Greenberg, Caprice C.

AbstractBackgroundRisk‐stratified follow‐up guidelines that account for the absolute risk and timing of recurrence may improve the quality and efficiency of breast cancer follow‐up. The objective of this study was to assess the relationship of anatomic stage and receptor status with timing of the first recurrence for patients with local‐regional breast cancer and generate risk‐stratified follow‐up recommendations.MethodsThe authors conducted a secondary analysis of 8007 patients with stage I–III breast cancer who enrolled in nine Alliance legacy clinical trials from 1997 to 2013 (ClinicalTrials.gov identifier NCT02171078). Patients who received standard‐of‐care therapy were included. Patients who were missing stage or receptor status were excluded. The primary outcome was days from the earliest treatment start date to the date of first recurrence. The primary explanatory variable was anatomic stage. The analysis was stratified by receptor type. Cox proportional‐hazards regression models produced cumulative probabilities of recurrence. A dynamic programming algorithm approach was used to optimize the timing of follow‐up intervals based on the timing of recurrence events.ResultsThe time to first recurrence varied significantly between receptor types (p < .0001). Within each receptor type, stage influenced the time to recurrence (p < .0001). The risk of recurrence was highest and occurred earliest for estrogen receptor (ER)‐negative/progesterone receptor (PR)‐negative/Her2neu‐negative tumors (stage III; 5‐year probability of recurrence, 45.5%). The risk of recurrence was lower for ER‐positive/PR‐positive/Her2neu‐positive tumors (stage III; 5‐year probability of recurrence, 15.3%), with recurrences distributed over time. Model‐generated follow‐up recommendations by stage and receptor type were created.ConclusionsThis study supports considering both anatomic stage and receptor status in follow‐up recommendations. The implementation of risk‐stratified guidelines based on these data has the potential to improve the quality and efficiency of follow‐up.

Objective: We sought to evaluate local/regional recurrence rates after breast-conserving surgery in a cohort of patients enrolled in legacy trials of the Alliance for Clinical Trials in Oncology and to evaluate variation in recurrence rates by receptor subtype. Background: Multiple randomized controlled trials have demonstrated equivalent survival between breast conservation and mastectomy, albeit with higher local/regional recurrence rates after breast conservation. However, absolute rates of local/regional recurrence have been declining with multi-modality treatment. Methods: Data from 5 Alliance for Clinical Trials in Oncology legacy trials that enrolled women diagnosed with breast cancer between 1997 and 2010 were included. Women who underwent breast-conserving surgery and standard systemic therapies (n=4,404) were included. Five-year rates of local/regional recurrence were estimated from Kaplan-Meier curves. Patients were censored at the time of distant recurrence (if recorded as the first recurrence), death, or last follow-up. Multivariable Cox proportional hazards models were used to identify factors associated with time to local/regional recurrence, including patient age, tumor size, lymph node status, and receptor subtype. Results: Overall 5-year recurrence was 4.6% (95% CI=4.0-5.4%). Five-year recurrence rates were lowest in those with ER+ or PR+ tumors (Her2+ 3.4% [95% CI 2.0-5.7%], Her2- 4.0% [95% CI 3.2-4.9%]) and highest in the triple-negative subtype (7.1% [95% CI 5.4-9.3%]). On multivariable analysis, increasing nodal involvement and triple-negative subtype were positively associated with recurrence (P<0.0001). Conclusions: Rates of local/regional recurrence after breast conservation in women with breast cancer enrolled in legacy trials of the Alliance for Clinical Trials in Oncology are significantly lower than historic estimates. This data can better inform patient discussions and surgical decision-making.

Abstract Background Guidelines for follow-up after locoregional breast cancer treatment recommend imaging for distant metastases only in the presence of patient signs and/or symptoms. However, guidelines have not been updated to reflect advances in imaging, systemic therapy, or the understanding of biological subtype. We assessed the association between mode of distant recurrence detection and survival. Methods In this observational study, a stage-stratified random sample of women with stage II-III breast cancer in 2006-2007 and followed through 2016 was selected, including up to 10 women from each of 1217 Commission on Cancer facilities (n = 10 076). The explanatory variable was mode of recurrence detection (asymptomatic imaging vs signs and/or symptoms). The outcome was time from initial cancer diagnosis to death. Registrars abstracted scan type, intent (cancer-related vs not, asymptomatic surveillance vs not), and recurrence. Data were merged with each patient’s National Cancer Database record. Results Surveillance imaging detected 23.3% (284 of 1220) of distant recurrences (76.7%, 936 of 1220 by signs and/or symptoms). Based on propensity-weighted multivariable Cox proportional hazards models, patients with asymptomatic imaging compared with sign and/or symptom detected recurrences had a lower risk of death if estrogen receptor (ER) and progesterone receptor (PR) negative, HER2 negative (triple negative; hazard ratio [HR] = 0.73, 95% confidence interval [CI] = 0.54 to 0.99), or HER2 positive (HR = 0.51, 95% CI = 0.33 to 0.80). No association was observed for ER- or PR-positive, HER2-negative (HR = 1.14, 95% CI = 0.91 to 1.44) cancers. Conclusions Recurrence detection by asymptomatic imaging compared with signs and/or symptoms was associated with lower risk of death for triple-negative and HER2-positive, but not ER- or PR-positive, HER2-negative cancers. A randomized trial is warranted to evaluate imaging surveillance for metastases results in these subgroups.

