Association of Attending Surgeon With Variation in the Receipt of Genetic Testing After Diagnosis of Breast Cancer

Importance

Genetic testing after diagnosis of breast cancer is common, but little is known about the influence of the surgeon on the variation in testing.

Objectives

To quantify and explain the association of attending surgeon with rates of genetic testing after diagnosis of breast cancer.

Design, Setting, and Participants

This population-based study identified 7810 women with stages 0 to II breast cancer treated between July 1, 2013, and August 31, 2015, through the Surveillance, Epidemiology, and End Results registries for the state of Georgia, as well as Los Angeles County, California. Surveys were sent approximately 2 months after surgery. Also surveyed were 488 attending surgeons identified by the patients.

Main Outcomes and Measures

The study examined the association of surgeon with variation in the receipt of genetic testing using information from patient and surgeon surveys merged to Surveillance, Epidemiology, and End Results and genetic testing data obtained from 4 laboratories.

Results

In total, 5080 women (69.6%) of 7303 who were eligible (mean [SD] age, 61.4 [0.8] years) and 377 surgeons (77.3%) of 488 (mean [SD] age, 53.8 [10.7] years) responded to the survey. Approximately one-third (34.5% [1350 of 3910] of patients had an elevated risk of mutation carriage, and 27.0% (1056 of 3910) overall had genetic testing. Surgeons had practiced a mean (SE) of 20.9 (0.6) years, and 28.9% (107 of 370) treated more than 50 cases of new breast cancer per year. The odds of a patient receiving genetic testing increased more than 2-fold (odds ratio, 2.48; 95% CI, 1.85-3.31) if she saw a surgeon with an approach 1 SD above that of a surgeon with the mean test rate. Approximately one-third (34.1%) of the surgeon variation was explained by patient volume and surgeon attitudes about genetic testing and counseling. If a patient with higher pretest risk saw a surgeon at the 5th percentile of the surgeon distribution, she would have a 26.3% (95% CI, 21.9%-31.2%) probability of testing compared with 72.3% (95% CI, 66.7%-77.2%) if she saw a surgeon at the 95th percentile.

Conclusions and Relevance

In this study, the attending surgeon was associated with the receipt of genetic testing after a breast cancer diagnosis. Variation in surgeon attitudes about genetic testing and counseling may explain a substantial amount of this association.

Uptake, Results, and Outcomes of Germline Multiple-Gene Sequencing After Diagnosis of Breast Cancer

Importance

Low-cost sequencing of multiple genes is increasingly available for cancer risk assessment. Little is known about uptake or outcomes of multiple-gene sequencing after breast cancer diagnosis in community practice.

Objective

To examine the effect of multiple-gene sequencing on the experience and treatment outcomes for patients with breast cancer.

Design, Setting, and Participants

For this population-based retrospective cohort study, patients with breast cancer diagnosed from January 2013 to December 2015 and accrued from SEER registries across Georgia and in Los Angeles, California, were surveyed (n = 5080, response rate = 70%). Responses were merged with SEER data and results of clinical genetic tests, either BRCA1 and BRCA2 (BRCA1/2) sequencing only or including additional other genes (multiple-gene sequencing), provided by 4 laboratories.

Main Outcomes and Measures

Type of testing (multiple-gene sequencing vs BRCA1/2-only sequencing), test results (negative, variant of unknown significance, or pathogenic variant), patient experiences with testing (timing of testing, who discussed results), and treatment (strength of patient consideration of, and surgeon recommendation for, prophylactic mastectomy), and prophylactic mastectomy receipt. We defined a patient subgroup with higher pretest risk of carrying a pathogenic variant according to practice guidelines.

