Oncotype DX in Bilateral Synchronous Primary Invasive Breast Cancer.
BACKGROUND
Synchronous bilateral breast cancers frequently share the same estrogen receptor (ER) status, yet may differ in other histopathologic features. We sought to examine concordance rates of Oncotype DX recurrence score (RS) testing in women with synchronous bilateral ER-positive breast cancer.


METHODS
Institutional databases were reviewed to identify patients with synchronous (within 6 months) bilateral primary invasive breast cancer and multiple RSs. RSs were stratified by risk group (RS < 18, low; RS 18-30, intermediate; RS ≥ 31, high) and considered discordant if they reflected different risk groups.


RESULTS
From 2005-2014, a total of 115 patients presented with synchronous bilateral invasive breast cancer; 43 (37 %) had two RSs available. Median patient age was 60 years (42-84), median tumor size was 1.2 cm (0.5-3.7), and all cases were HER2 negative and node negative. Of 86 RSs, 63 (73 %) were low risk, 20 (23 %) were intermediate risk, and 3 (3 %) were high risk. RSs were concordant in 29 (67 %) patients. Patients with concordant RSs were older (62 years vs. 56 years) and had median levels of progesterone receptor (PR) expression that were higher and more similar-80 and 85 % for bilateral cancers, respectively, compared with 55 and 75 % for bilateral cancers in discordant cases. Discordant RS led to a treatment change in 8/14 (57 %) cases.


CONCLUSIONS
Among women with synchronous bilateral ER-positive HER2-negative breast cancer, RSs were concordant in 67 % of cases. Concordance rates may be higher in older women or among those with comparable levels of PR expression. These data suggest that testing of both tumors should be considered in patients who are candidates for adjuvant chemotherapy.
Breast Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Maria
M
Karsten
Breast Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Michelle
M
Stempel
Breast Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Julia
J
Radosa
Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Sujata
S
Patil
Breast Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA. tking7@partners.org.
Tari A
TA
King
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018275:Carcinoma, Lobular / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D020869:Gene Expression Profiling; D006801:Humans; D007124:Immunoenzyme Techniques; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D009367:Neoplasm Staging; D009378:Neoplasms, Multiple Primary / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D011379:Prognosis; D011446:Prospective Studies; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012189:Retrospective Studies
D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone