MammaPrint Predicts Response To Neoadjuvant Chemotherapy In Breast Cancer

[gpawelski]

MammaPrint has the ability to predict response to neoadjuvant chemotherapy in breast cancer.

Dr. Laura van 't Veer, from the Netherlands Cancer Institute, presented the data at the 2008 San Antonio Breast Cancer Symposium (SABCS) during the session Molecular profiling for guiding therapeutic decisions. The study analyzed the association between the pathological complete response (pCR) rate and the results of the MammaPrint test.

Findings in the neoadjuvant setting support MammaPrint's predictive power for chemotherapy response, in addition to its previously demonstrated prognostic value for early stage disease. The achievement of pCR is a valuable indicator for long-term response in this clinical setting.

http://www.medicalnewstoday.com/articles/132903.php

[gpawelski]

The genetic analysis of MammaPrint predicts which women will have a greater chance of breast cancer recurrence, information that could save many patients from unnecessary chemotherapy. This test looks at the expression of 70 genes linked to breast cancer with an accuracy level of 96.7% as determined by a study published in the New England Journal of Medicine.

The correlations of this are vastly superior to those obtained with standard prognostic markers. The 70 genes in a woman's tumor analyzed by MammaPrint predict the 10-year survival of the patient at a significance level over three times greater than existing methods. Existing methods can't distinguish the patients with a high risk for recurrence from those with low risk with camparable accuracy.

These new gene expression profiling tests enable the oncologist and breast cancer surgeon to more accurately determine who should be treated and who should not be treated with chemotherapy, but they have been mostly or totally ineffective at identifying clinical responders to various therapies.

The molecular MammaPrint laboratory test is a tool for the oncologist. The oncologist should take advantage of all the tools available to him/her to evaluate a patient. And since studies show that only 25-30% of patients do respond to chemotherapy that is available to them (and even less for "targeted" drugs), there should be due consideration to looking at the advantage of molecular and cellular assay tests.

The combination of these tests can enhance the ability to distinguish between "low" risk and "high" risk patients. Patients in the "low" risk group can be spared the unnecessary toxicity, particularly associated with ineffective treatment, while those in the "high" risk group, who would benefit from chemotherapy can be pre-tested to see what treatments have the best opportunity of being successful, and offers a better chance of tumor response resulting in progression-free and overall survival.

Every breast cancer patient should have their own unique evaluation based on consultation of pathogenic profiles and drug sensitivity testing data. Research and application of these tests are being encouraged by growing patient demands, scientific advances and medical ethics. These tests are not a luxury but an absolute necessity, and a powerful strategy that cannot be overlooked.

Sources:
N Engl J Med 347:1999-2009, 2002
J Intern Med 264:275-287, September 2008