Participation in adjuvant clinical breast cancer trials: does study participation improve survival compared to guideline adherent adjuvant treatment? A retrospective multi-centre cohort study of 9,433 patients

Harnessing Real-World Evidence to Advance Cancer Research

Randomized controlled trials (RCTs) form a cornerstone of oncology research by generating evidence about the efficacy of therapies in selected patient populations. However, their implementation is often resource- and cost-intensive, and their generalisability to patients treated in routine practice may be limited. Real-world evidence leverages data collected about patients receiving clinical care in routine practice outside of clinical trial settings and provides opportunities to identify and address gaps in clinical trial evidence. This review outlines the strengths and limitations of real-world and RCT evidence and proposes a framework for the complementary use of the two bodies of evidence to advance cancer research. There are challenges to the implementation of real-world research in oncology, including heterogeneity of data sources, timely access to high-quality data, and concerns about the quality of methods leveraging real-world data, particularly causal inference. Improved understanding of the strengths and limitations of real-world data and ongoing efforts to optimise the conduct of real-world evidence research will improve its reliability, understanding and acceptance, and enable the full potential of real-world evidence to be realised in oncology practice.

The association between guideline adherence, age and overall survival among women with non-metastatic breast cancer: A systematic review

INTRODUCTION

Conformity with treatment guidelines should benefit patients. Studies have reported variation in adherence to breast cancer (BC) guidelines, particularly among older women. This study investigated (i) whether adherence to treatment guideline recommendations for women with non-metastatic BC improves overall survival (OS), (ii) whether that relationship varies by age.

METHODOLOGY

MEDLINE and EMBASE were systematically searched for studies on guideline adherence and OS in women with non-metastatic BC, published after January 2000, which examined recommendations on breast surgery, chemotherapy, radiotherapy or endocrine therapy. Study results were summarised using narrative synthesis.

RESULTS

Sixteen studies met the inclusion criteria. The recommendations for each treatment covered were similar, but studies differed in their definitions of adherence. 5-year OS rates among patients having compliant treatment ranged from 91.3% to 93.2%, while rates among patients having non-compliant treatment ranged from 75.9% to 83.4%. Six studies reported an adjusted hazard ratio (aHR) for non-compliant treatment compared with compliant treatment; all concluded OS was worse among patients whose overall treatment was non-compliant (aHR range: 1.52 [1.30-1.82] to 2.57 [1.96-3.37]), but adjustment for potential confounders was limited. Worse adherence among older women was reported in 12/16 studies, but they did not provide consistent evidence on whether OS was associated with treatment adherence and age.

CONCLUSIONS

Individual studies reported that better adherence to guidelines improved OS among women with non-metastatic BC, but the evidence base has weaknesses including inconsistent definitions of adherence. More precise and consistent research designs, including the evaluation of barriers to adherence across the spectrum of healthcare practice, are required to fully understand guideline compliance, as well as the relationship between compliance and OS following a BC diagnosis.

Outcome analysis of primary breast cancer patients who declined adjuvant chemotherapy-results from the prospective multi-center BRENDA II study

BACKGROUND

This study examined 5-year overall, recurrence and distant metastasis-free survival (OS, RFS, MFS) of high- and intermediate-risk breast cancer (BC) patients who declined guideline-recommended adjuvant chemotherapy (CHT).

METHODS

In the prospective multicenter cohort study BRENDA II, patients with primary BC were sampled over a period of four years (2009-2012). A multi-professional team (tumorboard) discussed recommendation for adjuvant CHT according to the German guideline. Potential differences in 5 year survival were analyzed using Kaplan-Meier curves and Cox regression. The hazard ratios (HR) were adjusted for age, Charlson Comorbidity Score, American Society of Anesthesiologist (ASA) physical status classification, and endocrine therapy.

RESULTS

A total of 759 patients were enrolled of which 688 could receive CHT according to the guidelines (n = 219 had a clear indication, in n = 304 it was possible). For 360 patients, the tumorboard advised to perform CHT, for 304 it advised against and in 24 cases, no decision was documented. Of those with a positive suggestion, 83% received CHT. Until 5 years after diagnosis, 57 patients were deceased, 41 had at least one distant metastasis and 29 a recurrence. There was no evidence for differences in OS and MFS in patients who declined CHT despite tumorboard recommendation (HR 3.5, 95% CI 0.8-15.1 for OS, HR 1.9, 95% 0.6-6.6 for MFS). Patients who received CHT had significantly better 5-year RFS compared to those who declined (HR 0.3, 95% CI 0.1-0.9, p = 0.03). There was no evidence for different survival in those who had no CHT because of comorbidity and those who declined actively, neither for OS, MFS nor RFS.

CONCLUSION

The prospective BRENDA II study demonstrates benefit in RFS by guideline adherence in adjuvant breast cancer treatment, indicating prospectively the value of internationally validated guidelines in breast cancer care.

Factors influencing treatment decision and guideline conformity in high-grade endometrial cancer patients: a population-based study

PURPOSE

Treatment according to guidelines has been demonstrated to improve survival in a number of different cancer entities. Deviations from guidelines depend on several factors, including the patient's preferences, age and comorbidities. The aim of this study was to assess the adherence to guideline recommendations concerning surgical and adjuvant treatment in endometrial cancer. Furthermore, we sought to evaluate the reasons for non-adherence to guidelines by further examining the influence of comorbidities and age.

METHODS

The influence of age, comorbidities, tumor stage and histological subtype on guideline adherence was evaluated by multivariable logistic regression in a cohort of 353 high-grade endometrial cancer patients. High-grade endometrial cancer was defined as carcinosarcoma, Type II (serous, clear cell, mixed cell carcinoma) and Type I G3 histology.

RESULTS

Extensive surgical procedures, particularly systematic LNE, were less frequently applied in patients with comorbidities (p = 0.015) or higher age (p < 0.01). Guideline adherence was not affected by comorbidities (p = 0.563), but was significantly reduced with higher age (p < 0.01). In a multivariable model, higher age (p < 0.01), obesity (p = 0.011), higher FIGO Stage (p < 0.01) and histologic subtype (p < 0.01) significantly decreased OS. Surgery (p < 0.001), chemotherapy (p < 0.01) and systematic LNE (p = 0.011) were associated with higher OS.

CONCLUSION

Age seems to be the strongest independent factor leading to guideline deviation. Comorbidities were associated with less aggressive treatment, but not with deviations from guidelines.

Clinical Predictors of Early Trial Discontinuation for Patients Participating in Phase I Clinical Trials in Oncology

Simple Summary

About 20% of patients with cancer who participate in a phase I clinical trial discontinue the trial early. Early trial discontinuation is undesirable both for the wellbeing of the patient as well as for the trial efficiency and the development of new anticancer drugs. We investigated which clinical predictors at baseline were significantly associated with early trial discontinuation of patients with cancer who participated in phase I clinical trials. The clinical predictors which were identified in this study were hyponatremia, elevated alkaline phosphatase level, performance score of 1 or higher and opioid use. Hyponatremia especially, which was the strongest predictor, should be considered to be used as an additional eligibility criterion in order to reduce the early trial discontinuation of patients with cancer who participate in phase I clinical trials.

Abstract

Despite stringent eligibility criteria for trial participation, early discontinuation often occurs in phase I trials. To better identify patients unlikely to benefit from phase I trials, we investigated predictors for early trial discontinuation. Data from 415 patients with solid tumors who participated in 66 trials were pooled for the current analysis. Early trial discontinuation was defined as (i) trial discontinuation within 28 days after start of treatment or (ii) discontinuation before administration of the first dosage in eligible patients. Multilevel logistic regression analyses were conducted to identify predictors for early trial discontinuation. Eighty-two participants (20%) demonstrated early trial discontinuation. Baseline sodium level below the lower limit of normal (OR = 2.95, 95%CI = 1.27–6.84), elevated alkaline phosphatase level > 2.5 times the upper limit of normal (OR = 2.72, 95%CI = 1.49–4.99), performance score ≥ 1 (OR = 2.07, 95%CI = 1.03–4.19) and opioid use (OR = 1.82, 95%CI = 1.07–3.08) were independent predictors for early trial discontinuation. Almost 50% of the patients with hyponatremia and all four patients in whom all four predictors were present together discontinued the trial early. Hyponatremia, elevated alkaline phosphatase level, performance score ≥ 1 and opioid use were identified as significant predictors for early trial discontinuation. Hyponatremia was the strongest predictor and deserves consideration for inclusion in eligibility criteria for future trials.

Do hospital type or caseload make a difference in chemotherapy treatment patterns for early breast cancer? Results from 104 German institutions, 2008-2017

BACKGROUND

Over the past decade, chemotherapy has been used more selectively in early breast cancer (EBC) due to better risk stratification. Neoadjuvant chemotherapy (NACT) has evolved to the primary treatment option. The type and size of hospitals is known to have a substantial influence on the kinds of treatment they provide, and therefore on patient outcomes (e.g. rates for pathological complete response, pCR), but it is not yet known how this has affected delivery of chemotherapy for EBC in Germany.

METHODS

This study analyzed chemotherapy use and pCR rates after NACT for EBC patients treated at 104 German institutions 2008-2017. Institutions were separated into associated hospital type (university hospital; teaching hospital; community hospital) and annual caseload (≤100; 101-250; >250 cases/year).

RESULTS

Overall, 124,084 patients were included, of whom 11.6% were treated at university hospitals, 63.1% at teaching hospitals, and 25.3% at community hospitals. In total, 46,274 (37.3%) received chemotherapy, of whom 44,765 had information available about systemic treatment and surgery. From 2008 to 2017, chemotherapy use declined from 48.3% to 36.4% for university hospitals, from 40.7% to 30.3% for teaching hospitals, and from 42.4% to 33.7% for community hospitals. Furthermore, the proportion of NACT increased the most in university hospitals (from 32.0% to 68.1%); whereas, the rate of pCR (defined as ypT0 ypN0) increased irrespective of institutional type. Analyses regarding annual caseload did not show any differences.

CONCLUSIONS

The results from this large, nationwide cohort reflect a more selective use of chemotherapy in Germany, irrespective of institutional type or case load.

Survivors of primary breast cancer 5 years after surgery: follow-up care, long-term problems, and treatment regrets. Results of the prospective BRENDA II-study

PURPOSE

This study aims to answer the questions where breast cancer patients in Germany receive follow-up care (with what types of doctors) and what are the long-term problems and treatment regrets of breast cancer patients.

METHODS

In the prospective multicenter cohort study BRENDA II ("Breast Cancer under Evidence-Based Guidelines"), 456 patients with primary breast cancer were sampled consecutively over a period of 4 years (2009-2012) and contacted again 5 years after surgery. Long-term problems were elicited on a 4-point Likert scale ranging from 0 ('not at all') to 3 ('very much').

RESULTS

82% of the patients receive follow-up (FU) at the private practice gynecologist. In 22%, the initial treating hospital is involved in the FU, and in 20% the general practitioner does this (multiple answers possible). Long-term problems attributed to the treatment were most often related to endocrine therapy (mean 1.29) and to chemotherapy (mean 0.94). Most of the patients were happy to have had radiotherapy (95%). For chemotherapy, endocrine therapy, and antibody therapy, the satisfaction for the treatment decision was 87%, 87%, and 84% respectively. Among patients who reported they regretted having undergone a recommended treatment, it was most often for endocrine therapy (5%) and chemotherapy (4%).

CONCLUSION

In Germany, different specialists are involved in the patients' FU care for BC. The detection of long-term problems due to BC treatment is an essential part of FU care.

Update Breast Cancer 2019 Part 3 - Current Developments in Early Breast Cancer: Review and Critical Assessment by an International Expert Panel

The treatment of breast cancer patients in a curative situation is special in many ways. The local therapy with surgery and radiation therapy is a central aspect of the treatment. The complete elimination of tumour cells at the site of the primary disease must be ensured while simultaneously striving to keep the long-term effects as minor as possible. There is still focus on the continued reduction of the invasiveness of local therapy. With regard to systemic therapy, chemotherapies with taxanes, anthracyclines and, in some cases, platinum-based chemotherapies have become established in the past couple of decades. The context for use is being continually further defined. Likewise, there are questions in the case of antihormonal therapy which also still need to be further defined following the introduction of aromatase inhibitors, such as the length of therapy or ovarian suppression in premenopausal patients. Finally, personalisation of the treatment of early breast cancer patients is also being increasingly used. Prognostic tests could potentially support therapeutic decisions. It must also be considered how the possible use of new therapies, such as checkpoint inhibitors and CDK4/6 inhibitors could look in practice once study results in this regard are available. This overview addresses the backgrounds on the current votes taken by the international St. Gallen panel of experts in Vienna in 2019 for current questions in the treatment of breast cancer patients in a curative situation.

Association between cognitive impairment and guideline adherence for application of chemotherapy in older patients with breast cancer: Results from the prospective multicenter BRENDA II study

BACKGROUND

This study examined the association between cognitive impairment and guideline adherence for application of chemotherapy in older patients with breast cancer.

PATIENTS AND METHODS

In the prospective multicenter cohort study BRENDA II, patients aged ≥65 years with primary breast cancer were sampled over a period of 4 years (2009-2012). A multiprofessional team (tumor board) discussed recommendation for adjuvant chemotherapy according to the German S3 guideline. Cognitive impairment was screened by the clock-drawing test (CDT) prior to adjuvant treatment.

RESULTS

Two hundred and sixty-three patients were included in the study and CDT data were available for 193 patients. Thirty-one percent of the patients had cognitive impairment with different degree of severity. In high-risk patients (n = 61) tumor board recommendation in favor of chemotherapy was 90% and in intermediate-risk patients (n = 170) 27%. Not receiving recommendation for chemotherapy in spite of guideline recommendation was more frequent in patients with cognitive impairment (67%) vs patients without cognitive impairment (46%) with P = 0.02 (OR 2.4, 95% confidence interval (CI) 1.2-4.9). Age, education, migration background and comorbidities were not associated with chemotherapy recommendation by the tumor board among cognitively impaired patients. Once the tumor board had recommended chemotherapy, application of chemotherapy was similar in both groups of patients with or without cognitive impairment.

CONCLUSION

Almost one third of older patients with breast cancer are affected by cognitive impairment prior to adjuvant treatment. In these patients, cognitive impairment was associated with tumor board decision against chemotherapy in spite of a positive guideline recommendation.

The effect of participation in neoadjuvant clinical trials on outcomes in patients with early breast cancer

BACKGROUND

Clinical trials can offer novel and more advanced and/or novel treatments to cancer patients in advance of them being approved and available for all patients. While several studies have examined the effect of clinical trial participation on prognosis, there has been no clear conclusion from these studies. Therefore, we chose to test the influence of trial participation on pathological complete response (pCR) and mastectomy rates after neoadjuvant chemotherapy.

METHODS

In this retrospective study, all patients treated with neoadjuvant chemotherapy from 2001 to 2014 were selected. A total of 1038 patients with complete treatment, patient, and tumor characteristics were included. A total of 260 of those were treated in clinical trials. We examined whether study participation status in addition to commonly known predictors for pCR improves prediction of pCR. Similar analyses were conducted for the mastectomy rate outcome measure. Finally, survival analyses were also conducted as part of an exploratory analysis.

RESULTS

Study participation was an independent predictor of pCR in addition to commonly known predictors. Adjusted odds ratio (OR) for trial participants versus non-participants was 1.53 (95% CI 1.03-2.28). Additionally, study participation improved the prediction of mastectomy risk. The adjusted OR for trial participants versus non-participants was 0.62 (95% CI 0.42-0.90). Subgroup-specific differences concerning the impact of study participation could not be shown for either pCR or mastectomy rate. Survival comparisons could not be conducted due to large differences in follow-up data in patients participating in clinical trials versus those who did not participate; however, pCR was a predictor of prognosis in both groups.

CONCLUSION

Patients taking part in neoadjuvant chemotherapy clinical trials have a higher pCR rate and a lower mastectomy risk than patients not participating in clinical trials for their cancer care. This finding is a supporting factor for trial participation in neoadjuvant chemotherapy trials.

Comorbidity-dependent adherence to guidelines and survival in breast cancer-Is there a role for guideline adherence in comorbid breast cancer patients? A retrospective cohort study with 2137 patients

In the treatment of breast cancer, decisions on adjuvant treatment reflect individual patient characteristics like age and comorbidity. This study assessed the association between adherence to guidelines for adjuvant treatment and survival while taking into account age at diagnosis and comorbidities. We collected the Charlson comorbidity index at baseline for 2179 women treated for primary breast cancer from 1992 to 2008 who participated in a German retrospective multicenter cohort study. We assessed subsequent adjuvant therapy guideline adherence and survival in relation to baseline comorbidities. Guidelines for adjuvant chemotherapy and radiotherapy were more often violated in patients with higher Charlson score. Patients with higher Charlson scores received chemotherapy and radiotherapy less often and had higher rates of mastectomy. Irrespective of comorbidity (Charlson score 0, 1-2, ≥3), patients with 100% guideline-adherent adjuvant treatment showed better overall and disease-free survival (DFS) compared to patients with guideline violations (GVs). Controlling for age, comorbidity and tumor characteristics, the hazard ratio for at least one GV was 1.65 (95% confidence interval [CI]: 1.33-2.07) for overall survival and 1.84 (95% CI: 1.53-2.22) for DFS. Guideline-adherent treatment was significantly less frequent in comorbid patients, although guideline adherence was strongly associated with improved survival, irrespective of severity, and number of comorbid diseases.

The Impact of Age on Quality of Life in Breast Cancer Patients Receiving Adjuvant Chemotherapy: A Comparative Analysis From the Prospective Multicenter Randomized ADEBAR trial

BACKGROUND

Elderly breast cancer patients are affected by poorer quality of life (QoL) compared to younger patients. Because QoL has a relevant impact on guideline-adherent treatment, elderly breast cancer patients are often undertreated, especially with regard to adjuvant chemotherapy, and overall survival is decreased. Thus, understanding the impact of chemotherapy on QoL in elderly patients is crucial. This study compared QoL in patients aged < 65 years and 65 to 70 years receiving adjuvant chemotherapy as a secondary outcome in the prospective randomized multicenter ADEBAR trial.

PATIENTS AND METHODS

Patients with lymph node-positive breast cancer were prospectively randomized for either sequential anthracycline-taxane or epirubicin/fluorouracil/cyclophosphamid chemotherapy (FEC) therapy. QoL was assessed at baseline (t1), before cycle 4 FEC, and cycle 5 epirubicin/cyclophosphamid-docetaxel (EC-DOC) (t2), 4 weeks after chemotherapy (t3), and 6 weeks after radiation (t4) using the European Organization for Research and Treatment for Cancer (EORTC) Quality of Life Core Questionnaire (QLQ-C30) and the Breast Cancer-Specific Module (QLQ-BR23). We compared patients aged < 65 years and 65 to 70 years with respect to QoL and discontinuation of chemotherapy.

RESULTS

A total of 1363 patients were enrolled onto the ADEBAR trial, with 16.7% of the patients aged 65 to 70 years. In elderly patients, Eastern Cooperative Oncology Group performance status was higher and global health status and physical functioning were lower at baseline. Global health status decreased between t1 and t3 by 7 points in patients < 65 years and by 11 points in patients 65 to 70 years, and physical functioning decreased in the same period by 13.4 points in patients aged < 65 years and by 15.9 points in patients 65 to 70 years. In both groups, at t4 global health status exceeded baseline by 6 points, and physical functioning was 1.3 points under baseline in patients < 65 years old and 3 points under baseline in patients 65 to 70 years. There was a trend to more fatigue in elderly patients and to more nausea and vomiting while receiving chemotherapy in younger patients at t3. There was a higher dropout rate in patients aged 65 to 70 years (25.7%) than in patients aged < 65 years (16.2%).

CONCLUSION

There were only small or trivial differences in QoL in patients aged < 65 years versus 65 to 70 years who were receiving adjuvant chemotherapy, although the dropout rate from chemotherapy was notably higher in elderly breast cancer patients.

Impact of clinical trial on survival outcomes

The number of patients with breast cancer who participate in therapeutic clinical trials remains low. One reason is a lack of opportunity; another is health care providers who do not recommend trials because they fear poorer outcome from the use of new drugs. Thus, we compared survival outcome in patients with metastatic breast cancer (MBC) who participated in first-line therapeutic clinical trials with outcome in patients who had never enrolled in a clinical trial and received only standard care. We hypothesized that first-line therapeutic clinical trials does not have a negative survival outcome. We reviewed the records of patients with MBC who were treated at MD Anderson Cancer Center between January 2000, and December 2010. The medical records of 5501 patients with MBC were screened, and 652 patients-285 in the trial arm and 367 in the control arm-met our specific eligible criteria. The median follow-up of our cohort was 7.16 years (95 % confidence interval [CI] 6.53-7.64 years). Among the global population, no significant differences in progression-free survival (PFS) or overall survival (OS) were observed between the treatment arms: for the clinical trial cohort, median PFS was 7 months (95 % CI 5.72-8.71 months), and median OS was 28.48 months (95 % CI 22.70-34.60 months). For the control cohort, median PFS was 10.02 months (95 % CI 7.13-11.99 months), and median OS was 28.71 months (95 % CI 24.41-31.31 months) (P = .089 and .335, respectively). Enrollment in first-line MBC therapeutic clinical trials does not result in less favorable survival outcome than that in MBC patients who never enrolled in a clinical trial.

Under-representation of racial minorities in prostate cancer studies submitted to the US Food and Drug Administration to support potential marketing approval, 1993-2013

BACKGROUND

US Food and Drug Administration (FDA) approval of new drugs depends on results from clinical trials that must be generalized to the US population. However, racial minorities are frequently under-represented in clinical studies. The enrollment of racial minorities was compared in key clinical studies submitted to the FDA in the last 10 years in support of potential marketing approval for prostate cancer (PCa) prevention or treatment.

METHODS

Patient demographic data were obtained from archival data sets of large registration trials submitted to the FDA to support proposed PCa indications. Six countries/regions were analyzed: the United States, Canada, Australia, Europe, the United Kingdom, and Eastern Europe. Background racial demographics were collected from national census data.

RESULTS

Seventeen key PCa clinical trials were analyzed. These trials were conducted in the past 20 years, comprising 39,574 patients with known racial information. Most patients were enrolled in the United States, but there appeared to be a trend toward increased non-US enrollment over time. In all countries, racial minorities were generally under-represented. There was no significant improvement in racial minority enrollment over time. The United States enrolled the largest nonwhite population (7.1%).

CONCLUSIONS

Over the past 20 years, racial minorities were consistently under-represented in key PCa trials. There is a need for effective measures that will improve enrollment of racial minorities. With increased global enrollment, drug developers should aim to recruit a patient population that resembles the racial demographics of the patient population to which drug use will be generalized upon approval.

Patients' rationale for declining participation in a cancer-associated weight loss study

BACKGROUND

Fewer than 5 % of cancer patients participate in clinical research. Although this paltry rate has led to extensive research on this topic, previous studies have not sought verbatim comments in a real-time, comprehensive manner to understand why patients decline.

METHODS

This study used a low-risk, non-interventional parent study that focused on cancer-associated weight loss to understand patients' reasons for declining research participation. A research assistant wrote down the name and verbatim reason of all patients who declined to participate. These comments with accompanying patient demographic data are the subject of this report.

RESULTS

Of the 334 patients, 51 (15 %) declined parent study enrollment; three comment-related themes emerged: (1) a repelling sense of too much institutional research, (2) overwhelming personal health issues, and (3) a low likelihood of returning to the institution. In univariate and multivariate analyses, only age (older) and gender (female) were associated with non-enrollment. Interestingly, 41 patients with fatigue scores of 7 or worse and 26 with pain scores of 7 or worse were enrolled.

CONCLUSIONS

Although many factors were associated with declining to participate in research, symptom severity was not. Upfront education might help cancer patients better prioritize their participation in research, particularly as some patients felt overwhelmed by too much research in the institution; and for now, investigators should continue to keep asking patients for their participation.

Guideline concordant therapy prolongs survival in HER2-positive breast cancer patients: results from a large population-based cohort of a cancer registry

Even though randomized controlled clinical trials demonstrated improved survival by adjuvant trastuzumab treatment of HER2-positive breast cancer patients, data on its effect in clinical routine are scarce. This study evaluated the use and efficacy of trastuzumab in routine treatment of HER2-positive breast cancer patients. Data from the clinical cancer registry Regensburg (Germany) were analyzed. The present study investigated 6,991 female patients with primary invasive breast cancer. In premenopausal HER2-positive patients a considerable increase of trastuzumab therapy was observed from 58.1% in 2006 to 90.9% in 2011, whereas in postmenopausal patients trastuzumab was rather used on a constant rate of 49.1%. Best overall survival (OS) was found in HER2/steroid hormone receptor-positive patients receiving guideline concordant treatment with trastuzumab plus chemotherapy (CHT) plus antihormone therapy (AHT) with a 7-year OS rate of 96% compared to the non-trastuzumab group with a 7-year OS rate of 92%. In multivariable analysis, HER2-positive patients treated with CHT or AHT who did not get trastuzumab, had a worse 7-year OS (65%, P = 0.006 versus 79%, P = 0.017) than the control groups. This population-based study demonstrated that guideline concordant use of adjuvant trastuzumab improves OS for HER2-positive breast cancer patients treated in routine clinical care.

The impact of adjuvant radiotherapy on the survival of primary breast cancer patients: a retrospective multicenter cohort study of 8935 subjects

BACKGROUND

Radiotherapy (RT) is proven to be an important backbone for adjuvant therapy in randomized, controlled trials, but it is unclear if these effects are provable in a daily routine cohort of breast cancer patients. This study sought to answer the following questions in a daily routine cohort of breast cancer patients: 1. Does guideline-adherent RT improve primary breast cancer patient survival? 2. Is breast-conserving surgery (BCS) followed by RT equal to a mastectomy (MA) with regard to outcome parameters? 3. Does adjuvant RT compensate for an incomplete tumor resection (R1)?

PATIENTS AND METHODS

In this retrospective, multicenter cohort study, we investigated data from 8935 primary breast cancer patients recruited from 17 participating certified breast cancer centers in Germany between 1992 and 2008. Guideline adherence based on internationally validated guidelines.

RESULTS

The patients who received guideline-adherent RT for primary breast cancer were associated with significantly improved survival parameters [recurrence-free survival (RFS): P < 0.001; overall survival (OS): P < 0.001] compared with patients who did not receive guideline-adherent adjuvant RT. Furthermore, the results demonstrated that there were no significant differences in RFS and OS between BCS followed by RT and MA [RFS: P = 0.293; OS: P = 0.104]. Adjuvant RT did not improve the outcome of patients receiving nonguideline-adherent incomplete tumor resection via BCS (R1); these patients showed a significantly impaired RFS [P < 0.001] and OS [P < 0.001] compared with patients who underwent guideline-adherent complete tumor resection via BCS (R0). In addition, non-guideline-adherent RT after MA (overtherapy) did not significantly influence survival [RFS: P = 0.838; OS: P = 0.613].

CONCLUSION

Our study confirms the importance of guideline-adherent adjuvant RT. It shows highly significant associations between RFS or OS and guideline adherent RT. Nevertheless, inadequate (R1-) surgical resection in a daily routine cohort of patients increases the risk of local recurrence and appears not to be compensated by the following RT.

Adherence to treatment guidelines and survival in triple-negative breast cancer: a retrospective multi-center cohort study with 9,156 patients

Background

Triple-negative breast cancer (TNBC) remains a challenging topic for clinical oncologists. This study sought to evaluate TNBC versus other breast cancer subtypes with respect to survival parameters. We evaluated possible differences in survival in TNBC by age and by the extent to which evidence-based treatment guidelines were adhered.

Methods

This German retrospective multi-center cohort study included 9156 patients with primary breast cancer recruited from 1992 to 2008.

Results

The rates of guideline adherence are significantly lower in TNBC compared to non-TNBC subtypes. These lower rates of guideline adherence can be observed in all age groups and are most pronounced in the >65 subgroup [<50 (20.9% vs. 42.0%), 50–64 (25.1% vs. 51.1%), and >65 (38.4% vs. 74.6%)]. In TNBC patients of all age groups, disease-free survival and overall survival were associated with an improvement by 100% guideline-adherent adjuvant treatment compared to non-adherence. Furthermore, TNBC patients of all ages had similar outcome parameters if 100% guideline-adherent adjuvant treatment was applied.

Conclusion

The rates of guideline-adherent treatment were significantly lower in TNBC, even though guideline adherence was strongly associated with improved survival. In the case of 100% guideline-adherent treatment, no difference in survival was observed over all the age groups examined, even in the group of >65-year-old TNBC patients.