Metabolite profiles of medulloblastoma for rapid and non-invasive detection of molecular disease groups

BACKGROUND

The malignant childhood brain tumour, medulloblastoma, is classified clinically into molecular groups which guide therapy. DNA-methylation profiling is the current classification 'gold-standard', typically delivered 3-4 weeks post-surgery. Pre-surgery non-invasive diagnostics thus offer significant potential to improve early diagnosis and clinical management. Here, we determine tumour metabolite profiles of the four medulloblastoma groups, assess their diagnostic utility using tumour tissue and potential for non-invasive diagnosis using in vivo magnetic resonance spectroscopy (MRS).

METHODS

Metabolite profiles were acquired by high-resolution magic-angle spinning NMR spectroscopy (MAS) from 86 medulloblastomas (from 59 male and 27 female patients), previously classified by DNA-methylation array (WNT (n = 9), SHH (n = 22), Group3 (n = 21), Group4 (n = 34)); RNA-seq data was available for sixty. Unsupervised class-discovery was performed and a support vector machine (SVM) constructed to assess diagnostic performance. The SVM classifier was adapted to use only metabolites (n = 10) routinely quantified from in vivo MRS data, and re-tested. Glutamate was assessed as a predictor of overall survival.

FINDINGS

Group-specific metabolite profiles were identified; tumours clustered with good concordance to their reference molecular group (93%). GABA was only detected in WNT, taurine was low in SHH and lipids were high in Group3. The tissue-based metabolite SVM classifier had a cross-validated accuracy of 89% (100% for WNT) and, adapted to use metabolites routinely quantified in vivo, gave a combined classification accuracy of 90% for SHH, Group3 and Group4. Glutamate predicted survival after incorporating known risk-factors (HR = 3.39, 95% CI 1.4-8.1, p = 0.025).

INTERPRETATION

Tissue metabolite profiles characterise medulloblastoma molecular groups. Their combination with machine learning can aid rapid diagnosis from tissue and potentially in vivo. Specific metabolites provide important information; GABA identifying WNT and glutamate conferring poor prognosis.

FUNDING

Children with Cancer UK, Cancer Research UK, Children's Cancer North and a Newcastle University PhD studentship.

Review of standard paediatric neuroradiology MRI protocols from 12 UK tertiary paediatric hospitals: is there much variation between centres?

AIM

To investigate how magnetic resonance imaging (MRI) examinations are protocolled in tertiary paediatric neuroradiology centres around the UK for some of the more common presentations encountered in paediatric neuroradiology, and to identify any variations of note.

MATERIALS AND METHODS

All 19 UK tertiary paediatric neuroradiology centres registered with the British Society of Neuroradiologists-Paediatric Group were contacted and asked if they could provide a copy of their standard MRI protocols. Twelve responded (63%) and 10 of the more common presentations were selected and the standard acquired sequences obtained at each participating centre were compared. Where available the collated protocols were also compared against current published guidance.

RESULTS

The basic sequences carried out by centres around the UK are similar; however, there are lots of variations overall. The only standardised protocol currently being implemented nationally in paediatric imaging is that for brain tumours. Otherwise, chosen protocols are generally dependent on the preferences and technical capabilities of individual centres. Suggested published protocols also exist for non-accidental injury (NAI), multiple sclerosis, epilepsy, and head and neck imaging.

CONCLUSIONS

The differences in MRI protocolling depend in part on technical capabilities and in part on the experience and preferences of the paediatric neuroradiologists at each centre. For most presentations, there is no consensus as to what constitutes the perfect protocol. The present results will be useful for specialist centres who may wish to review their current protocols, and for more generalist centres to use as a reference to guide their MRI protocolling.

Feasibility and Clinical Implementation of Electron FLASH Radiation Therapy in the Yorkshire Swine Model

PURPOSE/OBJECTIVE(S)

Preclinical studies have shown FLASH radiation therapy (RT) increases the therapeutic index through reduction in normal tissue toxicity but with retained tumor control compared to conventional dose rate (CONV) RT. Dosimetry in FLASH beams is challenging and complex as beam monitoring and proper dosimetry analysis remain uncertain and under investigation. Despite these limitations, clinical translation of FLASH RT has already begun. For translation of FLASH RT from the preclinical stage, it is critical that robust clinical workflows and dosimetry methods be confidently established to ensure patient safety. Here, we present the clinical workflow for the Yorkshire pig, an animal that resembles the body dimension, weight, and biology of a human patient, with the goal to establish standard operating procedures to ensure a safe and robust clinical translation in our upcoming phase I study in cutaneous tumors. The study determines feasibility and safety while finding incidence of dose-limiting toxicities and maximum tolerable dose for future Phase II trials.

MATERIALS/METHODS

All procedures were approved by the institutional animal care and use committee. 6 pigs (40-50 kg) were placed under general anesthesia and underwent CT imaging for radiation therapy simulation purposes. The skin was first shaven, and targets on the dorsolateral flanks were marked with tattoos and BBs for CT visualization. Vacloc immobilization was used to allow for reproducible setup on the treatment couch. A treatment planning model was established for treatment planning and dose evaluation purposes. CONV and FLASH single and fractionated dose regimens were prescribed to the 90% isodose line in a 9 MeV beam. Skin collimation and bolus minimized beam penumbra and increased skin dose. Treatment time and pulse repetition frequency were constant between all FLASH fields. Prescription levels were varied via dose per pulse. Calibration and verification of these settings were performed utilizing a multi-dosimeter method for verification in solid water. Output of the beam was verified on the day of the treatment using beam current transformers. This same multi-dosimeter method was used as in-vivo dosimetry on treatment day and compared to the dose verification ensure full dose was received.

RESULTS

Variation between the three dosimeter methods was found to be within 5% among all pigs within the study. The maximum percent difference between dose verification and dose delivery was 6%. Consideration must be taken in dosimeter readout error due to the surface of the pig skin. FLASH and CONV toxicity results are currently under evaluation and will be published upon completion of the study.

CONCLUSION

Establishing guidelines and protocols for electron FLASH clinical translation is important to instill confidence in patient safety with this new technique. This study has further optimized and developed dosimetry tools and setup to be used in future clinical trials.

Association of Parental Status and Gender with Burden of Multidisciplinary Tumor Boards

PURPOSE/OBJECTIVE(S)

Tumor boards are an integral part of the management of patients with cancer. However, there is limited data investigating the burden of tumor boards on physicians. Our objective was to determine what physician-related, and tumor board-related factors associate with higher burden.

MATERIALS/METHODS

Tumor board start times were collected by email from 22 National Cancer Institute-designated cancer centers and/or U.S. World and News Report Top 40 hospitals for cancer. Tumor board burden was assessed by a cross-sectional convenience survey posted on social media and by email to Cedars-Sinai Medical Center cancer physicians between March 3, 2022, and April 3, 2022. Tumor board burden was measured on a 4-point scale (1, not at all; 2, slightly; 3, moderately; 4, very burdensome). Univariable and multivariable analyses were performed using a probabilistic index model.

RESULTS

The timing of 392 tumor boards was collected from 22 institutions. The most common tumor board start time was at or before 0730 (24.6%). Surveys were completed by 111 physicians, of which 52.3% identified as women and 42.3% as men. Reported specialties were radiation oncology (39.6%), medical oncology (18.0%), surgery (15.3%), radiology (12.6%), and pathology (9.9%). On average, 41.4% attended ≥3 hours/week total of tumor boards and 1-2 hours/week of early/late tumor boards (defined as starting before 0800 or 1700 or after). Overall, 37.8% reported tumor boards were at least moderately burdensome. On multivariable analysis, radiology/pathology specialty (probability 0.68; 95% confidence interval [CI], 0.54-0.79; p = 0.015), attending ≥3 hours/week of tumor boards (probability 0.68; 95% CI, 0.58-0.76; p<.001), and having ≥2 children (probability 0.65; 95% CI, 0.52-0.77; p = 0.029), were associated with higher burden. Early/late tumor boards were frequently considered burdensome (20.7% moderately, 29.7% very burdensome). On multivariable analysis, identifying as a woman (probability 0.69; 95% CI, 0.57-0.78; p = 0.003) and having children (probability 0.75; 95% CI, 0.62-0.84; p<.001) remained associated with a higher level of burden from early/late tumor boards. Further, parents frequently reported that early/late tumor boards negatively affected childcare (55.8%), feeding and/or sleep logistics (33.8%), and overall family dynamics (63.7%).

CONCLUSION

Identifying as a woman and having children were associated with a higher level of burden from early/late tumor boards. The negative impact of early/late tumor boards on overall family dynamics, including children feeding, sleeping, and childcare logistics, was commonly reported by parents. Having ≥2 children, attending ≥3 hours/week of tumor boards, and radiology/pathology specialty were associated with a higher level of burden overall. Future strategies should aim to decrease burden, particularly the disparate impact on parents and women.

Adjuvant Radiation Therapy Improves Local Control in the Treatment of Adnexal Carcinoma

PURPOSE/OBJECTIVE(S)

Adnexal carcinoma (AC) is a rare subset of cutaneous malignancies derived from skin adnexa. There are limited data on the role of adjuvant radiation therapy (RT). This study investigates outcomes associated with adjuvant RT at our high-volume referral center.

MATERIALS/METHODS

Using an institutional pathology database we identified 45 patients with locoregionally-confined AC treated between 2001-2020 with curative intent surgery and RT at initial diagnosis or at the time of locoregionally-confined recurrence. Clinicopathologic variables were described and time to relapse events were assessed by the Kaplan-Meier method.

RESULTS

Median age was 64 yrs (IQR 57-71). Primary tumors were in the head and neck (H&N, n = 36, 80%), trunk/extremities (n = 8, 18%) or unknown (n = 1). The most common histologic subtypes were: sebaceous-14 (31%), microcystic adnexal carcinoma-9 (20%), eccrine-6 (13%), and trichilemmal-5 (11%). Twenty-two (50% of known primaries) had PNI. All patients had primary tumor excision. Six had clinically evident lymphadenopathy (13%), all of whom had lymph node dissection (LND). Five patients without evidence of nodal disease (13%) had sentinel lymph node biopsy (SLNB) with one having SLN+ disease. Thirty patients (67%) received adjuvant locoregional RT at initial diagnosis with the following targets: 21 (30%) primary only, 4 (13%) nodal only, and 5 (17%) both. Of those receiving nodal RT, 7 (78%) had LN+ LND with 2 of those receiving concurrent platinum-based chemoradiation. Sixteen were treated at recurrence with the following targets: 4 (25%) primary only (1 having had prior adjuvant nodal RT), 4 (25%) nodal only, and 8 (50%) both. Across the full cohort, median RT dose was 60 Gy in 30 fractions. Median follow-up from initial surgical resection was 60 months (IQR 30-160). 5-year LC, NC, DFS and DSS were 71%, 86%, 66%, and 91% respectively. The only evaluated factor associated with better outcome was adjuvant primary site RT (5-yr LC 83% vs. 56%, p = 0.01 and 5-yr DFS 83% vs. 46%, p = 0.0003). All 15 patients with local recurrence (LR) had salvage surgery with median subsequent follow-up of 75 months (IQR 2-94). Overall, 5 patients receiving adjuvant primary site RT at any time (initial or salvage) developed subsequent local recurrence (13%). Of the 8 patients who developed nodal recurrence (NR) during follow-up, 1 received adjuvant nodal RT at initial diagnosis. Six of 7 who did not receive prior RT then received adjuvant nodal RT after LND and only 1 developed subsequent NR.

