Importance of interdisciplinarity in modern oncology: results of a national intergroup survey of the Young Oncologists United (YOU)

Purpose Modern, personalized treatment concepts in oncology require an interdisciplinary and multiprofessional collaboration. In addition to its relevance in patient care, interdisciplinary collaboration is also becoming increasingly important in clinical research as well as medical education and resident training in oncology. Methods Between November 2021 and March 2022, an online survey was conducted among German early career research groups, represented by Young Oncologists United (YOU). The aim was to identify the status and need for interdisciplinarity at clinic, educational, and research levels. Results A total of 294 participants completed the questionnaire in full. 90.7% of the respondents fully or predominantly agreed with the statement that interdisciplinary work plays a major role in their daily clinical work. 78.9% wished for more interdisciplinary collaboration. Of the 49.7% of participants who have never participated in an interdisciplinary research project, 80.1% said they would like to participate in such a study project in the future. Lack of time resources, too much organizational effort, and possible political conflicts between institutions were identified as factors that make practical implementation difficult. 74.1% declared their willingness to become active in an oncology early career research group. Conclusion Interdisciplinary collaboration has become increasingly important in oncology. Networks that span different disciplines could help to promote interdisciplinary research projects among young scientists and improve exchange in professional practice and education with the implication of improved patient care. Supplementary Information The online version contains supplementary material available at 10.1007/s00432-023-04937-2.


Introduction
Modern, personalized oncological treatment concepts can only be implemented through optimal interdisciplinary and multiprofessional collaboration (Soukup et al. 2018). Interdisciplinary care has been recommended best practice in oncology for more than 25 years and has been adopted by many institutions (Selby et al. 2019). The tumorboard is a prime example for interdisciplinary decision-making of treatment regiments and is a central component of every certified cancer centre. It is seen as indispensable for patient care, and its implementation has been strongly recommended in many guidelines (Homayounfar et al. 2014). The German Cancer Society has proposed a three-stage model for certified institutions treating cancer patients. In this model, organ-specific centres for common tumor types represent a basis for interdisciplinary care. The next stage is the networking oncological centre (Cancer Centre), which pursues the diagnosis and therapy of all tumor entities and promotes interdisciplinary and multiprofessional cooperation between these organ-specific centres. The third level is represented by oncological centres (so-called Comprehensive Cancer Centre, CCC) which integrate oncological translational and clinical research in cancer patients' care. Such structures require interdisciplinary trained physicians who operate as a team for every individual patient (Güttler et al. 2012). Interdisciplinary care is sometimes used to describe care teams Extended author information available on the last page of the article 1 3 from different professions such as nurses, physical therapists and physicians as well as teams formed by physicians from different specialities (e.g. surgeons, radiologists and medical oncologists).
To reduce ambiguity in this article, we will follow the definition suggested by Laura Petri, who understands interdisciplinary care as "an interpersonal process characterized by healthcare professionals from multiple disciplines with shared objectives, decision-making, responsibility, and power working together to solve patient care problems; the process is best attained through an interprofessional education that promotes an atmosphere of mutual trust and respect" (Petri 2010). We explicitly include all medical professionals directly and indirectly partaking in cancer patient care, including but not limited to nurses, physical therapists, physicist, biologists, scientists geneticist and physicians of all fields.
A recent meta-analysis of studies showed that discussion of oncologic patient cases in an interdisciplinary setting lead to a change in diagnostic procedures in around a third of cases and a change in therapeutical management in over half of cases. However, those studies were heterogeneous and a significant number of the studies reported much smaller proportion of cases with changed diagnostic or therapeutic approach (Pillay et al. 2016). Despite some studies reporting improved patient outcomes including overall survival, significant differences in methodology and cohort characteristics impede the impact quantification of the interdisciplinary care (Liu et al. 2020;Hong et al. 2010;Munro et al. 2015). Another recent meta-analysis reports a positive effect of interdisciplinary tumorboards on 5-year survival, meanwhile only five hereby analyzed studies question the generality of the results for all oncologic entities. "The results of one trial were censored because it "increased heterogeneity of results" by failing to demonstrate a survival benefit, although it met inclusion criteria (Wille-Jørgensen et al. 2013;Algwaiz et al. 2020). Of note, the main research focus on effects of multidisciplinary tumorboards. Although comprehensive studies of the interdisciplinary care following the patient case discussions seems to be hardly quantifiable, it might be the parameter of consequence. Some indirect benefits of cooperation between different healthcare specialties as reduced length of hospital stay or medication use could be demonstrated. Some data insights point toward an increased patient recruitment in clinical studies following case discussion in multidisciplinary tumorboards. Nevertheless, patientcentred outcome analysis is of urgent need. (Walkenhorst, et al. 2015;Kuroki et al. 2010).
In Germany, we are moving toward a competence-oriented learning structure in the medical studies programme, which is currently undergoing a transformation. The planned interlinking of theory and practice as well as the strong focus on higher level competences instead of individual topics is a fundamental step toward an interdisciplinary education.
However, an even greater paucity of data with regard to interdisciplinary training in oncology impedes discussion and improvement of training conditions. A recent study investigating frequency of interdisciplinary training in different oncologic specialties in the US showed that trainees report a significant lower frequency of interdisciplinary training when compared to program directors, and that even according to program directors interdisciplinary education is only part of the curriculum of less than half of surgical or geriatric oncologists (Akthar et al. 2018).
Even though there is a strong goal of alignment in medical education in Germany, the definitions of interdisciplinary medical training in oncology remain unclear. Neither the extent of interdisciplinary training nor the views of the next generation of oncologists regarding interdisciplinarity in clinical care and research are known. Current reports highlight the importance of interdisciplinary research in science education (Daniel et al. 2022).
An example of interdisciplinary cooperation in research are the collaborative structures (Collaborative Research Centres, Research Training Groups) set up by the German Research Foundation, in which young researchers from different disciplines work together on a superordinate goal. Although interdisciplinary cooperation is proven to be powerful, it requires overcoming a number of barriers with the need for constant communication (Haythornthwaite 2006).
The initiative "Young Oncologist United" is a joint effort of junior groups of different German medical societies with a clinical or preclinical oncologic interest to improve interdisciplinary cooperation in patient care, research, and training in oncology (Mäurer et al. 2022). Another important goal is to build and strengthen a community of mutual support, communication, and exchange e.g. through joint meetings and events.
In the following, we present results from a survey on the importance of interdisciplinary oncology care as seen by future oncologists from multiple different specialties.

Methods
The aim of the online survey was to assess the need for interdisciplinarity at both the educational and research levels, as well as the needs of young oncologists and other disciplines involved in oncology.
The survey language was German and it consisted of both single-and multiple choice questions; six-point-Likert-Scales as well as fill-in responses were utilized (for the complete questionnaire, see Supplemental I. An English translation can be found in Supplemental II) (Likert 1932). The response to all questions was voluntary, anonymous and every question was skippable. After completion of the survey, a computerized matrix was programmed, and the questionnaire was distributed to all participating groups.
The survey was conducted among all junior oncology groups represented in YOU between November 2021 and March 2022. The junior research groups listed in Table 1 participated in the survey. A total of 294 participants completed the questionnaire in full. As the aim of the survey was to investigate opinions on interdisciplinary care in the next generation, answers from respondents holding a professorship (n = 4) were excluded. Table 2 summarizes participants' characteristics and demographics. The median age of the participants was 33.6 years.

General aspects and demographics
The majority of participants were associated with the profession of medicine (92.2%). The specialty of gastroenterology was most frequently represented (24.5%), followed by gynecology (18.7%).

Interdisciplinarity in everyday work life
90.7% of the respondents completely or mostly agreed with the statement that interdisciplinary work plays a major role in their daily work (Fig. 1). Most participants even wished for interdisciplinary work to a greater or significantly greater extent (78.9%).

Interdisciplinarity in education
With regard to residency training, the vast majority assigned a high priority to interdisciplinary training (63.1% completely or mostly agree). Only 53 participants (18.3%) had the opportunity to take planned rotations to other specialties beyond the continuing education catalog. For 43 respondents (14.8%), rotations are not part of residency training. Yet, our data indicated a high interest in other specialties (Fig. 2). 207 participants would like to participate in rotations to other specialties (71.4%). The majority of those who completed rotations stated that they had benefited mostly or greatly from them (73.1%).

