Development and application of a weighted change score to evaluate interventions for vasomotor symptoms in patients with breast cancer using regression trees: a cohort study

PURPOSE

Vasomotor symptoms (VMS) are common among individuals with breast cancer (BC) and poorly managed symptoms are associated with reduced quality of life, treatment discontinuation, and poorer breast cancer outcomes. Direct comparisons among therapies are limited, as prior studies evaluating VMS interventions have utilized heterogeneous change measures which may not fully assess the perceived impact of change in VMS severity.

METHODS

We performed a prospective study where BC patients chose one of four categories of interventions to manage VMS. Change in VMS severity at 6 weeks was assessed using the validated Hot Flush Rating Scale (HFRS). A novel weighted change score integrating baseline symptom severity and directionality of change was computed to maximize the correlation between the change score and a perceived treatment effectiveness score. Variables influencing change in VMS severity were included in a regression tree to model factors influencing the weighted change score.

RESULTS

100 baseline and follow-up questionnaires assessing VMS were completed by 88 patients. Correlations between treatment effectiveness and VMS outcomes strengthened following adjustment for baseline symptoms. Patients with low VMS severity at baseline did not perceive change in treatment effectiveness. Intervention category was predictive of change in HFRS at 6 weeks.

CONCLUSION

Baseline symptom severity and the directionality of change (improvement or deterioration of symptoms) influenced the perception of clinically meaningful change in VMS severity. Future interventional studies utilizing the weighted change score should target moderate-high baseline severity patients.

Immigration Status and Breast Cancer Surgery Quality of Care Metrics: A Population-Level Analysis

INTRODUCTION

As immigrant women face challenges accessing health care, we hypothesized that immigration status would be associated with fewer women with breast cancer receiving surgery for curable disease, fewer undergoing breast conserving surgery (BCS), and longer wait time to surgery.

METHODS

A population-level retrospective cohort study, including women aged 18-70 years with Stage I-III breast cancer diagnosed between 2010 and 2016 in Ontario was conducted. Multivariable analysis was performed to assess odds of undergoing surgery, receiving BCS and wait time to surgery.

RESULTS

A total of 31,755 patients were included [26,253 (82.7%) Canadian-born and 5502 (17.3%) immigrant women]. Immigrant women were younger (mean age 51.6 vs. 56.1 years) and less often presented with Stage I/II disease (87.4% vs. 89.8%) (both p < .001). On multivariable analysis, there was no difference between immigrant women and Canadian-born women in odds of undergoing surgery [Stage I OR 0.93 (95% CI 0.79-1.11), Stage II 1.04 (0.89-1.22), Stage III 1.22 (0.94-1.57)], receiving BCS [Stage I 0.93 (0.82-1.05), Stage II 0.96 (0.86-1.07), Stage III 1.00 (0.83-1.22)], or wait time [Stage I 0.45 (-0.61-1.50), Stage II 0.33 (-0.86-1.52), Stage III 3.03 (-0.05-6.12)]. In exploratory analysis, new immigrants did not have surgery more than established immigrants (12.9% vs. 10.1%), and refugee women had longer wait time compared with economic-class immigrants (39.5 vs. 35.3 days).

CONCLUSIONS

We observed differences in measures of socioeconomic disadvantage and disease characteristics between immigrant and Canadian-born women with breast cancer. Upon adjusting for these factors, no differences emerged in rate of surgery, rate of BCS, and time to surgery. The lack of disparity suggests barriers to accessing basic components of breast cancer care may be mitigated by the universal healthcare system in Canada.

Validation of the Prognostic Performance of Breast Cancer Index in Hormone Receptor-Positive Postmenopausal Breast Cancer Patients in the TEAM Trial

PURPOSE

Patients with early-stage hormone receptor-positive (HR+) breast cancer face a prolonged risk of recurrence even after adjuvant endocrine therapy. The Breast Cancer Index (BCI) is significantly prognostic for overall (0-10 years) and late (5-10 years) distant recurrence (DR) risk in N0 and N1 patients. Here, BCI prognostic performance was evaluated in HR+ postmenopausal women from the Tamoxifen and Exemestane Adjuvant Multinational (TEAM) trial.

EXPERIMENTAL DESIGN

3,544 patients were included in the analysis (N = 1,519 N0, N = 2,025 N+). BCI risk groups were calculated using pre-specified cutoff points. Kaplan-Meier analyses and log-rank tests were used to assess the prognostic significance of BCI risk groups based on DR. Hazard ratios (HR) and confidence intervals (CI) were calculated using Cox models with and without clinical covariates.

RESULTS

For overall 10-year DR, BCI was significantly prognostic in Ni0 (N = 1,196) and N1 (N = 1,234) patients who did not receive prior chemotherapy (P < 0.001). In patients who were DR-free for 5 years, 10-year late DR rates for low- and high-risk groups were 5.4% and 9.3% (N0 cohort, N = 1,285) and 4.8% and 12.2% (N1 cohort, N = 1,625) with multivariate HRs of 2.25 (95% CI, 1.30-3.88; P = 0.004) and 2.67 (95% CI, 1.53-4.63; P < 0.001), respectively. Late DR performance was substantially improved using previously optimized cutoff points, identifying BCI low-risk groups with even lower 10-year late DR rates of 3.8% and 2.7% in N0 and N1 patients, respectively.

CONCLUSIONS

The TEAM trial represents the largest prognostic validation study for BCI to date and provides a more representative assessment of late DR risk to guide individualized treatment decision-making for HR+ patients with early-stage breast cancer.

Gender and Racial Diversity Among Obstetrics and Gynecology Departments and Gynecologic Oncology Divisions in Canada: Are We There Yet?

OBJECTIVES

Gender and racial diversity in academic Canadian departments of obstetrics and gynecology (OBGYN) have not been previously described. We examined gender representation in leadership in academic OBGYN departments and gynecologic oncology (GO) divisions, and determined factors predictive of leadership and promotion including racialized status.

METHODS

This cross-sectional study of Canadian residency-affiliated academic OBGYN departments queried institutional websites in January 2021 to compile a list of academic faculty. Subjective gender was assessed using photographs and pronouns, and racialized status was determined using photographs. Logistic regression analyses determined predictive factors for leadership roles. Fassiotto et al. rank equity indices (REI) and Hofler et al. representation ratios were calculated.

RESULTS

Within 16 Canadian institutions there were 354 (33.6%) men and 699 (66.4%) women, with 18.3% racialized faculty. Men were more likely to reach full professorship (P < 0.00001) and leadership positions of department chair, vice-chair or division head (P = 0.01). Representation ratios for women in OBGYN were <1 for all administrative leadership positions, and pairwise comparisons of the probability of promotion for women OBGYNs using REI reveal significant disparities between senior and junior administrative leadership and professorial ranks. Racialized physicians were less likely to have attained full professorship (P = 0.002). Ninety-seven academic GOs were identified: 68 (70.1%) were women, 17 (17.5%) racialized. Seven GO divisions (44%) had no racialized members. On multivariate analysis, only year of completion of fellowship was predictive of leadership.

CONCLUSION

In academic Canadian OBGYN departments women are underrepresented in leadership and full professor positions. Racialized faculty are underrepresented in full professorship.

The COVID-19 pandemic and its effects on follow-up of patients with early breast cancer: A patient survey

PURPOSE

Despite limited evidence supporting its effectiveness, most guidelines recommend long-term, routinely scheduled in-person surveillance of patients with early breast cancer (EBC). The COVID-19 pandemic led to increased use of virtual care. This survey evaluated patient perspectives on follow-up care.

METHODS

Patients with EBC undergoing surveillance were surveyed about follow-up protocols, perceptions, and interest in clinical trials assessing different follow-up strategies.

RESULTS

Of 402 approached patients 270 completed the survey (response rate 67%). Median age 62.5 years (range 25-86) and median time since breast cancer diagnosis was 3.8 years (range < 1-33 years). Most (n = 148/244, 60%) were followed by more than one provider. Routine follow-ups with breast examination were mostly conducted by medical/radiation oncologists every 6 months (n = 110/236, 46%) or annually (n = 106/236, 44%). Participants felt routine follow-up was useful to monitor for recurrence, manage side effects of cancer treatment and to provide support/reassurance. Most participants felt regular follow-up care would detect recurrent cancer earlier (n = 214/255, 96%) and increase survival (n = 218/249, 88%). The COVID-19 pandemic reduced the number of in-person visits for 54% of patients (n = 63/117). Patients were concerned this reduction of in-person visits would lead to later detection of both local (n = 29/63, 46%) and distant recurrences (n = 25/63, 40%). While many felt their medical and radiation oncologists were the most suited to provide follow-up care, 55% felt comfortable having their primary care provider (PCP) conduct surveillance. When presented with a scenario where follow-up has no effect on earlier detection or survival, 70% of patients still wanted routine in-person follow-up for reassurance (63%) with the goal of earlier recurrence detection (56%).

CONCLUSIONS

Despite limited evidence of effectiveness of routine in-person assessment, patients continue to place importance on regularly scheduled in-person follow-up.

The REthinking Clinical Trials Program Retreat 2023: Creating Partnerships to Optimize Quality Cancer Care

Patients, families, healthcare providers and funders face multiple comparable treatment options without knowing which provides the best quality of care. As a step towards improving this, the REthinking Clinical Trials (REaCT) pragmatic trials program started in 2014 to break down many of the traditional barriers to performing clinical trials. However, until other innovative methodologies become widely used, the impact of this program will remain limited. These innovations include the incorporation of near equivalence analyses and the incorporation of artificial intelligence (AI) into clinical trial design. Near equivalence analyses allow for the comparison of different treatments (drug and non-drug) using quality of life, toxicity, cost-effectiveness, and pharmacokinetic/pharmacodynamic data. AI offers unique opportunities to maximize the information gleaned from clinical trials, reduces sample size estimates, and can potentially "rescue" poorly accruing trials. On 2 May 2023, the first REaCT international symposium took place to connect clinicians and scientists, set goals and identify future avenues for investigator-led clinical trials. Here, we summarize the topics presented at this meeting to promote sharing and support other similarly motivated groups to learn and share their experiences.

Enhancing Nutrition Support for Esophageal Cancer Patients: Understanding Factors Influencing Feeding Tube Utilization

Objective: We sought to identify factors that can predict esophageal cancer (EC) patients at high risk of requiring feeding tube insertion. Methods: A retrospective cohort review was conducted, including all patients diagnosed with EC at our cancer center from 2013 to 2018. Multivariate logistic regression was performed comparing the group that required a reactive feeding tube insertion to those who did not require any feeding tube insertion to identify risk factors. Results: A total of 350 patients were included in the study, and 132/350 (38%) patients received a feeding tube. 50 out of 132 (38%) patients had feeding tube inserted reactively. Severe dysphagia (OR 19.9, p < 0.001) at diagnosis and decision to undergo chemotherapy (OR 2.8, p = 0.008) appeared to be predictors for reactive feeding tube insertion. The reactive insertion group had a 7% higher rate of complications relating to feeding tube. Conclusion: Severe dysphagia at diagnosis and undergoing chemotherapy were identified as risk factors for requiring a feeding tube. Ultimately, the aim is to create a predictive tool that utilizes these risks factors to accurate identify high-risk patients who may benefit from prophylactic feeding tube insertion.

Multisystem Immune-Related Adverse Events from Dual-Agent Immunotherapy Use

BACKGROUND

little is known about the incidence and characteristics of multisystem immune-related adverse events (irAEs) associated with dual-agent ipilimumab and nivolumab use.

METHODS

A retrospective cohort review was completed that included cancer patients seen at the Juravinski Cancer Centre who received at least one dose of ipilimumab and nivolumab from 2018 to 2022. Patient characteristics, cancer types, and irAEs were recorded. Multivariate logistic and cox regressions were completed, comparing those who developed multisystem irAEs, single irAE, and no irAE.

RESULTS

A total of 123 patients were included in this study. Out of 123 patients, 72 (59%) had melanoma, 50/123 (41%) had renal cell carcinoma (RCC), and 1/123 (1%) had breast cancer. Multisystem irAEs were seen in 40% of the overall cohort. The most common irAE type was dermatitis (22%), followed by colitis (19%) and hepatitis (17%).

CONCLUSIONS

Our study demonstrated that multisystem irAEs are prevalent amongst patients receiving ipilimumab and nivolumab. It is important for both physician education and the counseling and consent of patients to monitor the potential for multiple irAEs.

Shorter Durations of Anti-HER2 Therapy for Patients with Early-Stage, HER2-Positive Breast Cancer: The Physician Perspective

Despite evidence from clinical trials showing the efficacy of shorter durations of therapy, most HER2-positive early breast cancer (EBC) patients receive a year of anti-HER2 therapy. A survey of Canadian oncologists was conducted online, with electronic data collection, and the analysis is reported descriptively. Measures collected included current practices with respect to the duration of adjuvant anti-HER2 therapy, perspectives on data regarding shorter durations of treatment, and interest in further trials on this subject. Responses were received from 42 providers across Canada. Half (50%, 21/42) reported having never recommended 6 months of anti-HER2 therapy. The primary reason physicians consider a shorter duration is in response to treatment-related toxicities (76%, 31/41). Most participants (79%, 33/42) expressed the need for more data to determine which patients can be safely and effectively treated with shorter durations. Patient factors such as young age, initial stage, hormone receptor status, and type of neoadjuvant chemotherapy were attributed to reluctance to offer shorter durations of treatment. Many respondents (83%, 35/42) expressed interest in participating in the proposed clinical trial of 6 months of anti-HER2 therapy. In contemporary Canadian practice, 12 months of anti-HER2 therapy remains the primary practice. Future trials are required to better define the role of shorter treatment durations.

Circulating Growth Differentiation Factor 15 as a Biomarker in Patients with Unresected Locally Advanced Non-Small Cell Lung Cancer Treated with Chemo-Radiotherapy with or without Metformin

PURPOSE/OBJECTIVE(S)

Growth differentiation factor 15 (GDF15) is a member of the TGFβ family suggested to have prognostic value in cancer. Plasma GDF15 levels are elevated in humans during cellular stress, chronic diseases, and cancer and in response to cytotoxic (chemotherapy and radiation) or metabolic (metformin) therapies. Currently, the effect of combined metformin and cytotoxic treatment on circulating GDF15 is not known, and it is unclear whether GDF15 can serve as a biomarker in patients receiving such therapy. To examine this question, we analyzed circulating GDF15 levels in stage IIIA or IIIB NSCLC patients that participated in the randomized phase II clinical trial OCOG-ALMERA (NCT02115464).

MATERIALS/METHODS

In OCOG-ALMERA patients were randomized to treatment with concurrent platinum-based chemotherapy and chest radiotherapy (60-66 Gy), with or without consolidation chemotherapy (CRT) or the same treatment plus metformin (2000mg/d). Dosimetric parameters and survival outcomes were collected by the trial. EDTA Plasma was collected from patients at baseline, 2 weeks into CRT treatment, at completion of CRT and 6 months after treatment initiation and assayed for GDF15 using an ELISA method. Statistical analyses were conducted to explore potential associations between plasma GDF15 with survival and dosimetric parameters.

RESULTS

Fifteen patients from the metformin arm and 18 from the control arms provided EDTA plasma for this analysis. Average baseline GDF15 levels for all participants were elevated compared to those reported for healthy individuals. Baseline plasma GDF15 was statistically prognostic for RFS and OS (hazard ratio = 1.19, 95% CI = 1.06 to 1.34, p = 0.005). GDF15 levels increased during CRT treatment reaching the highest value at the end of cytotoxic therapy. Addition of metformin to CRT treatment was associated with further increase in circulating GDF15 (p<0.001). Plasma GDF15 levels at 2 weeks of CRT were positively correlated with size of the radiotherapy clinical target volume and volumes of esophagus and heart receiving high dose radiotherapy.

CONCLUSION

This work suggests that GDF15 may be a promising prognostic marker to predict response to standard chemoradiation therapy in NSCLC. Future studies should aim to validate these results in larger datasets and examine whether GDF15 may have value as early biomarker of radiation toxicity in lung cancer patients.

Omitting Radiotherapy after Breast-Conserving Surgery in Luminal A Breast Cancer

BACKGROUND

Adjuvant radiotherapy is prescribed after breast-conserving surgery to reduce the risk of local recurrence. However, radiotherapy is inconvenient, costly, and associated with both short-term and long-term side effects. Clinicopathologic factors alone are of limited use in the identification of women at low risk for local recurrence in whom radiotherapy can be omitted. Molecularly defined intrinsic subtypes of breast cancer can provide additional prognostic information.

METHODS

We performed a prospective cohort study involving women who were at least 55 years of age, had undergone breast-conserving surgery for T1N0 (tumor size <2 cm and node negative), grade 1 or 2, luminal A-subtype breast cancer (defined as estrogen receptor positivity of ≥1%, progesterone receptor positivity of >20%, negative human epidermal growth factor receptor 2, and Ki67 index of ≤13.25%), and had received adjuvant endocrine therapy. Patients who met the clinical eligibility criteria were registered, and Ki67 immunohistochemical analysis was performed centrally. Patients with a Ki67 index of 13.25% or less were enrolled and did not receive radiotherapy. The primary outcome was local recurrence in the ipsilateral breast. In consultation with radiation oncologists and patients with breast cancer, we determined that if the upper boundary of the two-sided 90% confidence interval for the cumulative incidence at 5 years was less than 5%, this would represent an acceptable risk of local recurrence at 5 years.

RESULTS

Of 740 registered patients, 500 eligible patients were enrolled. At 5 years after enrollment, recurrence was reported in 2.3% of the patients (90% confidence interval [CI], 1.3 to 3.8; 95% CI, 1.2 to 4.1), a result that met the prespecified boundary. Breast cancer occurred in the contralateral breast in 1.9% of the patients (90% CI, 1.1 to 3.2), and recurrence of any type was observed in 2.7% (90% CI, 1.6 to 4.1).

CONCLUSIONS

Among women who were at least 55 years of age and had T1N0, grade 1 or 2, luminal A breast cancer that were treated with breast-conserving surgery and endocrine therapy alone, the incidence of local recurrence at 5 years was low with the omission of radiotherapy. (Funded by the Canadian Cancer Society and the Canadian Breast Cancer Foundation; LUMINA ClinicalTrials.gov number, NCT01791829.).

Surgical margin status in relation to surgical approach in the management of early-stage cervical Cancer: A Canadian cervical Cancer collaborative (4C) study

OBJECTIVE

Surgical margin status in women undergoing surgery for early-stage cervical cancer is an important prognostic factor. We sought to determine whether close (<3 mm) and positive surgical margins are associated with surgical approach and survival.

METHODS

This is a national retrospective cohort study of cervical cancer patients treated with radical hysterectomy. Patients with stage IA1/LVSI-Ib2(FIGO 2018) with lesions up to 4 cm at 11 Canadian institutions from 2007 to 2019 were included. Surgical approach included robotic/laparoscopic (LRH), abdominal (ARH) or combined laparoscopic-assisted vaginal/vaginal (LVRH) radical hysterectomy. Recurrence free survival(RFS) and overall survival (OS) were estimated using Kaplan-Meier analysis. Chi-square and log-rank tests were used to compare groups.

RESULTS

956 patients met inclusion criteria. Surgical margins were as follows: negative (87.0%), positive (0.4%) or close <3 mm (6.8%), missing (5.8%). Most patients had squamous histology (46.9%); 34.6% had adenocarcinomas and 11.3% adenosquamous. Most were stage IB (75.1%) and 24.9% were IA. Mode of surgery included: LRH(51.8%), ARH (39.2%), LVRH (8.9%). Predictive factors for close/positive margins included stage, tumour diameter, vaginal involvement and parametrial extension. Surgical approach was not associated with margin status (p = 0.27). Close/positive margins were associated with a higher risk of death on univariate analysis (HR = non calculable for positive and HR = 1.83 for close margins, p = 0.017), but not significant for OS when adjusted for stage, histology, surgical approach and adjuvant treatment. There were 7 recurrences in patients with close margins (10.3%, p = 0.25). 71.5% with positive/close margins received adjuvant treatment. In addition, MIS was associated with a higher risk of death (OR = 2.39, p = 0.029).

CONCLUSION

Surgical approach was not associated to close or positive margins. Close surgical margins were associated with a higher risk of death. MIS was associated with worse survival, suggesting that margin status may not be the driver of worse survival in these cases.

BRACHY: A Randomized Trial to Evaluate Symptom Improvement in Advanced Non-Small Cell Lung Cancer Treated With External Beam Radiation With or Without High-Dose-Rate Intraluminal Brachytherapy

PURPOSE

Uncontrolled studies suggest that the addition of high-dose-rate intraluminal brachytherapy (HDRIB) to external beam radiation therapy (EBRT) may improve palliation for patients with advanced non-small cell lung cancer (NSCLC). The purpose of this study was to evaluate the potential clinical benefit of adding HDRIB to EBRT in a multicenter randomized trial.

METHODS AND MATERIALS

Patients with symptomatic stage III or IV NSCLC with endobronchial disease were randomized to EBRT (20 Gy in 5 daily fractions over 1 week or 30 Gy in 10 daily fractions over 2 weeks) or the same EBRT plus HDRIB (14 Gy in 2 fractions separated by 1 week). The primary outcome was the proportion of patients who achieved symptomatic improvement in patient-reported overall lung cancer symptoms on the Lung Cancer Symptom Scale (LCSS) at 6 weeks after randomization. Secondary outcomes included improvement in individual symptoms, symptom-progression-free survival, overall survival, and toxicity. The planned sample size was 250 patients based on detection of symptomatic improvement from 40% to 60% with a 2-sided α of .05 and 80% power.

RESULTS

A total of 134 patients were randomized over 4.5 years: 67 to each arm. The study closed early owing to slow accrual. The mean age was 69.8 years, and 67% of patients had metastatic disease. At 6 weeks, 19 patients (28.4%) in the EBRT arm and 20 patients (29.9%) in the EBRT plus HDRIB arm experienced an improvement in lung cancer symptoms (P = .84). When limited to patients who completed the LCSS, percentages were 40.4% versus 47.6%, respectively (P = .49). Between group differences in mean change scores (0.3-0.5 standard deviations) in favor of EBRT plus HDRIB were observed for overall symptoms, but only hemoptysis was significantly improved (P = .03). No significant differences were observed in progression-free or overall survival. Grade 3/4 toxicities were similar between groups.

CONCLUSIONS

Small to moderate improvements were seen in symptom relief with the combined therapy, but they did not reach statistical significance. Further research is necessary before recommending HDRIB in addition to EBRT for palliation of lung cancer symptoms.

Increasing palliative care capacity in primary care: study protocol of a cluster randomized controlled trial of the CAPACITI training program

BACKGROUND

Primary care providers play a critical role in providing early palliative care to their patients. Despite the availability of clinical education on best practices in palliative care, primary care providers often lack practical guidance to help them operationalize this approach in practice. CAPACITI is a virtual training program aimed at providing practical tips, strategies, and action plans to provide an early palliative approach to care. The entire program consists of 12 sessions (1 h each), divided evenly across three modules: (1) Identify and Assess; (2) Enhance Communication Skills; (3) Coordinate for Ongoing Care. We report the protocol for our planned evaluation of CAPACITI on its effectiveness in helping primary care providers increase their identification of patients requiring a palliative approach to care and to strengthen other core competencies.

METHODS

A cluster randomized controlled trial evaluating two modes of CAPACITI program delivery: 1) self-directed learning, consisting of online access to program materials; and 2) facilitated learning, which also includes live webinars where the online materials are presented and discussed. The primary outcomes are 1) percent of patients identified as requiring palliative care (PC), 2) timing of first initiation of PC, and self-reported PC competency (EPCS tool). Secondary outcomes include self-reported confidence in PC, practice change, and team collaboration (AITCS-II tool), as well as qualitative interviews. Covariates that will be examined are readiness for change (ORCA tool), learning preference, and team size. Primary care teams representing interdisciplinary providers, including physicians, nurse practitioners, registered nurses, care coordinators, and allied health professionals will be recruited from across Canada. The completion of all three modules is expected to take participating teams a total of six months.

DISCUSSION

CAPACITI is a national trial aimed at behavior change in primary care providers. This research will help inform future palliative care educational initiatives for generalist health care providers. Specifically, our findings will examine the effectiveness of the two models of education delivery and the participant experience associated with each modality.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05120154.

Artichoke phytocomplex modulates serum microRNAs in patients exposed to asbestos: a first step of a phase II clinical trial

Background

Malignant pleural mesothelioma is a highly aggressive tumor associated with asbestos exposure. There are few effective treatment options for mesothelioma, and patients have a very poor prognosis. Mesothelioma has the potential to represent an appropriate disease to prevent because of its strong association with asbestos exposure and the long latency from exposure to the disease on-set.

Methods

In the present study, we tested biological activity and toxicity of an artichoke freeze-dried extract (AWPC) as potential complementary preventive/early stage treatment agent for mesothelioma. This phase II clinical study then was conducted in 18 male-patients with evidence of radiographic characteristics related to asbestos exposure such as asbestosis or benign pleural disease as surrogate disease for mesothelioma clinical model.

Results

We investigate AWPC biological activity assessing its effect on mesothelin serum level, a glycoprotein with low expression in normal mesothelial cells and high expression in mesothelioma and asbestos related diseases. We also assess the AWPC effect on circulating miRNAs, as novel biomarkers of both cancer risk and response to therapeutic targets. While we found a small and not significant effect of AWPC on mesothelin serum levels, we observed that AWPC intake modulated 11 serum miRNAs related to gene-pathways connected to mesothelioma etiology and development. In terms of toxicity, we also did not observe any severe adverse effects associated to AWPC treatment, only gastro-intestinal symptoms were reported by five study participants.

Conclusions

We observed an interesting AWPC effect on miRNAs which targets modulate mesothelioma development. New and much larger clinical studies based on follow-up of workers exposed to asbestos are needed to corroborate the role of AWPC in prevention and early treatment of mesothelioma.

Trial registration

ClinicalTrials.gov, NCT02076672. Registered 03/03/2014.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02455-6.

Abstract OT1-11-02: A pragmatic, randomised, multicentre trial evaluating the dose timing (morning vs evening) of endocrine therapy and its effects on tolerability and compliance (REaCT-CHRONO Study)

Background. Endocrine therapy (ET) is the mainstay treatment for hormonal receptor positive (HR+) breast cancer. ET non-compliance and non-persistence vary from 30 to 70% and are associated with reduced disease-free and overall survival. ET side effects are an important cause of non-adherence. In clinical practice, there are anecdotal reports that time of the day at which ET is taken may affect ET side effects and compliance. However, we are not aware of any high-quality studies supporting this practice. In other fields of medicine, there is evidence to suggest that the time of the day at which medication is taken can alter its effect and/or the adherence. This is known as chronotherapy. Methods. In this pragmatic, open-label, multicenter trial, eligible and consented patients with an early stage or locally advanced HR+ breast cancer will be randomized (1:1) to receive either: an ET morning dose (Arm A: within 1 hour of the patient wake up time) or an ET evening dose (Arm B: within 1 hour of patient bed time). The primary endpoint is endocrine toxicity and tolerability measured by the change in total Functional Assessment of Cancer Therapy-Endocrine Subscale (FACT-ES) score from baseline to 12 weeks following the beginning of ET. Secondary endpoints include: endocrine toxicity/tolerability and quality of life measured respectively by the change in total score and individual items of FACT-ES and FACT-B (a validated Functional Assessment of Cancer Therapy for patients with a Breast cancer) from baseline to 4, 8, 12 and 52 weeks following the beginning of ET, rates of non-persistence or non-compliance and cost-effectiveness. A timing preference questionnaire will be filled out at the beginning and the end of the study by patients to evaluate their preferred time. As per the Rethinking Clinical Trials (REaCT) program, the integrated consent model will be used and patients will complete questionnaires in the online patient portal. For randomization, a permuted block design developed by the Ottawa Methods Centre will be used and patients will be stratified by center, type of endocrine therapy (tamoxifen yes/no) and if prior chemotherapy was received. Using a two-sided, alpha=0.05 Fisher’s exact test, and assuming a 10% of loss to follow up, the planned sample size is 235 patients. Accrual. This study opened for enrollment at The Ottawa Hospital Cancer Centre on June 30, 2021 and will open soon at the Thunder Bay Regional Health Sciences Centre. The maximum accrual period is 2 years. Conclusion. This will be world’s first prospective randomized clinical trial to evaluate ET dose timing (morning versus evening) and its effects on tolerability and adherence. Changing the time of the day at which a medication is taken is a new, simple and easy intervention that does not generate additional costs and can improve the quality of life of breast cancer patients. Funding provided by: NOAMA (Northern Ontario Academic Medicine Association) Innovation Grant (2021) Clinical Trial Registration: NCT04864405

Citation Format: Marie-France Savard, Mohammed Ibrahim, Gregory Pond, Deanna Saunders, Lisa Vandermeer, Ana-Alicia Beltran-Bless, Lesley Fallowfield, Mark Clemons. A pragmatic, randomised, multicentre trial evaluating the dose timing (morning vs evening) of endocrine therapy and its effects on tolerability and compliance (REaCT-CHRONO Study) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT1-11-02.

Abstract OT1-01-01: A randomized, pragmatic trial investigating the timing of radiotherapy and endocrine in patients with early stage breast cancer (REaCT-RETT trial)

The optimal timing of commencing adjuvant endocrine therapy (ET) relative to adjuvant radiotherapy (RT) (i.e. concurrent with or sequential to radiotherapy) remains unknown. A systematic review performed by our team was unable to answer this question due to a lack of high quality, randomized data on concurrent versus sequential ET and RT. Surveys of physicians confirmed this uncertainty and highlighted theoretical concerns for increased side effects with concurrent treatment. Respondents showed keen interest in obtaining real world, randomized data to guide clinical practice. REaCT-RETT is a pragmatic, randomized, non-inferiority trial comparing concurrent and sequential ET and RT in early breast cancer (EBC). The primary endpoint will assess the change in ET side effects at baseline and 3 months post radiation, using the Functional Assessment of Cancer Therapy-Endocrine Subscale (FACT-ES), with primary analysis based on an analysis of covariance (ANCOVA). With a sample size of 176 patients (88 per arm), an ANCOVA would have 80% power (α=0.05) to detect effect sizes as small as 0.25 regardless of the correlation with covariates. It is hypothesized that concurrent therapy will be non-inferior to sequential therapy in terms of ET side effects. Secondary endpoints will examine RT toxicity, ET compliance, quality of life, and cost-effectiveness. Patients with HR positive EBC planned to receive both adjuvant ET and RT were eligible. Patients who previously received ET for invasive breast cancer, or RT in the same breast, were excluded. The trial is conducted by The Ottawa Hospital’s (TOH) innovative Rethinking Clinical Trials (REaCT) program (https://react.ohri.ca/) which strives to improve access to patient-centered, pragmatic clinical trials by removing barriers for patients and researchers. Integral features of the program include broad eligibility criteria, a verbal consent model, and pragmatic data collection and assessment procedures. REaCT is the largest pragmatic cancer clinical trials program in Canada, with over 3,200 patients randomized in 18 clinical trials at 15 sites across Canada. REaCT-RETT accrued patients from September 2019 to January 2021. Data collection is ongoing, with final patient follow up expected April 2022. The timing of accrual provided a unique opportunity to adapt in response to restrictions due to the COVID-19 pandemic, which began to impact trial sites in March 2020. The target sample size was met with 262 patients randomized (1:1) across 3 sites in Ontario, 98% from TOH. A mean of 19 patients/month were accrued prior to the pandemic, compared to a mean of 13 patients/month after March 2020. Twenty-two patients were removed due to withdrawal of consent, ineligibility, or physician choice, and the pandemic was not a significant contributing factor. Since March 2020 there have been 772 patient follow ups, of which 47% (364/772) have been virtual. Only 10% (102/1028) of trial mandated appointments have been missed to date. Compliance with baseline and 3-month FACT-ES questionnaires for the primary endpoint in evaluable patients was 90% (215/240) and 83% (198/240), respectively. The pandemic posed several challenges to the REaCT-RETT study including a decline in patient accrual, poor accrual at peripheral sites due to delayed opening, and a rapid switch to virtual patient care. However, the nimble REaCT methodology enabled virtual patient consent and data collection during the pandemic, allowing the trial to continue successfully, with final data expected for presentation summer 2022. Finally, despite the challenges of COVID-19 we have seen that patients and physicians remain interested in research, and we are applying valuable lessons learned to forthcoming REaCT trials to strengthen their performance during and beyond the ongoing pandemic.

Citation Format: Sharon F Mc Gee, Mark Clemons, Michelle Liu, Mashari Jemaan Alzahrani, Terry Ng, Arif Awan, Sandeep Sehdev, John Hilton, Jean Michel Caudrelier, Marie France Savard, Lesley Fallowfield, Vikaash Kumar, Orit Freedman, Dean Fergusson, Gregory Pond, Brian Hutton, Jean Marc Bourque. A randomized, pragmatic trial investigating the timing of radiotherapy and endocrine in patients with early stage breast cancer (REaCT-RETT trial) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT1-01-01.

Abstract OT1-07-01: MRI screening versus symptom-directed surveillance for brain metastases among patients with triple negative or HER2+ metastatic breast cancer: A pilot study (nct03881605)

Background: The incidence of brain metastases (BrM) has steadily increased over time as women with metastatic breast cancer (MBC) live longer and survive to experience spread of cancer to the central nervous system (CNS). Women with triple negative and HER2+ MBC, which represent 30-40% of the MBC population, are at particularly high risk of BrM. At present, MBC patients are not screened for BrM; rather, they undergo imaging of the brain only after symptoms suggestive of CNS involvement develop. Unfortunately, by the time that patients experience potentially debilitating symptoms of BrM, they often have a significant burden of disease with limited treatment options and a poor prognosis. We hypothesize that early detection of BrM via magnetic resonance imaging (MRI)-based screening may allow for early intervention and, ultimately, improved outcomes for MBC patients. Methods: A multi-centre, open-label prospective phase II study, randomizing 50 women with triple negative or HER2+ MBC to either MRI-based BrM screening or symptom-directed surveillance. Randomization is stratified for tumor subtype. Intervention arm: Contrast-enhanced MRI of the brain at baseline, 4-, 8- and 12-months with concurrent chemical exchange saturation transfer (CEST) imaging, a new metabolic MRI sequence that may detect BrM even earlier than standard MRI. Control arm: Symptom-directed surveillance (brain imaging only if patients develop symptoms suggestive of BrM). All participants complete questionnaires at baseline, 6- and 15-months to assess overall (EORTC QLQ BN20) and neurologic-specific (FACT-BR tools) quality of life (QoL) as well as cancer-related anxiety (NCI PRO-CTCAE). A blood sample is collected for ctDNA analysis at baseline in all patients at diagnosis of BrM, if applicable. Key inclusion criteria: 1) Age ≥18; 2) Triple negative MBC, with metastatic disease diagnosed ≤12 weeks prior to study entry OR HER2+ MBC with no restrictions regarding timeline of diagnosis; 3) No symptoms of BrM or known asymptomatic BrM at study entry. Key exclusion criteria: 1) ECOG&gt;2; 2) Inability to complete an MRI (e.g., claustrophobia). Analyses: The primary goal of this study is to determine the feasibility of a randomized trial of BrM screening versus symptom-directed surveillance in the proposed patient population. The pilot study will be considered “not feasible” if &lt;30% of eligible patients enroll, &lt;50% complete the study protocol, and/or &gt;50% of patients allocated to the control arm are screened for BrM with CT or MRI. Overall survival will be assessed as a secondary endpoint. We will also investigate how screening for BrM influences the detection rate of BrM and explore how subsequent intervention affects both overall and neurologic-specific QoL. Our data will enable a power calculation to determine a sample size for a future, larger trial. 28 of 50 planned patients have enrolled in the study to-date.

Citation Format: Katarzyna J Jerzak, Arjun Sahgal, Gregory Pond, Priscilla K Brastianos, Orit Freedman, Gregory Stanisz, Ellen Warner. MRI screening versus symptom-directed surveillance for brain metastases among patients with triple negative or HER2+ metastatic breast cancer: A pilot study (nct03881605) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT1-07-01.

A Randomized Trial Comparing 3- versus 4-Monthly Cardiac Monitoring in Patients Receiving Trastuzumab-Based Chemotherapy for Early Breast Cancer

PURPOSE

The optimal frequency for cardiac monitoring of left ventricular ejection fraction (LVEF) in patients receiving trastuzumab-based therapy for early breast cancer (EBC) is unknown. We conducted a randomized controlled trial comparing 3- versus 4-monthly cardiac monitoring.

PATIENTS AND METHOD

Patients scheduled to receive trastuzumab-containing cancer therapy for EBC with normal (>53%) baseline LVEF were randomized to undergo LVEF assessments every 3 or 4 months. The primary outcome was the change in LVEF from baseline. Secondary outcomes included the rate of cardiac dysfunction (defined as a decrease in the LVEF of ≥10 percentage points, to a value <53%), delays in or discontinuation of trastuzumab therapy, and cardiology referral.

RESULTS

Of the 200 eligible and enrolled patients, 100 (50%) were randomized to 3-monthly and 100 (50%) to 4-monthly cardiac monitoring. Of these patients, 98 and 97 respectively underwent at least one cardiac scan. The estimated mean difference in LVEF from baseline was -0.94% (one-sided 95% lower bound: -2.14), which exceeded the pre-defined non-inferiority margin of -4%. There were also no significant differences between the two study arms for any of the secondary endpoints. The rate of detection of cardiac dysfunction was 16.3% (16/98) and 12.4% (12/97) in the 3- and 4-monthly arms, respectively (95% CI: 4.0 [-5.9, 13.8]).

CONCLUSIONS

Cardiac monitoring every 4 months was deemed non-inferior to that every 3 months in patients with HER2-positive EBC being treated with trastuzumab-based therapy. Given its costs and inconvenience, cardiac monitoring every 4 months should be considered standard practice. Registration: NCT02696707, 18 February 2016.

Extent of Surgical Resection in Inflammatory Bowel Disease Associated Colorectal Cancer: a Population-Based Study

BACKGROUND

The extent of surgical resection in inflammatory bowel disease (IBD) patients who develop colorectal cancer (CRC) is not prescribed by guidelines. We aim to evaluate, at a population level, the association of extent of surgical resection with survival outcomes.

METHODS

Using a validated Ontario registry of Crohn's disease (CD) and ulcerative colitis (UC) patients, we identified patients who underwent colorectal cancer resection between 2007 and 2015. Patient, tumor, and treatment factors, including type of surgical resection, were collected. Resections were grouped as segmental, total colectomy, and proctocolectomy. Multivariable cox proportional hazard regression was performed to identify factors associated with survival, including extent of surgical resection.

RESULTS

Between 2007 and 2015, 84,694 patients had resections for CRC in the province of Ontario, 599 had ulcerative colitis (UC), and 366 had Crohn's disease (CD). Segmental resection was the most common operation performed and was more common in CD patients compared to UC (68% vs. 45.6%, p < 0.001). Five-year survival was 63.7% (95% CI 59.5-67.7) in UC patients and 57.5% (95% CI 51.9-62.7) in CD patients (p = 0.033). Multivariable analysis showed worse survival in patients undergoing total colectomy, compared to segmental resection [HR 1.70 (95% CI 1.31-2.21), p < 0.001]. There was no significant difference in survival between patients undergoing segmental resection and proctocolectomy [HR 0.99 (95% CI 0.78-1.27)]. This pattern was similar within the subtypes of IBD.

CONCLUSION

In the setting of IBD-associated CRC, segmental resection and proctocolectomy are associated with similar survival outcomes in both UC and CD patients. Prospective study is essential to explore these findings.

Two-year results of a randomised trial comparing 4- versus 12-weekly bone-targeted agent use in patients with bone metastases from breast or castration-resistant prostate cancer

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Optimal dosing interval of bone-targeting agents (BTAs) has not been fully defined.

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Study of 4 vs 12-weekly BTAs in breast or prostate cancer pts with bone metastases.

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Study arms showed no significant differences SSE rates, time to SSEs or toxicity.

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There were however significant differences in cost-effectiveness results.

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On study SSE (12-weekly arm) associated with slight increase in subsequent SSEs.

Background

We present the 2-year results of a randomised trial comparing 4- versus 12-weekly bone-targeting agents (BTAs) in patients with bone metastases from breast or castration-resistant prostate cancer (CRPC).

Patients and Methods

Patients with bone metastases from breast or CRPC, who were going to start or were already receiving BTAs, were randomised to 4- or 12-weekly BTA treatment for 2 years. The endpoints were: symptomatic skeletal events (SSE) rates, time to SSEs, toxicity and cost-effectiveness.

Results

Of 263 patients (160 breast cancer, 103 CRPC), 133 (50.6%) and 130 (49.4%) were randomised to the 4- and 12-weekly groups, respectively. BTAs included denosumab (56.3%), zoledronate (24.0%) and pamidronate (19.8%). After 2 years, the cumulative incidence rate (95% CI) of SSEs was 32.7% (24.6% to 41.1%) and 28.1% (20.3% to 36.4%) for the 4- and 12-weekly intervention groups respectively. The hazard ratio for time to first SSE was 0.96 (95% CI = 0.63 to 1.47). However, in a post hoc analysis, those patients who had an on-study SSE, there was a small non-statistical increased risk of subsequent SSEs among patients on the 12-weekly dosing arm (HR = 1.14; 95% CI – 0.90–1.44). BTA-related toxicity rates were similar between study arms. A cost-utility analysis showed that 12-weekly BTA is cost-effective from a public payer’s perspective.

Conclusion

These results in addition to those previously reported for de-escalating zoledronate, would support that de-escalation of commonly used BTAs is a reasonable and economically valid treatment option. While not statistically significant, the increase in subsequent SSEs in the 12-weekly arm requires further exploration.

A multi-centre study comparing granulocyte-colony stimulating factors to antibiotics for primary prophylaxis of docetaxel-cyclophosphamide induced febrile neutropenia

BACKGROUND

Primary febrile neutropenia (FN) prophylaxis with ciprofloxacin or granulocyte-colony stimulating factors (G-CSF) is recommended with docetaxel-cyclophosphamide (TC) chemotherapy for early-stage breast cancer (EBC). A pragmatic randomised trial compared the superiority of G-CSF to ciprofloxacin and a cost-utility analysis were conducted.

METHODS

EBC patients receiving TC chemotherapy were randomised to ciprofloxacin or G-CSF. The primary outcome was a composite of FN and non-FN treatment-related hospitalisation. Secondary outcomes included; rates of FN, non-FN treatment-related hospitalisation, chemotherapy dose reductions/delays/discontinuations. Primary analysis was performed with the intention to treat population. Cost-utility analyses were conducted from the Canadian public payer perspective.

RESULTS

458 eligible patients were randomised: 228 to ciprofloxacin and 230 to G-CSF. For the primary endpoint there was non-statistically significant difference (Risk difference = -6.7%, 95%CI = -13.5%-0.1%, p = 0.061) between ciprofloxacin patients (46,20.2%) and G-CSF (31,13.5%). Patients receiving ciprofloxacin were more likely to experience FN (36/228, 15.8% vs 13/230, 5.7%) than patients receiving G-CSF (p < 0.001). Non-FN treatment-related hospitalisation occurred in 40/228 (17.5%) of ciprofloxacin patients vs 28/230 (12.2%) of G-CSF patients (p = 0.12). There were no differences in other secondary outcomes. G-CSF was associated with an incremental cost-effectiveness ratio of C$1,760,796 per one quality-adjusted life year gained.

CONCLUSION

The primary endpoint of superiority of G-CSF over ciprofloxacin was not demonstrated. While there were reduced FN rates with G-CSF, there were no differences in chemotherapy dose delays/reductions or discontinuations. With the commonly used willingness to pay value of C$50,000/QALY, G-CSF use was not cost-effective compared to ciprofloxacin and deserves scrutiny from the payer perspective.

Outcomes in Elderly Patients with Glioblastoma Multiforme Treated with Short-Course Radiation Alone Compared to Short-Course Radiation and Concurrent and Adjuvant Temozolomide Based on Performance Status and Extent of Resection

(1) Background: Studies in elderly patients over the age of 65 with glioblastoma have shown survival benefits of short-course radiation therapy with concurrent and adjuvant temozolomide, making it the standard of care adopted at Juravinski Cancer Center. Our study retrospectively examines patients with GBM aged ≥ 70 at the JCC treated with short-course radiation alone compared to those treated with short-course radiation and concurrent and adjuvant TMZ, to determine if there is a difference in outcomes based on performance status. (2) Methods: A retrospective chart review was conducted at JCC using patients diagnosed with GBM in 2014–2017 (treated with the old protocol of short-course RT alone) versus those diagnosed in 2017–2019 (treated with the new protocol of short-course radiation and TMZ). Patient demographics, treatments, outcomes, and baseline KPS were analyzed. (3) Results: No clear benefit and more neurologic decline post treatment were seen in patients with borderline performance status and subtotal resection who underwent concurrent treatment with temozolomide and radiation. The addition of temozolomide was most helpful in patients with good performance status and a gross total resection. Variable outcomes were seen in patients with mixed traits. (4) Conclusions: This study suggests that performance status and extent of resection are significant determinants of patient response to treatment. In the case of elderly patients with borderline performance status and GTR or those with good performance status and STR, also described as “mixed traits”, it may be beneficial to pursue single modality treatment, ideally based on MGMT promoter methylation status as opposed to bimodality treatment in order to maintain the best QOL.

EPCT-11. RURALITY INDEX SCORE AND PEDIATRIC NEURO-ONCOLOGICAL OUTCOME IN ONTARIO

Introduction

Rapid access to neurosurgical decisions and definitive management are vital for the outcome of neurocritical patients. There are increased challenges of providing services and to maintain critical infrastructure for rural citizens. The relationship between rurality, marginalization and health outcomes has been identified as associated with higher mortality rates and higher rates of many diseases[G1].

Methods

Employing linked administrative databases, we retrospectively analyzed a population based cohort of patients diagnosed with a pediatric brain tumour between 1996 to 2017 in Ontario, Canada. The Ontario Marginalization Index was employed as a surrogate for rurality providing an overall Rurality Index for Ontario (RIO) in addition to the 2016 Ontario Marginalization Index (ON-MARG).

Results

Of 1457 patients included, 54.0% were male, 277 of whom were diagnosed in infancy (i.e., &lt; 3 years of age). Income quintile was evenly distributed with 11.5% classified as living in a rural area of Ontario. The median[G2] distance to the nearest pediatric neurosurgical hospital was 59.6km. The rurality index score (RIO) was 0 in 38.8% of children with the majority of patients with a RIO score of &lt;39. The ON-MARG identified 51.9% of patients living in communities with low concentration of individuals without income from employment. A higher RIO score was not a significant factor (Continuous p=0.092/Ordinal p=0.20) associated with length[G3] of follow up, indicating rurality was not a significant factor for determining compliance to[G4] clinical follow-up. However, a trend towards reduced follow-up compliance in the higher RIO score cohort was identified.

Conclusion

Rurality and social determinants of health of the region pediatric neuro-oncological patients reside were not associated with patient outcome but a trend towards lower follow-up compliance was identified when children were from regions with RIO&gt;39. Implementation of telehealth follow-up for these patients may overcome barrier to clinical follow-up.[G5]

Perceptions around bone-modifying agent use in patients with bone metastases from breast and castration resistant prostate cancer: a patient survey

BACKGROUND

Optimal use of bone-modifying agent (BMA) therapy in patients with bone metastases from breast and castrate-resistant prostate cancer (CRPC) is evolving.

METHODS

Patients receiving BMA for bone metastases from breast or CRPC were surveyed. Information was collected on patient and disease characteristics, BMA treatments and perceptions regarding BMA benefits and side effects. Interest in participation in trials of de-escalated BMA therapy was also gauged.

RESULTS

Of 220 patients contacted, 172 eligible patients responded (response rate 78%). Median age was 67 (range: 21-91); 137 (80%) had breast cancer and 35 (20%) CRPC. Symptomatic skeletal events (SSEs) occurred prior to starting BMAs in 61% (84/137) of breast and 48% (17/35) of CRPC patients. Among breast cancer patients, 47, 33 and 13% received zoledronate, pamidronate and denosumab, respectively. Eighty-five percent (30/35) of CRPC patients received denosumab. De-escalation of therapy was more common among breast cancer patients. Although most patients correctly reported the goals of BMA therapy were to "help stop fractures" (62%) and "[improve] quality of life" (63%), 46.5% felt it prolonged survival and 54% felt it reduced bone progression. Most respondents (102/129, 79%) were comfortable with de-escalating to 6-monthly treatment after 2 years of BMA therapy. Patients considered the most important endpoints of de-escalation studies to be "stability of bone metastases" (45%), "quality of life" (22%) and "SSE rates" (14%).

CONCLUSION

Twelve weekly BMA was more common in breast than in prostate cancer. There remain misconceptions about the benefits of BMAs, highlighting potential gaps in patient education. Patients were interested in further BMA de-escalation after 2 years of prior BMA and provided study endpoints that were most important to them.

Adjuvant bisphosphonate use in patients with early stage breast cancer: a physician survey

Purpose

Despite the increasing use of adjuvant bone-modifying agents (BMAs) such as zoledronate and clodronate in the treatment of patients with early stage breast cancer (EBC), little is known about real world practice patterns. A physician survey was performed to address this deficit and determine interest in clinical trials of alternative strategies for BMA administration.

Methods

Canadian oncologists treating patients with EBC were surveyed via an anonymized online survey. The survey collected information on: physician demographics, knowledge and interpretation of adjuvant bisphosphonate guidelines, and real world prescribing practices. Questions also determined thoughts around the design of future adjuvant BMA trials.

Results

Of 127 surveyed physicians, 53 eligible invitees responded (response rate 42%). The majority of physicians are offering high-risk postmenopausal patients adjuvant BMAs. The most common BMA regimen was adjuvant zoledronate (45/53, 85%) every 6 months for 3 years. Concerns around toxicities and repeated visits to the cancer centre were perceived as the greatest barriers to adjuvant bisphosphonate use. Respondents were interested in future trials of de-escalation of BMAs comparing a single infusion of zoledronate vs. 6-monthly zoledronate for 3 years. The most favoured primary endpoints for such a trial included disease recurrence and fragility fracture rates.

Conclusion

Questions around optimal use of adjuvant bisphosphonates in patients with EBC still exist. There is interest among physicians in performing trials of de-escalation of these agents. The results of this survey will assist in designing pragmatic clinical trials to address this question.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06147-1.

Adjuvant bisphosphonate use in patients with early stage breast cancer: Patient perspectives on treatment acceptability and potential de-escalation

Background

Despite the increasing use of adjuvant bisphosphonates for early stage breast cancer (EBC), little is known about the patient experience with such treatments. A patient survey was performed to identify current prescribing practices, perceptions around the role of treatment, the impact of treatment on patients' quality of life, and future trial designs.

Methods

EBC patients who had either completed or were currently receiving adjuvant bisphosphonates were sent an anonymized survey. The survey collected information on patient and disease characteristics, bisphosphonate scheduling, compliance, and tolerance. Questions also assessed patient interest in trials of de-escalated bisphosphonate therapy.

Results

A total of 255 patients were contacted, with 164 eligible respondents (eligible response rate 164/255, 64.3%). Median patient age was 52 years (range 28 to 82 years). The majority (111/163, 68.1%) were postmenopausal at the time of diagnosis, 23.3% (38/163) were premenopausal, and 7.4% (12/163) were perimenopausal. Most patients (78%) had received chemotherapy. Zoledronate was the most commonly used bisphosphonate (92%), with the majority receiving treatment every 6 months for 3 years (73%). While 66% (107/161) of respondents had experienced side effects with treatment, most had, or expected to, complete treatment (154/163, 94%). Provided there was no detriment in breast cancer outcomes, there was strong interest in future studies of de-escalating adjuvant bisphosphonate therapy.

Conclusion

While most patients tolerate their treatment, there is interest in performing trials of de-escalation of these agents.

Abstract PS14-18: A physician survey evaluating real-world practice patterns and attitudes towards de-escalation of bone-modifying agents in patients with bone metastases from breast cancer

Background: Despite extensive use of bone modifying agents (BMA) in patients with bone metastases from breast cancer (BC), the optimal choice, frequency, and duration of BMA treatment remains unclear. A physician survey was performed to identify current practices and attitudes towards performing trials of de-escalation after 2 years of treatment, where very little prospective data exists.

Methods: Canadian oncologists treating breast cancer were surveyed from May to June 2020 via an anonymized online survey. Physicians were approached by e-mail invitation, and a follow-up e-mail was sent 2 weeks later. The study was approved by the Ontario Cancer Research Ethics Board. The survey collected physician demographics, current practice patterns, perception on risk of symptomatic skeletal events (SSE) and BMA-associated toxicity. It also assessed attitudes towards conducting a study evaluating further de-escalation of BMAs after 2 years of treatment.

Results: Of 238 potentially eligible breast oncologists on initial screening, 40 responded (response rate 16.8%; 97.5% medical oncologist). The most common BMA regimens during the first 2 years in patients with no limitations in drug coverage were denosumab q4wks for 3-4 months then q12wks [13/40 physicians (32.5%)], denosumab q4wks [7/40 (17.5%)], and zoledronate q12wks [8/40 (20%)]. For patients with no public funding for denosumab, the most common regimens were zoledronate q4wks for 3-4 months then q12wks [14/40 (35%)] and zoledronate q12wks [12/40 (30%)]. Most physicians [33/40 (82.5%)] routinely de-escalated BMA, with the most common approaches being de-escalation from the start of treatment [9/33 (27.3%)], after 3 months [7/33 (21.2%)], 6 months [6/33 (18.2%)], or 12 months [5/33 (15.2%)]. In terms of continuing BMA after 2 years, 11/40 (27.5%) felt there was benefit, 5/40 (12.5%) felt there was no benefit, and 24/40 (60%) were unsure. There was no consensus on the perceived risk of SSE or BMA-related toxicity after ≥ 2 years of BMA in breast cancer. Most physicians treating breast cancer-related bone metastases felt a de-escalation study after more than 2 years of BMA would be clinically important [i.v. bisphosphonate (BP) q12wks vs q24wks: 65%; i.v. BP q12wks vs. discontinue: 70%; denosumab q12wks vs q24wks: 57.5%; denosumab q12wks vs. discontinue: 67.5%]. Most physicians would accept SSE rate increase of &lt; 5% with BMA de-escalation. If a study of BMA de-escalation showing non-inferiority in terms of SSE rate was not feasible, physicians would consider changing practice to de-escalated therapy if: BMA toxicity was reduced (64.1%), pain was no worse (48.7%), physical function was no worse (48.7%), or cost-utility or cost-effectiveness was improved (41%). 38.5% would only change practice if the SSE rate was not significantly worse.

Conclusion: Despite their extensive use and costs, questions around optimal use of BMAs still exist. It is evident that practice varies according to patient insurance coverage, however most physicians are de-escalating BMAs. There is interest amongst clinicians in performing trials of de-escalation, especially after 2 years of treatment.

Citation Format: Mashari Alzahrani, Mark Clemons, Lisa Vandermeer, Marta Sienkiewicz, Arif Awan, Brian Hutton, Gregory Pond, Terry Ng. A physician survey evaluating real-world practice patterns and attitudes towards de-escalation of bone-modifying agents in patients with bone metastases from breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS14-18.

Tyrosine kinase inhibitors in chronic myeloid leukaemia and emergent cardiovascular disease

OBJECTIVES

(1) Describe how the risk of major adverse cardiovascular events (MACE) in individuals with chronic myeloid leukaemia (CML) has evolved; (2) evaluate the risk of MACE associated with the prescription of different CML tyrosine kinase inhibitors (TKI).

METHODS

A population-based retrospective study including all patients (n=4238) diagnosed with CML in Ontario, Canada between 1986 and 2017 and and age-matched and sex-matched individuals who received healthcare but who did not have CML (controls: n=42 380). The cohort was divided into those entering before 2001 vs from 2001 onwards (when TKIs were introduced). We developed competing risks models to compare time-to-event in CML cases versus controls. We adjusted for baseline comorbidities and present subdistribution HRs and 95% CIs. The relationship between TKI use and MACE was assessed by logistic regression.

RESULTS

Before 2001 and from 2001 on, patients with CML had a higher crude incidence of MACE than patients without CML (19.8 vs 15.3 and 20.3 vs 12.6 per 1000 person-years, respectively). After adjustment for cardiovascular risk factors, patients with CML had a lower subdistribution hazard for MACE (0.59, 95% CI 0.46 to 0.76) before 2001; but from 2001, the adjusted subdistribution HR for MACE (1.27, 95% CI 0.96 to 1.43) was similar to age-matched and sex-matched patients. The incidence (9.3 vs 13.8 per 1000 person-years) and subdistribution hazard for cardiovascular death (0.43, 95% CI 0.36 to 0.52) were lower in patients with CML than controls before 2001. From 2001 on, the incidence (6.3 vs 5.4 per 1000 person-years) and subdistribution hazard for cardiovascular death (0.99, 95% CI 0.84 to 1.18) were similar to age-matched and sex-matched patients without CML with a higher risk of cerebrovascular events (8.6 vs 5.6 per 1000 person-years; 1.35, 95% CI 1.00 to 1.83) and peripheral arterial events (6.9 vs 3.0 per 1000 person-years; 1.66 95% CI, 1.15 to 2.39) in patients with CML than patients without CML. Compared with imatinib, there was no difference in the risk of MACE among those prescribed dasatinib (OR 0.67, 95% CI 0.41 to 1.10) or nilotinib (OR 1.22, 95% CI 0.70 to 1.97).

CONCLUSIONS

In a contemporary CML population, the risk of MACE and cardiovascular death is at least as high as among age-matched and sex-matched patients without CML and may be higher for cerebrovascular and peripheral arterial events. No difference in the risk of MACE between imatinib, dasatinib and nilotinib was observed.

A randomised trial of 4- versus 12-weekly administration of bone-targeted agents in patients with bone metastases from breast or castration-resistant prostate cancer

BACKGROUND

Optimal dosing of bone-targeted agents (BTAs), in patients with bone metastases remains an important clinical question. This trial compared 4-weekly versus 12-weekly therapy.

PATIENTS AND METHODS

Patients with bone metastases from breast or castration-resistant prostate cancer (CRPC), who were going to start or already on BTAs, were randomised 1:1 to 4-weekly or 12-weekly BTA treatment for one year. Primary end point was change in health-related quality of life (HRQoL)-physical function European Organisation for Research and Treatment of Cancer (EORTC)-QLQ-C30). Secondary end points included pain (EORTC-QLQ-BM22), global health status (EORTC-QLQ-C30), symptomatic skeletal events (SSEs) rates and time to SSEs. Primary analysis was per protocol and a non-inferiority margin of 5 points was used.

RESULTS

Of 263 patients (160 breast cancer, 103 CRPC), 133 (50.6%) and 130 (49.4%) were randomised to the 4- and 12-weekly groups, respectively. BTAs included denosumab (56.3%), zoledronate (24.0%) and pamidronate (19.8%). Using repeated-measures analysis, across all time points, patients in the 4-weekly arm had a mean HRQL-physical subdomain score which was 1.2 (95% confidence interval: -1.6 to 4.0) higher than the 12-weekly arm. The study met the definition of non-inferiority for our primary outcome. Secondary outcomes showed no significant difference in scores for pain, global health status, SSE rates and SSE-free survival between arms. Subgroup analyses for cancer type, prior BTA use or BTA type showed no significant difference between arms.

CONCLUSION

These results in addition to those previously reported for de-escalating zoledronate and systematic reviews in both breast and prostate cancers, would support that de-escalation of commonly used BTAs is a reasonable treatment option.

A Randomized Controlled Trial Comparing Alloderm-RTU with DermACELL in Immediate Subpectoral Implant-Based Breast Reconstruction

Background: The effectiveness of different acellular dermal matrices (ADM) used for implant-based reconstruction immediately following mastectomy is an important clinical question. A prospective randomized clinical trial was performed to evaluate the superiority of DermACELL over Alloderm-RTU in reducing drain duration. Methods: Patients undergoing mastectomy with subpectoral immediate and permanent implant-based breast reconstruction were randomized to Alloderm-RTU or DermACELL. The primary outcome was seroma formation, measured by the duration of postoperative drain placement. Secondary outcomes included: post drain removal seroma aspiration, infection, redbreast syndrome, wound dehiscence, loss of the implant, and unplanned return to the operating room. Results: 62 patients were randomized for 81 mastectomies (41 Alloderm-RTU, 40 DermACELL). Baseline characteristics were similar. There was no statistically significant difference in mean drain duration (p = 0.16), with a trend towards longer duration in the Alloderm-RTU group (1.6 days; 95%CI, 0.7 to 3.9). The overall rate of minor and major complications were statistically similar between the two groups; although patients with Alloderm-RTU had 3 times as many infections requiring antibiotics (7.9% vs. 2.5%) with a risk difference of 5.4 (95%CI −4.5 to 15.2), and twice as many unplanned returns to the operating room (15.8% vs. 7.5%) with a risk difference of 8.3 (95% CI −5.9 to 22.5) as DermACELL. Conclusion: This is the first prospective randomized clinical trial comparing the two most commonly used human-derived ADMs. There was no statistically significant difference in drain duration, minor, or major complications between DermACELL over Alloderm-RTU in immediate subpectoral permanent implant-based breast reconstruction post-mastectomy.

Oncologists and medical assistance in dying: where do we stand? Results of a national survey of Canadian oncologists

Background

In June 2016, when the Parliament of Canada passed Bill C-14, the country joined the small number of jurisdictions that have legalized medical assistance in dying (maid). Since legalization, nearly 7000 Canadians have received maid, most of whom (65%) had an underlying diagnosis of cancer. Although Bill C-14 specifies the need for government oversight and monitoring of maid, the government-collected data to date have tracked patient characteristics, rather than clinician encounters and beliefs. We aimed to understand the views of Canadian oncologists 2 years after the legalization of maid.

Methods

We developed and administered an online survey to medical and radiation oncologists to understand their exposure to maid, self-perceived knowledge, willingness to participate, and perception of the role of oncologists in introducing maid as an end-of-life care option. We used complete sampling through the Canadian Association of Medical Oncologists and the Canadian Association of Radiation Oncology membership e-mail lists. The survey was sent to 691 physicians: 366 radiation oncologists and 325 medical oncologists. Data were collected during March-June 2018. Results are presented using descriptive statistics and univariate or multivariate analysis.

Results

The survey attracted 224 responses (response rate: 32.4%). Of the responding oncologists, 70% have been approached by patients requesting maid. Oncologists were of mixed confidence in their knowledge of the eligibility criteria. Oncologists were most willing to engage in maid with an assessment for eligibility, and yet most refer to specialized teams for assessments. In terms of introducing maid as an end-of-life option, slightly more than half the responding physicians (52.8%) would initiate a conversation about maid with a patient under certain circumstances, most commonly the absence of viable therapeutic options, coupled with unmanageable patient distress.

Conclusions

In this first national survey of Canadian oncologists about maid, we found that most respondents encounter patient requests for maid, are confident in their knowledge about eligibility, and are willing to act as assessors of eligibility. Many oncologists believe that, under some circumstances, it is appropriate to present maid as a therapeutic option at the end of life. That finding warrants further deliberation by national or regional bodies for the development of consensus guidelines to ensure equitable access to maid for patients who wish to pursue it.

Investigating the appropriateness of different concordance measures in a time-to-event setting

PURPOSE

Prediction models that assess a patient's risk of an event are used to inform treatment options and confirm screening tests. The concordance (c) statistic is one measure to validate the accuracy of these models, but has many extensions when applied to censored data. The purpose was to determine which c-statistic is most accurate at different rates of censoring.

METHODS

A simulation study was conducted for n = 750, and censoring rates of 20%, 50%, and 80%. The mean of three different concordance definitions were compared as well as the mean of three different c-statistics, including one, parametric c-statistic for exponentially distributed data, developed by the authors. The SE was also calculated but was of secondary interest.

RESULTS

The c-statistic developed by the authors yielded the a mean closest to the gold standard concordance measure when censoring is present in data, even when the exponentially distributed parametric assumptions do not hold. Similar results were found for SE.

CONCLUSIONS

The c-statistic developed by the authors appears to be the most robust to censored data. Thus, it is recommended to use this c-statistic to validate prediction models applied to censored data. This will improve the reliability and comparability across future time-to-event studies.

Abstract P4-10-29: Identifying novel molecular markers of response to trastuzumab in metastatic breast cancer

Background: The survival of women with HER2+ metastatic breast cancer (MBC) has improved with the introduction of the anti-HER2 antibody trastuzumab, but responses vary greatly among individuals. A predictive signature of response (and lack thereof) to trastuzumab may help personalize therapy for women with HER2+ MBC and enable the discovery of new “druggable” targets. Methods: In this retrospective cohort study, 256 patients with HER2+ MBC at the Sunnybrook Odette Cancer Centre were identified sequentially from January 1999 to December 2013 using the Cancer Care Ontario Registry. In total, 53 patients (21%) had archived metastatic tissue available for analysis, 29 (55%) of whom had samples obtained &lt;3 years prior to the initiation of trastuzumab. Nanostring molecular testing was used to measure the expression of commonly known oncogenes and gene signatures using the Nanostring technologies nCounter Analysis System TM (Seattle, Washington, USA). Descriptive statistics were used to summarize patient results and prognostic scores. Patients were categorized into short-term survivors (died within 12 months) and long-term survivors (survived &gt;30 months after starting trastuzumab). Results were compared between these two groups of patients using a Fisher’s exact test (dichotomous groups) and Wilcoxon rank sum tests (continuous scores). Univariable Cox regression models were evaluated using all patients, to evaluate if risk scores were prognostic of overall survival (OS). Statistical significance was set at the p=0.05 level and all tests were two-sided. Results: The median patient age was 60 years (interquartile range 53-65 years), 24% (n=7) had de-novo MBC and the majority of patients (52%) had ER or PR positive tumors. Among 29 included patients, the median OS was 23.4 months (95%CI 10.3-34.3 months); 10 patients died within 12 months and 10 patients survived &gt;30 months after starting trastuzumab-based therapy. A median of 155 days (range 4-812) elapsed between metastatic biopsy and initiation of trastuzumab. The distribution of the Prosigna ROR Score, Basal Cor, HER2 Cor, Luminal A Cor, Luminal B Cor, Mammaprint Subtype/Risk Group, Oncotype Risk Score/Risk Group, IHC4 mRNA Risk Group and GGI Risk Score/Risk Group did not differ between the short- and long-term survivors. However, the Mammaprint Predictor Score was significantly higher [mean 0.34 (std 5.50) versus -4.95 (std 5.24), p=0.033] and the IHC4 Risk Score was significantly lower among long-term as compared to short-term survivors [mean 99.3 (std 67.1) versus 160.3 (std 40.9), p=0.044]. The association between molecular gene signatures and OS are described in Table 1. Conclusion: Several gene signatures were associated with OS in this exploratory analysis of women with HER2+ MBC who received trastuzumab-based therapy. The Mammaprint Predictor and the IHC4 Risk Scores differed among short- versus long-term survivors, warranting validation in an independent dataset.

Table 1. Univariable Survival Results (n=29)ComparatorHR (95% CI)p-valueProsigna ROR Score/ 10 units1.23 (0.92, 1.65)0.17ProsignaHER2 vs Other1.25 (0.50, 3.13)0.64Basal Cor/ unit3.61 (1.10, 11.78)0.034Her2 Cor/ unit0.99 (0.15, 6.40)0.99Luminal A Cor/ unit0.22 (0.05, 0.95)0.042Luminal B Cor/ unit0.26 (0.06, 1.06)0.060Mammaprint Predictor Score/ unit1.10 (1.02, 1.19)0.015Mammaprint SubtypeHER2 vs Other0.85 (0.37, 2.00)0.72Mammaprint RiskHigh vs Low4.20 (1.37, 12.86)0.012Oncotype Risk Score/ 10 units1.27 (0.95, 1.70)0.11Oncotype Risk GroupHigh vs Intermediate4.83 (0.60, 39.07)0.14IHC4 Risk Score/ 10 units1.09 (1.00, 1.18)0.046IHC4 mRNA Risk GroupHigh vs Intermediate4.83 (0.60, 39.07)0.14GGI Risk Score/ 10 units1.63 (1.02, 2.61)0.043GGI Risk GroupHigh vs Low5.14 (1.13, 23.51)0.035

Citation Format: Katarzyna Joanna Jerzak, Danielle N Desautels, Phillip S Blanchette, Jane Bayani, Sharon Nofech-Mozes, Martin J Yaffe, Gregory Pond, Kathleen I Pritchard, John MS Bartlett. Identifying novel molecular markers of response to trastuzumab in metastatic breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-10-29.

A Phase II Multi-institutional Clinical Trial Assessing Fractionated Simultaneous In-Field Boost Radiotherapy for Brain Oligometastases

Purpose/Objective Published preclinical and phase I clinical trial data suggest that fractionated lesional radiotherapy with 60 Gy in 10 fractions can serve as an alternative approach to single fraction radiosurgical boost for brain oligometastases.  Methods and Materials A phase II clinical trial (NCT01543542) of a total of 60 Gy in 10 fractions of lesional (one to three) radiotherapy (given simultaneously with whole-brain helical tomotherapy with 30 Gy in 10 fractions) was conducted at five institutions. We hypothesized that fractionated radiotherapy would be considered unsuitable if the median overall survival (OS) was degraded by two months or if six-month intracranial control (ICC) and intracranial lesion (ILC) were inferior by 10% compared with the published RTOG 9508 results. Results A total of 87 patients were enrolled over a 4.5-year accrual period. Radiological lesion and extralesional central nervous system progression were documented in 15/87 (17%) and 11/87 (13%) patients, respectively. Median OS for all patients was 5.4 months. Six-month actuarial estimates of ICC and ILC were 78% and 89%, respectively. However, only the ILC estimate achieved statistical significance (p=0.02), demonstrating non-inferiority to the a priori historical controls (OS: p=0.09, ICC=0.31). Two patients developed suspected asymptomatic radionecrosis. Conclusions The phase II estimates of ILC were demonstrated to be non-inferior to the results of the RTOG 9508.

Age-Related Survival Differences in Patients With Inflammatory Bowel Disease-Associated Colorectal Cancer: A Population-Based Cohort Study

BACKGROUND

Reported outcomes for colorectal cancer associated with inflammatory bowel disease are inconsistent. We compared survival outcomes in colorectal cancer patients with and without inflammatory bowel disease using a population-based cohort and elicited prognostic factors associated with survival.

METHODS

Adult patients with a diagnosis of colorectal cancer in 2007-2015 were identified from the Ontario Cancer Registry. Those with inflammatory bowel disease (IBD) were detected via the validated Ontario Crohn's and Colitis Cohort. The primary outcome measure was overall survival from time of colorectal cancer diagnosis until the date of death. Secondary outcome measures included treatments received and publicly provided health care costs.

RESULTS

Colorectal cancer was diagnosed in 67,137, with inflammatory bowel disease present in 783 (1.2%). The IBD-associated colorectal cancer patients were younger at diagnosis (median range, 55-59 vs 70-74 years; P < 0.001). Five-year survival in IBD-associated patients was 56.4% (95% confidence interval [CI], 52.6%-59.9%) and 57.0% (95% CI, 56.6%-57.4%) in sporadic colorectal cancer (P = 0.8). Inflammatory bowel disease was a significant predictor of death (hazard ratio, 1.45; 95% CI, 1.29-1.63; P < 0.001) after adjusting for other variables. In patients under 50, 5-year survival was significantly (P < 0.001) reduced in the IBD population (56.8%; 95% CI, 49.4%-63.5%) compared with the sporadic colorectal cancer population (71.4%; 95% CI, 70.0%-72.7%). Similar results were observed in those 50-64 years old.

CONCLUSIONS

Patients with IBD-associated CRC appear to have worse survival than those with sporadic CRC. In subgroups based on age, this difference appears to be driven by young (<65 years old) patients with IBD. These findings may direct future research on treatment for this high-risk population.

Outcomes of trimodality bladder-sparing therapy for muscle-invasive bladder cancer

INTRODUCTION

Although radical cystectomy is considered the standard of care for muscle-invasive bladder cancer (MIBC), recent data has suggested comparable survival outcomes for bladder-sparing trimodality therapy (TMT). We conducted a retrospective, single-institution analysis of MIBC patients to evaluate the efficacy of TMT as an alternative, curative approach to surgical intervention.

METHODS

We conducted a retrospective analysis of MIBC patients assessed by a multidisciplinary team at the Juravinski Cancer Centre from 2010-2016. Patients underwent transurethral resection of bladder tumor (TURBT) followed by radiotherapy with or without concurrent chemotherapy. Patients could receive neoadjuvant treatment. Clinical data and response rates were summarized, and overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method.

RESULTS

Our analytic cohort included 115 patients, of whom 53 underwent TMT and 62 underwent radiotherapy alone following TURBT. Median age at diagnosis was 79 years and median followup was 21 months. Complete response rates in those receiving TMT and radiation without chemotherapy were 84.4% and 66.7%, respectively. For TMT patients, three-year OS and DFS were 68.5% and 49.6%, respectively. Patients who received TMT had reduction in risk of mortality (hazard ratio [HR] 0.49; p=0.026) and disease recurrence (HR 0.55; p=0.017) compared to those who had radiation without chemotherapy. Overall, four patients had grade 3 or higher late toxicity.

CONCLUSIONS

In this single-institution analysis, TMT appears to be a safe and effective approach in the short-term management of MIBC in appropriately selected patients. Extended followup and analysis are necessary to validate these results.