Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How do cancers spread?

  1. Jun 5, 2010 #1
    Hello everyone,

    First of all I don't know much about cancer. I'm assuming cancer is some mutation in dna and causes the cells to uncontrollably replicate. So let's say a person has lymphoma. Now this cancer spread into lungs? Then what happens? Do lung cells start to replicate there or lymphoid cells start to replicate there?If lung cells start to replicate, how does a lymphomatic cancerous cell spread the mutation to a lung cell? I mean it is not like a virus that can inject DNA right? Also how do cancers spread through lymphatic system? Lymphatic system can not carry cells right, only interstitial fluid so how does cancer spread through them? Thanks :smile:
  2. jcsd
  3. Jun 7, 2010 #2


    User Avatar
    Science Advisor
    2017 Award

    In your example, a lymphoma that spreads to the lung will create a tumor consisting of lymphoid cells, not lung cells. Cancers do not have the ability to transform other cells into cancer cells.

    Unfortunately, I don't know the answer to this either.
  4. Jun 7, 2010 #3


    User Avatar
    Science Advisor
    Gold Member

    Cancer is an accumulation of errors in cellular lineages. It normally takes many 'mutations' to break a lineage to the point where the cells become cancerous.

    Think of cancerous cells in light of a evolutionary process. You (your body) is a colony of cells all working together to achieve a goal (passing on genes). To accomplish this goal many cells have to forgo the chance to pass on their genes. This turns out to be okay, because all the cells in your body share (for all intents and purposes) the same genes. Your body requires these cells which don't participate in reproducing to take on specialized tasks (such as 'liver cell' or 'lung cell'), to support the cells responsible for reproduction.

    Cancerous cells loose their specialized function, when they do we call them undifferentiated and call cancers of undifferentiated cells; anaplastic.

    Once cells become cancerous they become selfish. They use all their local resources toward replicating themselves and out competing near by tissues. This is when tumors form.

    As a tumor grows parts can 'break' off and travel throughout the body, where these cells land they start new 'colonies' which grow into new tumors.

    Ultimately the selfish behavior of a cancerous lineage kills the organism and their lineages (expect in rare cases where lineages are transmissible, don't worry none in humans yet!).

    Lymphoma simply describes the tissue origination of the cancer--One arising from lymph tissue.

    The lymphatic system is a network of 'tubes' which transport fluid and cells throughout the body. Cancerous cells can 'break' in to the network and hitch a free ride to be deposited else where in the body. Travel in this way isn't limited to lymphomas, cancer arising from other tissues can 'break' in as well.

    Edit: B and T cells can travel through the lymph system. In a healthy person only immune cells should be found traversing the lymph network to areas they maybe needed.
  5. Jun 8, 2010 #4
    Hey thanks Ygggdrasil and bobze for their help :smile: Bobze your answer covered the question really well, so cancer cells can travel through lymphatics system. I'm assuming the same, but since Yggdrasil is also unsure can you provide further evidence. It's ok this knowledge is enough for me upto now.
  6. Jun 11, 2010 #5
    Just complementing the excellent response from Ygggdrasil:
    There is some steps that a tumor cell need to do as becoming a full grow cancer.
    The first thing is loose control of cell cycle, allowing then to replicate faster than the cells surrounding. Even if they replicate faster, they will not do too much harm, because the tumorous mass can’t grow bigger than a pea, since the interior cells will die of starvation.
    To pass this barrier the cell needs to secrete some angiogenic factors that will induce formation of vessels inside de tumor mass. Now they can grow bigger and become a localized problem. To spread, the cell needs ability to invade basal lamina. Now you have some really nasty carcinoma cells.
  7. Jun 13, 2010 #6


    User Avatar
    Gold Member

    I know that inaccurate surgery will dislodge cancer cells from an original site and they, in turn, will travel through the blood stream until they lodge elsewhere and continue metastatic growth. That's why you will often see the "spread" of cancer from lung (where surgery was performed) to spine or even all the way to the brain. Unless surgery is performed with cauterizing laser or cryonic techniques, I wouldn't have a lot of faith in its use to combat cancer.
  8. Jun 13, 2010 #7


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    It is very common for cancer cells to travel through the lymphatic system. This is why the pathways of lymphatic drainage are taught in detail to med students, because that's also the path that cancer will travel as it metastasizes, and the reason that lymph nodes are collected as "sentinal" nodes as part of staging cancer and determining how far it has spread.
  9. Jun 15, 2010 #8
    It was thought that a particular cell type belonging to a particular tissue, won't be able to survive in a different tissue competing with the other cells in the other tissue. This turned out to be false.

    In your example, if any cancer travels to the lung and you end up with some type of lung cancer. This cancer would be caused by the traveling cancer cells not by the lung cells. A cell can't spread cancer to another cell. Although the example you gave is very uncommon, usually in the DNA of some lung cells, outside causes or spontaneous events may cause mutation of some of the anticancer genes. And a series of bunch of other events will lead to lung cancer.
  10. Jun 15, 2010 #9
    All of the above works, but one word sums it up when it comes to metastatic (especially lymphatic) cancers: Neoplasms. This is part of the concern with the need to program stem cells so you aren't just shooting potential cancer into people.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook