The clinical study was terminated prior to completion due to challenges in enrolling a sufficient number of participants.

Sarcopenia is a condition of reduced skeletal muscle associated with aging. It leads to poor outcome and increased risk of postoperative complications. Achieving protein and energy requirements is crucial point in sarcopenia treatment. In preoperative patients, daily consumption of protein should be at least 1.2-2.0 g of protein/kg/day or 25-35 g of protein in a meal to provide muscular protein synthesis.

The objective of this study is to show that preoperative enteral protein supplementation in elderly cancerous patients, who are diagnosed with sarcopenia, can decrease morbidity such as postoperative complications; mortality and improve postoperative clinical outcomes after elective surgery.

Sarcopenia is a condition of reduced skeletal muscle mass associated with aging process leading to decrease muscle strength and function. International Working Group on Sarcopenia defines Sarcopenia as an age-associated loss of skeletal muscle mass and function, and the European Working Group on Sarcopenia in Older People (EWGSOP) defines sarcopenia as a syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength with a risk of adverse outcomes such as physical disability, poor quality of life, and death. The prevalence of sarcopenia is higher in population older than 65 years and leading to poor outcomes such as mobility disorders, disability, poor quality of life and death. Sarcopenia is also associated with an increased risk of postoperative complications such as overgrowth of bacteria in the gastrointestinal tract, postoperative infections, sepsis, delayed wound healing prolonged inpatient rehabilitation, mortality and consequently a longer length of hospital stay, even without nutritional risk.

Sarcopenia contains multifactorial etiology, such as age-related, inadequate energy and/or protein intake, sedentary activity such as bed rest, and coexisting disease such as organ failure, inflammatory disease or endocrine disease. One important goal of developing treatment strategies in sarcopenic patients is to achieve protein and energy requirements. In preoperative patients, daily consumption of protein should be at least 1.2-2.0 g of protein/kg/day or 25-35 g of protein in a meal to provide muscular protein synthesis. Perioperative oral protein supplements have been demonstrated to increase serum albumin and total protein, improve postoperative functional walking capacity and decrease postoperative infection in elderly or critically ill patients. However, there have been no studies on the benefit of preoperative protein supplement in cancerous patients.

The objective of this study is to show that preoperative enteral protein supplementation in elderly cancerous patients, who are diagnosed with sarcopenia, can decrease morbidity such as postoperative complications; mortality and improve postoperative clinical outcomes after elective surgery.

Inclusion Criteria:

• Age of equal or more than 65 years.
• Diagnosed cancer of gastrointestinal tract, hepatopancreaticobiliary tract, urology, head and neck, ear-nose-throat or gynecological cancer.
• Scheduled for elective surgery with the duration more than 2 hours will be enrolled in this study.

Exclusion Criteria:

• Unable to walk, stand up, perform hand grip test, communicate and follow commands.
• Having factors affect bioimpedance (BIA) analysis such as pacemaker, alcohol drinking or heavy exercise within 12 hours prior to analysis or take medication, herb or hormone that affect muscle mass and strength such as estrogen, testosterone, thyroxine, steroid.
• Patients diagnosed with no sarcopenia or probable sarcopenia or have a contraindication for enteral nutrition will be excluded from this study.

The allocation sequence will be concealed from the researcher enrolling and assessing participants in sequentially numbered, opaque, sealed and stapled envelopes. Corresponding envelopes will be opened only after the enrolled participants completed all baseline assessments and it was time to allocate the intervention. Whereas patients and physicians allocated to the intervention group are aware of the allocated arm, outcome assessors and data analysts will be kept blinded to the allocation.