Growing up, I remember the first
weekend of October meant a lot of pink during NFL games as October is breast
cancer awareness month. It is estimated that 1 in 8 women and 1 in 883 men will
develop breast cancer during their lifetime (“U.S. Breast Cancer Statistics,”
2019). Unfortunately, these statistics may not come as a surprise to many, but
they do exemplify the importance of increasing the awareness for breast and
associated cancers. Continued research efforts should be undertaken to better
understand the many forms of breast cancer and possible treatments for the
disease.
One such research study published findings
in September on the effects that the local anesthetics ropivacaine and
levobupivacaine have on triple-negative breast cancer and melanoma (Castelli et
al., 2019). The study was inspired by preliminary research indicating that
anesthetics improve the conditions of cancer patients after surgery (Castelli
et al., 2019). With this logic, it is possible that local anesthetics could be
combined with radiation and chemotherapy in the treatment of cancer.
Results from the experiments
indicate that both ropivacaine and levobupivacaine reduce the viability of the
cancerous cells, but both drugs did not have an equal effect on each cancer
type. At a concentration of 50 micromolar, levobupivacaine reduced the cell viability
of both types of cancer by 50% at 24 hours (Castelli et al., 2019). At the same
concentration of 50 micromolar, ropivacaine reduced the viability of triple-negative
breast cancer by 50% at 24 hours but did not have the same influence on
melanoma (Castelli et al., 2019).
Reducing the viability of cancer
cells by the application of local anesthetic provides a unique approach to aid
the currently used treatments for cancer. The results provide promise and a pave
pathway for more research into the use of local anesthetics for the treatment
of cancer. What other anesthetics can be used and what combinations of
anesthetics can give the most promise in reducing cancer cell viability? Hopefully
in time, more answers will become available and the rates of breast cancer can
be reduced.
U.S. Breast Cancer Statistics. (2019,
February 13). Retrieved October 4, 2019, from Breastcancer.org website: https://www.breastcancer.org/symptoms/understand_bc/statistics
This is a very interesting finding! With my personal experience shadowing anesthesiologist this past summer, I watched them use Ropivacaine and Bupivacaine for numerous nerve blocks. Nerve blocks serve to numb the body part of which the patient is having surgery on to minimize pain.
ReplyDeleteRopivacaine and Levobupivacaine are very similar to each other as they are both isomers of bupivacaine and produce similar effects on how they inhibit sodium channels (Khan et al., 2016). However, the potency of these differ slightly in anesthetics, were Levobupivacaine has a greater potency than ropivacaine. It is found that, therefore, ropivacaine may be less toxic than levobupivacaine (Khan et al., 2016). Maybe even at same concentrations, a slight variation in toxicity could be the reason why we see a difference in effects of these anesthetic agents in this study.
Moreover, this study showing that these numbing medications can have an effect on cancer growth is fascinating. It is found that Lidocaine, another type of local anesthetic, is shown to increase natural killer cell activity. However, other anesthetics such as ketamine is an immunosuppressor, were it decreases Natural Killer cell activity and stimulates T-cell apoptosis (Kim, 2018).
Combining the appropriate anesthetics with chemotherapy may be a great therapy option for treating cancer. However, we have to note the effects of chemo on the organs and how that will affect the administration of these anesthesia drugs.
References
Khan A, Nanda HS, Chandra R. Levobupivacaine versus Ropivacaine: A Comparative Study of the Analgesic and Hemodynamic Spectrum. Int J Sci Stud 2016;4(1):190-195.
Kim, R. (2018). Effects of surgery and anesthetic choice on immunosuppression and cancer recurrence. Journal of Translational Medicine, 16(1). doi: 10.1186/s12967-018-1389-7
Austin,
ReplyDeleteI agree with Kirsten, this is a very interesting find!
I did some more digging on the subject and I found additional information that you might find interesting. Just a year prior to the study that you referenced in your post study was done that also looked at the effects of local anesthetics on cell migration and cancer cell proliferation. According to the study surgical resection of cancer, although necessary and associated with improved prognosis, has also been shown to dislodge cancerous cells allowing for recurrence and metastasis (Li et al., 2018). As such the researchers were interested in why local anesthetic use seemed to show more positive outcomes in patients than in those that just received general anesthesia (as you mentioned).
To study cell migration a wound-healing assay was used to determine if levobupivacaine, ropivacaine, and chloroprocaine had any effect at plasma concentrations (what is normally administered for a nerve block) and at 10x plasma concentration. What they found was that each of the local anesthetics significantly inhibited cell migration in both cancer cell lines (Li et al., 2018). Additionally, upon treatment with the same anesthetics cancer cell lines were halted at the G2 phase of the cell cycle by ropivacaine specifically (Li et al., 2018).
Given the findings of the study that you referenced, which found that ropivacaine was less toxic to cancer cells, it might be interesting for researchers to investigate "drug cocktials" or regimented therapies so that we may take advantage of both the cytotoxicity of levobupivacaine and the anti-metastatic and anti-proliferation effects of ropivacaine.
Li, R., Xiao, C., Liu, H., Huang, Y., Dilger, J. P., & Lin, J. (2018). Effects of local anesthetics on breast cancer cell viability and migration. BMC cancer, 18(1), 666. doi:10.1186/s12885-018-4576-2.