CONCLUSION

AC is a rare skin cancer with a primarily locoregional recurrence pattern. In our experience, adjuvant RT was associated with improved LC which, depending on the tumor location, may help prevent morbid or cosmetically-impactful salvage surgery. Patients with AC would benefit from radiation oncology referral to discuss adjuvant treatment.

Evaluating the Utility of Traditional Bowel Dose Constraints when Treating Abdominal and Pelvic Sarcomas with Preoperative Radiation Therapy

PURPOSE/OBJECTIVE(S)

Abdominopelvic soft tissue sarcomas (AP-STS) are selectively treated with preoperative radiation therapy (RT) followed by surgery. Due to their rarity, most bowel dose constraints are extrapolated from dosimetric studies for other abdominal or pelvic malignancies where concurrent chemotherapy is often given in addition to RT. We sought to investigate associations between dosimetric bowel constraints and the risk for developing acute and long-term toxicities in patients who received preoperative RT for AP-STS.

MATERIALS/METHODS

We performed a retrospective review of patients treated at a tertiary cancer center for non-metastatic AP-STS between 2005 and 2020. Dosimetric parameters for the "bowel bag" organ at risk structure were extracted for each patient. Chi-Square or Fisher's Exact Test, where appropriate, was utilized to compare the proportion of patients who exceeded constraints to the bowel bag contour as per the consensus RT retroperitoneal sarcoma guidelines, and the development of acute and long-term toxicities.

RESULTS

We identified 39 patients with available dosimetric data. The median follow-up was 34 months (IQR 20-47). Approximately half of the tumors were located in the pelvis (n = 20, 51%), and the majority were treated with IMRT/VMAT (n = 35, 90%). 31 patients (80%) presented with de novo disease, and 20% (n = 8) were recurrent presentations but had not received prior RT. The most common histology was leiomyosarcoma (n = 15, 38%), followed by de-differentiated liposarcoma (n = 8, 21%). The median bowel max dose (defined as D0.1cc) was 5309cGy [IQR 5262-5830]. Thirteen patients (33%) exceeded the volumetric V15 Gy <830cm3 bowel bag constraint, and 18 (46%) exceeded the V45 Gy ≤ 195cm3 bowel bag constraint. Overall, 17 patients (44%) had acute grade 1 diarrhea, and 11 (28%) had grade 1-2 nausea. Five patients (13%) had long-term radiation-related toxicities, including 1 patient who developed an enterocutaneous fistula. There was no association between exceeding V15 Gy>830 cm3 (p = 0.31) or V45 Gy≥195cm3 (p = 0.65) bowel bag constraints and developing a long-term RT toxicity. Similarly, exceeding V15 Gy>830 cm3 or V45 Gy≥195cm3 did not lead to increased risks of developing acute diarrhea, nausea, or any other acute RT toxicity (all p>0.05).

CONCLUSION

Traditional volumetric bowel bag dose constraints are frequently exceeded given the large size of AP-STS at presentation and thus the large RT target volumes. Despite a significant proportion of patients exceeding these constraints, these data suggest that RT is overall well-tolerated, and the risk of developing toxicities does not correlate with traditional bowel bag volumetric constraints. There are ongoing efforts to substantially expand this cohort for further investigation into the relationship between dosimetric data and bowel toxicities in order to identify more predictive bowel constraints that can be used during treatment planning of AP-STS.

Outcomes for Patients with Head and Neck Sarcoma Treated Curatively with Radiation Therapy and Surgery

PURPOSE/OBJECTIVE(S)

Soft tissue sarcomas (STS) of the head and neck are rare and diverse entities that are challenging to manage. Definitive treatment requires surgery, often with radiation therapy (RT). We sought to describe the outcomes of patients treated curatively with surgery and RT for head and neck STS.

MATERIALS/METHODS

We performed a retrospective review of patients treated at a tertiary cancer center for non-metastatic STS of the head and neck between 1968 and 2020; over half were treated in the modern era defined as 2005 or after. Patients with rhabdomyosarcomas or cutaneous angiosarcoma were excluded. The Kaplan-Meier method was used to estimate actuarial overall survival (OS), disease-specific survival (DSS) and local control (LC). Multivariable analyses (MVA) were conducted using Cox proportional hazards model.

RESULTS

Median follow-up was 82 months. Of the 192 patients, the majority were male (n = 111, 58%), White (n = 158, 82%), and median age was 49.5 [IQR 32.5-64]. The highest proportion of tumors were in the neck (n = 50, 26%), paranasal sinuses (n = 36, 19%), or face (n = 23, 12%). The most common histology was sarcoma, not otherwise specified (n = 44, 23%), followed by undifferentiated pleomorphic sarcoma (n = 32, 17%), and neurogenic sarcoma (n = 15, 8%). Most patients were treated with postoperative RT (n = 134, 70%). Patients treated with preoperative RT were older (median 56.5 yrs vs post-op 44 yrs, p = 0.009). Post-op RT doses were higher (median 60 Gy, pre-op 50 Gy, p<0.001), and margins were more likely to be negative in those treated with pre-op RT (n = 39, 67%, post-op 69, 51%, p = 0.02). 5-year LC, DSS, and OS for the entire cohort was 76% (95% CI 69-82), 74% (67-80), and 71% (64-77), respectively. LC was not affected by treatment sequence (pre-op RT 78% (63-88), post-op RT 75% (66-82), p = 0.48). Patients with negative margins had improved 5-yr LC (86% (77-92), positive/uncertain 65% (53-74), p = 0.003). On MVA, positive/uncertain margin was the only variable associated with LC (HR 2.54 (1.34-4.82), p = 0.004). Poorer 5-yr DSS was associated with higher grade (grade 3 75% (63-84), grade 1-2 89% (75-94), p = 0.02), and treatment era (pre-2005 68% (57-76), on/after 2005 80% (70-87), p = 0.04). These both remained significant on MVA (grade 3 HR 2.39 (1.07-5.36), p = 0.034; pre-2005 HR 2.31 (1.03-5.21), p = 0.043). Sixteen patients (8%) developed a late RT toxicity, including fibrosis (n = 4, 2%), necrosis (osteoradionecrosis n = 2, brain necrosis n = 1, soft tissue necrosis n = 1), and eye dryness (n = 2, 1%). Neither the timing of RT nor dose was found to be associated with developing a late RT toxicity.

CONCLUSION

Head and neck STS continues to have relatively poorer local control than STS of the trunk or extremities. Timing of RT did not impact oncologic or long-term RT-related toxicity outcomes. However, more data are needed to ascertain whether preoperative RT may impact acute surgical toxicities. These data contribute to multidisciplinary care planning for patients with STS in these challenging anatomic locations.

Subacute Cutaneous Toxicity with Single-Fraction Electron FLASH RT in Yorkshire Swine

PURPOSE/OBJECTIVE(S)

Information regarding acute/subacute skin toxicity of electron FLASH radiation therapy (RT) is limited. We evaluated short-term safety of electron FLASH for human trials by investigating subacute toxicity compared to conventional dose-rate RT (CONV) in the Yorkshire pig, an animal model known to closely approximate human skin and routinely used for toxicity studies.

MATERIALS/METHODS

Two healthy 50 kg pigs underwent CT imaging for RT treatment planning with field visualization via BBs and tattoos on each dorsolateral flank. Each target received a single fraction of 20, 25 or 30 Gy with FLASH and CONV on opposing sides delivered using a dedicated mobile linear accelerator. FLASH dose rates ranged from 164-245 Gy/sec (12 pulses delivered over 0.122 sec) while the CONV dose rate was set at 0.18 Gy/sec. Doses were verified using thermo- and optically stimulated luminescent dosimeters, and Gafchromic films. We obtained baseline and weekly images up to 98 days post-RT (D98) for blinded toxicity grading by 3 expert radiation oncologists using the modified RTOG radiation dermatitis (RD) scale. We measured erythema and pigmentation indices on those timepoints using a handheld spectrophotometer. We also obtained punch biopsies of targets and non-irradiated controls on D10 and D30 for RNA sequencing and two 6-marker multiplex immunofluorescence analyses of inflammation, immune response, and fibrosis. FLASH and CONV data were compared using repeated measures ANOVA and transcriptomic analyses using DESeq2.

RESULTS

All RT targets developed peak median grade 4 (ulceration, hemorrhage, or necrosis) RD by D84 regardless of FLASH or CONV delivery. However, FLASH targets developed peak RD later than CONV targets after 20 Gy (D84 vs D63), 25 Gy (D84 vs D49) and 30 Gy (D63 vs D42). FLASH induced qualitatively lower mean pigmentation and erythema indices than CONV for all 3 doses. Similarly, peak mean pigmentation indices occurred later with FLASH vs CONV for 20 Gy (D84 vs D63), 25 Gy (D84 vs D49) and 30 Gy (D77 vs D63). However, peak mean erythema indices occurred on the same day for FLASH and CONV (D63 for 20 Gy and D42 for 25 and 30 Gy). Transcriptomic analyses revealed significantly upregulated signals for wound healing (including TGF-beta, cell adhesion and extracellular matrix receptor interaction) and leukocyte infiltration with 20 Gy CONV mostly by D10, while FLASH upregulated those pathways only after 25 or 30 Gy, or by D30, or never at all. Preliminary immunofluorescence data showed FLASH may induce less T cell infiltrate and TGF-beta-expressing macrophages than CONV.

CONCLUSION

Single-fraction electron FLASH resulted in delayed onsets of both subacute cutaneous toxicity and wound healing with leukocytic infiltration signaling than dose-matched CONV based on both subjective and objective metrics of skin injury. Our findings suggest further investigations of optimal dose of electron FLASH for safe clinical translation is warranted, and we have a dose-finding study currently underway.

