Exploring Capabilities of Large Language Models such as ChatGPT in Radiation Oncology

Purpose

Technological progress of machine learning and natural language processing has led to the development of large language models (LLMs), capable of producing well-formed text responses and providing natural language access to knowledge. Modern conversational LLMs such as ChatGPT have shown remarkable capabilities across a variety of fields, including medicine. These models may assess even highly specialized medical knowledge within specific disciplines, such as radiation therapy. We conducted an exploratory study to examine the capabilities of ChatGPT to answer questions in radiation therapy.

Methods and Materials

A set of multiple-choice questions about clinical, physics, and biology general knowledge in radiation oncology as well as a set of open-ended questions were created. These were given as prompts to the LLM ChatGPT, and the answers were collected and analyzed. For the multiple-choice questions, it was checked how many of the answers of the model could be clearly assigned to one of the allowed multiple-choice-answers, and the proportion of correct answers was determined. For the open-ended questions, independent blinded radiation oncologists evaluated the quality of the answers regarding correctness and usefulness on a 5-point Likert scale. Furthermore, the evaluators were asked to provide suggestions for improving the quality of the answers.

Results

For 70 multiple-choice questions, ChatGPT gave valid answers in 66 cases (94.3%). In 60.61% of the valid answers, the selected answer was correct (50.0% of clinical questions, 78.6% of physics questions, and 58.3% of biology questions). For 25 open-ended questions, 12 answers of ChatGPT were considered as "acceptable," "good," or "very good" regarding both correctness and helpfulness by all 6 participating radiation oncologists. Overall, the answers were considered "very good" in 29.3% and 28%, "good" in 28% and 29.3%, "acceptable" in 19.3% and 19.3%, "bad" in 9.3% and 9.3%, and "very bad" in 14% and 14% regarding correctness/helpfulness.

Conclusions

Modern conversational LLMs such as ChatGPT can provide satisfying answers to many relevant questions in radiation therapy. As they still fall short of consistently providing correct information, it is problematic to use them for obtaining medical information. As LLMs will further improve in the future, they are expected to have an increasing impact not only on general society, but also on clinical practice, including radiation oncology.

Extraction of Interoperable Data from Healthcare Documents by Identifying Common Data Elements: An Analysis of Radiation Therapy Planning CT Physician Order Entry Records

INTRODUCTION

Documentation as well as IT-based management of medical data is of ever-increasing relevance in modern medicine. As radiation oncology is a rather technical, data-driven discipline, standardization, and data exchange are in principle possible. We examined electronic healthcare documents to extract structured information. Planning CT order entry documents were chosen for the analysis, as this covers a common and structured step in radiation oncology, for which standardized documentation may be achieved. The aim was to examine the extent to which relevant information may be exchanged among different institutions.

MATERIALS AND METHODS

We contacted representatives of nine radiation oncology departments. Departments using standardized electronic documentation for planning CT were asked to provide templates of their records, which were analyzed in terms of form and content. Structured information was extracted by identifying definite common data elements, containing explicit information. Relevant common data elements were identified and classified. A quantitative analysis was performed to evaluate the possibility of data exchange.

RESULTS

We received data of seven documents that were heterogeneous regarding form and content. 181 definite common data elements considered relevant for the planning CT were identified and assorted into five semantic groups. 139 data elements (76.8%) were present in only one document. The other 42 data elements were present in two to six documents, while none was shared among all seven documents.

CONCLUSION

Structured and interoperable documentation of medical information can be achieved using common data elements. Our analysis showed that a lot of information recorded with healthcare documents can be presented with this approach. Yet, in the analyzed cohort of planning CT order entries, only a few common data elements were shared among the majority of documents. A common vocabulary and consensus upon relevant information is required to promote interoperability and standardization.

(Common) Data Elements in Radiation Oncology: A Systematic Literature Review

PURPOSE

Structured medical data documentation is highly relevant in a data-driven discipline such as radiation oncology. Defined (common) data elements (CDEs) can be used to record data in clinical trials, health records, or computer systems for improved standardization and data exchange. The International Society for Radiation Oncology Informatics initiated a project for a scientific literature analysis of defined data elements for structured documentation in radiation oncology.

METHODS

We performed a systematic literature review on both PubMed and Scopus to analyze publications relevant to the utilization of specified data elements for the documentation of radiation therapy (RT)-related information. Relevant publications were retrieved as full-text and searched for published data elements. Finally, the extracted data elements were quantitatively analyzed and classified.

RESULTS

We found a total of 452 publications, of which 46 were considered relevant for structured data documentation. Twenty-nine publications addressed defined RT-specific data elements, of which 12 publications provided data elements. Only two publications focused on data elements in radiation oncology. The 29 analyzed publications were heterogeneous regarding the subject and usage of the defined data elements, and different concepts/terms for defined data elements were used.

CONCLUSION

The literature about structured data documentation in radiation oncology using defined data elements is scarce. There is a need for a comprehensive list of RT-specific CDEs the radio-oncologic community can rely on. As it has been done in other medical fields, establishing such a list would be of great value for clinical practice and research as it would promote interoperability and standardization.

Designing a Digital Medical Interview Assistant for Radiology

Radiologists rarely interact with the patients whose radiological images they are reviewing due to time and resource constraints. However, relevant information about the patient's medical history could improve reporting performance and quality. In this work, our objective was to collect requirements for a digital medical interview assistant (DMIA) that collects the medical history from patients by means of a conversational agent and structures as well as provides the collected data to radiologists. Requirements were gathered based on a narrative literature review, a patient questionnaire and input from a radiologist. Based on these results, a system architecture for the DMIA was developed. 37 functional and 17 non-functional requirements were identified. The resulting architecture comprises five components, namely Chatbot, Natural language processing (NLP), Administration, Content Definition and Workflow Engine. To be able to quickly adapt the chatbot content according to the information needs of a specific radiological examination, there is a need for developing a sustainable process for the content generation that considers standardized data modelling as well as rewording of clinical language into consumer health vocabulary understandable to a diverse patient user group.

