Self-Assessment: Predictive and Prognostic Rule of Pathological Complete Response in Breast Cancer Treatment

Dr. Shaheenah Dawood is the Head of Medical Oncology and the Head of the Breast Cancer Program at Dubai Hospital in the United Arab Emirates. Dr. Dawood completed her M.B.B.Ch at Dubai Medical College in 1998 and a Master of Public Health degree at the Harvard School of Public Health, Boston, USA in 2008. Her postgraduate medical training programs include a Fellowship at McGill University in Canada in 2006, and the Susan Komen Breast Cancer Fellowship at the University of Texas M.D. Anderson Cancer Center in 2007. Dr. Dawood is a member of various professional organizations, including the American Society of Clinical Oncology (ASCO), the American Association of Cancer Research (AACR), the Canadian Association of Medical Oncologists, the Emirates Medical Association, and the Inflammatory Breast Cancer Research Group. She is also the co-director of the Middle East Research Network. If you enjoyed this podcast, make sure to subscribe for more weekly education content from ASCO University. We truly value your feedback and suggestions, so please take a minute to leave a review. If you are an oncology professional and interested in contributing to the ASCO University Weekly Podcast, email ascou@asco.org for more information.

TRANSCRIPT

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Welcome to the self-evaluation episode of the ASCO University Weekly Podcast. My name is Shaheena Dawood, and I am a consulting medical oncologist and lead of the Oncology Research program at the Comprehensive Cancer Center at the Mediclinic City Hospital in Dubai, United Arab Emirates. Today, we feature a self-evaluation question looking at the predictive and prognostic role of pathological complete response attained in the treatment of breast cancer.

Let us begin by reading the question stem. Here, we have a 55-year-old woman who presents with a 4 centimeter right breast mass and palpable right axillary lymph nodes. A needle biopsy of the breast mass and a lymph node are both positive for infiltrating ductal carcinoma negative for hormone receptors and negative for HER2/neu expression. The patient is interested in breast-conserving therapy, and she is referred to you for consideration of neoadjuvant chemotherapy. Which of the following do you tell her? Your choices are, A-- patients having a complete response to neoadjuvant chemotherapy have lower local and regional recurrence rates, B-- mastectomy will be required regardless of clinical response to chemotherapy, C-- chemotherapy will be administered before and after surgery, or D-- randomized trials have shown that radiotherapy is not necessary following surgery and chemotherapy if she has a complete response.

At this point, please feel free to pause the recording before we discuss the correct answer.

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The correct answer to this question is A. Pathological complete response in the breast and lymph nodes is associated with lower local and regional recurrence rates. A combined analysis of the NSABP B18 and B27, two large trials that evaluated the role of neoadjuvant chemotherapy, revealed that the rate of local regional recurrence decreased amongst patients who initially presented with positive lymph nodes prior to neoadjuvant chemotherapy, and who become pathologically node negative after neoadjuvant chemotherapy, especially if they also achieved a pathological complete response in the breast.

Briefly, the other choices presented in this question do not represent the most appropriate answer for the following reasons. The decision regarding type of surgery in the form of mastectomy versus breast-conserving surgery is dependent on multiple factors. One of the early established benefits of neoadjuvant therapy is that it increases the probability of breast-conserving surgery, making more women candidates for lumpectomy and breast radiotherapy, who otherwise would have been treated with mastectomy. Studies have shown that chemotherapy before surgery in the neoadjuvant setting versus chemotherapy after surgery in the adjuvant setting is associated with similar outcomes. And finally, attaining a pathological complete response currently does not preclude the need for adjuvant radiation therapy, the decision of which would be made on clinical stage of disease at presentation. The NSABP51 RTOG phase III trial is ongoing to evaluate the role of regional radiotherapy in women presenting with clinical N1 axillary node disease before neoadjuvant chemotherapy, and who become pathologically node negative at the time of surgery.

Thank you for listening to this week's episode of the ASCO University Weekly Podcast. For more information on the treatment of breast cancer, including opportunities for self-evaluation and board review, please visit the comprehensive e-learning center at university.asco.org. [MUSIC PLAYING]

The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care, and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.