The Hallmarks of Cancer
October 02 2011
Cancer is different from other diseases because it is not just one disease, but a collection of more than 100 distinct diseases. If so, what are the commonalities shared by different cancers?
Picture: A breast cancer cell
In 2000, the journal Cell published a ground breaking article titled “The Hallmarks of cancer”. This paper has turned out to be the most cited paper in the cancer field. Below are these 6 hallmarks of cancer.
And if you are wondering about the topic, I keep up with most of the health-related topics. This site is not just about bench press and biceps. This topic is also a bit dear to me since my Mom passed away a year back after battling with cancer for almost 3 years. I have blunted the language a bit so that it makes some sense.
Growing out of control: Or Sustained proliferative signaling. Normal tissues carefully control the production and release of signals which control growth. But cancer cells have developed their own signals . They chose when to replicate and when to grow.
Evading growth suppressors: Just like there are signals to trigger growth, there are signals that suppress growth in normal cells. But cancer cells somehow are resistant or suppress these growth blocking signals.
Blood vessel growth: Or Inducing Angiogenisis. To sustain the growing size of the tumor, cells need a good blood supply to ensure enough oxygen and nutrients. Cancer cells activates the process of making new blood vessels(angiogenesis) to sustain themselves.
Evading Death: Or Resisting Cell Death. Normal cells are programmed to die or commit suicide after so many cell cycles or when they get damaged. It is called programmed cell death or apoptosis. It is a fundamental property of normal multi cell tissue. It is just another check to prevent abnormal growth. But cancer cells earn how to avoid cell death.
Invading other cells: Or Activating Invasion and metastasis. Most of the deaths from human cancers (90%) are due to cancer cells spreading and establishing colonies in other parts of the body. Cancer cells have learned to migrate to other parts in the body and invade healthy cells.
Unlimited copies: Or Enabling Replicative Immortality. Normal cells can only divide so many times, but cancer cells just keep dividing and making unlimited copies.
Journal nature had an article on how these hallmarks are common to even benign tumors (harmless) and hence cannot be called 'hallmarks'. The only hallmark not common to both benign and harmful cancer is the ability to invade other cells and metastasize.
Very recently, in March 2011, the authors updated the hallmarks by adding two more:
- Dis-regulating energy systems : Cancer cells come up with their own energy systems to sustain their uncontrolled growth and proliferation.
- Avoiding immune destruction: It is assumed that many potential cancer cells are destroyed by the immune system, but many cancer cells know how to hide from such immune surveillance.
Cancer is a deadly disease, but it is most fascinating to learn and wonder about the intricacies of such an extraordinary disease.
Anoop | Sat October 08, 2011
I was reading the article in CNN about pancreatinc cancer which Steve Jobs had.
And they write” Two new drugs approved this year may help patients with pancreatic neuroendocrine tumors. They are believed to suppress the blood supply and metabolism of the tumor cells.
Blood supply and the cancer cell metabolism is one of the hallmarks of cancer as written int he article. Almost all drugs developed or being developed attack one or more of these hallmarks.