Antineoplastic Therapy Administration Safety Standards for Adult and Pediatric Oncology: ASCO-ONS Standards.

PURPOSE: To update the ASCO-Oncology Nursing Society (ONS) standards for antineoplastic therapy administration safety in adult and pediatric oncology and highlight current standards for antineoplastic therapy for adult and pediatric populations with various routes of administration and location. METHODS: ASCO and ONS convened a multidisciplinary Expert Panel with representation of multiple organizations to conduct literature reviews and add to the standards as needed. The evidence base was combined with the opinion of the ASCO-ONS Expert Panel to develop antineoplastic safety standards and guidance. Public comments were solicited and considered in preparation of the final manuscript. RESULTS: The standards presented here include clarification and expansion of existing standards to include home administration and other changes in processes of ordering, preparing, and administering antineoplastic therapy; the advent of immune effector cellular therapy; the importance of social determinants of health; fertility preservation; and pregnancy avoidance. In addition, the standards have added a fourth verification. STANDARDS: Standards are provided for which health care organizations and those involved in all aspects of patient care can safely deliver antineoplastic therapy, increase the quality of care, and reduce medical errors.Additional information is available at www.asco.org/standards and www.ons.org/onf.

Supportive Care for Cancer Patients Via Telehealth: Breaking Bad News and Providing Palliative Care Virtually.

ABSTRACT: Delivering oncologic care via telemedicine has presented a unique set of benefits and challenges. Discussions of sensitive topics between patients and providers can be difficult on a virtual platform. Although it was imperative to utilize telemedicine to keep cancer patients safe during the height of the pandemic, its continued use in the postvaccination era has provided important conveniences to both providers and patients. In the case of breaking bad news and end-of-life discussions, however, in-person care has remained the overwhelming preference of both groups. If face-to-face consultation is not possible or feasible in these situations, virtual visits are a viable option to connect oncologists with their patients.

Physician Disruptive Behavior Compromising Safe Care Delivery.

The negative impact and management of disruptive behavior are discussed in the article by Monika Kumar, et al.

Virtual Molecular and Precision Medicine Clinic to Improve Access to Clinical Trials for Patients With Metastatic Breast Cancer: An Academic/Community Collaboration.

PURPOSE: There is a demand for improved care delivery surrounding genomic testing and clinical trial enrollment among patients with metastatic breast cancer (MBC). We sought to improve the current process via real-time informal consultation and prescreening assessment for patients with MBC treated by community and academic medical oncologists by implementing a virtual molecular and precision medicine (vMAP) clinic. METHODS: The vMAP program used a virtual referral system directed to a multidisciplinary team with precision medicine expertise. Providers contacted vMAP regarding patients with MBC, and on receipt of referral, the vMAP team engaged in discussion to identify if further diagnostics were needed (including genomic testing) and to identify potential clinical trials or standard treatment options. Recommendations were then sent to the referring provider within 72 hours. Pre-/postsurveys were issued to network physicians to assess for barriers, clinical trial access, and vMAP referral experience. Program implementation was evaluated with the Squire 2.0 reporting guidelines for quality improvement in health care as a framework. RESULTS: Eighty-one cases from 22 providers were referred to vMAP over a 26-month period. The average response time to the referring provider with a finalized recommendation was 1.90 ± 1.82 days. A total of 86.4% of cases had clinical trial options on vMAP prescreen, with 40.7% initiating formal screening assessments and 27 patients (33.3%) ultimately enrolling on trials. On resurvey, 92% of survey responses across community oncology referring providers said that they were very likely to use vMAP again. CONCLUSION: In the initial 2-year period, vMAP demonstrated an efficient means to offer real-time interpretation of genomic testing and identification of clinical trials for patients with MBC, with effective clinical trial enrollment and high rates of referring provider satisfaction.

Uncovering the Risks of Anticancer Therapy Through Incident Report Analysis Using a Newly Developed Medical Oncology Incident Taxonomy.

