The surgical removal of the primary tumor has been the cornerstone of treatment for most types of cancer. The rationale for this approach is straightforward -- if you can get rid of the cancer by removing it from the body, then a cure can likely be achieved. Unfortunately, this approach does not take into account that following surgery, the cancer will frequently metastasize (spread to different organs). Quite often the metastatic recurrence is far more serious than the original tumor. In fact, for many cancers it is the metastatic recurrence, and not the primary tumor that ultimately proves to be fatal (Bird 2006).
A growing body of scientific evidence has revealed that cancer surgery can increase the risk of metastasis (van der Bij 2009). Even though this contradicts conventional medical thinking, the facts are undeniable.
A complicated sequence of events must occur in order for cancer to metastasize (van der Bij 2009). Isolated cancer cells that break away from the primary tumor must first breach the connective tissue immediately surrounding the cancer. Once this occurs, the cancer cell enters a blood or lymphatic vessel. To gain entry, the cancer cell must secrete enzymes that degrade the basement membrane of the blood vessel (Wagennar-Miller 2004). This is vitally important for the metastatic cancer cell as it uses the bloodstream for transport to other vital organs of the body (i.e., the liver, brain, or lungs) where it can form a new deadly tumor.
Traveling within the bloodstream can be a hazardous journey for cancer cells. Turbulence from the fast moving blood can damage and destroy the cancer cell. Furthermore, cancer cells must avoid detection and destruction from white blood cells circulating in the blood stream.
To complete its voyage, the cancer cell must adhere to the lining of the blood vessel where it degrades through and exits the basement membrane of the blood vessel. Its final task is to burrow through the surrounding connective tissue to arrive at its final destination, the organ. Now the cancer cell can multiply and form a growing colony, serving as the foundation for a new metastatic cancer.
We now see that cancer metastasis is a complicated and difficult process. Fraught with peril, very few free-standing cancer cells survive this arduous journey (van der Bij 2009).
In a groundbreaking study, researchers reported that cancer surgery itself can greatly lessen the cancer cell’s obstacles to metastasis (van der Bij 2009). Cancer surgery can produce an alternate route of metastasis that bypasses natural barriers. During cancer surgery, the removal of the tumor almost always disrupts the structural integrity of the tumor and/or blood vessels feeding the tumor. This can lead to either an unobstructed dispersal of cancer cells into the bloodstream or seeding of these cancer cells directly into the chest or abdomen (Ben-Eliyahu 2003; Yamaguchi 2000; Da Costa 1998; Shakhar 2003).This surgery-induced “alternate route” can greatly simplify the path to metastasis.
To illustrate, a study compared the survival of women with breast cancer who had surgery to that of women with breast cancer who did not have surgery. As expected, surgery substantially improved survival in the early years. However, further analysis of the data revealed that the surgery group had a spike in their risk of death at eight years that was not evident in the non-surgery group (Demicheli 2001).
Given these findings, a worthwhile strategy to protect against the increased risk of metastasis would be to examine all of the mechanisms by which surgery promotes metastasis, and then create a comprehensive plan that counteracts each and every one of these mechanisms.
What You Need to Know: Cancer Surgery
- Surgical removal of cancer typically provides the best chance of disease-free survival.
- Since metastatic disease is often deadlier than the original tumor, it is important to utilize preventive strategies to prevent cancer metastasis.
- A growing body of evidence suggests that cancer surgery itself may increase the risk of metastasis (spread to other areas) via numerous mechanisms including increasing cancer cell adhesion, suppressing immune function, promoting angiogenesis (growth of new blood vessels from pre-existing vessels), and stimulating inflammation.
- Choose surgeons and anesthesiologists who utilize advanced techniques that may reduce metastatic risk.
- Certain nutrients and drugs are associated with reduced risk of metastasis.