Current Research and Development in Hyperthermic Intraperitoneal Chemotherapy (HIPEC)-A Cross-Sectional Analysis of Clinical Trials Registered on ClinicalTrials.gov

INTRODUCTION

Over the past two decades, cytoreductive surgery and HIPEC has improved outcomes for selected patients with peritoneal metastasis from various origins. This is a cross-sectional study with descriptive analyses of HIPEC trials registered on ClinicalTrials.gov. This study aimed to characterize clinical trials on HIPEC registered on ClinicalTrials.gov with the primary objective of identifying a trial focus and to examine whether trial results were published.

METHODS

The search included trials registered from 1 January 2001 to 14 March 2022. We examined the associations of exposure variables and other trial features with two primary outcomes: therapeutic focus and results reporting.

RESULTS

In total, 234 clinical trials were identified; 26 (11%) were already published, and 15 (6%) trials have reported their results but have not been published as full papers. Among ongoing nonpublished trials, 81 (39%) were randomized, 30 (14%) were blinded, n = 39 (20%) were later phase trials (i.e., phases 3 and 4), n = 152 (73%) were from a single institution, and 91 (44%) had parallel groups. Most of the trials were recruiting at the time of this analysis (75, 36%), and 39 (20%) were completed but had yet to publish results. In total, 68% of the trials focused on treatment strategies, and 53% investigated the oncological outcome. The most studied neoplasms for HIPEC trials were peritoneally metastasized colorectal cancer (32%), gastric cancer (29%), and ovarian cancer (26%). Twenty different drugs were analyzed in these clinical trials.

CONCLUSIONS

Many study results are awaited from ongoing HIPEC trials. Most HIPEC trials focused on gastric, colorectal, or ovarian cancer. Many clinical trials were identified involving multiple entities and chemotherapeutic agents.

Accuracy of the Apple Watch Oxygen Saturation Measurement in Adults: A Systematic Review

The purpose of this review is to summarize the research on the accuracy of oxygen saturation (spO2) measurements using the Apple Watch (Apple Inc., Cupertino, California). The Medline and Google Scholar databases were searched for papers evaluating the spO2 measurements of the Apple Watch vs. any kind of ground truth and records were analyzed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The five publications with 973 total patients that met the inclusion criteria all used the Apple Watch Series 6 and described 95% limits of agreement of +/- 2.7 to 5.9% spO2. However, outliers of up to 15% spO2 were reported. Only one study had patient-level data uploaded to a public repository. The Apple Watch Series 6 does not show a strong systematic bias compared to conventional, medical-grade pulse oximeters. However, outliers do occur and should not cause concern in otherwise healthy individuals. The impact of race on measurement accuracy should be investigated.

Toward Data-Driven Radiation Oncology Using Standardized Terminology as a Starting Point: Cross-sectional Study

Background

The inability to seamlessly exchange information across radiation therapy ecosystems is a limiting factor in the pursuit of data-driven clinical practice. The implementation of semantic interoperability is a prerequisite for achieving the full capacity of the latest developments in personalized and precision medicine, such as mathematical modeling, advanced algorithmic information processing, and artificial intelligence approaches.

Objective

This study aims to evaluate the state of terminology resources (TRs) dedicated to radiation oncology as a prerequisite for an oncology semantic ecosystem. The goal of this cross-sectional analysis is to quantify the state of the art in radiation therapy specific terminology.

Methods

The Unified Medical Language System (UMLS) was searched for the following terms: radio oncology, radiation oncology, radiation therapy, and radiotherapy. We extracted 6509 unique concepts for further analysis. We conducted a quantitative analysis of available source vocabularies (SVs) and analyzed all UMLS SVs according to the route source, number, author, location of authors, license type, the lexical density of TR, and semantic types. Descriptive data are presented as numbers and percentages.

Results

The concepts were distributed across 35 SVs. The median number of unique concepts per SV was 5 (range 1-5479), with 14% (5/35) of SVs containing 94.59% (6157/6509) of the concepts. The SVs were created by 29 authors, predominantly legal entities registered in the United States (25/35, 71%), followed by international organizations (6/35, 17%), legal entities registered in Australia (2/35, 6%), and the Netherlands and the United Kingdom with 3% (1/35) of authors each. Of the total 35 SVs, 16 (46%) did not have any restrictions on use, whereas for 19 (54%) of SVs, some level of restriction was required. Overall, 57% (20/35) of SVs were updated within the last 5 years. All concepts found within radiation therapy SVs were labeled with one of the 29 semantic types represented within UMLS. After removing the stop words, the total number of words for all SVs together was 56,219, with a median of 25 unique words per SV (range 3-50,682). The total number of unique words in all SVs was 1048, with a median of 19 unique words per vocabulary (range 3-406). The lexical density for all concepts within all SVs was 0 (0.02 rounded to 2 decimals). Median lexical density per unique SV was 0.7 (range 0.0-1.0). There were no dedicated radiation therapy SVs.

Conclusions

We did not identify any dedicated TRs for radiation oncology. Current terminologies are not sufficient to cover the need of modern radiation oncology practice and research. To achieve a sufficient level of interoperability, of the creation of a new, standardized, universally accepted TR dedicated to modern radiation therapy is required.

Contemporary treatment patterns and survival of cervical cancer patients in Ethiopia

Background

Cervical cancer is the second commonly diagnosed cancer and the second leading cause of cancer death in women in Ethiopia, with rates among the highest worldwide. However, there are limited data on cervical cancer treatment patterns and survival in the country. Herein, we examine treatment patterns and survival of cervical cancer patients treated in Tikur Anbessa Hospital Radiotherapy Center (TAHRC), the only hospital with radiotherapy facility in the country.

Methods

Women with histologically verified cervical cancer who were seen in 2014 (January 1, 2014 to December 31, 2014) at TAHRC were included. Information about clinical characteristics and treatments were extracted from the patients’ medical record files. The information on vital status was obtained from medical chart and through telephone calls.

Result

Among 242 patients included in the study, the median age at diagnosis was 48 years. The median waiting time for radiotherapy was 5.6 months (range 2 to 9 months). Stage migration occurred in 13% of patients while waiting for radiotherapy. Consequently, the proportion of patients with stage III or IV disease increased from 66% at first consultation to 74% at the initiation of radiotherapy. Among 151 patients treated with curative intent, only 34 (22.5%) of the patients received concurrent chemotherapy while the reaming patients received radiotherapy alone. The 5-year overall survival rate was 28.4% (20.5% in the worst-case scenario). As expected, survival was lower in patients with advanced stage at initiation of radiotherapy and in those treated as palliative care.

Conclusion

The survival of cervical cancer patients remains low in Ethiopia because of late presentation and delay in receipt of radiotherapy, leading to stage migration in substantial proportion of the cases. Concerted and coordinated multisectoral efforts are needed to promote early presentation of cervical cancer and to shorten the unacceptable, long waiting time for radiotherapy.

Pressurized Intraperitoneal Aerosol Chemotherapy-Related Clinical Trials in the Treatment of Peritoneal Metastases

INTRODUCTION

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a treatment option for patients with peritoneal metastases. We evaluated the current status of ongoing prospective clinical trials investigating PIPAC to provide an overview and predict trends in this field.

METHODS

All 367,494 records of clinical trials registered at ClinicalTrials.gov were searched for trials dealing with PIPAC. Active or unpublished trials were further analyzed.

RESULTS

In total, 22 clinical trials were identified and selected for further analyses. Most trials had a single-arm design and were phase I or II. No phase III trials were registered. Academic centers were recorded as primary sponsors in the majority of trials (63.6%). Every year, between 2 and 5 new trials were initiated. In 17 trials (81.8%), PIPAC was used in a palliative setting only, 2 trials performed PIPAC in a neoadjuvant setting, and 2 trials performed PIPAC in an adjuvant setting. Six different drugs (doxorubicin, cisplatin, oxaliplatin, nab-paclitaxel, 5-fluorouracil, and docetaxel) were used in these clinical trials. Most trials investigated the efficacy (n = 15) or safety (n = 7) of PIPAC therapies.

CONCLUSIONS

The results of ongoing clinical trials will bring specific information on indications for PIPAC as well as the impact of PIPAC on quality of life and overall survival.

Multidisciplinary Cancer Management of Colorectal Cancer in Tikur Anbessa Specialized Hospital, Ethiopia

PURPOSE

Multidisciplinary cancer care is currently considered worldwide as standard for the management of patients with cancer. It improves patient diagnostic and staging accuracy and provides patients the benefit of having physicians of various specialties participating in their treatment plan. The purpose of this study was to describe the profile of patients discussed in the Tikur Anbessa Multidisciplinary Tumor Board (MTB) and the potential benefits brought by multidisciplinary care.

METHODS

The study involved the retrospective assessment of all patient cases presented to the Tikur Anbessa Hospital colorectal cancers MTB between March 2016 and November 2017. The data were collected from the MTB medical summary documents and were analyzed using SPSS version 20 (SPSS, Chicago, IL).

RESULTS

Of 147 patients with colorectal cancer, 96 (65%) were men. The median age at presentation was 46 years (range, 17-78 years). The predominant cancer was rectal (n = 101; 69%), followed by colon (n = 24; 16%). Of these, 68 (45%) and 22 (15%) had stage III and IV disease, respectively, on presentation to the MTB. The oncology department presented the majority of the patients for discussion. Most patients had undergone surgery before the MTB discussion but had no proper preoperative clinical staging information. The majority of patients with rectal cancer treated before the MTB discussion had undergone surgery upfront; however, most of the patients who were treatment naive before MTB received neoadjuvant chemoradiotherapy before surgery.

CONCLUSION

Decisions made by tumor boards are more likely to conform to evidence-based guidelines than are those made by individual clinicians. Therefore, early referral of patients to MTB before any treatment should be encouraged. Finally, other hospitals in Ethiopia should take a lesson from the Tikur Anbessa Hospital colorectal cancers MTB and adopt multidisciplinary cancer management.

Breast cancer care in northern Ethiopia - cross-sectional analysis

BACKGROUND

In Ethiopia, the incidence of new cases of breast cancer is currently increasing resulting to high rates of morbidity and mortality. Breast cancer is by far the most common cancer accounting for more than one out of three cancer cases in women and one out of every five in the general population. The study was conducted in University of Gondar Hospital cancer center, located in the North-West Ethiopia; to evaluate the clino-pathologic characteristics of breast cancer and care provided for patients.

METHODS

All biopsy proven breast cancer patients treated between 2016 and 2017, were identified and information regarding histology, stage, therapeutic procedure and follow up was retrospectively collected from their individual medical records and descriptive analysis was done.

RESULTS

Among 82 patients treated, 67 (82%) were women and 15 (18%) were men. The median age at the time of diagnosis was 45 years (25-82 years). Operation was performed for 56 (68%) patients. The predominant histology was ductal carcinoma in 61 patients (74%), followed by breast carcinoma of No Special Type (NST) in 17 (21%). The late presentation of the patients and the advanced stage at the time of presentation was observed in most of the patients. Chemotherapy was administered in 79 (96%) patients. Radiotherapy was not available in the hospital.

CONCLUSION

Breast cancer incidence is rising and becoming a major public health problem in Northern Ethiopia. Breast cancer care in northern-Ethiopia is limited in terms of both pathology, imaging and the offered treatment modalities, which need to be improved.

Emerging patient-specific treatment modalities in head and neck cancer - a systematic review

INTRODUCTION

Head and neck cancer (HNC) is an immunosuppressive disease that demonstrates heterogeneous molecular characteristics and features of tumor-host interaction. Beside radiotherapy and surgery, the current standard of care in systemic treatment involves the use of cytotoxic chemotherapy, monoclonal antibodies (mAbs), and tyrosine kinase inhibitors (TKIs). There are also other modalities being developed under the category of immunotherapy, but they are overshadowed by the recent advancements of immune checkpoint inhibitors.

AREAS COVERED

This systematic review covers recent advancements in 'patient-specific' treatment modalities, which can be only administered to a given patient.

EXPERT OPINION

Currently, patient-specific treatment modalities in HNC mainly consist of active immunotherapy using adoptive cell therapies and/or gene engineered vectors. Despite the slow pace of development, the interest continues in these treatment modalities. The future of HNC treatment is expected to be guided by biomarkers and personalized approaches with tailored combinations of local treatments (radiotherapy, surgery), systemic agents and immune system modulation. Systematic research is required to generate robust data and obtain a high-level of evidence for the effectiveness of such treatment modalities.

Clinical trials involving positron emission tomography and prostate cancer: an analysis of the ClinicalTrials.gov database

Background

The goal of this study is to evaluate the status and future perspectives of clinical trials on positron emission tomography in prostate cancer for diagnostic or therapeutic as well as for surveillance purposes.

Methods

The www.ClinicalTrials.gov database was searched on the 20th of January 2017 for all trials containing terms describing “prostate cancer” (prostate, prostatic, malignant, malignancy, cancer, tumor) and “positron emission tomography”. In total 167 trials were identified. Trials that included diseases other than PCa were excluded (n = 27; 16%). Furthermore, we excluded trials (n = 4, 2%) withdrawn prior to first patient enrollment. The remaining trials (n = 137, 82%) were selected for further manual classification analysis.

Results

One hundred thirty-seven trials were detected and analyzed. Majority of trials were in “active” recruitment status (n = 46, 34%) followed by trials that had been “completed” - (n = 34, 25%) and trials with “closed recruitment but active follow-up” (n = 23, 17%). Phase 1 and 2 comprised 46% of the complete trial portfolio. Locally confined disease was of major interest (n = 46, 34%), followed by metastatic disease – not otherwise specified (n = 43, 13%). Evaluation of PET was the primary goal of the trial in 114 (83%) cases. Most of the trials evaluated only one agent (n = 122, 89%). Choline and PSMA represented two major groups (total 50%) and they were equally distributed across trial portfolio with 25% (n = 34) each. PSMA trials showed the highest average annual growth rate of 56%. The trials were conducted in 17 countries.

Conclusion

The scientific community is showing a strong and ever-growing interest in the field and we expect that in the coming years, more phase III trials will be initiated ultimately delivering the required Level 1 evidence.

Electronic supplementary material

The online version of this article (10.1186/s13014-018-1057-3) contains supplementary material, which is available to authorized users.

PSMA-PET based radiotherapy: a review of initial experiences, survey on current practice and future perspectives

⁶⁸Gallium prostate specific membrane antigen (PSMA) ligand positron emission tomography (PET) is an increasingly used imaging modality in prostate cancer, especially in cases of tumor recurrence after curative intended therapy. Owed to the novelty of the PSMA-targeting tracers, clinical evidence on the value of PSMA-PET is moderate but rapidly increasing. State of the art imaging is pivotal for radiotherapy treatment planning as it may affect dose prescription, target delineation and use of concomitant therapy.

This review summarizes the evidence on PSMA-PET imaging from a radiation oncologist’s point of view. Additionally a short survey containing twelve examples of patients and 6 additional questions was performed in seven mayor academic centers with experience in PSMA ligand imaging and the findings are reported here.

Multifractal-based nuclei segmentation in fish images

The method for nuclei segmentation in fluorescence in-situ hybridization (FISH) images, based on the inverse multifractal analysis (IMFA) is proposed. From the blue channel of the FISH image in RGB format, the matrix of Holder exponents, with one-by-one correspondence with the image pixels, is determined first. The following semi-automatic procedure is proposed: initial nuclei segmentation is performed automatically from the matrix of Holder exponents by applying predefined hard thresholding; then the user evaluates the result and is able to refine the segmentation by changing the threshold, if necessary. After successful nuclei segmentation, the HER2 (human epidermal growth factor receptor 2) scoring can be determined in usual way: by counting red and green dots within segmented nuclei, and finding their ratio. The IMFA segmentation method is tested over 100 clinical cases, evaluated by skilled pathologist. Testing results show that the new method has advantages compared to already reported methods.

Highly conformal combined radiotherapy with cisplatin and gemcitabine for treatment of loco-regionally advanced cervical cancer - a retrospective study

BACKGROUND

Cisplatin and gemcitabine combined with conventional radiation therapy in the treatment of cervical cancer patients results in a favorable outcome but with excess toxicity. The purpose of this study was to evaluate the toxicity profile of dual chemotherapy and highly conformal external beam radiotherapy with image guided adaptive brachytherapy.

METHODS

Seventeen patients with cervical carcinoma FIGO stage IB2-IIIB were treated with curative intent between 2011 and 2015. A total dose of 50.4 Gy was prescribed to the elective pelvic nodal volume. Patients with ¹⁸FDG-PET/CT positive lymph nodes (n = 15; 83.3%) received an additional boost to a total dose of 62 Gy. Chemotherapy prescription goals were: concomitant during 5 weeks of external beam radiotherapy (EBRT) 40 mg/m2 cisplatin and 125 mg/m² gemcitabine, followed by adjuvant chemotherapy from week 10 (2 cycles 50 mg/m² cisplatin and 1000 mg/m² gemcitabine). EBRT was followed by 3-4 fractions (6 Gy per fraction) of intrauterine image guided adaptive brachytherapy. Toxicities were graded according to the common terminology criteria for adverse events (CTCAE v 4.0).

RESULTS

One (6%) patient developed acute grade 3 diarrhea. We did not record any other acute or late gastrointestinal or urogenital toxicity higher that grade 3. Most common acute hematological toxicity was anemia grade 2 recorded in 10 (59%) patients. There was only one case of grade 3 neutropenia (6%). The number of patients that received the complete chemotherapy regimen was gradually declining during the course of therapy. From week 2 to 5, gemcitabine was omitted in 4 (24%),7 (41%), 8 (47%), and 12 (71%) patients respectively, similarly, cisplatin was omitted in 2 (12%),3 (18%),1 (6%) and 7 (41%) patients respectively. Adjuvant chemotherapy was omitted in 8 patients (47%). During a median follow-up time of 20 months (5 to 63 months) 6 (35%) patients developed disease relapse with 5 (29%) of them in the form of systemic disease.

