Older Breast Cancer Patients Much Less Likely to Receive 21-Gene Recurrence Score Testing

MedicalResearch.com Interview with:

Valentina Petkov, MD, MPH Health Scientist/Program Officer NIH/NCI/DCCPS/Surveillance Research Program

Dr. Petkov

Valentina Petkov, MD, MPH
Health Scientist/Program Officer
NIH/NCI/DCCPS/Surveillance Research Program

MedicalResearch.com: What is the background for this study?

Dr. Petkov: The number of breast cancer diagnoses is increasing in older patients because of increasing life expectancy and changing population demographics. Despite high incidence, little is known about breast cancer biology and outcomes in patients older than 70, which are often under-represented in clinical trials. The 21-gene Oncotype DX Breast Recurrence Score assay has been used in clinical practice to predict distant recurrence risk and chemotherapy benefit in lymph node negative, hormonal receptor positive (estrogen and/or progesterone receptor positive) invasive breast cancer since 2004. The goal of our study was to evaluate the role of the 21 gene assay in older patients at population level.

We used Surveillance Epidemiology and End Results (SEER) data. We included in the analysis 40,134 patients who were diagnosed with invasive breast cancer between 2004 and 2011, had negative nodes and their tumors were hormonal receptor positive and HER2 negative. Breast Cancer Specific Mortality (BCSM) was assessed at 5 years after diagnosis in patients with low risk (Recurrence Score <18), intermediate risk (Recurrence Score 18-30) and high risk (Recurrence Score >30).

MedicalResearch.com: What are the main findings?

Dr. Petkov: We found that patients older than 70 were three times less likely to be tested than younger patients. Little disparity in testing was observed by race or socioeconomic status. Reported chemotherapy use was generally much lower in older patients. Recurrence Score results predicted survival in older patients similar to younger patients. Patients with Recurrence Score less than 18 had very low chance of dying from breast cancer regardless of age. However, there was a notable increase in breast cancer deaths in older patients with Recurrence Score results 18-30 and greater than 30.

MedicalResearch.com: What should readers take away from your report?

Dr. Petkov: There was a huge disparity of who was tested that was associated with age. The older the patient, the less likely she/he was tested. The 21-gene Recurrence Score assay (Oncotype DX) predicts the survival from breast cancer irrespective of age. Patients with Recurrence Score less than 18 have excellent 5-year survival.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Dr. Petkov: The worse breast cancer survival in older patients with Recurrence Score greater than 30 compared to younger patients needs further investigation. For example, could co-morbidities (existing other diseases) and sub-optimal health status contribute to the poor outcome? Or is it the well-known undertreatmet of the elderly that primarily drives the worse survival?

MedicalResearch.com: Is there anything else you would like to add?

Dr. Petkov: The Surveillance Epidemiology and End Results (SEER) Program at the National Cancer Institute (NCI) is one of the premier cancer surveillance programs in the world which covers 30% of the US population. Each SEER registry collects cancer related data as mandated by state specific laws. The SEER Program collaborated with Genomic Health Clinical Lab (the only lab performing the test) to supplement each SEER registry data with Oncotype DX Recurrence Score results which has been a required data element for cancer surveillance.

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Citation: Abstract presented at the 2016 ASCO meeting

Outcome disparities by age and 21-gene recurrence score (RS) in hormone receptor positive (HR+) breast cancer (BC).
Citation:
J Clin Oncol 34, 2016 (suppl; abstr 574)
Author(s): Valentina I. Petkov, Dave P. Miller, Nadia Howlader, Nathan Gliner, Will Howe, Nicola C. Schussler, Kathleen Cronin, Frederick L. Baehner, Lynne Penberthy, Steven Shak; National Cancer Institute, Bethesda, MD; Genomic Health, Inc., Redwood City, CA; Information Management Services, Inc., Calverton, MD; University of California, San Francisco, San Francisco, CA

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