Results

Among 5026 patients (mean [SD] age, 59.9 [10.7] years), 1316 (26.2%) were linked to genetic results from any laboratory. Multiple-gene sequencing increasingly replaced BRCA1/2-only testing over time: in 2013, the rate of multiple-gene sequencing was 25.6% and BRCA1/2-only testing, 74.4%; in 2015 the rate of multiple-gene sequencing was 66.5% and BRCA1/2-only testing, 33.5%. Multiple-gene sequencing was more often ordered by genetic counselors (multiple-gene sequencing, 25.5% and BRCA1/2-only testing, 15.3%) and delayed until after surgery (multiple-gene sequencing, 32.5% and BRCA1/2-only testing, 19.9%). Multiple-gene sequencing substantially increased rate of detection of any pathogenic variant (multiple-gene sequencing: higher-risk patients, 12%; average-risk patients, 4.2% and BRCA1/2-only testing: higher-risk patients, 7.8%; average-risk patients, 2.2%) and variants of uncertain significance, especially in minorities (multiple-gene sequencing: white patients, 23.7%; black patients, 44.5%; and Asian patients, 50.9% and BRCA1/2-only testing: white patients, 2.2%; black patients, 5.6%; and Asian patients, 0%). Multiple-gene sequencing was not associated with an increase in the rate of prophylactic mastectomy use, which was highest with pathogenic variants in BRCA1/2 (BRCA1/2, 79.0%; other pathogenic variant, 37.6%; variant of uncertain significance, 30.2%; negative, 35.3%).

Conclusions and Relevance

Multiple-gene sequencing rapidly replaced BRCA1/2-only testing for patients with breast cancer in the community and enabled 2-fold higher detection of clinically relevant pathogenic variants without an associated increase in prophylactic mastectomy. However, important targets for improvement in the clinical utility of multiple-gene sequencing include postsurgical delay and racial/ethnic disparity in variants of uncertain significance.

Preliminary safety and efficacy of first-line pertuzumab combined with trastuzumab and taxane therapy for HER2-positive locally recurrent or metastatic breast cancer (PERUSE)

BACKGROUND

Pertuzumab combined with trastuzumab and docetaxel is the standard first-line therapy for HER2-positive metastatic breast cancer, based on results from the phase III CLEOPATRA trial. PERUSE was designed to assess the safety and efficacy of investigator-selected taxane with pertuzumab and trastuzumab in this setting.

PATIENTS AND METHODS

In the ongoing multicentre single-arm phase IIIb PERUSE study, patients with inoperable HER2-positive advanced breast cancer (locally recurrent/metastatic) (LR/MBC) and no prior systemic therapy for LR/MBC (except endocrine therapy) received docetaxel, paclitaxel or nab-paclitaxel with trastuzumab [8 mg/kg loading dose, then 6 mg/kg every 3 weeks (q3w)] and pertuzumab (840 mg loading dose, then 420 mg q3w) until disease progression or unacceptable toxicity. The primary end point was safety. Secondary end points included overall response rate (ORR) and progression-free survival (PFS).

RESULTS

Overall, 1436 patients received at least one treatment dose (initially docetaxel in 775 patients, paclitaxel in 589, nab-paclitaxel in 65; 7 discontinued before starting taxane). Median age was 54 years; 29% had received prior trastuzumab. Median treatment duration was 16 months for pertuzumab and trastuzumab and 4 months for taxane. Compared with docetaxel-containing therapy, paclitaxel-containing therapy was associated with more neuropathy (all-grade peripheral neuropathy 31% versus 16%) but less febrile neutropenia (1% versus 11%) and mucositis (14% versus 25%). At this preliminary analysis (52 months' median follow-up), median PFS was 20.6 [95% confidence interval (CI) 18.9-22.7] months overall (19.6, 23.0 and 18.1 months with docetaxel, paclitaxel and nab-paclitaxel, respectively). ORR was 80% (95% CI 78%-82%) overall (docetaxel 79%, paclitaxel 83%, nab-paclitaxel 77%).

CONCLUSIONS

Preliminary findings from PERUSE suggest that the safety and efficacy of first-line pertuzumab, trastuzumab and taxane for HER2-positive LR/MBC are consistent with results from CLEOPATRA. Paclitaxel appears to be a valid alternative taxane backbone to docetaxel, offering similar PFS and ORR with a predictable safety profile.

CLINICALTRIALS.GOV

NCT01572038.

Abstract P6-13-03: Not presented

This abstract was not presented at the conference.

Citation Format: Glaspy J, Tang T, Rutty D, Yan X, Bondarenko I, Burdaeva O. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-13-03.

Recent Trends in Chemotherapy Use and Oncologists' Treatment Recommendations for Early-Stage Breast Cancer

Background

There is growing concern about overtreatment of breast cancer as outcomes have improved over time. However, little is known about how chemotherapy use and oncologists' recommendations have changed in recent years.

Methods

We surveyed 5080 women (70% response rate) diagnosed with breast cancer between 2013 and 2015 and accrued through two Surveillance, Epidemiology, and End Results registries (Georgia and Los Angeles) about chemotherapy receipt and their oncologists' chemotherapy recommendations. We surveyed 504 attending oncologists (60.3% response rate ) about chemotherapy recommendations in node-negative and node-positive case scenarios. We conducted descriptive statistics of chemotherapy use and patients' report of oncologists' recommendations and used a generalized linear mixed model of chemotherapy use according to time and clinical factors. All statistical tests were two-sided.

Results

The analytic sample was 2926 patients with stage I-II, estrogen receptor-positive, human epidermal growth factor receptor 2-negative breast cancer. From 2013 to 2015, keeping other factors constant, chemotherapy use was estimated to decline from 34.5% (95% confidence interval [CI] = 30.8% to 38.3%) to 21.3% (95% CI = 19.0% to 23.7%, P < .001). Estimated decline in chemotherapy use was from 26.6% (95% CI = 23.0% to 30.7%) to 14.1% (95% CI = 12.0% to 16.3%) for node-negative/micrometastasis patients and from 81.1% (95% CI = 76.6% to 85.0%) to 64.2% (95% CI = 58.6% to 69.6%) for node-positive patients. Use of the 21-gene recurrence score (RS) did not change among node-negative/micrometastasis patients, and increasing RS use in node-positive patients accounted for one-third of the chemotherapy decline. Patients' report of oncologists' recommendations for chemotherapy declined from 44.9% (95% CI = 40.2% to 49.7%) to 31.6% (95% CI = 25.9% to 37.9%), controlling for other factors. Oncologists were much more likely to order RS if patient preferences were discordant with their recommendations (67.4%, 95% CI = 61.7% to 73.0%, vs 17.5%, 95% CI = 13.1% to 22.0%, concordant), and they adjusted recommendations based on patient preferences and RS results.

Conclusions

For both node-negative/micrometastasis and node-positive patients, chemotherapy receipt and oncologists' recommendations for chemotherapy declined markedly over time, without substantial change in practice guidelines. Results of ongoing trials will be essential to confirm the quality of this approach to breast cancer care.

Abstract P1-14-01: Final analysis of overall survival (OS) for the epoetin alfa (EPO) phase 3 study, EPO-ANE-3010, of EPO plus standard supportive care (SOC) versus SOC in anemic patients with metastatic breast cancer (MBC) receiving standard chemotherapy

Background: In the interim analysis of study EPO-ANE-3010, for the primary endpoint of progression-free survival (PFS), the non-inferiority objective in ruling out a 15% increased risk in progressive death (PD) or death per investigator-determined PD was not achieved (JCO 34:1197-1207, 2016). PFS, based on independent review committee (IRC)-determined PD, however, met the non-inferiority criteria. At the interim analysis, OS with 1,337 deaths was reported; we now report the final analysis at 1,653 deaths and the updated PFS.

Methods: This multinational (19 countries and 132 participating sites), phase 3, randomized, open-label noninferiority study included anemic (≤11.0 g/dL hemoglobin) women receiving first- or second-line standard chemotherapy for MBC (Eastern Cooperative Oncology Group performance status of 0 or 1). Subjects were randomized (1:1) to receive either standard SOC for treatment of anemia plus EPO (40,000 IU subcutaneous) weekly up to 4 weeks after the last dose of cytotoxic chemotherapy, or SOC alone. The primary endpoint was PFS (using Cox's regression model). Secondary endpoints included OS, time to tumor progression (TPP), overall response rate (ORR) and safety assessments.

Results: A total of 2,098 subjects were enrolled (EPO plus SOC: n=1,050; SOC alone: n=1048). Demographic and baseline characteristics were well-balanced across the groups; median age was 52 years, most were white (67.5%) or Asian (30.5%) and median BMI was 26.0 kg/m2. Primary efficacy analysis (based on investigator-determined PD) showed a median PFS of 7.4 months for both groups (hazard ratio [HR], 1.094; 95% CI: 0.996, 1.201);upper bound exceeded prespecified noninferiority margin of 1.15. A 9% increased risk for PD/death in the EPO plus SOC group was observed and did not statistically rule out a 15% increased risk. Median PFS per IRC-determined PD was 7.6 months in both groups (HR, 1.028; 95% CI: 0.922, 1.146), this met pre-defined non-inferiority margin of 1.15 with a 3% risk increase in PD/death in EPO plus SOC group. At the final analysis for OS, median OS was 17.8 months in the EPO plus SOC group and 18.0 months in the SOC group; HR: 1.073 (95% CI: 0.974, 1.182); median TPP was 7.5 months in both groups (HR, 1.099; 95% CI, 0.998 to 1.210), and ORR was 50% in the EPO plus SOC group and 51% in the SOC group (odds ratio, 0.939; 95% CI, 0.789, 1.117). Red blood cell (RBC) transfusions were 5.8% versus 11.5% (P&lt;0.001), and thrombotic vascular events were 2.8% versus 1.4% (P=0.038), respectively, in EPO plus SOC group and SOC group. The incidence of death due to PD were similar in both groups (EPO plus SOC: 93%; SOC: 91%).

Conclusion:The primary endpoint, PFS based on investigator-determined PD, did not meet noninferiority criteria but for PFS based on IRC-determined PD, noninferiority criteria was met. Overall, this study did not statistically rule-out a 15% increased risk in PD/death. The final analysis did not show statistically different OS in the EPO plus SOC group versus the SOC group. No new safety signals were noted with EPO treatment and the results are consistent with the known safety profile of EPO.

Citation Format: Leyland-Jones B, Bondarenko I, Nemsadze G, Smirnov V, Litvin I, Kokhreidze I, Abshilava L, Janjalia M, Li R, Lakshmaiah KC, Samkharadze B, Tarasova O, Shparyk Y, Polenkov S, Vladimirov V, Han J, Safonov I, Appiani C, Leitz G. Final analysis of overall survival (OS) for the epoetin alfa (EPO) phase 3 study, EPO-ANE-3010, of EPO plus standard supportive care (SOC) versus SOC in anemic patients with metastatic breast cancer (MBC) receiving standard chemotherapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-14-01.

Dabrafenib plus trametinib versus dabrafenib monotherapy in patients with metastatic BRAF V600E/K-mutant melanoma: long-term survival and safety analysis of a phase 3 study

Background

Previous analysis of COMBI-d (NCT01584648) demonstrated improved progression-free survival (PFS) and overall survival (OS) with combination dabrafenib and trametinib versus dabrafenib monotherapy in BRAF V600E/K-mutant metastatic melanoma. This study was continued to assess 3-year landmark efficacy and safety after ≥36-month follow-up for all living patients.

Patients and methods

This double-blind, phase 3 study enrolled previously untreated patients with BRAF V600E/K-mutant unresectable stage IIIC or stage IV melanoma. Patients were randomized to receive dabrafenib (150 mg twice daily) plus trametinib (2 mg once daily) or dabrafenib plus placebo. The primary endpoint was PFS; secondary endpoints were OS, overall response, duration of response, safety, and pharmacokinetics.

Results

Between 4 May and 30 November 2012, a total of 423 of 947 screened patients were randomly assigned to receive dabrafenib plus trametinib (n = 211) or dabrafenib monotherapy (n = 212). At data cut-off (15 February 2016), outcomes remained superior with the combination: 3-year PFS was 22% with dabrafenib plus trametinib versus 12% with monotherapy, and 3-year OS was 44% versus 32%, respectively. Twenty-five patients receiving monotherapy crossed over to combination therapy, with continued follow-up under the monotherapy arm (per intent-to-treat principle). Of combination-arm patients alive at 3 years, 58% remained on dabrafenib plus trametinib. Three-year OS with the combination reached 62% in the most favourable subgroup (normal lactate dehydrogenase and <3 organ sites with metastasis) versus only 25% in the unfavourable subgroup (elevated lactate dehydrogenase). The dabrafenib plus trametinib safety profile was consistent with previous clinical trial observations, and no new safety signals were detected with long-term use.

Conclusions

These data demonstrate that durable (≥3 years) survival is achievable with dabrafenib plus trametinib in patients with BRAF V600-mutant metastatic melanoma and support long-term first-line use of the combination in this setting.

Veliparib with temozolomide or carboplatin/paclitaxel versus placebo with carboplatin/paclitaxel in patients with BRCA1/2 locally recurrent/metastatic breast cancer: randomized phase II study

Background

Homologous recombination defects in BRCA1/2-mutated tumors result in sensitivity to poly(ADP-ribose) polymerase inhibitors, which interfere with DNA damage repair. Veliparib, a potent poly(ADP-ribose) polymerase inhibitor, enhanced the antitumor activity of platinum agents and temozolomide in early phase clinical trials. This phase II study examined the safety and efficacy of intermittent veliparib with carboplatin/paclitaxel (VCP) or temozolomide (VT) in patients with BRCA1/2-mutated breast cancer.

Patients and methods

Eligible patients ≥18 years with locally recurrent or metastatic breast cancer and a deleterious BRCA1/2 germline mutation were randomized 1 : 1 : 1 to VCP, VT, or placebo plus carboplatin/paclitaxel (PCP). Primary end point was progression-free survival (PFS); secondary end points included overall survival (OS) and overall response rate (ORR).

Results

Of 290 randomized patients, 284 were BRCA+, confirmed by central laboratory. For VCP versus PCP, median PFS was 14.1 and 12.3 months, respectively [hazard ratio (HR) 0.789; 95% CI 0.536-1.162; P = 0.227], interim median OS 28.3 and 25.9 months (HR 0.750; 95% CI 0.503-1.117; P = 0.156), and ORR 77.8% and 61.3% (P = 0.027). For VT (versus PCP), median PFS was 7.4 months (HR 1.858; 95% CI 1.278-2.702; P = 0.001), interim median OS 19.1 months (HR 1.483; 95% CI 1.032-2.131; P = 0.032), and ORR 28.6% (P < 0.001). Safety profile was comparable between carboplatin/paclitaxel arms. Adverse events (all grades) of neutropenia, anemia, alopecia, and neuropathy were less frequent with VT versus PCP.

Conclusion

Numerical but not statistically significant increases in both PFS and OS were observed in patients with BRCA1/2-mutated recurrent/metastatic breast cancer receiving VCP compared with PCP. The addition of veliparib to carboplatin/paclitaxel significantly improved ORR. There was no clinically meaningful increase in toxicity with VCP versus PCP. VT was inferior to PCP. An ongoing phase III trial is evaluating VCP versus PCP, with optional continuation single-agent therapy with veliparib/placebo if chemotherapy is discontinued without progression, in this patient population.

Clinical trial information

NCT01506609.

Oncologists' influence on receipt of adjuvant chemotherapy: does it matter whom you see for treatment of curable breast cancer?

PURPOSE

We know little about whether it matters which oncologist a breast cancer patient sees with regard to receipt of chemotherapy. We examined oncologists' influence on use of recurrence score (RS) testing and chemotherapy in the community.

METHODS

We identified 7810 women with stages 0-II breast cancer treated in 2013-15 through the SEER registries of Georgia and Los Angeles County. Surveys were sent 2 months post-surgery, (70% response rate, n = 5080). Patients identified their oncologists (n = 504) of whom 304 responded to surveys (60%). We conducted multi-level analyses on patients with ER-positive HER2-negative invasive disease (N = 2973) to examine oncologists' influence on variation in RS testing and chemotherapy receipt, using patient and oncologist survey responses merged to SEER data.

RESULTS

Half of patients (52.8%) received RS testing and 27.7% chemotherapy. One-third (35.9%) of oncologists treated >50 new breast cancer patients annually; mean years in practice was 15.8. Oncologists explained 17% of the variation in RS testing but little of the variation in chemotherapy receipt (3%) controlling for clinical factors. Patients seeing an oncologist who was one standard deviation above the mean use of RS testing had over two-times higher odds of receiving RS (2.47, 95% CI 1.47-4.15), but a parallel estimate of the association of oncologist with the odds of receiving chemotherapy was much smaller (1.39, CI 1.03-1.88).

CONCLUSIONS

Clinical algorithms have markedly reduced variation in chemotherapy use across oncologists. Oncologists' large influence on variation in RS use suggests that they variably seek tumor profiling to inform treatment decisions.