Baseline characteristics
A total of 87 patients with GI cancer were included in this retrospective analysis, comprising 46 patients in the ONS group and 41 patients in the control group (Figure 1). Patients aged ≥60 years accounted for 63.22% of the overall cohort, with a slight male predominance (66.67%). As shown in Table 1, there were no significant differences in baseline age or sex distribution between the ONS and control groups (P > 0.05), indicating comparability with respect to these characteristics. However, significant between-group differences were observed in tumor site, body weight status, and body weight change. Stomach cancer was observed only in the ONS group (39.13% vs. 0.00%), whereas rectal cancer was more prevalent in the control group than in the ONS group (48.78% vs. 17.39%, P < 0.001). The ONS group also had a higher proportion of patients with normal or underweight status (86.96% vs. 63.41%, P = 0.010) and a significantly higher prevalence of baseline weight loss than the control group (34.78% vs. 0.00%, P < 0.001). The distributions of oncological treatment and supportive treatment categories did not differ significantly between the groups (P = 0.933 and P = 0.751, respectively; Table 1).
Changes in hematological parameters
As shown in Table 2, WBC, NE, and PLT counts decreased from baseline to week 3 in both groups. In the control group, the median changes in WBC, NE, and PLT were −1.30 × 109/L (P < 0.001), −1.41 × 109/L (P < 0.001), and −75.00 × 109/L (P < 0.001), respectively. The corresponding changes in the ONS group were −0.50 × 109/L (P = 0.023), −0.50 × 109/L (P = 0.005), and −24.50 × 109/L (P = 0.004), respectively. The between-group difference in the change in NE was statistically significant (P = 0.007), whereas the differences in WBC and PLT changes did not reach statistical significance (P = 0.073 and P = 0.078, respectively).
After adjustment for the corresponding baseline value, tumor site, and baseline weight-loss status, documented ONS exposure was associated with higher week-3 WBC (adjusted difference, 1.08 × 109/L; 95% CI, 0.244 to 1.919; P = 0.012) and NE counts (adjusted difference, 0.97 × 109/L; 95% CI, 0.304 to 1.637; P = 0.005) compared with the control group. No significant adjusted between-group differences were observed for PLT (P = 0.384), LY (P = 0.597), or hemoglobin (P = 0.511; Table 3).
Changes in immuno-inflammatory markers
NLR, PLR, and SII decreased from baseline to week 3 in both groups. The reductions were greater in the control group than in the ONS group. The median change in NLR was −1.14 versus −0.27 (P for Δ < 0.001), the mean change in PLR was −73.16 versus −31.93 (P for Δ = 0.009), and the median change in SII was −445.71 versus −94.38 × 109/L (P for Δ < 0.001), respectively (Table 2). In the adjusted analyses, the week-3 NLR remained significantly higher in the ONS group than in the control group (adjusted difference, 0.60; 95% CI, 0.066–1.131; P = 0.028). However, no significant adjusted between-group differences were observed for PLR (P = 0.446) or SII (P = 0.079) (Table 3).
CRP decreased significantly within the control group (median change, −0.55 mg/L; P = 0.035) but not within the ONS group (median change, 0.04 mg/L; P = 0.772; Table 2). Neither the unadjusted between-group comparison of change values (P = 0.085) nor the adjusted analysis (P = 0.087) showed a statistically significant difference (Table 2 and Table 3).
Changes in nutritional and metabolic markers
The median increases in body weight and BMI were 0.45 kg and 0.15 kg/m2, respectively, in the ONS group, compared with no change (0.00 kg and 0.00 kg/m2) in the control group. The unadjusted between-group differences in both change values were statistically significant (P = 0.040 for both; Table 2). After adjustment for the corresponding baseline value, tumor site, and baseline weight-loss status, documented ONS exposure was associated with higher week-3 body weight (adjusted difference, 1.49 kg; 95% CI, 0.579–2.393; P = 0.002) and BMI (adjusted difference, 0.51 kg/m2; 95% CI, 0.190–1.015; P = 0.002) compared with the control group (Table 3).
No significant adjusted between-group differences were observed for total protein, albumin, or PNI (P = 0.813, P = 0.076, and P = 0.107, respectively; Table 3). Although the unadjusted change in triglycerides differed significantly between the groups (P = 0.030), this difference was no longer significant after adjustment (adjusted difference, −0.03 mmol/L; 95% CI, −0.496 to 0.445; P = 0.914). Likewise, no significant adjusted between-group differences were observed for total cholesterol, creatinine, or uric acid (all P > 0.05; Table 2 and Table 3).
DATA AVAILABILITY:
The de-identified dataset underlying the findings of this study is provided as Supplementary Table 2.

Figure 1: Flowchart of patient selection and inclusion. A total of 160 patients attended nutritional counseling. Seventy-two patients elected to receive omega-3 PUFA-enriched oral nutritional supplements (ONS), and 88 received dietary counseling alone. After applying the eligibility criteria, 46 patients in the ONS group and 41 in the control group were included in the final analysis. Please click here to view a larger version of this figure.
| Variable | Total Baseline (87) | Control (41) | ONS (46) | P Value |
| N | % | N | % | N | % | |
| Age | | | | | | | 0.630 |
| <60 | 32 | 36.78 | 14 | 34.15 | 18 | 39.13 | |
| ≥60 | 55 | 63.22 | 27 | 65.85 | 28 | 60.87 | |
| Sex | | | | | | | 0.129 |
| Female | 29 | 33.33 | 17 | 41.46 | 12 | 26.09 | |
| Male | 58 | 66.67 | 24 | 58.54 | 34 | 73.91 | |
| Tumor Site | | | | | | | <0.001 |
| Sigmoid Colon | 17 | 19.54 | 8 | 19.51 | 9 | 19.57 | |
| Ascending Colon | 17 | 19.54 | 10 | 24.39 | 7 | 15.22 | |
| Transverse Colon | 1 | 1.15 | 1 | 2.44 | 0 | 0 | |
| Descending Colon | 6 | 6.9 | 2 | 4.88 | 4 | 8.7 | |
| Rectum | 28 | 32.18 | 20 | 48.78 | 8 | 17.39 | |
| Stomach | 18 | 20.69 | 0 | 0 | 18 | 39.13 | |
| Body Weight | | | | | | | 0.010 |
| Normal and Underweight | 66 | 75.86 | 26 | 63.41 | 40 | 86.96 | |
| Overweight and Obese | 21 | 24.14 | 15 | 36.59 | 6 | 13.04 | |
| Body Weight Change | | | | | | | <0.001 |
| Maintained or Gained | 71 | 81.61 | 41 | 100 | 30 | 65.22 | |
| Lost | 16 | 18.39 | 0 | 0 | 16 | 34.78 | |
| Treatment category | | | | | | | 0.933 |
| Oxaliplatin-containing combination chemotherapy | 48 | 55.17 | 24 | 58.54 | 24 | 52.17 | |
| Fluoropyrimidine monotherapy | 21 | 24.14 | 9 | 21.95 | 12 | 26.09 | |
| Irinotecan-containing combination chemotherapy | 3 | 3.45 | 1 | 2.44 | 2 | 4.35 | |
| No concurrent systemic chemotherapy | 15 | 17.24 | 7 | 17.07 | 8 | 17.39 | |
| Supportive treatment | | | | | | | 0.751 |
| Granulocyte colony-stimulating factor | 2 | 2.3 | 1 | 2.44 | 1 | 2.17 | |
| Oral leukopoietic agents | 31 | 35.63 | 13 | 31.71 | 18 | 39.13 | |
| None | 54 | 62.07 | 27 | 65.85 | 27 | 58.7 | |
Table 1: Baseline characteristics of GI cancer patients in the control and ONS groups. Data are presented as n (%). The control group (n = 41) received dietary counseling alone, whereas the ONS group (n = 46) received omega-3 PUFA-enriched ONS plus dietary counseling. P values represent between-group comparisons using the chi-square test or Fisher's exact test, as appropriate. Oxaliplatin-containing combination chemotherapy included FOLFOX, TOMOX, XELOX, and SOX; fluoropyrimidine monotherapy included capecitabine and S-1; irinotecan-containing combination chemotherapy included FOLFIRI; and no concurrent systemic chemotherapy included surgery alone. Supportive treatments were categorized as granulocyte colony-stimulating factor, oral leukopoietic agents, or none. All P values are two-sided, and P < 0.05 was considered statistically significant. Abbreviations: ONS = oral nutritional supplement; PUFA = polyunsaturated fatty acid.