Interdisciplinary in research
About half of the respondents (50.3%) reported, having participated in a scientific study involving various oncology disciplines. Of those who had not yet been involved in interdisciplinary research, 80.1% indicated an interest in participating in a multidisciplinary/interdisciplinary study project in the future (Fig. 3). High organizational costs, lack of time resources, and possible political conflicts were cited as reasons against participating in or initiating an interdisciplinary study (Fig. 4).

Interdisciplinary networks
Of the 294 respondents, 151 (51.4%) indicated that they were active in an oncological junior group (Fig. 5). Of the 143 previously inactive participants, 106 (74.1%) again  indicated that they would be interested in joining the group. Only 37 participants declined to actively participate. 161 of the 290 participants (55.5%) indicated that they were already aware of interdisciplinary networks. 104 (35.9%) were aware of interdisciplinary funding opportunities (Fig. 6).

Discussion
We here present the first survey on opinions on interdisciplinary care and research among junior oncologists in Germany. Our survey results underscore the perception of the importance of interdisciplinary collaboration in modern oncology. The majority of respondents welcomed the already existing interdisciplinary cooperation in the areas of daily work, education and research. Most respondents wished for even stronger collaboration and training.
However, only half of the respondents have actively participated in interdisciplinary oncology study activities so far, more than 70% of the non-participants would like to do so. Participants believe interdisciplinarity is important and would welcome expansion of existing support programs.
Interdisciplinary work has become indispensable in oncology and is a substantial guarantor of quality in cancer care practices (Tremblay et al. 2017;Velde et al. 2014;Jemal et al. 2011). In fact, oncology has been a driver in institutionalized collaboration in the medical field, as evidenced by the early establishment of regularly scheduled interdisciplinary expert conferences ("tumorboard review") and a well-regulated certification process of interdisciplinary cancer centers (Hawk and Viner 2006;Kowalski et al. 2017;Wallwiener et al. 2012;Henson et al. 1990). Furthermore, scientific progress in oncology heavily benefits from interdisciplinary cooperation, also on an international level of collaboration (Pui et al. 2015;Gaspar et al. 2015;Jaffee et al. 2017). As the population is aging, an increasing demand of interdisciplinary care is expected due to a growing number of oncologic patients (Sung et al. 2021;Terret et al. 2007). Simultaneously interdisciplinarity is highly valued in the management of pediatric oncologic patients (Wein et al. 2010).
Cancer medicine is developing rapidly and cancer is increasingly becoming a chronic disease. The constant improvements in the management of acute complications make it more and more possible to treat elderly and multimorbid patients with intensive oncological treatment strategies. As well as the path to treatment, the increasingly complex therapies with a broader spectrum of adverse effects and more nuanced approaches to treating these side effects require intensive interdisciplinary cooperation (Bergwelt-Baildon et al. 2010;Schellongowski and Staudinger 2012

Fig. 3 Statements on interdisciplinary research
A catalyst for interdisciplinary collaboration in oncology is the increasing complexity of diagnostic and therapeutic options (Meric-Bernstam et al. 2021;Lambin et al. 2017). For instance, the increasing use of next-generation sequencing (NGS) for patients with metastatic cancers and the use of DNA methylation profiles demand high expertise in data interpretation and a meticulous evaluation of potential clinical consequences and have, therefore, led to the implementation of specialized interdisciplinary molecular tumorboards (Mosele et al. 2020;Capper et al. 2018;Heinrich et al. 2022).
Although interdisciplinary patient care is now part of everyday clinical practice, studies on multidisciplinary teams and on an improvement of patient outcome through multidisciplinary teams have shown nonuniform results. However, negative results were probably mostly related to shortcomings of the chosen study design and the majority of studies rather suggest a benefit of the implementation of interdisciplinary tumorboards on patient management, also regarding hard outcome parameters such as overall survival (Pillay et al. 2016;Wille-Jørgensen et al. 2013;Lamb et al. 2011;Forrest et al. 2005;Freeman, et al. 2011;Freeman, et al. 2010;Brännström et al. 2015;Davies et al. 2006). For instance, in a study evaluating differences in overall survival in patients with Hepatocellular Carcinoma (HCC) before and after the establishment of a Multidisciplinary Clinic (MDC) for HCC, patients diagnosed after the MDC initiation had a median survival of 13.2 months compared to only 4.8 months in patients diagnosed before the MDC initiation (p = 0.005). In the multivariate analysis, being seen in the MDC was independently associated with improved overall survival after adjusting for tumor stage and reception of curative treatment regimen (hazard ratio 2.5, 95% confidence interval 2-3) (Yopp et al. 2014). As interdisciplinarity