Outcomes after definitive treatment for cutaneous angiosarcomas of the face and scalp: Reevaluating the role of surgery and radiation therapy

INTRODUCTION

We investigated outcomes and prognostic factors for patients treated for cutaneous angiosarcoma (CA).

METHODS

We conducted a retrospective review of patients treated for CA of the face and scalp from 1962 to 2019. All received definitive treatment with surgery, radiation (RT), or a combination (S-XRT). The Kaplan-Meier method was used to estimate outcomes. Multivariable analyses were conducted using the Cox proportional hazards model.

RESULTS

For the 143 patients evaluated median follow-up was 33 months. Five-year LC was 51% and worse in patients with tumors >5 cm, multifocal tumors, those treated pre-2000, and with single modality therapy (SMT). These remained associated with worse LC on multivariable analysis. The 5-year disease-specific survival (DSS) for the cohort was 56%. Tumor size >5 cm, non-scalp primary site, treatment pre-2000, and SMT were associated with worse DSS.

CONCLUSION

Large or multifocal tumors are negative prognostic factors in patients with head and neck CA. S-XRT improved outcomes.

HANSEN’S DISEASE DIAGNOSED AFTER ANTI-CANCER CHEMOTHERAPY

Background. Leprosy or Hansen’s disease is a chronic granulomatous disease involving predominantly skin, peripheral nerves and nasal mucosa but capable of affecting any tissue or organ. Histoid leprosy is a very rare well-defined clinicopathological variant of multibacillary lepromatous leprosy, which is very difficult to diagnose due to different specific clinical and histopathological findings that mimic a fibromatous disorder. Histoid leprosy occurs generally after treatment failure and sometimes de novo. Objective. The aim of the study was to explore histoid leprosy throughout a case report. Methods. A case report of histoid leprosy diagnosed after cancer chemotherapy is presented. Results. A 25-year-old healthy male presented with multiple skin coloured, discrete, well defined, painless papules and nodules scattered over nape of neck, right side of the trunk and both arms along with numbness as well as tingling sensation over both the arms and trunk. It was a case of non-seminomatous germ cell tumour (NSGCT), left testis, diagnosed and treated with a high inguinal orchidectomy with adjuvant chemotherapy in 2016. Ziehl Neelsen (ZN) stain for Acid Fast Bacilli (Mycobacterium leprae) – a modified Fite stain method showed numerous acid-fast bacilli. Histopathological diagnosis of Hansen’s disease (Histoid) was conducted. The patient was admitted and started on triple drug multi-bacillary multi-drug therapy (MB-MDT). A remarkable improvement was noticed in the lesion status within one month of institution of the therapy. Conclusions. Histoid leprosy is a discrete infrequent form of multibacillary leprosy with distinctive clinical, bacteriological and histomorphological features. Histopathologic examination with modified Fite stain is still the mainstay of diagnosis.

Abstract P6-18-36: Real world treatment patterns and outcomes of patients receiving palbociclib plus aromatase inhibitor in the United States: Sub-groups analysis based on age, performance status and sites of metastases from the IRIS study

Background: Ibrance Real World Insights (IRIS) is a multi-country study aimed to describe clinical characteristics, treatment patterns and clinical outcomes of patients receiving palbociclib plus aromatase inhibitor. Previously the results on the overall population within the US have been communicated. The current analysis focuses on subgroups stratified by age, performance status and visceral status.

Materials and methods: A retrospective chart review of HR+/HER2- ABC/MBC patients who received palbociclib plus aromatase inhibitor as initial endocrine based therapy for their advanced disease was conducted between June and October 2017. Physicians completed electronic case report forms, extracting data on patient demographics, clinical characteristics, treatment history/patterns and clinical outcomes.Progression free and survival rates at 12 and 24 months were estimated via Kaplan-Meier analysis.

Results: Data for the US are reported here. In total 63 physicians completed 360 eCRFs with a mean follow up time since palbociclib initiation of 12 months. Majority of the patients were &gt;65 years (53%), and had ECOG status of 0 (30%) or 1 (56%). Overall 293 (81%) patients had metastatic disease, of which 50% had visceral metastases. Across all sub-groups, majority of patients prescribed an initial palbociclib dose of 125mg did not require a change of dose while on treatment. The 12-month and 24-month progression free and overall survival rates across subgroups are presented in Table 1. Patients with a performance status of ECOG=1 had a slightly lower progression and survival rates at 12 and 24 months compared to those with a score =0. Likewise, patients with visceral disease were observed to have slightly lower progression free and survival rates than others.

Table 1:Clinical Outcomes for the different sub-groups.Patient Sub-groups AgeECOG statusVisceral Status Up to 65 n=169Over 65 n=1910 n=1071 n=200Visceral metastases n=147Non-visceral metastases n=146Progression free survival rate at 12 months, %86.382.194.386.580.285.8Progression free survival rate at 24 months, %59.769.071.267.450.780.6Overall survival rate At 12 months, %97.992.8100.099.590.599.3Overall survival rate at 24 months, %95.185.695.796.487.290.7

Conclusions: The analysis indicates consistent trends in different clinical outcomes were observed with palbociclib plus aromatase inhibitor across patients sub-groups based on age, performance status and visceral metastases.

Citation Format: Taylor-Stokes G, Mitra D, Waller J, Gibson K, Milligan G, Zhan L, Iyer S. Real world treatment patterns and outcomes of patients receiving palbociclib plus aromatase inhibitor in the United States: Sub-groups analysis based on age, performance status and sites of metastases from the IRIS study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-36.

