Advanced Cancer in Young Adults (YAs): Living in a Liminal Space

Young adults (YAs), defined as individuals between the ages of 18 and 39 years, experience unique challenges when diagnosed with advanced cancer. Using the social constructivist grounded theory approach, we aimed to develop a theoretical understanding of how YAs live day to day with their diagnosis. A sample of 25 YAs (aged 22-39 years) with advanced cancer from across Canada participated in semi-structured interviews. Findings illustrate that the YAs described day-to-day life as an oscillating experience swinging between two opposing disease outcomes: (1) hoping for a cure and (2) facing the possibility of premature death. Oscillating between these potential outcomes was characterized as living in a liminal space wherein participants were unsure how to live from one day to the next. The participants oscillated at various rates, with different factors influencing the rate of oscillation, including inconsistent and poor messaging from their oncologists or treatment team, progression or regression of their cancer, and changes in their physical functioning and mental health. These findings provide a theoretical framework for designing interventions to help YAs adapt to their circumstance.

The impact of survivorship care plans on adolescent and young adult head and neck cancer survivors and their primary care providers

PURPOSE

A cross sectional study of adolescent and young adult (AYA) head and neck (H&N) cancer survivors was performed to assess late effects. Survivorship care plans (SCPs) were generated and evaluated by participants and their primary care providers (PCPs).

METHODS

AYA H&N survivors who had been discharged over 5 years prior from our institution were assessed in recall consultation by a radiation oncologist. Late effects were assessed and individualized SCPS were created for each participant. Participants completed a survey evaluating the SCP. PCPs were surveyed before the consultation and after evaluating the SCP.

RESULTS

31/36 participants (86%) completed the SCP evaluation. The SCP was considered to be a positive experience for 93% of participants. Most of the AYA participants indicated that the information provided in the SCP helped them understand the need for follow-up to assess late effects (90%). The pre-consultation PCP survey response rate was 13/27 (48%) and only 34% were comfortable in providing survivorship care for AYA H&N cancer patients. The PCP response rate to the survey that accompanied the SCP was 15/27 (55%) and the majority (93%) reported that the SCP would be helpful to care for other AYA and non-AYA cancer survivors in their practice.

CONCLUSIONS

Our research suggested that AYA head and neck cancer survivors valued the SCPs as did their PCPs.

IMPLICATIONS FOR CANCER SURVIVORS

The introduction of SCPs is likely to help improve survivorship and transitioning of care from the oncology clinic to PCP in this population.

Outcomes of a radiation sparing approach in medulloblastoma by subgroup in young children: an institutional review

OBJECTIVE

To describe disease outcomes including overall survival and relapse patterns by subgroup in young pediatric patients treated for medulloblastoma with a radiation-sparing approach.

METHODS

Retrospective analysis of clinical outcomes includes treatment, relapse, and salvage therapy and late effects in children treated for medulloblastoma with a radiation-sparing approach at British Columbia Children's Hospital (BCCH) between 2000 and 2020.

RESULTS

There were 30 patients (median age 2.8 years, 60% male) treated for medulloblastoma with a radiation-sparing approach at BCCH. Subgroups included Sonic Hedgehog (SHH) (n = 14), group 3 (n = 7), group 4 (n = 6), and indeterminate status (n = 3). Three- and 5-year event-free survival (EFS) were 49.0% (30.2-65.4%) and 42.0% (24.2-58.9%) and overall survival (OS) 66.0% (95% CI 46.0-80.1%) and 62.5% (95% CI 42.5 and 77.2%), respectively, with a median follow-up of 9.5 years. Relapse occurred in 12/25 patients following a complete response, of whom six (group 4: n = 4; group 3: n = 1; unknown: n = 1) were successfully salvaged with craniospinal axis (CSA) RT and remain alive at a median follow-up of 7 years. Disease/treatment-related morbidity included endocrinopathies (n = 8), hearing loss n = 16), and neurocognitive abnormalities (n = 9).

CONCLUSIONS

This radiation sparing treatment approach for young patients with medulloblastoma resulted in a durable cure in most patients with SHH subgroup medulloblastoma. In those patients with groups 3 and 4 medulloblastoma, relapse rates were high; however, most group 4 patients were salvaged with RT.

Results of the c-TRAK TN trial: a clinical trial utilising ctDNA mutation tracking to detect molecular residual disease and trigger intervention in patients with moderate- and high-risk early-stage triple-negative breast cancer

BACKGROUND

Post-treatment detection of circulating tumour DNA (ctDNA) in early-stage triple-negative breast cancer (TNBC) patients predicts high risk of relapse. c-TRAK TN assessed the utility of prospective ctDNA surveillance in TNBC and the activity of pembrolizumab in patients with ctDNA detected [ctDNA positive (ctDNA+)].

PATIENTS AND METHODS

c-TRAK TN, a multicentre phase II trial, with integrated prospective ctDNA surveillance by digital PCR, enrolled patients with early-stage TNBC and residual disease following neoadjuvant chemotherapy, or stage II/III with adjuvant chemotherapy. ctDNA surveillance comprised three-monthly blood sampling to 12 months (18 months if samples were missed due to coronavirus disease), and ctDNA+ patients were randomised 2 : 1 to intervention : observation. ctDNA results were blinded unless patients were allocated to intervention, when staging scans were done and those free of recurrence were offered pembrolizumab. A protocol amendment (16 September 2020) closed the observation group; all subsequent ctDNA+ patients were allocated to intervention. Co-primary endpoints were (i) ctDNA detection rate and (ii) sustained ctDNA clearance rate on pembrolizumab (NCT03145961).

RESULTS

Two hundred and eight patients registered between 30 January 2018 and 06 December 2019, 185 had tumour sequenced, 171 (92.4%) had trackable mutations, and 161 entered ctDNA surveillance. Rate of ctDNA detection by 12 months was 27.3% (44/161, 95% confidence interval 20.6% to 34.9%). Seven patients relapsed without prior ctDNA detection. Forty-five patients entered the therapeutic component (intervention n = 31; observation n = 14; one observation patient was re-allocated to intervention following protocol amendment). Of patients allocated to intervention, 72% (23/32) had metastases on staging at the time of ctDNA+, and 4 patients declined pembrolizumab. Of the five patients who commenced pembrolizumab, none achieved sustained ctDNA clearance.

CONCLUSIONS

c-TRAK TN is the first prospective study to assess whether ctDNA assays have clinical utility in guiding therapy in TNBC. Patients had a high rate of metastatic disease on ctDNA detection. Findings have implications for future trial design, emphasising the importance of commencing ctDNA testing early, with more sensitive and/or frequent ctDNA testing regimes.

Patient-Reported Outcomes in Adolescent and Young Adult Head and Neck Cancer Survivors Treated with Radiotherapy

Purpose: There are few studies of adolescent and young adult (AYA) head and neck (H&N) cancer survivors treated with radiotherapy. A recall of AYA H&N survivors was performed and this article evaluates their cross-sectional patient-reported outcomes. Methods: AYA H&N cancer survivors who had received radiotherapy in British Columbia between 1970 and 2010 participated in this study. Participants completed the Psychosocial Screen for Cancer-Revised (PSSCAN-R), Research and Development (RAND)-36 health-related quality of life, and the Vanderbilt Head and Neck Symptom Survey, version 2.0 (VHNSS 2.0), to evaluate late effects from treatment. Results: There were 36 participants in the study. Severe symptoms (greater than or equal to 4/10) were reported on the VHNSS 2.0 by 51% of participants for xerostomia, 35% for dysphagia, and 37% for dental/mucosal sensitivity. On the PSSCAN-R, 35% had moderate/high anxiety scores and 48% had moderate/high depression scores. The mean RAND-36 participant scores were as follows: physical functioning, 86.1; physical role functioning, 71.4; emotional role functioning, 75.1; energy/fatigue, 56.6; emotional well-being, 74.6; social functioning, 76.3; bodily pain, 71.7; and general health, 65.6. Conclusions: AYA survivors in our study reported significant late effects from H&N radiotherapy and high depression and anxiety scores, but generally high health-related quality of life. Prospective evaluation of psychosocial needs and H&N-related complications is warranted in this subgroup at high risk of late effects from treatment.

Adult Survivors of Childhood Cancer: Views on COVID-19 and Vaccination

Purpose/Objective(s)

Adult childhood cancer survivors (ACCS) are at increased risk of developing late effects because of their childhood cancer treatment, including cognitive delay, diabetes, metabolic syndrome, and organ damage. Consequently, many ACCS may be at increased risk for worse outcomes with COVID-19 infection. It is important to determine ACCS views on the COVID-19 pandemic and vaccination.

Materials/Methods

A non-validated survey was created using multi-disciplinary input. Prior to the widespread rollout of COVID-19 vaccinations in Canada, we emailed an online survey to 235 ACCS followed through the BC Cancer Late Effects and Follow-Up clinic who had provided informed consent to email contact, receiving 89 responses (37.9% RR) which were analyzed. Statistical analysis was calculated using Chi-Squared test of association.

Results

Survey respondents were majority female (61%). The most common age range was 30-39 (30%) followed by 20-29 (28%). Most were of European descent (47%) and lived in an urban center (75%). The vast majority completed high school (97%), as well as post-secondary education (PSE, 73%). Only 29% did not use Complimentary or Alternative medicines (CAM), with herbal products being most common (48%), as well as massage therapy or other bodywork (46%). The most reported sources of health information were primary care practitioners (PCP, 80%), traditional media (60%), and specialized hospital clinics (46%). Of all respondents, 67% believed that ACCS should be prioritized for vaccination, with 87% indicating they would receive a COVID-19 vaccination if available. 78% and 89% believed that COVID-19 was a serious health problem for themselves or others, respectively. Views were evaluated across multiple subgroups. Respondents who had completed PSE were more likely to see COVID-19 as a risk to themselves (80% vs 71%, p = 0.358), to others (94% vs 75%, p = 0.012), and more likely to receive a vaccine (89% vs 79%, p=0.217). Respondents who received health information from traditional media felt COVID-19 was more likely to harm themselves (79% vs 75%, p=0.638), to harm others (93% vs 83%, p=0.181) and more likely to receive a vaccine (93% vs 78%, p=0.047). A similar trend was seen in those who receive information from a PCP, but without statistical significance. The opposite is true if health information is received from family or friends, with these respondents being less likely to feel COVID-19 poses a risk of harm to themselves (76% vs 78%, p=0.79), less likely to harm others (86% vs 90%, p=0.595), and a lower likelihood to get a vaccine (76% vs 92%, p=0.041). There was no discernable trend when examining by further subgroups, including CAM usage, age group, location, or other sources of health information.

Conclusion

Many ACCS appear to underestimate their risk from COVID-19; whether patients had completed PSE and the location from which they receive health information appeared to correlate most strongly with these results.

A cross-sectional assessment of long-term effects in adolescent and young adult head and neck cancer survivors treated with radiotherapy

PURPOSE

Adolescent and young adult (AYA) head and neck (H&N) cancer survivors are at risk of long-term complications. A cross-sectional study of survivors recalled for clinical evaluation was performed to evaluate late effects in this population.

METHODS

Surviving patients who had been diagnosed with H&N cancer between the ages of 15 and 39 years and treated with radiation therapy (RT) in British Columbia between 1970 and 2010 were invited to participate in this study. Survivors were assessed in consultation by a radiation oncologist for a complete history and physical exam. Comprehensive data collection of subjective and objective late effects of RT and screening investigations were completed.

RESULTS

Of 36 AYA H&N participants, the majority were female (61%), and the most common tumour sites were thyroid (28%), oropharynx (17%), salivary gland (14%) and larynx (14%). Dental extractions post treatment was performed for 33% and dental implants for 17%. The majority (72%) reported xerostomia, 50% had dysphagia to solids and 25% hearing loss. Of the non-thyroid cancer patients who underwent RT to their neck, 45% developed hypothyroidism. There were 28% of participants with asymptomatic carotid stenosis and 27% with thyroid nodules; all were diagnosed after recall screening.

CONCLUSIONS

Survivors of AYA H&N cancer treated with RT reported numerous long-term complications. Comprehensive follow-up and screening guidelines should be established for this at-risk population.

IMPLICATIONS FOR CANCER SURVIVORS

AYA H&N cancer survivors and their primary care practitioners should be educated on screening recommendations and the risk of late effects.

Palliative radiation therapy for children with cancer

Radiation therapy (RT) is often used as a palliative treatment for children with recurrent malignant disease to ameliorate or prevent symptoms. However, no guidelines exist regarding the clinical indications or dose fractionation for palliative RT. The goal of this report is to provide guidelines for the use of palliative RT in children with cancer. In this guideline, appropriate indications for palliative RT, recommended dose-fractionation schedules, relevant toxicities, and avenues for future research are explored. RT is an effective palliative treatment for bone, brain, liver, lung, abdominopelvic and head-and-neck metastases, spinal cord compression, superior vena cava syndrome, and bleeding. Single-fraction regimens (8 Gy in one fraction) for children with short life expectancy are recommended for simple, uncomplicated bone metastases and can be considered for some patients with lung or liver metastases. A short, hypofractionated regimen (20 Gy in five fractions) may be used for other indications to minimize overall burden of therapy. There are little data supporting use of more prolonged fractionation regimens, though they may be considered for patients with very good performance status. Future research should focus on response and outcomes data collection, and to rigorously evaluate the role of stereotactic body RT in well-designed, prospective studies.

A case series of pediatric survivors of anaplastic pleomorphic xanthoastrocytoma

Background

Anaplastic pleomorphic xanthoastrocytoma (APXA) is a rare subtype of CNS astrocytoma. They are generally treated as high-grade gliomas; however, uncertainty exists regarding the optimal therapy. Here, we report on 3 pediatric cases of APXA.

Methods

Our institutional database was queried for cases of APXA and 3 cases were identified. Surgical samples were processed for methylation profiling and chromosomal microarray analysis. Methylation data were uploaded to the online CNS tumor classifier to determine methylation-based diagnoses to determine copy number variations (CNVs).

Results

Two patients were male, 1 female, and all were aged 12 years at diagnosis. All underwent a gross total resection (GTR) and were diagnosed with an APXA. Immunohistochemical analysis demonstrated that 2 cases were BRAF V600E positive. Methylation-based tumor classification supported the APXA diagnosis in all cases. CNV analyses revealed homozygous CKDN2A deletions in all and chromosome 9p loss in 2 cases. All patients received radiation therapy (54 Gy in 30 fractions) with concurrent temozolomide. Two patients received maintenance chemotherapy with temozolomide and lomustine for 6 cycles as per the Children’s Oncology Group ACNS0423. The third patient recurred and went on to receive a second GTR and 6 cycles of lomustine, vincristine, and procarbazine. All are alive with no evidence of disease >4 years post-treatment completion (overall survival = 100%, event free survival = 67%).

Conclusions

The natural history and optimal treatment of this rare pediatric tumor are not well understood. This case series supports the use of adjuvant chemoradiotherapy in the treatment of APXA. The genetic landscape may be informative for optimizing treatment and prognosis.

Late effects in survivors treated for lymphoma as adolescents and young adults: a population-based analysis

PURPOSE

The study objective is to describe and quantify the incidence of treatment-induced late effects in AYA lymphoma patients.