CONCLUSIONS

In contrast to previous findings cisplatin and gemcitabine in combination with highly conformal radiation therapy seems to have an acceptable toxicity profile. Further studies are needed to determine the optimal dosage of the proposed therapy concept.

Immunophenotypic profile of tumor buds in breast cancer

BACKGROUND

Tumor buds are associated with lympho-vascular invasion and lymph node metastases leading to the assumption that they are involved in the early metastatic process. Hence, it would be important to know if tumor buds can be targeted with the most widely used targeted therapies in breast cancer (BC) and if changes in hormone and Her2 status occur. The aim of this study was to answer these questions by determining whether hormone receptor (HR) and Her2 status are expressed in the tumor buds of a large cohort of BCs.

DESIGN

We constructed a tumor bud next-generation tissue microarray (ngTMA) consisting of n = 199 BCs of non-special type. Generally, two 1 mm punches were taken from the tumor bud areas in the periphery (PTB) and within the tumor center (ITB). HR and Her2 status was assessed using immunohistochemistry and fluorescence in situ hybridization, respectively. HR status was positive if ≥1% of tumor bud cells were positive. Her2 status was considered positive if bud cells showed strong complete membranous Her2 over-expression or Her2 amplification.

RESULTS

Most tumor buds were positive for estrogen (ER) (PTB: 86%; ITB: 88.3) and progesterone receptor (PgR) (PTB: 72%; ITB: 72.8%) and Her2 was positive in: PTB 11.5% and ITB 11%. A difference between the main tumor mass and tumor buds (PTB and ITB) was seen for PgR in 3.5% of cases (n = 7). No differences were seen for ER and Her2 between tumor buds and main tumor mass.

CONCLUSION

Most tumor buds (96.5%) share the same HR and Her2 expression profile of the main tumor mass, implying that tumor buds relay on the same pathways as the main tumor mass and might be equally responsive to targeted therapies.

Radiation Therapy in Extensive Stage Small Cell Lung Cancer

Lung cancer is the major cancer killer in the Western world, with the small cell lung cancer (SCLC) representing around 15–20% of all lung cancers. Extensive disease small cell lung cancer (ED SCLC) is found in approximately two-thirds of all cases, composed of both metastatic (M1) and non-metastatic (but presumably with tumor burden too large for locoregional-only approach) variant. Standard treatment options involve chemotherapy (CHT) over the past several decades. Radiation therapy (RT) had mostly been used in palliation of locoregional and/or metastatic disease. In contrast to its established role in treating metastatic disease, thoracic RT (TRT) had never been established as important part of the treatment aspects in this setting. In the past two decades, thoracic oncologists have witnessed wide introduction of modern RT and CHT aspects in ED SCLC, which led to more frequent use of RT and rise in the number of clinical studies. Since the pivotal study of Jeremic et al., who were the first to show importance of TRT in ED SCLC, a number of single-institutional studies have reconfirmed this observation, while recent prospective randomized trials (CREST and RTOG 0937) brought more substance to this issue. Similarly, the issue of prophylactic cranial irradiation was investigated in EORTC and the Japanese study, respectively, bringing somewhat conflicting results and calling for additional research in this setting. Future studies in ED SCLC could incorporate questions of RT dose and fractionation as well as the number of CHT cycles and type of combined Rt-CHT (sequential vs concurrent).

Outcome of proximal esophageal cancer after definitive combined chemo-radiation: a Swiss multicenter retrospective study

Objective

To report oncological outcomes and toxicity rates, of definitive platin-based chemoradiadiationtherapy (CRT) in the management of proximal esophageal cancer.

Methods

We retrospectively reviewed the medical records of patients with cT1-4 cN0-3 cM0 cervical esophageal cancer (CEC) (defined as tumors located below the inferior border of the cricoid cartilage, down to 22 cm from the incisors) treated between 2004 and 2013 with platin–based definitive CRT in four Swiss institutions. Acute and chronic toxicities were retrospectively scored using the National Cancer Institute’s Common Terminology Criteria for Adverse Events, version 4.0 (CTCAE-NCI v.4.0). Primary endpoint was loco-regional control (LRC). We also evaluated overall survival (OS) and disease-free survival (DFS) rates. The influence of patient- and treatment related features have been calculated using the Log-rank test and multivariate Cox proportional hazards model.

Results

We enrolled a total of 55 patients. Median time interval from diagnosis to CRT was 78 days (6–178 days). Median radiation dose was 56Gy (28–72Gy). Induction chemotherapy (ICHT) was delivered in 58% of patients. With a median follow up of 34 months (6–110months), actuarial 3-year LRC, DFS and OS were 52% (95% CI: 37–67%), 35% (95% CI: 22–50%) and 52% (95% CI: 37–67%), respectively. Acute toxicities (dysphagia, pain, skin-toxicity) ranged from grade 0 – 4 without significant dose-dependent differences. On univariable analyses, the only significant prognostic factor for LRC was the time interval > 78 days from diagnosis to CRT. On multivariable analysis, total radiation dose >56Gy (p <0.006) and ICHT (p < 0.004) were statistically significant positive predictive factors influencing DFS and OS.

Conclusion

Definitive CRT is a reliable therapeutic option for proximal esophageal cancer, with acceptable treatment related toxicities. Higher doses and ICHT may improve OS and DFS and. These findings need to be confirmed in further prospective studies.