Abstract P6-18-27: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Odom D, Mitra D, Hollis K, Richardson D, Kaye JA, McRoy L. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-27.

Abstract P6-18-33: GI toxicities in metastatic breast cancer: A comprehensive literature review

Background

Treatments for advanced or metastatic breast cancer (aBC/mBC) are associated with gastrointestinal (GI) toxicities. The objective of this study was to assess the association between GI toxicities in mBC/aBC and health-related quality of life (HRQoL) and economic burden.

Methods

We conducted a comprehensive literature search of the Cochrane Central Register of Controlled Trials (2017), NHS Economic Evaluation Database (2016), Embase (1988 – 2017 week 34), and Ovid MEDLINE (1946 to August 2017). Eligible studies evaluated an intervention/comparator treatment in adult patients (age ≥18 years) with aBC/mBC and reported a direct connection between GI toxicities (ie, diarrhea, constipation, nausea, vomiting) and HRQoL and economic evidence. All studies published from January 2000 to August 2017 were assessed for eligibility. Editorials, case reports, conference abstracts, and studies of early, locally advanced, or inflammatory BC were excluded. Abstract and title screening, and full-text screening were conducted by single reviewers. Data were extracted by a single reviewer and verified by a second. Results were synthesized narratively.

Results

Database searches identified 3,428 articles; an additional 16 articles were identified through other sources. Ninety-four studies underwent full-text review, of which 27 reported a direct connection between GI toxicities and HRQoL (n = 11) and economic burden (n = 19). Some studies reported both HRQoL and economic data.

Patients identified treatment-related adverse events (AEs), such as GI events, as an important aspect of treatment that can affect therapy choice, discontinuation, and switching. Generally, patients with mBC had lower HRQoL than other BC groups, and increasing toxicity was associated with a greater degree of HRQoL impairment. When patients were asked to rank which AEs they most wanted to avoid, only pain ranked higher than nausea and vomiting. In a willingness to pay study, women with mBC were willing to pay $3,894 (2014 USD) per year to avoid severe diarrhea and $3,211 to avoid severe nausea.

Gastrointestinal events were among the costliest class of AEs, with mean costs as high as $4,809 (2016 USD) per episode; costs increased by 24% if events were persistent or recurrent.

Conclusions

Gastrointestinal toxicities are common in patients with aBC/mBC and have significant consequences for HRQoL and system-level economic outcomes. Frequency and implications of GI effects of treatment regimens should be considered carefully during patient counseling,, prescribing and coverage decisions in metastatic breast cancer.

Citation Format: Disher T, Siddiqui M, Mitra D, Cameron C, Zhan L, Iyer S. GI toxicities in metastatic breast cancer: A comprehensive literature review [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-33.

Abstract P6-18-21: Real world treatment patterns and outcomes of patients receiving palbociclib plus fulvestrant in the United States: Sub-groups analysis based on age, performance status and sites of metastases

Background: Ibrance Real World Insights (IRIS) is a multi-country study aimed to describe the clinical characteristics and understand treatment patterns and clinical outcomes of patients receiving palbociclib plus fulvestrant in real world clinical practice. Previously the results on the overall population within the US have been communicated. The current analyses focus on subgroups stratified by age, performance status and visceral status.

Materials and methods: A retrospective chart review of HR+/HER2- ABC/MBC patients was conducted between June and October 2017. Physicians extracted data from patient medical records for HR+/HER2- ABC patients who received palbociclib plus fulvestrant following disease progression with endocrine based therapy for their advanced disease. Electronic case report forms collected data covering patient demographics, clinical characteristics, treatment history/patterns and clinical outcomes.Progression free rates and survival rates at 6 and 12 months were estimated via Kaplan-Meier analysis.

Results: Data for the US are reported here. In total, 65 physicians extracted data for 292 patients who had a mean follow up time of 7.4 months. Majority of the patients were &gt;65 years (54%), and had ECOG status of 0 (32%) or 1 (48%). Overall 224 (77%) patients had metastatic disease, of which 93 (42%) had visceral metastases. Across all sub-groups, majority of patients prescribed an initial palbociclib dose of 125mg did not require a change of dose while on treatment. The 6-month and 12-month progression free and survival rates across subgroups are presented in Table 1. Patients with a performance status of ECOG ≥ 2 had a slightly lower progression and survival rates at 6 and 12 months compared to those with a score &lt;1. Likewise, patients with visceral disease were observed to have slightly lower progression free and survival rates than others.

Table 1:Clinical Outcomes by Patient Sub-groups.Patient Sub-groups AgeECOGstatusVisceral Status Up to 65 n=158Over 65 n=1340 n=931 n=1392+ n=60Visceral Metastases n=93Non-visceral Metastases n=131Progression free survival rate at 6 months, %95.293.297.893.490.689.694.8Progression free survival rate at 12 months, %81.277.884.683.0-73.276.5Survival rate at 6 months, %98.096.3100.098.290.692.298.9Survival rate at 12 months, %90.085.197.695.1-80.892.7

Conclusions: The analysis indicates consistent trends in different clinical outcomes were observed with palbociclib plus fulvestrant across patients sub-groups based on age, performance status and visceral metastases.

Citation Format: Waller J, Mitra D, Taylor-Stokes G, Gibson K, Milligan G, Zhan L, Iyer S. Real world treatment patterns and outcomes of patients receiving palbociclib plus fulvestrant in the United States: Sub-groups analysis based on age, performance status and sites of metastases [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-21.