BACKGROUND: Incident reporting systems were developed to identify possible and actual harm in healthcare facilities. They have the potential to capture important safety trends and to enable improvements that can mitigate the risk of future patient harm and suffering. We recently developed and validated a taxonomy specific for medical oncology designed to enhance the identification, tracking, and trending of incidents that may lead to patient harm. The current project was designed to test the ability of such a taxonomy to be applied across different organizations delivering medical oncology care and to identify specific risks that could result in future harm. METHODS: We analyzed 309 randomly selected medical oncology-related incident reports from 3 different cancer centers that had been posted between January 2019 and December 2020. Each report was assigned up to 2 incident categories. We used a 2-step process to reconcile reviewer discrepancies. In a secondary analysis, each of the incidents was reviewed and recoded to identify events which may result in major or catastrophic harm. RESULTS: Three hundred four incidents met criteria for inclusion. Three hundred incidents (98.7%) were successfully coded. Sixty-seven percent of incidents were encompassed by the following 4 of 21 categories: prescriber ordering (22%), nursing care (15%), pharmacy (14%), and relational/communication issues (15%). Of 297 evaluable incidents, 47% did not reach the patient, 44.7% reached the patient without harm, 7.7% caused minor injury, and 0.7% caused severe injury or death. Submission rates by physicians varied between the 3 sites accounting for 1.7%, 10.7%, and 16.1% of reports. Secondary analysis identified 9 distinct scenarios that may result in major or catastrophic patient harm. CONCLUSIONS: A medical oncology-specific incident reporting taxonomy has the potential to increase our understanding of inherent risks and may lead to process improvements that improve patient safety.

Preventing Future Harm: Identifying the Drivers of an Unsafe Discharge to Improve Safety on an Inpatient Oncology Service.

Cancer Morbidity, Mortality, and Improvement Rounds is a series of articles intended to explore the unique safety risks experienced by oncology patients through the lens of quality improvement, systems and human factors engineering, and cognitive psychology. For purposes of clarity, each case focuses on a single theme, although, as is true for all medical incidents, there are almost always multiple, overlapping, contributing factors. The quality improvement paradigm used here, which focuses on root cause analyses and opportunities to improve care delivery systems, was previously outlined in this journal.This article describes the care of a young patient with aggressive breast cancer, declining performance status, and multiple hospital admissions who died shortly after being discharged home without essential medications or an adequate plan for follow-up. The patient's death due to her malignancy was unavoidable, but she had inadequate resources before her death, leading to avoidable suffering. This outcome resulted from a series of minor errors attributable to inadequate handoffs, challenges establishing realistic goals of care, and hierarchy within and between medical teams that resulted in major lapses at the time of discharge. We explore these issues and discuss how this case led to the establishment of programs designed to empower health care providers and increase engagement of outpatient oncologists at critical points of patients' disease courses.

Cardiac outcomes of subjects on adjuvant trastuzumab emtansine vs paclitaxel in combination with trastuzumab for stage I HER2-positive breast cancer (ATEMPT) study (TBCRC033): a randomized controlled trial.