Current status and perspectives of interventional clinical trials for glioblastoma - analysis of ClinicalTrials.gov

The records of 208.777 (100%) clinical trials registered at ClinicalTrials.gov were downloaded on the 19th of February 2016. Phase II and III trials including patients with glioblastoma were selected for further classification and analysis. Based on the disease settings, trials were classified into three groups: newly diagnosed glioblastoma, recurrent disease and trials with no differentiation according to disease setting. Furthermore, we categorized trials according to the experimental interventions, the primary sponsor, the source of financial support and trial design elements. Trends were evaluated using the autoregressive integrated moving average model. Two hundred sixteen (0.1%) trials were selected for further analysis. Academic centers (investigator initiated trials) were recorded as primary sponsors in 56.9% of trials, followed by industry 25.9%. Industry was the leading source of monetary support for the selected trials in 44.4%, followed by 25% of trials with primarily academic financial support. The number of newly initiated trials between 2005 and 2015 shows a positive trend, mainly through an increase in phase II trials, whereas phase III trials show a negative trend. The vast majority of trials evaluate forms of different systemic treatments (91.2%). In total, one hundred different molecular entities or biologicals were identified. Of those, 60% were involving drugs specifically designed for central nervous system malignancies. Trials that specifically address radiotherapy, surgery, imaging and other therapeutic or diagnostic methods appear to be rare. Current research in glioblastoma is mainly driven or sponsored by industry, academic medical oncologists and neuro-oncologists, with the majority of trials evaluating forms of systemic therapies. Few trials reach phase III. Imaging, radiation therapy and surgical procedures are underrepresented in current trials portfolios. Optimization in research portfolio for glioblastoma is needed.

Portfolio of prospective clinical trials including brachytherapy: an analysis of the ClinicalTrials.gov database

Background

To evaluate the current status of prospective interventional clinical trials that includes brachytherapy (BT) procedures.

Methods

The records of 175,538 (100 %) clinical trials registered at ClinicalTrials.gov were downloaded on September 2014 and a database was established. Trials using BT as an intervention were identified for further analyses. The selected trials were manually categorized according to indication(s), BT source, applied dose rate, primary sponsor type, location, protocol initiator and funding source. We analyzed trials across 8 available trial protocol elements registered within the database.

Results

In total 245 clinical trials were identified, 147 with BT as primary investigated treatment modality and 98 that included BT as an optional treatment component or as part of the standard treatment. Academic centers were the most frequent protocol initiators in trials where BT was the primary investigational treatment modality (p < 0.01). High dose rate (HDR) BT was the most frequently investigated type of BT dose rate (46.3 %) followed by low dose rate (LDR) (42.0 %). Prostate was the most frequently investigated tumor entity in trials with BT as the primary treatment modality (40.1 %) followed by breast cancer (17.0 %). BT was rarely the primary investigated treatment modality for cervical cancer (6.8 %).

Conclusion

Most clinical trials using BT are predominantly in early phases, investigator-initiated and with low accrual numbers. Current investigational activities that include BT mainly focus on prostate and breast cancers. Important questions concerning the optimal usage of BT will not be answered in the near future.

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-016-0624-8) contains supplementary material, which is available to authorized users.

Dose escalated intensity modulated radiotherapy in the treatment of cervical cancer

PURPOSE

Standard dose of external beam radiotherapy seems to be insufficient for satisfactory control of loco-regionally advanced cervical cancer. Aim of our study is to evaluate the outcome as well as early and chronic toxicities in patients with loco-regionally advanced cervical cancer, treated with dose escalated intensity modulated radiotherapy (IMRT) combined with cisplatin chemotherapy.

MATERIAL AND METHODS

Thirty-nine patients with cervical carcinoma FIGO stage IB2 - IVA were treated with curative intent between 2006 and 2010. The dose of 50.4 Gy was prescribed to the elective pelvic nodal volume. Primary tumors < 4 cm in diameter (n = 6; 15.4 %) received an external beam radiotherapy (EBRT) boost of 5.4 Gy, primary tumors > 4 cm in diameter (n = 33; 84.6 %) received an EBRT boost of 9 Gy. Patients with positive lymph nodes detected with (18)FDG-PET/CT (n = 22; 56.4 %) received a boost to a total dose of 59.4 - 64.8 Gy. The para-aortic region was included in the radiation volume in 8 (20.5 %) patients and in 5 (12.8 %) patients the para-aortic macroscopic lymph nodes received an EBRT boost. IMRT was followed with a 3D planned high dose rate intrauterine brachytherapy given to 36 (92.3 %) patients with a total dose ranging between 15-18 Gy in three fractions (single fraction: 4-6.5 Gy). Patients without contraindications (n = 31/79.5 %) received concomitantly a cisplatin-based chemotherapy (40 mg/kg) weekly. Toxicities were graded according to the common terminology criteria for adverse events (CTCAE v 4.0).

RESULTS

Mean overall survival for the entire cohort was 61.1 months (±3.5 months). Mean disease free survival was 47.2 months (±4.9 months) and loco-regional disease free survival was 55.2 months (±4.4 months). 65 % of patients developed radiotherapy associated acute toxicities grade 1, ca. 30 % developed toxicities grade 2 and just two (5.2 %) patients developed grade 3 toxicities, one acute diarrhea and one acute cystitis. 16 % of patients had chronic toxicities grade 1, 9 % grade 2 and one patient (2.6 %) toxicities grade 3 in the form of vaginal dryness.

CONCLUSION

Dose escalated IMRT appears to have a satisfactory outcome with regards to mean overall survival, disease free and loco-regional disease free survival, whereas the treatment-related toxicities remain reasonably low.

Androgen receptor status is highly conserved during tumor progression of breast cancer

Background

With the advent of new and more efficient anti-androgen drugs targeting androgen receptor (AR) in breast cancer (BC) is becoming an increasingly important area of investigation. This would potentially be most useful in triple negative BC (TNBC), where better therapies are still needed. The assessment of AR status is generally performed on the primary tumor even if the tumor has already metastasized. Very little is known regarding discrepancies of AR status during tumor progression. To determine the prevalence of AR positivity, with emphasis on TNBCs, and to investigate AR status during tumor progression, we evaluated a large series of primary BCs and matching metastases and recurrences.

Methods

AR status was performed on 356 primary BCs, 135 matching metastases, and 12 recurrences using a next-generation Tissue Microarray (ngTMA). A commercially available AR antibody was used to determine AR-status by immunohistochemistry. AR positivity was defined as any nuclear staining in tumor cells ≥1 %. AR expression was correlated with pathological tumor features of the primary tumor. Additionally, the concordance rate of AR expression between the different tumor sites was determined.

