Body weight measured in kilograms (kg). The tools used for anthropometric data collection included a weighing scale with an integrated stadiometer (Asimed® brand, manufactured by Sibelmed, Barcelona, Spain) and an anthropometric measuring tape.

Height measured in meters (m). The tools used for anthropometric data collection included a weighing scale with an integrated stadiometer (Asimed® brand, manufactured by Sibelmed, Barcelona, Spain) and an anthropometric measuring tape.

Calf circumference measured in centimeters (cm) at the point of maximum circumference. The tools used for anthropometric data collection included a weighing scale with an integrated stadiometer (Asimed® brand, manufactured by Sibelmed, Barcelona, Spain) and an anthropometric measuring tape.

Body mass index calculated as weight in kilograms divided by height in meters squared (kg/m²).

Self-reported usual body weight prior to disease or treatment, measured in kilograms (kg).

Percentage and absolute change in body weight from baseline during osimertinib treatment. It was calculated using the following formula: %WL = [(usual weight - current weight)/usual weight] × 100

Dietary intake assessed 24-hour food recall, including total caloric and macronutrient intake.

Fat mass measured in kilograms using bioelectrical impedance analysis (BIA) the InBody S10® body composition analyzer (manufactured by InBody Co., Ltd., Seoul, Republic of Korea), was used, which is a device that measures impedance using 6 frequencies (1, 5, 50, 250, 500, and 1000 kHz) for each of the 5 body segments: right arm, left arm, trunk, right leg, and left leg.

The measurements were performed with patients standing barefoot, with their legs apart and arms not touching the torso. The 8-point tactile electrodes were placed on the thumb and middle finger of each hand and on both ankles. The data obtained were analyzed using the LookinBody 120® software.

Lean body mass measured in kilograms using bioelectrical impedance analysis (BIA) the InBody S10® body composition analyzer (manufactured by InBody Co., Ltd., Seoul, Republic of Korea), was used, which is a device that measures impedance using 6 frequencies (1, 5, 50, 250, 500, and 1000 kHz) for each of the 5 body segments: right arm, left arm, trunk, right leg, and left leg.

The measurements were performed with patients standing barefoot, with their legs apart and arms not touching the torso. The 8-point tactile electrodes were placed on the thumb and middle finger of each hand and on both ankles. The data obtained were analyzed using the LookinBody 120® software.

Lean body mass index calculated as lean body mass divided by height squared (kg/m²). A reduced muscle mass was considered for LBMI < 17 kg/m2 in men and <15 kg/m2 in women. Using bioelectrical impedance analysis (BIA) the InBody S10® body composition analyzer (manufactured by InBody Co., Ltd., Seoul, Republic of Korea), was used, which is a device that measures impedance using 6 frequencies (1, 5, 50, 250, 500, and 1000 kHz) for each of the 5 body segments: right arm, left arm, trunk, right leg, and left leg.

The measurements were performed with patients standing barefoot, with their legs apart and arms not touching the torso. The 8-point tactile electrodes were placed on the thumb and middle finger of each hand and on both ankles. The data obtained were analyzed using the LookinBody 120® software.

Muscle functionality was assessed through hand grip strength using a hydraulic dynamometer (Jamar®, manufactured by Performance Health, Warrenville, IL, USA), providing the strength of the dominant arm (kg). Three measurements were taken with the subject seated and without arm support, with a 60 s rest between each measurement to prevent muscle fatigue. Dynapenia or reduced strength was considered if the value was <27 kg in men and <16 kg in women.

Applying the EWGSOP2 algorithm proposed by the European Working Group on Sarcopenia in Older People (EWGSOP).

The screening was performed using the Strength, Assistance walking, Rise from a chair, Climb stairs, and Falls (SARC-F) questionnaire, and a score of 4 or higher was considered to indicate a risk of sarcopenia. Muscle strength was determined by dynamometry, and BIA or CC assessed muscle mass. Patients with low muscle strength were classified as dynapenic; presarcopenia was diagnosed in patients showing reduced muscle mass and no significant decrease in muscle strength; finally, sarcopenia was diagnosed in patients who, in addition to low hand grip strength, also exhibited a reduction in muscle mass.

It was assessed using the EQ-5D scale, a standardized tool that measures five dimensions of health: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Additionally, patients completed a visual Analog scale (VAS) ranging from 0 to 100, reflecting their general health status.