Appropriateness of multidisciplinary treatment related to the adequacy evaluation of gastric cancer from the surgeon's point of view: a retrospective cohort study.

INTRODUCTION
Multidisciplinary treatment (MDT) is known as an effective way to provide appropriate treatment to patients with various types of cancer and is actively being implemented [123]. In gastric cancer treatment, MDT has also been accepted as an effective strategy for establishing treatment plans [456]. According to Korean Practice Guidelines for Gastric Cancer 2022, the advantages of MDT may include correct diagnosis, change into a better treatment plan, shorter decision-making time, and survival benefits [7]. In Korea, the Health Insurance Review & Assessment Service (HIRA), a national medical evaluation agency under the Ministry of Health and Welfare, examines and evaluates medical expenses for services. This institution also evaluates and certifies hospitals' medical capabilities for diseases by assigning grades through an adequacy evaluation of various diseases. Similarly, gastric cancer adequacy evaluations are performed and graded for each hospital. The evaluation criteria include 12 “common indicators” and 3 “specific indicators for each cancer.” In the initial gastric cancer adequacy evaluation conducted from 2014 to 2019, the ratio of MDT involvement was not an evaluation item. However, it was introduced as an evaluation item in the second period of gastric cancer adequacy evaluations starting from July 2022, with the proportion of appropriate MDT patients suggested as 7.6% of all gastric cancer patients. The ratio of MDT is included in the 12 items of the “common indicator”; therefore, the number of patients conducting MDT in each hospital is increasing. While the advantages of MDT are apparent, it is also a practical challenge for each hospital to allocate resources such as manpower, time, and space to maintain MDT [8]. Additionally, no guidelines are available such as patient selection criteria for efficient MDT, and limited research is available in this area [7]; therefore, considering whether it is appropriate for the ratio of MDT to be included in the gastric cancer adequacy evaluation item is necessary. The appropriateness of using the ratio of MDT as an item for evaluating the adequacy of gastric cancer treatment has no prior research. Therefore, the purpose of this study is to evaluate whether MDT is appropriate as an item for gastric cancer adequacy evaluation by comparing the ratio of MDT between the 2 periods.

METHODS
This study was reviewed and approved by the Institutional Review Board of Asan Medical Center in Seoul, Korea (No.2024-0125). It was conducted according to the Declaration of Helsinki and written informed consent was waived due to its retrospective nature.
This study encompassed 142 patients who received MDT from a surgeon at Asan Medical Center between December 2015 and January 2023. Patients were allocated into 2 groups based on July 2022, the onset of the second period for gastric cancer adequacy evaluation, wherein the MDT ratio was introduced as a new evaluative criterion. During the first period, from December 2015 to June 2022, 71 patients received MDT, and an equivalent number were treated in the second period, from July 2022 to January 2023. Four specialists in surgery, gastroenterology, medical oncology, and radiology contributed to the MDT clinic. Before the MDT clinic commenced, a designated surgeon preliminarily reviewed patient information and documented an initial plan in the electronic medical record; this plan was later revised post-MDT clinic. The initial and final plans were assessed to determine any alterations. The average age, sex, and clinical TNM stage of patients in each group were analyzed to ascertain any disparities. Additionally, the rate of change in treatment plans before and after the MDT was calculated for each group, employing a P-value to evaluate the statistical significance of differences in change rates (P < 0.05). Statistical analysis was performed using IBM SPSS Statistics ver. 21.0 (IBM Corp.) with a chi-square test.

RESULTS
From December 2015 to January 2023, a total of 142 patients underwent MDT with a designated surgeon's participation. Overall, 71 patients were included in each of the 2 groups: group 1 received MDT before July 2022, coinciding with the start of the second period of gastric cancer adequacy evaluation, and group 2 received MDT thereafter. The average age was 64.8 (±11.07) and 62.2 (±12.52) years for groups 1 and 2, respectively. In both groups, of the 71 patients, 50 were male (70.4%) and 21 were female (29.6%). The clinical stage of group 2 MDT patients was lower than that of group 1, although the difference was not statistically significant. Similarly, no statistically significant differences were noted in TNM stage, sex, or age between the 2 groups (Table 1). In group 1, 26 patients (36.6%) altered their treatment plans post-MDT, compared to 15 patients (21.1%) in group 2. There was a statistically significant correlation between the MDT received and changes in treatment plans (P = 0.042) (Table 2). The number of patients hanging their treatment plans post-MDT in the second period decreased from 26 to 15, with a notably higher rate of change between endoscopic submucosal dissection and surgery (Table 3).

DISCUSSION
MDT, represented as team decision-making, and the establishment of an MDT in oncology have significantly influenced clinical decision-making [1910]. The composition of departments and experts in the MDT can vary. In gastric cancer, the MDT may include a range of professionals such as nutritionists, nurses, social workers, palliative care experts, surgeons, gastroenterologists, medical oncologists, radiologists, pathologists, and nuclear medicine specialists [111213]. Gastric cancer usually has a standard treatment approach for typical cases, and not all cases need a multidisciplinary approach [8]. However, certain patients require multidisciplinary care [1415]. Given the rapid development and the latest knowledge in each field related to the treatment of gastric cancer, establishing a patient treatment plan through an MDT in the same space and at the same time will provide optimal care. Moreover, the emotional impact on patients and guardians observing the consultation and decision-making process by experts in various fields should also be considered a positive factor.
As mentioned earlier, the HIRA, operating under the Ministry of Health and Welfare of Korea, conducts regular adequacy evaluations to evaluate the quality of treatment for various diseases. The first gastric cancer adequacy evaluation in the first period was launched in 2014, with subsequent evaluations continuing through 2019. The focus during the first period was primarily on the treatment processes for surgical patients, which inherently limited the scope of evaluation for metastatic cancer patients who were not candidates for surgery. Moreover, the evolving landscape of medical treatments and changes in the medical environment necessitated a revision of the evaluation metrics to better align with patient needs. Consequently, the first gastric cancer adequacy evaluation for the second period was initiated in July 2022. In this context, the “ratio of MDT” item was newly introduced.
MDT offers a distinct advantage by enabling the optimal treatment strategy through a comprehensive assessment of a patient's condition. This approach was also referenced in the Korean Practice Guidelines for Gastric Cancer 2022. Nevertheless, the absence of patient selection criteria and specific guidelines for MDT types poses risks, such as potential resource wastage and delays in urgent care for patients requiring MDT [78].
According to the results of this study, 71 patients received MDT from December 2015 to June 2022. This first period did not incorporate a “ratio of MDT” as an item in the gastric cancer adequacy evaluation. Among these patients, 26 patients (36.6%) underwent a change in their treatment plan. In the subsequent period from July 2022 to January 2023, another group of 71 patients received MDT, this time with the inclusion of an MDT ratio in the assessment. In this group, 15 patients (21.1%) experienced changes in their treatment plans. To summarize, the number of patients who received MDT in the second period increased enormously, yet the rate of treatment plan modifications decreased from 36.6% to 21.1%. While it is challenging to gauge the efficacy of MDT based solely on the factor of treatment plan changes, the findings prompt a reconsideration of whether the introduction of an MDT ratio truly ensures that the most suitable patients are receiving MDT in the context of gastric cancer adequacy evaluation.
This study has several limitations. First, the MDT conducted by a single surgeon at a single center was examined, and no specific quantitative assessment of the hospital resources was required to support the MDT system. Additionally, the efficiency of the MDT was evaluated using only one metric; whether treatment was altered. However, given the absence of appropriate selection criteria for patients requiring MDT, this study is significant as it is the first, to our knowledge, to investigate whether including the ratio of MDT is suitable as a measure of adequacy for gastric cancer evaluation. If detailed research into the human and material resources needed by hospitals to sustain MDT is performed, more comprehensive outcomes will be derived beyond this study's results.
In conclusion, in the absence of a guideline for patient selection that necessitates MDT and a lack of specific assessment of the resources used to maintain MDT, the inclusion of the MDT ratio as a measure of gastric cancer adequacy evaluation needs reassessment.