METHODS

Consecutive patients diagnosed with Hodgkin lymphoma (HL) or non-Hodgkin lymphoma (NHL) at 15-24 years of age were identified. All patients in British Columbia who received radiation therapy (RT) from 1974 to 2014 with ≥ 5-year survival post-RT were included. Late effects' analyses included only survivors who received RT to the relevant anatomical site(s) and/or relevant chemotherapy, and were reported as cumulative incidence (CI) ± standard error.

RESULTS

Three hundred and five patients were identified (74% HL). Median age of diagnosis was 21 years. Median follow-up was 19.1 years for secondary malignancy and 7.2 years for other endpoints. Hypothyroidism was the most prevalent late effect, with a CI of 22.4 ± 2.8% and 35.1 ± 4% at 5 and 10 years, respectively. CI of in-field secondary malignancy was 0.4 ± 0.4% at 10 years and 2.8 ± 1.2% at 20 years. CI of symptomatic pulmonary toxicity was 4.6 ± 1.5% and 6.8 ± 2.0% at 5 and 10 years, respectively, and was higher in patients receiving multiple RT courses (p = 0.009). Esophageal complications occurred at a CI of 1.4 ± 0.8% at 5 years and 2.2 ± 1.1% at 10 years. CI of xerostomia/dental decay was 2.6 ± 1.3% at 5 years and 4.9 ± 2.1% at 10 years. CI of cardiac disease was at 2.3 ± 0.9% at 5 years and 4.4 ± 1.5% at 10 years. CI of infertility was 6.5 ± 1.6% at 5 years and 9.4 ± 2.1% at 10 years.

CONCLUSION

Survivors of AYA lymphoma have a high incidence and diverse presentation of late effects.

IMPLICATIONS FOR CANCER SURVIVORS

AYA lymphoma survivors should be educated about their risks of late effects and offered screening and follow-up when appropriate.

Evaluation of the discussion of late effects and screening recommendations in survivors of adolescent and young adult (AYA) lymphoma

PURPOSE

The study objective was to assess the discussion of late effects (LEs) and screening recommendations (SRs) for adolescent and young adults (AYAs) treated for lymphoma.

METHODS

A retrospective study was conducted on AYA lymphoma survivors aged 15-24 years at diagnosis who received radiation therapy (RT) ± chemotherapy between 1984 and 2010 at any of the six British Columbia (BC) Cancer treatment centers across the province. Charts were reviewed to evaluate discussion of LEs and SRs. Susceptibility to specific LEs was determined by reviewing treatment details.

RESULTS

Of 305 patients, 212 (70%) had documented discussion of at least one specific LE, 39 (13%) had non-specific documentation only, and 54 (18%) had no documented discussion of LEs. Accounting only for patients susceptible to each LEs, the most frequently discussed LEs was radiation-induced (RI) neoplasm (42%), and the least frequently discussed LEs was carotid artery stenosis (0.4%). The most common SRs discussed in susceptible patients was for RI breast cancer (43%). Of patients discharged between 1985 and 1999 vs 2000 and 2014, LEs were discussed in 63 vs 93% (P < 0.0005), and SRs were discussed in 30 vs 65%, respectively (P < 0.0005). Older age at discharge, presence of a discharge note, and occurrence of a discharge appointment were associated with increased discussion of SRs.

CONCLUSIONS

Most survivors of AYA lymphoma received some discussion of LEs and SRs, but each relevant LEs and SRs was discussed in only a minority of susceptible patients.

IMPLICATIONS FOR CANCER SURVIVORS

Survivors of AYA lymphoma and their primary care professionals may not be appropriately informed of health risks and how to screen for them.

Patterns of Practice Survey: Radiotherapy for Soft Tissue Sarcoma of the Extremities

Background Neoadjuvant or adjuvant radiotherapy (RT) for extremity soft tissue sarcoma (STS) confers significant local control benefit. To determine patterns of practice, a survey of RT planning practices was undertaken. Method Members of the Connective Tissue Oncology Society and Canadian Association of Radiation Oncology participated in this survey pertaining to general practice patterns of RT for extremity STS, patterns of contouring and planning, and use of quality control measures such as guidelines, tumor boards, and quality assurance rounds. Results A total of 58 radiation oncologists treating extremity STS from 12 countries responded. 89.7% work in academically affiliated centres, and 55.2% saw at least 20 cases of extremity STS per year. Most (96.7%) had access to multidisciplinary sarcoma boards (85.5% of those discussed every referred sarcoma case). 78.6% held quality assurance rounds. Most (92.9%) used planning guidelines. Pre-operative RT was used nearly twice as much as post-operative RT. CT simulation with MR fusion was used by 94.6%. Patterns of clinical target volume (CTV) contouring for both superficial and deep STS were variable. 69.8% contoured a normal soft tissue strip for extremity sarcoma, 13.5% without routine constraints and the remainder with various constraints. Most (91.1%) used 50 Gy in 25 fractions pre-operatively and 39.6% reported using post-operative RT boost for positive margins. Post-operative dose was more variable from 59.4 Gy to 70 Gy. Conclusion Major aspects of RT planning for extremity STS were similar among the responders, and most were academically affiliated. Over twice as many employed pre-operative as opposed to post-operative RT. There was considerable heterogeneity in use of: margins for contouring, normal soft tissue strip as an avoidance structure, and boost for positive margins. This survey shows variable patterns of practice and identifies areas that may require further research.

Evolving Practice Patterns Over Two Decades (1993-2013) in the Management of Desmoid-type Fibromatosis in British Columbia

AIMS

Due to the rarity and varied natural history of desmoid-type fibromatosis, evidence-based treatment standards for this disease remain lacking. This study evaluated outcomes in patients with desmoid-type fibromatosis managed at a Canadian institution over two decades.

MATERIALS AND METHODS

Records of 227 patients with desmoid-type fibromatosis referred from 1990 to 2013 were retrospectively reviewed to investigate management strategies including active surveillance, surgery, radiation therapy, cryoablation, and systemic therapy, including tamoxifen and chemotherapy.

RESULTS

Thirty-two per cent of cases were men, median age 40 years, median tumour size 5.4 cm. Initial treatments were surgery (79%), tamoxifen (13%), radiation therapy (5.0%), chemotherapy (1.8%) and cryoablation (1.2%). Active surveillance was used upfront in 26% of cases, most after 2005. At a median follow-up of 77 months, one patient died of disease, 13 died of unrelated causes and the remainder were alive with no evidence of disease (56%), stable/responding disease (33%) or progressive disease (4%). The recurrence rate was 25% after upfront surgery. Response rates and disease control rates were 40% and 76% for active surveillance; 68% and 96% for radiation therapy; 31% and 67% for tamoxifen; and 53% and 80% for chemotherapy. On univariable analysis, factors associated with a higher recurrence after initial surgery were young age (P = 0.012), male gender (P = 0.012) and extremity location (P = 0.005). On multivariable analysis, only young age was significantly associated with recurrence risk (P = 0.010).

CONCLUSIONS

Active surveillance was associated with spontaneous regression and long-term disease control consistent with other studies. Primary radiation therapy appeared to provide a similar response and disease control compared with systemic treatments and may be a viable option for patients who are not candidates for surgery or active surveillance.

Utility of the number needed to treat in paediatric haematological cancer randomised controlled treatment trials: a systematic review

OBJECTIVES

The primary objective was to assess the utility of the number needed to treat (NNT) to inform decision-making in the context of paediatric oncology and to calculate the NNT in all superiority, parallel, paediatric haematological cancer, randomised controlled trials (RCTs), with a comparison to the threshold NNT as a measure of clinical significance.

DESIGN

Systematic review DATA SOURCES: MEDLINE, EMBASE and the Cochrane Childhood Cancer Group Specialized Register through CENTRAL from inception to August 2018.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Superiority, parallel RCTs of haematological malignancy treatments in paediatric patients that assessed an outcome related to survival, relapse or remission; reported a sample size calculation with a delta value to allow for calculation of the threshold NNT, and that included parameters required to calculate the NNT and associated CI.

RESULTS

A total of 43 RCTs were included, representing 45 randomised questions, of which none reported the NNT. Among acute lymphoblastic leukaemia (ALL) RCTs, 29.2% (7/24) of randomised questions were found to have a NNT corresponding to benefit, in comparison to acute myeloid leukaemia (ALM) RCTs with 50% (3/6), and none in lymphoma RCTs (0/13). Only 28.6% (2/7) and 33.3% (1/3) had a NNT that was less than the threshold NNT for ALL and AML, respectively. Of these, 100% (2/2 ALL and 1/1 AML) were determined to be possibly clinically significant.

CONCLUSIONS

We recommend that decision-makers in paediatric oncology use the NNT and associated confidence limits as a supportive tool to evaluate evidence from RCTs while placing careful attention to the inherent limitations of this measure.

Abstract P4-01-02: Early detection of residual breast cancer through a robust, scalable and personalized analysis of circulating tumour DNA (ctDNA) antedates overt metastatic recurrence

Background:

Many breast cancer patients relapse after primary treatment but there are no reliable tests to detect distant metastases before they become overt. Here we show earlier identification of recurring patients through a scalable personalised ctDNA analysis. The method is applicable to all patients, and not limited to hot-spot mutations typically detected by gene panels.

Methods:

Forty-nine non-metastatic breast cancer patients were recruited following surgery and adjuvant therapy. Plasma samples (n=208) were serially collected semi-annually. Using the analytically validated SignateraTM workflow, we determined mutational signatures from primary tumour whole exome data and designed personalised assays targeting 16 variants with high sensitivity by ultra-deep sequencing (average &gt;100,000X). The patient-specific assay was used to detect the presence of the mutational signature in the plasma.

Results:

In 16 of 18 (89%) clinically-relapsing patients, ctDNA was detected ahead of metastatic relapse being diagnosed by clinical examination, radiological and biochemical (CA15-3) measurements, and remained ctDNA-positive through follow-up. Of the 2 patients not detected by ctDNA, one had a small local recurrence only (now resected) and the other had three primary tumours. None of the 31 non-relapsing patients were ctDNA-positive at any time point (n=142). Metastatic relapse was predicted by Signatera with high accuracy and a lead time of up to 2 years (median=9.5 months).

Conclusions:

The use of a scalable patient-specific ctDNA-based validated workflow detects breast cancer recurrence ahead of clinical detection. Accurate and earlier prediction by ctDNA analysis could provide a means of monitoring breast cancer patients in need of second-line salvage adjuvant therapy in order to prevent overt life-threatening metastatic progression.

Citation Format: Coombes RC, Armstrong A, Ahmed S, Page K, Hastings RK, Salari R, Sethi H, Boydell A-R, Shchegrova SV, Fernandez-Garcia D, Gleason KL, Goddard K, Guttery DS, Assaf ZJ, Balcioglu M, Moore DA, Primrose L, Navarro SL, Aleshin A, Rehman F, Toghill BJ, Louie MC, Zimmermann BG, Lin C-HJ, Shaw JA. Early detection of residual breast cancer through a robust, scalable and personalized analysis of circulating tumour DNA (ctDNA) antedates overt metastatic recurrence [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-02.

Long-term effects of cancer on earnings of childhood, adolescent and young adult cancer survivors - a population-based study from British Columbia, Canada

Background

The patterns and determinants of long-term income among young people surviving cancer, and differences compared to peers, have not yet been fully explored. The objectives of this paper are to describe long-term income among young survivors of cancer, the impact of socio-demographic, disease, and treatment factors on long-term income, and income relative to the general population.

Methods

Retrospective cohort study with comparison group from the general population, using linked population-based registries, clinical data, and tax-records. Multivariate random effects regression models were used to determine survivor income, compare long-term income between survivors and comparators, and assess income determinants. Subjects included all residents of British Columbia (BC), Canada, diagnosed with cancer before 25 years of age and surviving 5 years or more. Comparators were selected from the BC general population matched by gender and birth year.

Results

Young cancer survivors earned significantly less than the general population. In addition, survivors of central nervous system tumors have significantly lower incomes than lymphoma survivors. Survivors who received radiation therapy have significantly lower income.

Results should be interpreted with caution as the comparator group was matched by gender and date of birth.

Conclusions

Depending on original diagnosis, treatment, and other characteristics, survivors face significantly lower income than peers and may require supports to gain and retain paid employment. Lower income will affect their opportunity for independent living, and will reduce productivity in the labour force.

Clinical significance in pediatric oncology randomized controlled treatment trials: a systematic review

Background

Clinical significance in a randomized controlled trial (RCT) can be determined using the minimal clinically important difference (MCID), which should inform the delta value used to determine sample size. The primary objective was to assess clinical significance in the pediatric oncology randomized controlled trial (RCT) treatment literature by evaluating: (1) the relationship between the treatment effect and the delta value as reported in the sample size calculation, and (2) the concordance between statistical and clinical significance. The secondary objective was to evaluate the reporting of methodological attributes related to clinical significance.

Methods

RCTs of pediatric cancer treatments, where a sample size calculation with a delta value was reported or could be calculated, were systematically reviewed. MEDLINE, EMBASE, and the Cochrane Childhood Cancer Group Specialized Register through CENTRAL were searched from inception to July 2016.

Results

RCTs (77 overall; 11 and 66), representing 95 (13 and 82) randomized questions were included for non-inferiority and superiority RCTs (herein, respectively). The minority (22.1% overall; 76.9 and 13.4%) of randomized questions reported conclusions based on clinical significance, and only 4.2% (15.4 and 2.4%) explicitly based the delta value on the MCID. Over half (67.4% overall; 92.3 and 63.4%) reported a confidence interval or standard error for the primary outcome experimental and control values and 12.6% (46.2 and 7.3%) reported the treatment effect, respectively. Of the 47 randomized questions in superiority trials that reported statistically non-significant findings, 25.5% were possibly clinically significant. Of the 24 randomized questions in superiority trials that were statistically significant, only 8.3% were definitely clinically significant.

Conclusions

A minority of RCTs in the pediatric oncology literature reported methodological attributes related to clinical significance and a notable portion of statistically insignificant studies were possibly clinically significance.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2925-8) contains supplementary material, which is available to authorized users.

Reirradiation in patients with diffuse intrinsic pontine gliomas: The Canadian experience

OBJECTIVE

Clinical trials have failed to demonstrate a survival benefit of adjuvant chemotherapy in diffuse intrinsic pontine gliomas (DIPG). Radiation therapy (RT) is the only effective treatment thus far and reirradiation (rRT) has become an option at the time of progression. The aim of this study was to review the Canadian experience of DIPG rRT with a focus on the safety and possible efficacy of this approach.

METHOD

We retrospectively reviewed the demographic, clinical, and RT data of patients with DIPG treated in Canada with rRT.

RESULTS

Since January 2011, we identified 16 patients with progressive DIPG who received rRT. Median time from diagnosis to progression was 10.5 months (range, 4-37 months). rRT was given focally in 14 patients at a dose ranging from 21.6 to 36 Gy. rRT was well tolerated by all children but one. All but three patients showed neurological improvement. With a median follow-up from original diagnosis of 19.2 months, all patients died, with a median time from rRT to death of 6.48 months (range, 3.83-13.26 months). When compared to a historic cohort of 46 consecutive patients, the median time from progression to death was 92 days in the non-reirradiated patients versus 218 days in the reirradiated ones (P = 0.0001).

CONCLUSION

In this limited experience, rRT was safe and feasible in patients with progressive DIPG, providing neurological improvement and a prolonged life span in most patients. Prospective Canadian rRT protocols are ongoing to further assess the benefit of this approach, including quality of life assessment.

Healthcare system barriers to long-term follow-up for adult survivors of childhood cancer in British Columbia, Canada: a qualitative study

PURPOSE

Risk-stratified life-long follow-up care is recommended for adult childhood cancer survivors (CCS) to ensure appropriate prevention, screening, and management of late effects. The identification of barriers to long-term follow-up (LTFU), particularly in varying healthcare service contexts, is essential to develop and refine services that are responsive to survivor needs. We aimed to explore CCS and healthcare professionals (HCP) perspectives of healthcare system factors that function as barriers to LTFU in British Columbia, Canada.

METHODS

We analyzed data from 43 in-depth interviews, 30 with CCS and 13 with HCP, using qualitative thematic analysis and constant comparative methods.

RESULTS

Barriers to accessible, comprehensive, quality LTFU were associated with the following: (1) the difficult and abrupt transition from pediatric to adult health services, (2) inconvenient and under-resourced health services, (3) shifting patient-HCP relationships, (4) family doctor inadequate experience with late effects management, and (5) overdue and insufficient late effects communication with CCS.

CONCLUSIONS

Structural, informational, and interpersonal/relational healthcare system factors often prevent CCS from initially accessing LTFU after discharge from pediatric oncology programs as well as adversely affecting engagement in ongoing screening, surveillance, and management of late effects.

IMPLICATIONS FOR CANCER SURVIVORS

Understanding the issues faced by adult CCS will provide insight necessary to developing patient-centered healthcare solutions that are key to accessible, acceptable, appropriate, and effective healthcare.

Abstract P2-04-01: Withdrawn

This abstract was withdrawn by the authors.

Multimodality imaging of a pulmonary artery sarcoma

Pulmonary artery sarcoma is a rare malignant neoplasm. Here, we describe a patient with a pulmonary artery sarcoma, which was only subtly visible and therefore not fully appreciated on initial transthoracic echocardiogram. Characterization of the tumor was aided by the use of multimodality imaging that included computed tomography, magnetic resonance imaging, and positron emission tomography. Familiarity with its appearance on multiple imaging modalities including echocardiography is important to ensure timely diagnosis, although the optimal treatment strategy is still unknown, and the prognosis remains poor.

"Assessing the methodological quality of systematic reviews in radiation oncology: A systematic review"

OBJECTIVE

The objective of our study was to evaluate the methodological quality of systematic reviews and meta-analyses in Radiation Oncology.

METHODS

A systematic literature search was conducted for all eligible systematic reviews and meta-analyses in Radiation Oncology from 1966 to 2015. Methodological characteristics were abstracted from all works that satisfied the inclusion criteria and quality was assessed using the critical appraisal tool, AMSTAR. Regression analyses were performed to determine factors associated with a higher score of quality.

RESULTS

Following exclusion based on a priori criteria, 410 studies (157 systematic reviews and 253 meta-analyses) satisfied the inclusion criteria. Meta-analyses were found to be of fair to good quality while systematic reviews were found to be of less than fair quality. Factors associated with higher scores of quality in the multivariable analysis were including primary studies consisting of randomized control trials, performing a meta-analysis, and applying a recommended guideline related to establishing a systematic review protocol and/or reporting.

CONCLUSIONS

Systematic reviews and meta-analyses may introduce a high risk of bias if applied to inform decision-making based on AMSTAR. We recommend that decision-makers in Radiation Oncology scrutinize the methodological quality of systematic reviews and meta-analyses prior to assessing their utility to inform evidence-based medicine and researchers adhere to methodological standards outlined in validated guidelines when embarking on a systematic review.

Comparison of hypersensitivity rates to intravenous and intramuscular PEG-asparaginase in children with acute lymphoblastic leukemia: A meta-analysis and systematic review

BACKGROUND

Pegylated-asparaginase (PEG-ASP) is a critical treatment for pediatric acute lymphoblastic leukemia (ALL) and has traditionally been delivered via intramuscular (IM) injection. In an attempt to reduce pain and anxiety, PEG-ASP has increasingly been delivered via intravenous (IV) administration. The study objective was to perform a meta-analysis and systematic review to compare and generate pooled hypersensitivity rates for IM and IV PEG-ASP.

METHODS

A systematic literature search was conducted for all epidemiological studies that investigated IV and IM hypersensitivity rates for pediatric ALL. Included studies were critically appraised using the GRACE checklist. Pooled estimates and odds ratios with 95% confidence intervals (CIs) for IM and IV hypersensitivity rates were derived based on either a random or fixed effects model.

RESULTS

Four studies satisfied the inclusion criteria and were of adequate quality. The random effects pooled hypersensitivity rates were 23.5% (95% CI 14.7-33.7) and 8.7% (95% CI 5.4-12.8) for IV and IM, respectively. The fixed effects pooled odds ratio after adjusting for publication bias was 2.49 (95% CI 1.62-3.83), indicating a significantly higher risk of hypersensitivity for IV over IM PEG-ASP. This risk is far more pronounced for high-risk (HR) patients compared with standard-risk (SR) patients (IV vs. IM: HR ↑35.2% and SR ↓2.9%).