Abstract P5-21-24: Retrospective assessment of treatment patterns and outcomes associated with palbociclib plus letrozole for postmenopausal women with HR+/HER2– advanced breast cancer enrolled in an early access program

Background: The objective of this study was to evaluate treatment patterns and clinical outcomes among patients who received palbociclib in combination with letrozole (P+L) for the treatment of HR+/HER2–advanced breast cancer (ABC) as part of an Expanded Access Program (EAP) in the United States.

Methods: Data were obtained by a retrospective chart review of patients previously enrolled in the EAP. Complete data from time of initial diagnosis of ABC until the date of chart abstraction (end of follow-up), including the post-EAP period, were obtained. Clinical outcomes assessed included clinical benefit rate (CBR), defined as complete response, partial response, or stable disease for ≥24 weeks from P + L initiation, progression free survival (PFS) and overall survival (OS). Survival outcomes were assessed using the Kaplan-Meier statistical analysis.

Results: Data from 126 patients were included in this analysis. Median age was 62.5 years at EAP enrollment, and a majority of patients were Caucasian (83%). Approximately 25% of patients had de novo metastatic disease. A majority of patients had a performance status of ECOG 0 (56%) or 1 (37%) at EAP enrollment. Visceral disease was present in 71% of patients and 16% had bone-only disease. The majority of patients in this cohort from the EAP were heavily pre-treated, having had up to 5 prior lines of therapy in the metastatic setting prior to initiating P + L therapy; nearly 59% received 3+ prior lines before initiating P + L. Only 11% of patients received P + L as their initial regimen for MBC. At the time of the last available record, 12 patients were still on P + L therapy, an average of 21 months after the start of the EAP program. Nearly 80% of patients had prior AI exposure and 69% had prior chemotherapy. CBR was 33% for the overall sample of patients treated with P + L and 22% in those with 3+ prior lines of treatment. Patients with prior AI exposure in the ABC setting (n=100) had a CBR of 27% while those without prior AI exposure had CBR of 58%. Patients with prior chemotherapy (n=87) had a CBR of 28% and those without prior chemotherapy had CBR of 46%. For the entire cohort, 6- and 12-month PFS rates were 40% and 25% respectively; 12- and 24-month OS rates were 66% and 44%, respectively. Patients receiving 3+ lines of prior therapy had 6- and 12-month PFS rates of 28% and 19%, respectively, and 12- and 24-month OS rates of 59% and 34% respectively.

Conclusions: Our results suggest that the majority of patients enrolled in the EAP program derived benefit from receiving treatment with P + L despite multiple prior lines of treatment and prior endocrine-based therapy, including prior AI. These findings further demonstrate the benefit of treatment with palbociclib combination therapy in HR+/HER2– MBC.

Citation Format: Brufsky A, Davis K, Mitra D, Nagar S, McRoy L, Cotter M, Stearns V. Retrospective assessment of treatment patterns and outcomes associated with palbociclib plus letrozole for postmenopausal women with HR+/HER2– advanced breast cancer enrolled in an early access program [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-24.

Unsupervised Learning in PET Radiomics

In this study, we investigated large scale radoimics on 116 breast cancer patients. We are particularly interested in unsupervised learning to bicluster patients and features in order to associate such biclusters with the disease characteristics. The results show that radiomics features with wavelet features have a better biclustering ability. And 172 radiomics features have shown a better classification capability.

Abstract OT3-03-01: MADELINE: A prospective observational study of mobile app-based patient reported outcomes in advanced breast cancer

BACKGROUND: There have been few studies evaluating the day-to-day effects of advanced breast cancer (ABC) and its treatment on patients in a real-world setting.Palbociclib is a novel CDK4/6 inhibitor approved in the US for hormone-receptor positive, human epidermal growth factor receptor negative (HR+, HER2-) ABC/metastatic breast cancer (MBC) in combination with letrozole as initial endocrine based therapy in postmenopausal women or with fulvestrant in women with disease progression following endocrine therapy. With the introduction of this first-in-class drug it is important to understand the experiences of patients initiating ABC therapies including palbociclib in real-world settings and to document the management of these therapies. A smartphone-based mobile application has been developed to collect patient-reported outcome (PRO) data to assess the impact of ABC and associated treatment on symptoms, functioning and quality of life (QOL) as reported by patients. The application is further designed to provide patients initiating palbociclib with a virtual community to connect to others enrolled in the study for peer support. Additionally, clinical data on therapy management (e.g. dose modifications, interruptions, discontinuations, adverse event management and monitoring) will be obtained from patients' medical records to explore the association between patient reported functioning and neutropenia.

Study Design: A prospective, observational, non-interventional study. PROs collected via a mobile application and clinical data via case report forms completed by investigator.

Eligibility Criteria: Women with HR+/HER2– ABC receiving palbociclib in combination with letrozole or fulvestrant as per US label (Group 1) orapproved therapies for ABC other than palbociclib (Group 2). No comparison is intended between the 2 groups.

Specific Aims: The primary goals are to describe changes in patients' general health status as measured by monthly administration of the 12-Item Short Form Health Survey, describe changes in patients' psychological distress as measured by monthly administration of the Center for Epidemiological Studies Depression Scale, and describe the extent to which ABC and its treatment are associated with changes in patients' lives in terms of symptoms, functioning and QOL as measured by daily and weekly administration of targeted patient-reported questions. Additionally, for patients who are employed at baseline, time lost from work in relation to breast cancer and its treatment will be quantified.Data from patients' medical records will be used to document changes in therapy as well as the incidence, severity, and duration of neutropenia. The association between patient reported functioning and neutropenia will also be assessed. Finally, real-world monitoring patterns will be assessed.