The excellent outcomes seen in patients treated with adjuvant trastuzumab emtansine (T-DM1) in the ATEMPT trial and the favorable toxicity profile associated with this agent make T-DM1 a potential therapeutic option for select patients with stage I HER2-positive breast cancer. Moreover, T-DM1 is an established adjuvant treatment for patients with HER2-positive breast cancer with the residual invasive disease after neoadjuvant therapy. Given that cardiotoxicity is the most significant adverse event of trastuzumab, which is a main molecular component of T-DM1, we conducted a sub-analysis of the ATEMPT trial to determine the cardiac safety of adjuvant T-DM1. In this analysis, the incidence of grade 3-4 left ventricular systolic dysfunction (LVSD) in T-DM1 or trastuzumab plus paclitaxel arms were respectively 0.8 and 1.8%. In addition, three (0.8%) patients in the T-DM1 arm and six (5.3%) patients in the adjuvant paclitaxel with trastuzumab (TH) arm experienced a significant asymptomatic left ventricular ejection fraction (LVEF) decline that per-protocol required holding T-DM1 or trastuzumab. All patients with available follow-up data experienced full resolution of cardiac symptoms and LVEF normalization. Furthermore, we performed an exploratory analysis to assess the relationship between age, baseline LVEF, and body mass index with cardiac outcomes. No significant association between these baseline characteristics and the incidence of significant asymptomatic LVEF decline or symptomatic LVSD was identified. The low incidence of significant cardiac adverse events in this population during therapy with adjuvant T-DM1 suggests that studies on the cost-effectiveness of cardiac monitoring during adjuvant therapy using anthracycline-free regimens are needed.Clinical Trial Registration: ClinicalTrials.gov, NCT01853748.

Telehealth in Oncology: ASCO Standards and Practice Recommendations.

PURPOSE: To provide standards and practice recommendations specific to telehealth in oncology. METHODS: A systematic review of the literature on telehealth in oncology was performed, including the use of technologies and telecommunications systems, and other electronic methods of care delivery and sharing of information with patients. The evidence base was combined with the opinion of the ASCO Telehealth Expert Panel to develop telehealth standards and guidance. Public comments were solicited and considered in preparation of the final manuscript. RESULTS: The Expert Panel determined that general guidance on implementing telehealth across general and specialty settings has been published previously and these resources are endorsed. A systematic search for studies on topics specific to oncology resulted in the inclusion of two clinical practice guidelines, 12 systematic reviews, and six primary studies. STANDARDS AND GUIDANCE: Standards and guidance are provided for which patients in oncology can be seen via telehealth, establishment of the doctor-physician relationship, role of allied health professionals, role of advanced practice providers, multidisciplinary cancer conferences, and teletrials in oncology. Additional information is available at www.asco.org/standards.

Chemotherapy-related amenorrhea (CRA) after adjuvant ado-trastuzumab emtansine (T-DM1) compared to paclitaxel in combination with trastuzumab (TH) (TBCRC033: ATEMPT Trial).

PURPOSE: Chemotherapy-related amenorrhea (CRA) is a surrogate for ovarian toxicity and associated risk of infertility and premature menopause. Here, we compare CRA rate with paclitaxel (T)-trastuzumab (H) to that with ado-trastuzumab emtansine (T-DM1). METHODS: Patients with T1N0 HER2 + early-stage breast cancer (eBC) enrolled on the ATEMPT trial and were randomized 3:1 to T-DM1 3.6 mg/kg IV every (q) 3 weeks (w) × 17 vs. T 80 mg/m2 with H IV qw × 12 (4 mg/kg load → 2 mg/kg), followed by H (6 mg/kg IV q3w × 13). Enrollees who self-reported as premenopausal were asked to complete menstrual surveys at baseline and every 6-12 months for 60 months. 18-month CRA (no periods reported during prior 6 months on 18-month survey) was the primary endpoint of this analysis. RESULTS: Of 512 ATEMPT enrollees, 123 who began protocol therapy and answered baseline and at least one follow-up menstrual survey were premenopausal at enrollment. 76 had menstrual data available at 18 months without having received a gonadotropin-releasing hormone agonist or undergone hysterectomy and/or oophorectomy. Median age was 45 (range 23-53) among 18 who had received TH and 46 (range 34-54) among 58 who had received T-DM1. The 18-month rate of CRA was 50% after TH and 24% after T-DM1 (p = 0.045). CONCLUSION: Amenorrhea at 18 months was less likely in recipients of adjuvant T-DM1 than TH. Future studies are needed to understand how T-DM1 impacts risk of infertility and permanent menopause, and to assess amenorrhea rates when T-DM1 is administered after standard HER2-directed chemotherapy regimens.

Adjuvant Trastuzumab Emtansine Versus Paclitaxel in Combination With Trastuzumab for Stage I HER2-Positive Breast Cancer (ATEMPT): A Randomized Clinical Trial.

PURPOSE: The ATEMPT trial was designed to determine if treatment with trastuzumab emtansine (T-DM1) caused less toxicity than paclitaxel plus trastuzumab (TH) and yielded clinically acceptable invasive disease-free survival (iDFS) among patients with stage I human epidermal growth factor receptor 2-positive (HER2+) breast cancer (BC). METHODS: Patients with stage I centrally confirmed HER2+ BC were randomly assigned 3:1 to T-DM1 or TH and received T-DM1 3.6 mg/kg IV every 3 weeks for 17 cycles or T 80 mg/m2 IV with H once every week × 12 weeks (4 mg/kg load →2 mg/kg), followed by H × 39 weeks (6 mg/kg once every 3 weeks). The co-primary objectives were to compare the incidence of clinically relevant toxicities (CRTs) in patients treated with T-DM1 versus TH and to evaluate iDFS in patients receiving T-DM1. RESULTS: The analysis population includes all 497 patients who initiated protocol therapy (383 T-DM1 and 114 TH). CRTs were experienced by 46% of patients on T-DM1 and 47% of patients on TH (P = .83). The 3-year iDFS for T-DM1 was 97.8% (95% CI, 96.3 to 99.3), which rejected the null hypothesis (P < .0001). Serially collected patient-reported outcomes indicated that patients treated with T-DM1 had less neuropathy and alopecia and better work productivity compared with patients on TH. CONCLUSION: Among patients with stage I HER2+ BC, one year of adjuvant T-DM1 was associated with excellent 3-year iDFS, but was not associated with fewer CRT compared with TH.

Telehealth Strategies to Support Patients and Families Across the Cancer Trajectory.

Effective delivery of cancer care via telehealth requires a planned care system that accounts for myriad patient, provider, and practice/cancer center resources before, during, and after the care episode. Telehealth is broadly defined as a method to have virtual, bidirectional communication between patients and providers. Telehealth can include methods such as audio-only, video-consultation, and tele-monitoring, which can occur in a synchronous, asynchronous, or blended format. The purpose of this review is to present common foundational principles for providing clinical cancer care via telehealth, followed by an overview of three distinct examples of comprehensive telehealth programs that have been developed to meet the needs of patients and families across the cancer trajectory, including survivorship, rehabilitation, and palliative care phases. The programs described are exemplars that were developed and implemented prior to the coronavirus pandemic, so they reflect many years of planning and evidence. Lessons learned include the need for ongoing patient support, clinician training, and cancer health system/practice programmatic considerations such as billing, scheduling, reimbursement, software, and hardware/platform security. Although the COVID-19 pandemic produced an explosive shift in regulations and implementation, sustainability of these changes may not be long-term. Nevertheless, a permanent shift in cancer care to include telehealth is likely here to stay.

Clinical Outcomes With Abemaciclib After Prior CDK4/6 Inhibitor Progression in Breast Cancer: A Multicenter Experience.

