How to predict if you would respond to chemotherapy?
Chemotherapy is important part of breast cancer treatment. Chemotherapy is often used to treat breast cancer or prevent recurrence of breast cancer. Chemotherapy drugs are designed to attack and kill the fast growing cancer cells, hence it is not surprising to note that these drugs are associated with significant side effects. Many patients who receive the chemotherapy may benefit from the treatment but a substantial number of patients may not derive any benefit from the chemotherapy and they may have the breast cancer recurrence or progression despite receiving chemotherapy.
A recent article published in Translational Medicine describes how it is possible to predict the effectiveness of chemotherapy in a given patient. Using DNA microarray analysis Olga Modlich and colleagues, from the University of Dusseldorf in Germany were able to predict correctly in 83 breast cancer patients, if they would respond to chemotherapy. The researchers were accurate in predicting which breast tumors would improve from chemotherapy in all cases of partial remission and nearly three quarters of the cases of complete remission based on the analysis of less than sixty genes present in the tumors. The authors of this study state that this is an important development and the ability to predict which patients will respond to chemotherapy, and which would not, would be a "powerful tool" in the treatment of breast cancer.
Olga Modlich and colleagues analyzed samples of breast tissue from five healthy individuals and tumor tissue from fifty-six breast cancer patients treated with preoperative systemic chemotherapy (neo-adjuvant chemotherapy) with a combination of the anti-cancer drugs epirubicin and cyclophosphamide. The genes present in the samples were analyzed using a DNA microarray which is a collection of microscopic DNA spots attached to a solid surface used to measure the expression levels of large numbers of genes simultaneously.
From the DNA microarray analysis the authors were able to identify a total of fifty-seven 'predictor' genes active in tumors: thirty-one genes associated with a favorable response and twenty-six genes associated with a poor response. The authors then tested the ability of these genes to predict the response of twenty-seven breast cancer patients, who were then treated with preoperative systemic chemotherapy.
The predictor genes could be used to correctly predict the outcome of preoperative systemic chemotherapy in all cases of partial remission and nearly 75% of cases of complete remission of primary tumors. According to the authors the use of microarray technology to identify genes that can predict response to chemotherapy could represent a powerful tool to identify patients for whom PST is the most appropriate, and would be the most successful form of treatment.
Currently, decisions about whether to use chemotherapy as a breast cancer treatment are based on factors such as patients' age and type and size of tumor. These factors do not provide sufficient information to tailor treatment to the individual patient. Nearly all breast cancer patients receive standard chemotherapy treatment, despite the potential for a poor response to therapy, adverse side effects and excess healthcare costs. According to the authors "the identification of molecular markers predictive of patients' responsiveness to treatment is becoming a central focus of research". The ability to predict a patient's response to chemotherapy for breast cancer would be of benefit to doctors and patients, shifting the focus away from a standard treatment for all patients and towards treatment based on predictions made from patients'
Invasive: Invading to surrounding tissues. A cancer is said to be invasive if it breaks the normal boundaries and invade to the surrounding tissues. Example an invasive cancer or carcinoma is a cancer or carcinoma that has broken down the normal surrounding boundaries. See cancer terms
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