Results

AR status was positive in: 87 % (307/353) of primary tumors, 86.1 % (105/122) of metastases, and in 66.7 % (8/12) of recurrences. TNBC tested positive in 11.4 %, (4/35) of BCs. A discrepant result was seen in 4.3 % (5/117) of primary BC and matching lymph node (LN) metastases. Three AR negative primary BCs were positive in the matching LN metastasis, representing 17.6 % of all negative BCs with lymph node metastases (3/17). Two AR positive primary BCs were negative in the matching LN metastasis, representing 2.0 % of all AR positive BCs with LN metastases (2/100). No discrepancies were seen between primary BC and distant metastases or recurrence (n = 17).

Conclusions

Most primary (87 %) and metastasized (86.1 %) BCs are AR positive including a significant fraction of TNBCs (11.4 %). Further, AR status is highly conserved during tumor progression and a change only occurs in a small fraction (4.1 %). Our study supports the notion that targeting AR could be effective for many BC patients and that re-testing of AR status in formerly negative or mixed type BC’s is recommended.

Abstract 5173: Androgen receptor status is highly conserved during tumor progression of breast cancer

Introduction: Many clinical trails are ongoing targeting androgen receptor (AR) in breast cancer (BC). Anti-androgen therapy is increasingly accepted in BC patients since the new compounds have less androgenic side effects. The assessment of AR status is generally performed on the primary tumor even when treating metastatic disease. To the best of our knowledge, nothing is known regarding discrepancies of AR status between the primary tumor and the metastatic site. Therefore, we investigated AR status on a large cohort of primary BCs and matched metastases.

Method: A next-generation Tissue Microarray (ngTMA) was constructed harboring 356 primary BCs, 133 matched metastases and 11 recurrences. A commercially available monoclonal AR antibody (DAKO) was used to evaluate AR-Status by immunohistochemistry. AR positivity was defined as ≥1% of nuclear staining in tumor cells. The results of the primary tumor and metastases/recurrences were compared. Additionally, the results of AR status were correlated with other pathological tumor features.

Result: AR could be evaluated in 353/356 (99.2%) of primary BCs and a positivity was detected in 307 (87%). A discordant result was seen in 4.3% metastasized BC's with informative results (5/117). Three negative BCs were positive in the metastases representing 16.7% of all negative BCs with informative results (3/18). Two BCs were positive in the primary and negative in the metastases representing 2.0% of all positive BCs with metastases and informative results (2/99). No discrepancies were seen between primary and loco-regional recurrences. Further, AR expression was significantly correlated with a positive estrogen (p&lt;0.001) and progesterone receptor (p&lt;0.001) status and a low proliferation (≤15%) (p&lt;0.001). Negative AR status was significantly (p&lt;0.001) associated with a higher tumor grade. Triple negative BCs were in 11.4% AR positive (4/35).

Conclusion: AR positivity is frequent in primary BCs (87%) and AR status is highly conserved during tumor progression. In a small fraction AR status changes (4.3%) either from positive to negative status or vise versa. However, even AR status is highly preserved we would recommend reevaluation of the metastatic site in negative BC's since a positive AR status can be seen in 16.7% of this subgroup.

Citation Format: André Grogg, Katrin Pfaltz, Claudia Lädrach, Nikola Cihoric, Martin Zweifel, Coya F. M. Tapia. Androgen receptor status is highly conserved during tumor progression of breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5173. doi:10.1158/1538-7445.AM2015-5173

Clinical Perspectives from Randomized Phase 3 Trials on Prostate Cancer: An Analysis of the ClinicalTrials.gov Database

BACKGROUND

It is not easy to overview pending phase 3 trials on prostate cancer (PCa), and awareness of these trials would benefit clinicians.

OBJECTIVE

To identify all phase 3 trials on PCa registered in the ClinicalTrials.gov database with pending results.

DESIGN AND SETTING

On September 29, 2014, a database was established from the records for 175 538 clinical trials registered on ClinicalTrials.gov. A search of this database for the substring "prostat" identified 2951 prostate trials. Phase 3 trials accounted for 441 studies, of which 333 concerned only PCa. We selected only ongoing or completed trials with pending results, that is, for which the primary endpoint had not been published in a peer-reviewed medical journal.

RESULTS AND LIMITATIONS

We identified 123 phase 3 trials with pending results. Trials were conducted predominantly in North America (n=63; 51%) and Europe (n=47; 38%). The majority were on nonmetastatic disease (n=82; 67%), with 37 (30%) on metastatic disease and four trials (3%) including both. In terms of intervention, systemic treatment was most commonly tested (n=71; 58%), followed by local treatment 34 (28%), and both systemic and local treatment (n=11; 9%), with seven (6%) trials not classifiable. The 71 trials on systemic treatment included androgen deprivation therapy (n=34; 48%), chemotherapy (n=15; 21%), immunotherapy (n=9; 13%), other systemic drugs (n=9; 13%), radiopharmaceuticals (n=2; 3%), and combinations (n=2; 3%). Local treatments tested included radiation therapy (n=27; 79%), surgery (n=5; 15%), and both (n=2; 2%). A limitation is that not every clinical trial is registered on ClinicalTrials.gov.

CONCLUSION

There are many PCa phase 3 trials with pending results, most of which address questions regarding systemic treatments for both nonmetastatic and metastatic disease. Radiation therapy and androgen deprivation therapy are the interventions most commonly tested for local and systemic treatment, respectively.

PATIENT SUMMARY

This report describes all phase 3 trials on prostate cancer registered in the ClinicalTrials.gov database with pending results. Most of these trials address questions regarding systemic treatments for both nonmetastatic and metastatic disease. Radiation therapy and androgen deprivation therapy are the interventions most commonly tested for local and systemic treatment, respectively.

