A prospective observational cohort study was conducted between September 2019 and November 2020 at Cancer Institute(WIA), Adyar, India after obtaining the approval from the institute ethics committee (IEC) (IEC 2019/Sept/01) for preoperative screening of cancer patients. The study was conducted in accordance to the Declaration of Helsinki of 1975, revised in 2000. A written informed consent was obtained from all the patients before the nutrition screening. The study was registered at Clinical Trial Registry-India (CTRI/2020/04/024733). All consecutive adult patients above the age of 18 years, with H & N or GI cancer scheduled for definitive surgeries were included. The exclusion criteria were 1. Patients having Poliomyelitis or lower limb edema 2. Patients for short procedures lasting less than three hours such as thyroidectomy or excision biopsies in the tongue or neck dissection.3. Patients for palliative or emergency procedures. Screening for malnutrition was performed using the nutrition tools (ESPEN, MNA-SF and MUST) and CC was measured in the immediate preoperative period (Fig. 1).
According to the ESPEN consensus, malnutrition was diagnosed when the patients met one of the following two options. Option 1 requires Body mass index (BMI) <18.5 kg/m2 while the second option requires unintentional weight loss and reduced BMI or reduced fat free mass index.
MNA-SF was designed especially for the elderly. It contains six questions as shown in Fig. 1. Each question is rated from 0 to 2 or 3 and the total score of MNA-SF is 14.
MUST include the following parameters: BMI, unintentional weight loss and any acute disease which compromises nutritional intake for more than 5 days. The three parameters rated as 0, 1 or 2 are as follows: BMI >20 kg/m2=0, 18.5–20 kg/m2=1, <18.5 kg/m2=2; unintentional weight loss in the past 3–6 months <5%=0, 5–10%=1; any acute disease present would mean 2 points. Overall risk of malnutrition is assessed by adding all the points together.
Calf Circumference (CC) is measured along the widest circumference of calf on either limb. Patients with CC< 26cm for women and CC<28cm for men were considered malnourished. CC could be wider due to pedal edema or smaller due to atrophied lower limb in poliomyelitis.
All patients were observed daily until discharge. Information on any patient who was readmitted within 30 days was retrieved from their medical records. Socio-demographic (age, gender, comorbidities, prior treatment history, habits), anthropometric (height, weight and CC) and clinical details (pedal edema, hemoglobin, albumin, total white blood cell count, diagnosis, planned surgery, and date of surgery) were collected. Weight (in kg) was measured using a digital weighing machine and the height (in cm) using a stadiometer. The postoperative outcome parameters are defined in Supplementary Table 1.
With an expected prevalence of malnutrition ranging from 20-52% , the estimated sample size with 90% power and 5% precision considering prevalence of malnutrition to be 20% in our population and the estimated proportion being 0.25, was calculated as 203.
The study sample was divided into three subsets namely H&N, Upper GI cancers and Lower GI cancers. Continuous variables were reported as mean (SD) while categorical variables were reported as frequency (percentage). MUST, MNA-SF were first classified into three categories namely malnourished, at risk and normal, which was further reorganised as normal and malnourished. Patients who were malnourished and at risk of it were included in the malnourished group for ease of understanding. CC was also classified into two groups. MNA-SF, MUST and CC versus ESPEN guidelines of malnutrition(reference standard) was evaluated by the estimation of sensitivity, specificity and their positive predictive (PPV) and negative predictive values (NPV).The concordance between the reference standard and each of the three tools was analysed using Cohen’s κ (Kappa) statistic and the Shrout classification was used to interpret the κ value as follows: 0–0.1, virtually nil ; 0.11–0.4, slight; 0.41–0.6, fair; 0.61–0.8, moderate; and 0.81–1, substantial agreement.[15, 16] Student t-test was used for comparison of means and Pearson’s Chi-square test for evaluation of frequency distribution. P value≤ 0.05 was considered significant. Clavien Dindo scores of patients were further classified into two groups as scores less than 3 (minor complications) and greater than or equal to 3 (major complications) to analyse postoperative complications using the different tools. The tools were evaluated using the MedCalc software, diagnostic test evaluation calculator (https://www.medcalc.org/calc/diagnostic_test.php) and Statistical Package for Social Sciences, SPSS Version 26.0(IBM, Armonk, NY, USA).