Unveiling hidden outcomes in malignant gastric outlet obstruction research – insights from a "Pancreas 2000" review

Table 1 Suggested clinical outcomes to be included in future gastric outlet obstruction research

Outcome	Instruments/measures	Definition	Advantages	Disadvantages
Nutrition
Body composition	Body mass index[20]	Weight (Kg) divided by the square of height (m)	Easy assessment No need for laboratory or instrumental tests	Affected by hypervolemia[5]; Does not accurately predict lean body mass[64]
	Bioelectrical impedance vector analysis[34,65]	Body composition measurement (fat, bone, water and muscle) through levels of resistance to electrical current	Noninvasive; Allows detailed knowledge of hydration status and cell mass	Requires extra resources; Equipment cost
	Dual-energy X-ray absorptiometry[34,66]	Low-dose radiation technique measuring bone mineral density and body composition, such as fat mass and fat free mass	Noninvasive; Radiation dose lower than CT; Short scan time; Whole-body scan	Availability; Cost of equipment; Training; Exposure to ionizing radiation
	CT-based assessment of skeletal muscle mass	Sarcopenia: Loss of skeletal muscle mass[31] Most widely assessed using SMI (calculated by adjusting the total muscle area at the L3 vertebral level to the body height of the patient)[63,67]	Defined by CT images routinely used in standard care of PC patients; Low cost of using available CT images[63]; Directly correlates with the whole-body skeletal muscle mass[63]; AI-based evaluation may decrease the time for segmentation[68]	Heterogeneity regarding radiological definition of sarcopenia due to varying indices used such as SMI, PMI, SBI[67,69]; Threshold values for sarcopenia vary for different patient populations[63,70]; Training and time for analysis[63]
Biochemical parameters	Prognostic nutrition index[35,38]	Calculated using serum albumin and total lymphocyte count; Reflects nutrition and immune status	Easy to calculate and to follow up; Good predictive ability for prognosis in several cancers	Need for further validation in patients undergoing invasive procedures
	Neutrophil-to-lymphocyte ratio[35,38]	Ratio between the neutrophil and lymphocyte counts measured in peripheral blood	Easy to calculate and to follow up	Need for further validation in patients undergoing invasive procedures
	Albumin-to-globulin ratio[40]	Ratio between albumin and globulin measured in peripheral blood	Easy to calculate and to follow up; Not affected by body fluid balance	Need for further validation in patients undergoing invasive procedures
QoL	EORTC QLQ-C30[49]	The 30 item core cancer questionnaire to assess health-related QoL	Easy to assess and administer	Time-consuming; Accuracy could vary depending on patient’s education and psychiatric medication consumption
	EORTC QLQ-PAN26[52]	To assess health-related QoL for people with pancreatic ductal adenocarcinoma	Easy to assess and administer; Validated in the palliative and surgical settings	Time-consuming; Accuracy could vary depending on patient’s education and psychiatric medication consumption
	EuroQol EQ-5D[48,55]	Five dimensions health-related QoL questionnaire for use in clinical and population health surveys	Easy to assess and administer	Time-consuming; Does not specifically evaluate nutrition or eating ability
	The FAACT[50,53]	A patient-reported measure designed to specifically assess anorexia/cachexia-related symptoms	Developed for adult cancer patients, experiencing anorexia/cachexia; Easy to assess and administer	Controversy around optimal cut-off
	The Anorexia/Cachexia Subscale (A/CS) of the FAACT questionnaire[50,53]	A specific subscale of FAACT	As FAACT	As FAACT
Chemotherapy tolerance	RDI[59,60]	The ratio of the delivered dose intensity (dose per unit body surface area per unit time [mg/m2 per week]) to the standard or planned dose intensity for a chemotherapy regimen	It may correlate with survival; RDI informs personalized treatment adjustments	Defining clinically meaningful RDI thresholds (e.g., 80% or 85%) remains challenging; Doesn’t directly account for non-hematologic toxicities; Difficult to calculate a merged RDI for regimens with multiple drugs; Relies on accurate dosing data, not consistently recorded in clinical practice
	Time to chemotherapy initiation or resumption[2,6,61]	Time from the procedure to chemotherapy initiation or resumption	Time-depending outcome; Detailed evaluation of the impact of the procedure on the systemic therapy	Better to be evaluated in prospective studies

AI: Artificial intelligence; CT: Computerized tomography; EORTC QLQ-C30: European Organization for Research and Treatment of Cancer 30 item core cancer questionnaire; EORTC QLQ-PAN26: European Organization for Research and Treatment of Cancer quality of life questionnaire for pancreatic cancer patients; EuroQol EQ-5D: EuroQol 5 dimension questionnaire; FAACT: Functional Assessment of Anorexia/Cachexia Therapy; PMI: Psoas muscle index; QoL: Quality of life; RDI: Relative dose intensity; SBI: Skeletal muscle area/Total body area; SMI: Skeletal muscle index.