BACKGROUND: Inhibitors of cyclin-dependent kinases 4 and 6 (CDK4/6i) are widely used as first-line therapy for hormone receptor-positive metastatic breast cancer (HR+ MBC). Although abemaciclib monotherapy is also FDA-approved for treatment of disease progression on endocrine therapy, there is limited insight into the clinical activity of abemaciclib after progression on prior CDK4/6i. PATIENTS AND METHODS: We identified patients with HR+ MBC from 6 cancer centers in the United States who received abemaciclib after disease progression on prior CDK4/6i, and abstracted clinical features, outcomes, toxicity, and predictive biomarkers. RESULTS: In the multicenter cohort, abemaciclib was well tolerated after a prior course of CDK4/6i (palbociclib)-based therapy; a minority of patients discontinued abemaciclib because of toxicity without progression (9.2%). After progression on palbociclib, most patients (71.3%) received nonsequential therapy with abemaciclib (with ≥1 intervening non-CDK4/6i regimens), with most receiving abemaciclib with an antiestrogen agent (fulvestrant, 47.1%; aromatase inhibitor, 27.6%), and the remainder receiving abemaciclib monotherapy (19.5%). Median progression-free survival for abemaciclib in this population was 5.3 months and median overall survival was 17.2 months, notably similar to results obtained in the MONARCH-1 study of abemaciclib monotherapy in heavily pretreated HR+/HER2-negative CDK4/6i-naïve patients. A total of 36.8% of patients received abemaciclib for ≥6 months. There was no relationship between the duration of clinical benefit while on palbociclib and the subsequent duration of treatment with abemaciclib. RB1, ERBB2, and CCNE1 alterations were noted among patients with rapid progression on abemaciclib. CONCLUSIONS: A subset of patients with HR+ MBC continue to derive clinical benefit from abemaciclib after progression on prior palbociclib. These results highlight the need for future studies to confirm molecular predictors of cross-resistance to CDK4/6i therapy and to better characterize the utility of abemaciclib after disease progression on prior CDK4/6i.

Implementation of a High-Risk Breast Clinic for Comprehensive Care of Women With Elevated Breast Cancer Risk Identified by Risk Assessment Models in the Community.

INTRODUCTION: Many radiology centers perform risk assessment at time of screening mammography. The Massachusetts General Hospital North Shore Cancer Center (MGHNS) developed a nurse practitioner (NP)-led high-risk breast clinic (HRBC) to provide comprehensive care for patients with elevated breast cancer risk by a validated tool. PATIENTS AND METHODS: Patient and administrative data from the MGHNS HRBC was collected to evaluate clinical and implementation outcomes. We compared patients from the HRBC with those identified as having ≥ 20% lifetime risk at 5 community imaging centers. RESULTS: From March 2018 to February 2019, 318 patients were seen in the HRBC; 264 (83%) had ≥ 20% lifetime risk, 13 (4%) had prior atypia/lobular carcinoma in situ, 9 (3%) had ≥ 1.7% 5-year risk, and 32 (10%) had no indication of elevated risk. Genetic testing was recommended for 159 patients (50%); 33 (21%) completed testing with 1 mutation identified. Chemoprevention was discussed with 99 patients (31%); 9 (9%) initiated treatment. Screening magnetic resonance imaging (MRI) was recommended for 284 patients (89%); 184 (65%) had MRI performed with 2 mammographically occult cancers identified. During this time period, 215,112 patients had risk assessment performed at time of breast imaging; of these, 1,170 were found to have ≥ 20% lifetime risk. Compared with those identified as high risk in the community, patients seen in the HRBC were more likely to be white (94.3% v 85.4%; P < .001) and have a family history of ovarian cancer (16.4% v 9.4%; P < .001). CONCLUSION: We demonstrate the feasibility of an NP-led HRBC. Follow-through of recommendations by patients was highest for screening MRI; use of genetic testing and chemoprevention was lower than anticipated. In our community, uptake of the HRBC by referring providers remains a barrier, with only a minority of identified high-risk patients assessed in our clinic.

The adjuvant use of capecitabine for residual disease following pre-operative chemotherapy for breast cancer: Challenges applying CREATE-X to a US population.