Statistical Methods: Descriptive statistics will be used to summarize all endpoints. Meta-data regarding use of virtual community resources will be explored for relationships to PRO data.

Present Accrual and Target Accrual: Approximately 450 patients from up to 30 US sites will be enrolled. Study duration will be approximately 12 months assuming 6 months of recruitment. It is expected the study will start enrollment Q3 2016.

Sponsor: Pfizer.

Citation Format: McRoy LL, Mitra D, Hollis K, Kaye JA, Zelnak A, Cheyl J. MADELINE: A prospective observational study of mobile app-based patient reported outcomes in advanced breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT3-03-01.

Columnar aerosol characteristics and radiative forcing over the Doon Valley in the Shivalik range of northwestern Himalayas

Spectral aerosol optical depth (AOD) measurements obtained from multi-wavelength radiometer under cloudless conditions over Doon Valley, in the foothills of the western Himalayas, are analysed during the period January 2007 to December 2012. High AOD values of 0.46 ± 0.08 and 0.52 ± 0.1 at 500 nm, along with low values of Ångström exponent (0.49 ± 0.01 and 0.44 ± 0.03) during spring (March-May) and summer (June-August), respectively, suggest a flat AOD spectrum indicative of coarse-mode aerosol abundance compared with winter (December-February) and autumn (September-November), which are mostly dominated by fine aerosols from urban/industrial emissions and biomass burning. The columnar size distributions (CSD) retrieved from the King's inversion of spectral AOD exhibit bimodal size patterns during spring and autumn, while combinations of the power-law and unimodal distributions better simulate the retrieved CSDs during winter and summer. High values of extinction coefficient near the surface (∼0.8-1.0 km^-1 at 532 nm) and a steep decreasing gradient above are observed via CALIPSO profiles in autumn and winter, while spring and summer exhibit elevated aerosol layers between ∼1.5 and 3.5 km due to the presence of dust. The particle depolarisation ratio shows a slight increasing trend with altitude, with higher values in spring and summer indicative of non-spherical particles of dust origin. The aerosol-climate implications are evaluated via the aerosol radiative forcing (ARF), which is estimated via the synergy of OPAC and SBDART models. On the monthly basis, the ARF values range from ∼ -30 to -90 W m^-2 at the surface, while aerosols cause an overall cooling effect at the top of atmosphere (approx. -5 to -15 W m^-2). The atmospheric heating via aerosol absorption results in heating rates of 1.2-1.6 K day^-1 during March-June, which may contribute to changes in monsoon circulation over northern India and the Himalayas.

Abstract OT2-04-02: A non-interventional study to characterize the real world treatment patterns and outcomes of women with ER+, HER2- advanced or metastatic breast cancer in Italy

Background: Breast cancer is the most common type of cancer in women. There were an estimated 1.67 million new cases of breast cancer worldwide in 2012. Approximately 75% of women have hormone receptor positive (ER positive or PR positive) disease (Buzdar et al., 2009) and most of these patients have HER2-negative disease (Partridge et al., 2014). Although there is evidence via clinical trials on the efficacy of a number of ER+, HER2- breast cancer treatments, real world treatment patterns and related outcomes among this population are poorly characterized. This study aims at examining real world practice patterns and its impact on outcomes to gain a better understanding of the limitations of current treatments, identify specific areas and subpopulations with the greatest unmet need, and demonstrate the economic impact of current treatments. Additionally, this study will provide a longitudinal assessment of the impact of breast cancer on quality of life and work productivity in this subpopulation.

Study design: This study uses a prospective, observational cohort design. Approximately 500 women with ER+, HER2- ABC or mBC within Italy will be enrolled across 50 to 80 sites that represent diverse geographical and treatment settings. All patients will be followed for a minimum of two years (or until patient withdrawal from the study, death, or study discontinuation).

Eligibility criteria: Women who have been diagnosed with ER+, HER2- mBC or locoregionally recurrent ABC not amenable to resection or radiation therapy with curative intent and are initiating their first or second therapy in the ABC/mBC setting will be eligible to participate. Patients could have a de novo diagnosis of ABC or mBC or recur from an earlier stage. Patients participating in any interventional clinical trial that includes investigational products at the time of enrollment will be excluded from the study.

Specific aims: The key measures of interest are demographic and clinical characteristics, treatment patterns, clinical outcomes (e.g. objective response, progression-free survival, and overall survival, disease specific health care resource use, patient reported quality of life (EQ-5D), work productivity (WPAI-SHP), and disease specific symptoms and functioning (FACT-B and FACT-ES).

Statistical methods: The study is descriptive and not designed for formal hypothesis testing. A sample size of 500 patients ensures that the half-width of the 95% CIs on the proportion of patients with objective response at one year is less than 0.06.

Accrual: Patient enrollment is expected to begin in September 2015.

Disclosure: This study is sponsored by Pfizer Inc.

Citation Format: De Laurentiis M, Mitra D, Bell T, Nuzzo CMA, De Placido S. A non-interventional study to characterize the real world treatment patterns and outcomes of women with ER+, HER2- advanced or metastatic breast cancer in Italy. [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 OT2-04-02.