprisingly, drugs meant to destroy vasculature can make
the repairs and may help reverse conditions that lead to
cardiovascular disease and blindness.
Taking a Jab at Cancer
Science News, August 11, 2007
- Combined with drugs, vaccines against tumors may finally
Is Chronic Inflammation the Key to Unlocking the Mysteries of
Scientific American, July 2007
- Understanding chronic inflammation, which contributes to
heart disease, Alzheimer's and a variety of other ailments,
may be a key to unlocking the mysteries of cancer.
[Originally published as A Malignant Flame.]
- Chemo Control
Scientific American, April 2007
Mapping the Cancer Genome
Francis S. Collins; Anna D. Barker
Scientific American, March 2007
- Deadly Dialogue
Scientific American, February 2007
Cancer Clues from Pet Dogs
David J. Waters; Kathleen Wildasin
Scientific American, November 2006
Stem Cells: The Real Culprits in Cancer?
Michael F. Clarke; Michael W. Becker
Scientific American, July 2006
- A dark side of stem cells--their potential to turn
malignant--is at the root of a handful of cancers and may be
the cause of many more. Eliminating the disease could depend
on tracking down and destroying these elusive killer cells.
- Overcoming Self
Scientific American, July 2004
- A company tries to turn the immune system against cancer.
The Ecology of Tumors
Parauc A. Kenny; Celeste M. Nelson; Mina J. Bissell
The Scientist, April 2006
- By perturbing the microenvironment, wounds and infection
may be key to tumor development.
Leukemia and Cancer Stem Cells
Irving Weissman; Michael Clarke
The Scientist, April 2006
- Cancers and normal tissue stem cells have much in common:
Both have self-renewal capacity, and both develop into
differentiated progeny. But do true cancer stem cells exist?
We believe that they do and that this realization will have a
major impact on the understanding and treatment of cancers.
Stem cells for brain cancer
Peter B. Dirks
The Scientist, April 2006
- Several groups showed that isolating stem cells from brain
tumors yielded cells that could clonally form colonies of cells
in vitro that expressed neural precursor markers and that
could be replated to reform colonies demonstrating self-renewal.
The Root of BRCA1's Evil
The Scientist, March 2006
- Uncovering the mechanism of cancer-causing defects in a