RESUMEN
BACKGROUND & OBJECTIVES: We previously described a predictive AAMC model that identifies patients (grade 1, hormonepositive) who would not benefit from OncotypeDX testing. The purpose of this study was to validate the AAMC model by assessing distant recurrence-free interval (DRFI) and invasive disease-free survival (IDFS) using TAILORx clinical trial data. MATERIALS & METHODS: We retrospectively analyzed TAILORx trial data and categorized patients based on the AAMC model. AAMC low-risk patients are those with grade 1 and hormone-positive tumors. Kaplan-Meier curves examined DRFI and IDFS. RESULTS: Of the 9195 cases, 2246 (24.4%) were identified by AAMC as low-risk. Among these AAMC low-risk patients, 55.2% had Recurrence Score (RS) 0-15, 42.3% had RS 15-25, and 2.4% had RS > 25. The 10-year DRFI did not differ for those who received adjuvant chemotherapy versus those who did not (98% vs. 96%, log-rank p = 0.46). Similarly, IDFS was comparable between those who received adjuvant chemotherapy and those that did not (86% vs. 86%, log-rank p = 0.66). Only 2.4% of AAMC low-risk patients were categorized as high-risk (RS > 25). A sensitivity analysis of this discordant group, wherein those with RS > 25 were re-classified into the no-chemotherapy group and assumed to have experienced recurrences at the rate expected without chemotherapy, did not find any difference in DRFI between those who received adjuvant chemotherapy and those who did not (log-rank p = 0.16). CONCLUSION: OncotypeDX testing does not benefit AAMC low-risk patients with hormone-positive grade 1 tumors. Based on these data, 1 in 4 TAILORx participants would not need OncotypeDX testing.
Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Receptores de Progesterona , Estudios Retrospectivos , Pronóstico , Estrógenos/uso terapéutico , Quimioterapia Adyuvante , Recurrencia Local de Neoplasia , Receptor ErbB-2RESUMEN
BACKGROUND: We previously described a risk prediction model (Anne Arundel Medical Center [AAMC] model) based on pathology which may eliminate the need for recurrence score (RS) testing in select early-stage breast cancers. There is a concern that patients in discordant risk prediction groups (AAMC vs. RS) may be overtreated or undertreated if RS testing were omitted. METHODS: We queried the Surveillance, Epidemiology, and End Results (SEER) database for all breast cancer patients between 2004 and 2015. AAMC low-risk was defined as Grade 1 and progesterone receptor-positive (PR + ) tumors, while AAMC high-risk was defined as Grade 3 or estrogen-negative tumors. RS low-risk group was defined as RS < 16 and age ≤ 50 years, or RS ≤ 25 and age > 50 years. RS high-risk group was defined as RS > 25. RESULTS: A total of 71,212 cases were analyzed. Of these, 590 were AAMC low-risk/RS high-risk discordant, while 5,596 were AAMC high-risk/RS low-risk discordant. For AAMC low-risk/RS high-risk discordant, 10-year breast cancer-specific survival (BCSS) did not differ for patients who received adjuvant chemotherapy versus those who did not (93% chemotherapy vs. 99% unknown/no chemotherapy, p = .12). Overall survival (OS) was also comparable (92% chemotherapy vs. 91% unknown/no chemotherapy, p = .42). In the AAMC high-risk/RS low-risk discordant group, 10-year BCSS (92% chemotherapy vs. 96% unknown/no chemotherapy, p = .06) and OS (87% chemotherapy vs. 90% unknown/no chemotherapy, p = .52) did not differ between adjuvant chemotherapy and unknown/no chemotherapy groups. CONCLUSIONS: Adjuvant chemotherapy in the AAMC low-risk/RS high-risk and AAMC high-risk/RS low-risk discordant groups did not improve survival. This supports consideration of omission of RS testing in Grade 1, PR + tumors. Patients with Grade 3 tumors do benefit from RS testing.