Effectiveness of DNA Repair Mechanisms Predicts Chemotherapy Sensitivity
Posted Mar 09 2010 7:21am
Chemotherapy is an important tool in our fight against breast cancer. However, breast cancer patients often have different individual responses to any one specific form of chemotherapy. For this reason, the breast cancer research community continues to look for ways to determine how each individual breast cancer patient might respond to specific types of chemotherapy. If physicians can determine whether a patient will respond to a particular treatment before the treatment is given, they can then assure that each patient receives the type of treatment to which they will best respond and which will provide the best possible outcome.
Anthracycline-based chemotherapies are one of the most common forms of chemotherapy and these typically work by damaging the DNA in breast cancer cells, causing their death. A new study (free to download) published a few days ago examined whether individual differences in the ability of breast cancer tumors to repair DNA damage caused by chemotherapy has an effect on chemotherapy effectiveness. For this study, breast cancer researchers collected core needle biopsy samples from 60 breast cancer cases before chemotherapy treatment and 18-24 hours after chemotherapy treatment in order to assess the possible relationships between the production of DNA damage repair proteins and the tumor's response to chemotherapy.
The results of this study showed that chemotherapy increased the level of proteins responsible for DNA repair in many cases. A higher level of these proteins individually either before or after chemotherapy was associated with lower response to chemotherapy, such that tumor size was not reduced as much as in individuals with low levels of these repair proteins. Overall, the results of the study indicated that breast cancer tumors with high functioning DNA repair mechanism were more resistant to chemotherapy, which resulted in poorer reductions in tumor size.
This new study reports that the ability of individual breast cancer tumors to repair DNA damage caused by chemotherapy has a substantial impact on the effectiveness of the chemotherapy. This in important new research that might one day have a real impact on breast cancer treatment and outcomes. By evaluating each tumor's ability to repair DNA damage, it might be possible to determine the effectiveness of a specific chemotherapy drug before use and permit individual treatment options that provide the best possible outcomes.
Although the medical and research communities continue to make amazing discoveries that will hopefully lead to better treatment options and survival rates, it is important to remember that we also can take steps to fight against breast cancer. To learn more, read my book Fight Now: Eat & Live Proactively Against Breast Cancer at www.fightBCnow.com .