High tumor budding stratifies breast cancer with metastatic properties

Tumor budding refers to single or small cluster of tumor cells detached from the main tumor mass. In colon cancer high tumor budding is associated with positive lymph nodes and worse prognosis. Therefore, we investigated the value of tumor budding as a predictive feature of lymph node status in breast cancer (BC). Whole tissue sections from 148 surgical resection specimens (SRS) and 99 matched preoperative core biopsies (CB) with invasive BC of no special type were analyzed on one slide stained with pan-cytokeratin. In SRS, the total number of intratumoral (ITB) and peripheral tumor buds (PTB) in ten high-power fields (HPF) were counted. A bud was defined as a single tumor cell or a cluster of up to five tumor cells. High tumor budding equated to scores averaging >4 tumor buds across 10HPFs. In CB high tumor budding was defined as ≥10 buds/HPF. The results were correlated with pathological parameters. In SRS high PTB stratified BC with lymph node metastases (p ≤ 0.03) and lymphatic invasion (p ≤ 0.015). In CB high tumor budding was significantly (p = 0.0063) associated with venous invasion. Pathologists are able, based on morphology, to categorize BC into a high and low risk groups based in part on lymph node status. This risk assessment can be easily performed during routine diagnostics and it is time and cost effective. These results suggest that high PTB is associated with loco-regional metastasis, highlighting the possibility that this tumor feature may help in therapeutic decision-making.

Prognostic role of FGFR1 amplification in early-stage non-small cell lung cancer

BACKGROUND

Recently, fibroblast growth factor receptor 1 (FGFR1) was discovered in squamous cell carcinomas (SCC) of the lung with FGFR1 amplification described as a promising predictive marker for anti-FGFR inhibitor treatment. Only few data are available regarding prevalence, prognostic significance and clinico-pathological characteristics of FGFR1-amplified and early-stage non-small cell lung carcinomas (NSCLC). We therefore investigated the FGFR1 gene status in a large number of well-characterised early-stage NSCLC.

METHODS

FGFR1 gene status was evaluated using a commercially available fluorescent in situ hybridisation (FISH) probe on a tissue microarray (TMA). This TMA harbours 329 resected, formalin-fixed and paraffin-embedded, nodal-negative NSCLC with a UICC stage I-II. The FISH results were correlated with clinico-pathological features and overall survival (OS).

RESULTS

The prevalence of an FGFR1 amplification was 12.5% (41/329) and was significantly (P<0.0001) higher in squamous cell carcinoma (SCC) (20.7%) than in adenocarcinoma (2.2%) and large cell carcinoma (13%). Multivariate analysis revealed significantly (P=0.0367) worse 5-year OS in patients with an FGFR1-amplified NSCLC.

CONCLUSIONS

FGFR1 amplification is common in early-stage SCC of the lung and is an independent and adverse prognostic marker. Its potential role as a predictive marker for targeted therapies or adjuvant treatment needs further investigation.

Late toxicity and five year outcomes after high-dose-rate brachytherapy as a monotherapy for localized prostate cancer

Background

To determine the 5-year outcome after high-dose-rate brachytherapy (HDR-BT) as a monotherapy.

Methods

Between 10/2003 and 06/2006, 36 patients with low (28) and intermediate (8) risk prostate cancer were treated by HDR-BT monotherapy. All patients received one implant and 4 fractions of 9.5 Gy within 48 hours for a total prescribed dose (PD) of 38 Gy. Five patients received concomitant androgen deprivation therapy (ADT). Toxicity was scored according to the common terminology criteria for adverse events from the National Cancer Institute (CTCAE) version 3.0. Biochemical recurrence was defined according to the Phoenix criteria and analyzed using the Kaplan Meier method. Predictors for late grade 3 GU toxicity were analyzed using univariate and multivariate Cox regression analyses.

Results

The median follow-up was 6.9 years (range, 1.5-8.0 years). Late grade 2 and 3 genitourinary (GU) toxicity was observed in 10 (28%) and 7 (19%) patients, respectively. The actuarial proportion of patients with late grade 3 GU toxicity at 5 years was 17.7%. Late grade 2 and 3 gastrointestinal (GI) toxicities were not observed. The crude erectile function preservation rate in patients without ADT was 75%. The 5 year biochemical recurrence-free survival (bRFS) rate was 97%. Late grade 3 GU toxicity was associated with the urethral volume (p = 0.001) and the urethral V₁₂₀ (urethral volume receiving ≥120% of the PD; p = 0.0005) after multivariate Cox regression.

Conclusions

After HDR-BT monotherapy late grade 3 GU was observed relatively frequently and was associated with the urethral V₁₂₀. GI toxicity was negligible, the erectile function preservation rate and the bRFS rate was excellent.

Clinically significant bleeding in incurable cancer patients: effectiveness of hemostatic radiotherapy

Background

This study was performed to evaluate the outcome after hemostatic radiotherapy (RT) of significant bleeding in incurable cancer patients.

Methods

Patients treated by hemostatic RT between November 2006 and February 2010 were retrospectively analyzed. Bleeding was assessed according to the World Health Organization (WHO) scale (grade 0 = no bleeding, 1 = petechial bleeding, 2 = clinically significant bleeding, 3 = bleeding requiring transfusion, 4 = bleeding associated with fatality). The primary endpoint was bleeding at the end of RT. Key secondary endpoints included overall survival (OS) and acute toxicity. The bleeding score before and after RT were compared using the Wilcoxon signed rank test. Time to event endpoints were estimated using the Kaplan Meier method.

Results

Overall 62 patients were analyzed including 1 patient whose benign cause of bleeding was pseudomyxoma peritonei. Median age was 66 (range, 37–93) years. Before RT, bleeding was graded as 2 and 3 in 24 (39%) and 38 (61%) patients, respectively. A median dose of 20 (range, 5–45) Gy of hemostatic RT was applied to the bleeding site. At the end of RT, there was a statistically significant difference in bleeding (p < 0.001); it was graded as 0 ( n = 39), 1 ( n = 12), 2 ( n = 6), 3 ( n = 4) and 4 (n = 1). With a median follow-up of 19.3 (range, 0.3-19.3) months, the 6-month OS rate was 43%. Forty patients died (65%); 5 due to bleeding. No grade 3 or above acute toxicity was observed.

Conclusions

Hemostatic RT seems to be a safe and effective treatment for clinically and statistically significantly reducing bleeding in incurable cancer patients.