INTRODUCTION: The CREATE-X study, conducted in Japan and South Korea, established capecitabine as an adjuvant treatment option for patients with triple negative breast cancer (TNBC) who have residual disease (RD) following neoadjuvant anthracycline or taxane-based chemotherapy. However, there are no reports on the tolerability and outcomes of adjuvant capecitabine in the US setting following publication of the CREATE-X data. METHODS: We retrospectively collected treatment and tolerability data from the medical records of the first 23 TNBC patients who received adjuvant capecitabine for RD post neoadjuvant chemotherapy at our institution. Disease-free survival was assessed using the Kaplan-Meier method. RESULTS: The median starting dosage of capecitabine was 1871 mg/m2/day, most commonly divided into two daily doses on days 1-14 of each 21 day cycle. 34.8% of patients completed the treatment as prescribed. Side effects associated with treatment were common with 69.6% of patients experiencing hand-foot syndrome, 39.1% of patients experiencing diarrhea, and 13.0% of patients requiring hospitalization for side effects. Of 23 patients treated with adjuvant capecitabine, 34.8% completed the planned dose, 30.4% completed with dose reduction, and 34.8% discontinued early. At a median follow-up time of 14 months, the median disease-free survival was 22 months, with 30.4% of patients experiencing recurrence. CONCLUSION: Tolerability was poor overall compared to the CREATE-X cohort. Administering adjuvant capecitabine for TNBC patients with residual disease in the United States is challenging given differences in tolerability. More research is needed to understand how poor tolerability will affect the efficacy of this approach in the US population.

Clinical Outcomes of Patients with Metastatic Cancer Receiving Immune Checkpoint Inhibitors in the Inpatient Setting.

BACKGROUND: As indications for immune checkpoint inhibitor (ICI) therapy have increased in recent years, so has the proportion of patients eligible for this type of therapy. However, a lack of data exists about the risks and benefits of ICI therapy in hospitalized patients, who tend to be frailer and sicker than patients enrolled in clinical trials. MATERIAL AND METHODS: We conducted a retrospective cohort study among hospitalized patients with metastatic solid tumors who received ICI therapy at a large academic cancer center over the course of 4 years. We analyzed the characteristics and outcomes of these patients and identified demographic and clinical factors that could be used to predict mortality. RESULTS: During the 4-year study period, 106 patients were treated with ICI therapy while admitted to the hospital; 70 (66%) had Eastern Cooperative Oncology Group Performance Status ≥2, which would have prevented them from enrolling in most clinical trials of ICIs. Fifty-two patients (49%) died either during admission or within 30 days of discharge; median overall survival was 1.0 month from discharge, and 16 patients (15%) were alive 6 months after discharge. Independent predictors of death following receipt of inpatient ICI included a diagnosis of non-small cell lung cancer relative to melanoma and prior treatment with two or more lines of therapy. CONCLUSION: The poor overall outcomes observed in this study may give clinicians pause when considering ICI therapy for hospitalized patients, particularly those with characteristics that are associated with a greater risk of mortality. IMPLICATIONS FOR PRACTICE: Immunotherapy strategies for patients with cancer are rapidly evolving and their use is expanding, but not all patients will develop a response, and secondary toxicity can be significant and challenging. This is especially evident in hospitalized patients, where the economic cost derived from inpatient immune checkpoint inhibitor (ICI) administration is important and the clinical benefit is sometimes unclear. The poor overall outcomes evidenced in the ICI inpatient population in this study highlight the need to better identify the patients that will respond to these therapies, which will also help to decrease the financial burden imposed by these highly priced therapies.

Associations of baseline patient-reported outcomes with treatment outcomes in advanced gastrointestinal cancer.