6531 Background: Annual mammography is recommended to screen residual breast tissue for new cancers and recurrent disease after treatment for early stage breast cancer. This study aimed to assess mammography rates over time in breast cancer survivors. Methods: We used administrative claims data from a large U.S. commercial insurance database, OptumLabs, to retrospectively identify privately- and Medicare Advantage-insured women with operable breast cancer who had residual breast tissue after definitive breast surgery between 2006 and 2015. We required coverage for at least 13 months following surgery. For each subsequent 13-month time period, we only included women without a loss of coverage, bilateral mastectomy, metastatic breast cancer diagnosis, or non-breast cancer diagnosis. We calculated the proportion of patients who had a mammogram during each 13-month period following breast surgery. We used multivariable logistic regression to test for factors associated with mammography in the first 13 months. Results: The cohort included 26,011 women followed for a median of 2.9 years (IQR 1.9-4.6) after surgery; 63.1% were less than 65 years of age, and 74.4% were white. In their first year of follow-up, 86% underwent mammography, but by year 7, this decreased to 73%. Fewer than 1% underwent MRI instead of mammography. In multivariable analysis, mammograms were less likely during the first year after surgery among women aged < 50 years (odds ratio [OR], 0.7; 95% confidence interval [CI], 0.6 to 0.8), African Americans (OR, 0.7; 95% CI, 0.7 to 0.8), patients who underwent mastectomy (OR, 0.7; 95% CI, 0.6 to 0.7), and patients residing in the Western part of the country (OR, 0.9; 95% CI, 0.7 to 0.9). Those with 1-2 comorbidities were more likely (OR, 1.1; 95% CI 1.1-1.2) than those with none to have a mammogram during that period. Mammography use did not differ significantly by year of diagnosis (2006-2015). Conclusions: Even in an insured cohort, a substantial proportion of breast cancer survivors do not undergo annual surveillance mammography. Mammography use falls as the time from the early stage breast cancer diagnosis increases. Understanding factors associated with lack of mammographic screening may help improve survivorship care.

6520 Background: Breast cancer follow-up guidelines recommend imaging for distant metastases only in the presence of signs/symptoms. However, data supporting this recommendation predates the current era of improved imaging and targeted therapies based on molecular subtype. The objective was to assess the relationship between mode of distant recurrence detection and survival. Methods: A stage-stratified random sample of Stage II-III breast cancer patients diagnosed in 2006-7 was selected from NCDB records from 1,217 CoC-accredited facilities (10/hospital n = 10,853). Women were categorized by subtype: 1) ER or PR+/HER2-; 2) ER and PR-/Her2- (triple negative); 3) HER2+. Medical records abstracted for 5-years post-surgery supplemented NCDB data and assessed distant recurrence and mode of detection (prompted by signs/symptoms or surveillance imaging), imaging (chest CT, abdomen/pelvis CT/MRI, head CT/MRI, bone scan, PET/CT), death date. The relationship between mode of recurrence detection and days from initial cancer diagnosis to death was assessed using propensity-weighted multivariable Cox proportional hazards regression stratified by subtype. Propensity weights, based on receipt of surveillance systemic imaging, accounted for sociodemographic and tumor/treatment factors. Results: 5-year distant recurrence was 22.3% for triple negative, 14.8% HER2+, and 11.2% for ER or PR+/ HER2- patients. Asymptomatic imaging detected recurrence in 22.9% and signs/symptoms in 77.1%. Patients with asymptomatic as compared to sign/symptom detected recurrences had reduced risk of death in 5 years if triple negative (HR = 0.68, 95% CI = 0.50-0.93) or HER2+ (HR = 0.40, 95% CI = 0.24-0.65) with no significant association for ER or PR+/HER2- (HR = 1.2, 95% CI = 0.88-1.51). This translated to a between-group difference in weighted median survival of 5 months for triple negative and 13 months for HER2+ patients. Conclusions: This is the first nationally representative study to show a survival advantage with asymptomatic detection of distant metastases for patients, with the benefit limited to triple negative and HER2+ disease. Further research to confirm observational findings is warranted.