CONCLUSIONS

Although administering PEG-ASP through IV is preferable for patients, it poses a significantly higher risk of hypersensitivity when compared with IM administration, especially for HR patients. We recommend pediatric oncologists consider treating patients with HR pediatric ALL with IM PEG-ASP to reduce the risk of hypersensitivity.

A Cross-Sectional Cohort Study of Cerebrovascular Disease and Late Effects After Radiation Therapy for Craniopharyngioma

BACKGROUND

The study objective was to describe radiation-induced vascular abnormalities, stroke prevalence, and stroke risk factors in survivors of childhood craniopharyngioma.

PROCEDURE

Twenty survivors of childhood craniopharyngioma who received radiotherapy (RT) were included in the study. A clinical history, quality of life assessment, cognitive functioning assessment, magnetic resonance angiogram or computed tomography angiogram, fasting lipid profile, and fasting glucose or hemoglobin A1c test were obtained.

RESULTS

Median age at diagnosis was 10.3 years and median age at time of study was 29.0 years. Vascular abnormalities were detected in six (32%) of 19 patients' angiograms (vascular stenosis, decreased artery size, aneurysm, cavernoma, and small vessel disease). Five (25%) of 20 patients experienced a stroke after RT. Median time since RT was 27.8 versus 9.1 years in patients with versus without vascular abnormalities (P = 0.02). A low level of high-density lipoproteiin (HDL) was present in 100% (5/5) of patients who had a post-RT stroke as compared with 13% (2/15) of patients who did not have any post-RT stroke (P = 0.02). Previous stroke had occurred in 0% (0/5) of patients receiving growth hormone (GH) replacement at the time of study, compared to 40% (6/15) of patients who were not receiving GH replacement (P = 0.09).

CONCLUSIONS

Patients with craniopharyngioma treated with RT have a high prevalence of stroke and vascular abnormalities, particularly those with low HDL and longer duration of time since RT. There is a trend to suggest that continual GH replacement may reduce the risk of stroke. These patients should undergo careful monitoring and aggressive modification of stroke risk factors.

Abstract P1-08-02: CYP2D6 gene variants and effectiveness of adjuvant tamoxifen in breast cancer: A population-based case-control study

Tamoxifen, a cornerstone of adjuvant therapy for hormone-receptor-positive breast cancer, is metabolized to the active metabolite endoxifen through enzymatic activity of cytochrome P450 2D6. CYP2D6 has numerous alleles that affect metabolizing phenotype. Among women who take tamoxifen, those homozygous for inactive alleles (poor metabolizers) have lower levels of serum endoxifen than those with two functional alleles (extensive metabolizers). Several studies have reported increased risk of breast cancer recurrence or death in women homozygous for CYP2D6 inactive alleles, but others have found no association between CYP2D6 function and outcome. We explored this question in the large member population of the Kaiser Permanente Northwest (KPNW) integrated health plan. We conducted a population-based case-control study to evaluate the hypothesis that, after adjuvant tamoxifen treatment for breast cancer, women with CYP2D6 genotypes associated with poor metabolism of tamoxifen have an elevated risk of breast cancer recurrence compared to women with CYP2D6 genotypes associated with extensive metabolism of tamoxifen. We further hypothesized that women with CYP2D6 genotypes associated with intermediate metabolism of tamoxifen are at intermediate risk of recurrence. Study subjects were women who were diagnosed from 1980 to 2011 with hormone-receptor positive breast cancer, who received at least 180 days of adjuvant tamoxifen treatment, and for whom stored formalin-fixed paraffin-embedded (FFPE) normal tissue was available for laboratory analysis. Cases (358) were women with breast cancer recurrence recorded in the KPNW Tumor Registry and validated by medical record review. Randomly selected controls (833), without recurrent breast cancer, were matched to cases on tumor stage, diagnosis year, diagnosis age, race/ethnicity, and patterns of health plan membership. We collected data from medical records and from pharmacy, laboratory, tumor registry, and membership health plan databases. The Oregon Health & Science University Molecular Genetics Laboratory extracted genomic DNA from stored FFPE tissue blocks and performed allelic discrimination assays and pyrosequencing to accurately determine CYP2D6 variant status for the alleles, *3, *4, *5, *10, *17, and *41. All assays have been completed and study subjects have been categorized according to CYP2D6 metabolizer phenotype (poor, intermediate, extensive) and activity score (0-2). Based on the ethnicities in our study population, the CYP2D6 allele frequencies are in Hardy-Weinberg equilibrium, and the frequencies of the predicted metabolizer phenotypes also fall within the expected range. Using multivariable logistic regression analysis, we will assess CYP2D6 functional status and activity score in relation to breast cancer recurrence, taking into account factors that may alter the association, including tamoxifen dose and duration of use, as well as concomitant medications that alter the activity of the CYP2D6 enzyme. Results will be available by 12/1/2015.

Citation Format: Weinmann S, Richert–Boe K, Goddard K, Chen C, Punj S, Schwarzkopf D, Kalter M, Richards CS. CYP2D6 gene variants and effectiveness of adjuvant tamoxifen in breast cancer: A population-based case-control study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-08-02.