BACKGROUND: Patient-reported outcomes (PROs) assessing quality of life (QOL) and symptom burden correlate with clinical outcomes in patients with cancer. However, to the authors' knowledge, data regarding associations between PROs and treatment response are lacking. METHODS: The authors prospectively approached consecutive patients with advanced gastrointestinal cancer who were initiating a new treatment. Prior to treatment, patients reported their QOL (Functional Assessment of Cancer Therapy-General [FACT-G], 4 subscales: Functional, Physical, Emotional, Social; higher scores indicate better QOL) and symptom burden (Edmonton Symptom Assessment System [ESAS], Patient Health Questionnaire-4 [PHQ-4]; higher scores represent greater symptoms). Regression models were used to examine associations of baseline PROs with treatment response (clinical benefit or progressive disease [PD] at time of first scan), healthcare utilization, and survival. RESULTS: From May 2019 to April 2020, a total of 112 patients with advanced gastrointestinal cancer were enrolled. For treatment response, 64.3% had CB and 35.7% had PD. Higher baseline ESAS-Physical (odds ratio, 1.04; P = .027) and lower FACT-G Functional (odds ratio, 0.92; P = .038) scores were associated with PD. Higher ESAS-Physical (hazard ratio [HR], 1.03; P = .044) and lower FACT-G Total (HR, 0.96; P = .005), FACT-G Physical (HR, 0.89; P < .001), and FACT-G Functional (HR, 0.87; P < .001) scores were associated with a greater hospitalization risk. Lower FACT-G Total (HR, 0.96; P = .009) and FACT-G Emotional (HR, 0.86; P = .012) scores as well as higher ESAS-Total (HR, 1.03; P = .014) and ESAS-Physical (HR, 1.04; P = .032) scores were associated with worse survival. CONCLUSIONS: Baseline PROs are associated with treatment response in patients with advanced gastrointestinal cancer, namely physical symptoms and functional QOL, in addition to health care use and survival. The findings of the current study support the association between PROs and important clinical outcomes, including the novel finding of treatment response.

Association of Peer Comparison Emails With Electronic Health Record Documentation of Cancer Stage by Oncologists.

Importance: Systematically capturing cancer stage is essential for any serious effort by health systems to monitor outcomes and quality of care in oncology. However, oncologists do not routinely record cancer stage in machine-readable structured fields in electronic health records (EHRs). Objective: To evaluate whether a peer comparison email intervention that communicates an oncologist's performance on documenting cancer stage relative to that of peer physicians was associated with increased likelihood that stage was documented in the EHR. Design, Setting, and Participants: This 12-month, randomized quality improvement pilot study aimed to increase oncologist staging documentation in the EHR. The pilot study was performed at Massachusetts General Hospital Cancer Center from October 1, 2018, to September 30, 2019. Participants included 56 oncologists across 3 practice sites who treated patients in the ambulatory setting and focused on diseases that use standardized staging systems. Data were analyzed from July 2, 2019, to March 5, 2020. Interventions: Peer comparison intervention with as many as 3 emails to oncologists during 6 months that displayed the oncologist's staging documentation rate relative to all oncologists in the study sample. Main Outcomes and Measures: The primary outcome was patient-level documentation of cancer stage, defined as the likelihood that a patient's stage of disease was documented in the EHR after the patient's first (eg, index) ambulatory visit during the pilot period. Results: Among the 56 oncologists participating (32 men [57%]), receipt of emails with peer comparison data was associated with increased likelihood of documentation of cancer stage using the structured field in the EHR (23.2% vs 13.0% of patient index visits). In adjusted analyses, this difference represented an increase of 9.0 (95% CI, 4.4-13.5) percentage points (P = .002) in the probability that a patient's cancer stage was documented, a relative increase of 69% compared with oncologists who did not receive peer comparison emails. The association increased with each email that was sent, ranging from a nonsignificant 4.0 (95% CI, -0.8 to 8.8) percentage points (P = .09) after the first email to a statistically significant 11.2 (95% CI, 4.9-17.4) percentage points (P = .003) after the third email . The association was concentrated among an oncologist's new patients (increase of 11.8 [95% CI, 6.2-17.4] percentage points; P = .001) compared with established patients (increase of 1.6 [95% CI, -2.9 to 6.1] percentage points; P = .44) and persisted for 7 months after the email communications stopped. Conclusions and Relevance: In a quality improvement pilot trial, peer comparison emails were associated with a substantial increase in oncologist use of the structured field in the EHR to document stage of disease.