INTERDISCIPLINARY STUDIES
In my opinion, the followi ng aspects hinder participation in an interdisciplinary study (multiple answers possible): In my opinion, the followi ng aspects hinder initiation in an interdisciplinary study (multiple answers possible):

I AM ACTIVE MEMBER OF A (ONCOLOGIC) JUNIOR GROUP
is considered the standard of care, it is becoming more and more difficult to deny patient interdisciplinary care in order to assess its impact on patient's outcome. About half of the respondents to this survey indicated that they had already participated in a study involving different oncology disciplines. Of those who had not yet been involved in interdisciplinary research, 80% indicated an interest. The main obstacles reported are lack of time, high organizational costs and political conflicts. Importantly, only few clinical trials are non-interdisciplinary as modern cancer medicine demands involvement of various medical specialties and allied healthcare professionals. Even study designing demands collaboration with other researchers and representatives from fields such as biostatistics, clinical trials management or regulatory bodies. The GTCSG (German Testicular Cancer Study Group) is a successful example of an interdisciplinary research collaborative, which keeps a low threshold for interested young colleagues in training. The results of our survey reveal that there remain many organizational barriers to interdisciplinary collaboration. These barriers can be avoided by working in a multi-institutional setting as recently shown (Brown et al. 2022).
This work is subject to certain limitations. The survey was primarily completed by physicians in advanced training, i.e., physicians who should have a deeper overview of interdisciplinary work. In addition, there may have been increased participation in the survey by individuals who are fundamentally favorable toward interdisciplinary collaboration and research (selection bias).
Participants were largely physicians in internal medicine, followed by gynecologists, radiation oncologists, and a large mixed remainder. However, we feel that this may well present the reality of oncological patient care and academia. Furthermore, this study primarily represents views on interdisciplinarity in the setting of the German health system and the transferability to other medical systems remains unclear.
The results generated by our survey highlight the wish for structured training programs that embrace working in interdisciplinary cancer teams. As most obstacles are organizational, these will need to be addressed from higher institutional hierarchies (Schafer 2010). Importantly, our study indicates that the long lamented lack of physician scientists is not due to a lack of enthusiasm from the next generation but perceived organizational hurdles. One way to approach the lack of time for research could be by strengthening clinician scientist programs (Richter-Kuhlmann 2023). Acknowledging the various gains, the additional workload of multidisciplinary teams should be compensated by appropriate remuneration (Winters et al. 2021). Medical students should concentrate at an early stage on consultation occasions that go beyond the pure acquisition of skills and knowledge, irrespective of the specialty. This basic training could provide a future foundation of interdisciplinary oncology education (Raes, et al. 2014;Wissing 2018).

Conclusion
Improved and expanded interdisciplinary collaboration is challenging but essential for the future of oncology. While interdisciplinary work already plays an important role for most survey participants interested in oncology, the majority would like to see even more interdisciplinary networking regarding daily clinical work and education. Although the interest in interdisciplinary research and network is high among the survey participants, various factors could be identified that make practical implementation difficult. Lack of time resources, excessive organizational effort, and possible political conflicts between institutions are the most frequently cited obstacles to successful interdisciplinary research projects. Likewise, there is no interdisciplinary organizational structure at the junior oncology level. Despite methodological weaknesses (selection bias), the survey provides valuable information on the importance of interdisciplinarity among young oncologists. Multi-professional and interdisciplinary networks could help to promote interdisciplinary research projects among young scientists and improve interdisciplinary exchange in professional practice, training and education.

Fig. 6 Bar chart on activity in junior groups
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