| Variable | Control (41) | ONS (46) | |
| N | Baseline | Final | Δ | P | N | Baseline | Final | Δ | P | P for Δ |
| Weight (kg) | 41 | 63.07(9.85) | 63.07(9.85) | 0.00(0.00, 0.00) | - | 46 | 56.75(8.99) | 57.09(8.75) | 0.45(-0.70,1.30) | 0.383 | 0.040 |
| BMI (kg/m²) | 41 | 23.00(2.78) | 23.00(2.78) | 0.00(0.00, 0.00) | - | 46 | 20.77(2.67) | 20.89(2.52) | 0.15
(-0.30,0.45) | 0.403 | 0.040 |
| WBC (×10⁹/L) | 41 | 5.90
(4.80,7.00) | 4.30
(3.70,5.80) | -1.30
(-1.90,-0.20) | <0.001 | 46 | 5.40
(3.80,7.20) | 5.00
(3.70,5.90) | -0.50
(-1.41,0.50) | 0.023 | 0.073 |
| NE (×10⁹/L) | 41 | 3.67
(3.30, 4.63) | 2.30
(1.80, 3.20) | -1.41
(-2.16,-0.40) | <0.001 | 45 | 3.20
(2.10, 4.60) | 2.70 (1.80, 3.20) | -0.50
(-1.30,0.20) | 0.005 | 0.007 |
| PLT (×10⁹/L) | 41 | 231.00
(199.00, 296.00) | 159.00
(123.00, 221.00) | -75.00
(-153.00,-7.00) | <0.001 | 46 | 242.50
(152.00, 308.00) | 188.00 (157.00, 231.00) | -24.50
(-101.00,10.00) | 0.004 | 0.078 |
| LY (×10⁹/L) | 41 | 1.39
(1.10,1.50) | 1.40
(1.20,1.70) | 0.15(0.48) | 0.082 | 45 | 1.60
(1.30,1.80) | 1.50(1.30, 2.10) | 0.02(0.39) | 0.883 | 0.187 |
| CRP (mg/L) | 41 | 1.63
(0.69,6.46) | 1.27
(0.67,2.40) | -0.55
(-2.15,0.48) | 0.035 | 46 | 1.90
(0.72,4.57) | 1.73
(0.82,4.05) | 0.04
(-1.09,1.89) | 0.772 | 0.085 |
| Hemoglobin(g/L) | 41 | 125.00
(114.00,
138.00) | 122.00
(109.00,
135.00) | -3.00
(-12.00,
11.00) | 0.726 | 46 | 122.00
(110.00,
134.00) | 119.50
(110.00,
135.00) | 2.50
(-3.00,6.00) | 0.150 | 0.222 |
| TC (mmol/L) | 33 | 4.87(1.24) | 4.69(1.22) | -0.19(-0.58,0.40) | 0.358 | 45 | 4.23(1.12) | 4.33(1.05) | 0.16(-0.15,0.40) | 0.337 | 0.102 |
| TG (mmol/L) | 33 | 1.27
(0.88,1.71) | 1.43
(1.02,1.93) | 0.18
(-0.14,0.30) | 0.118 | 45 | 0.97
(0.75,1.41) | 0.90
(0.73,1.26) | 0.00
(-0.20,0.13) | 0.349 | 0.030 |
| TP (g/L) | 41 | 68.39(5.40) | 69.47(5.48) | 1.08(5.30) | 0.199 | 46 | 69.70(4.49) | 69.55(4.95) | -0.15(4.55) | 0.819 | 0.246 |
| ALB (g/L) | 41 | 41.90
(39.20,43.70) | 41.70
(38.80,
44.20) | -0.30
(-3.20,2.90) | 0.846 | 46 | 41.70
(39.00,43.80) | 41.61
(39.50,44.10) | 0.35
(-1.40,1.20) | 0.814 | 0.652 |
| Creatinine (µmol/L) | 41 | 61.10
(50.50,73.40) | 65.00
(53.60,
74.60) | 2.80
(-5.00,10.60) | 0.176 | 46 | 67.20
(58.30,76.00) | 64.50
(55.70,73.50) | -2.45
(-7.00,1.60) | 0.071 | 0.057 |
| Uric acid (µmol/L) | 41 | 290.50
(240.60,
334.40) | 316.10
(258.70,
385.10) | 46.70
(-35.00,83.49) | 0.061 | 46 | 292.50
(235.00,
339.60) | 293.60
(254.10,
342.80) | -0.50
(-30.10,
33.60) | 0.939 | 0.064 |
| NLR | 41 | 2.93
(2.31,3.34) | 1.71
(1.13,2.22) | -1.14
(-1.97,-0.68) | <0.001 | 45 | 1.88
(1.33,2.81) | 1.50
(1.025,2.00) | -0.27
(-0.71,0.16) | 0.013 | <0.001 |
| PLR | 41 | 193.33
(150.91,233.08) | 110.00
(87.37,
150.00) | -73.16
(70.69) | <0.001 | 45 | 143.75
(95.71,
185.00) | 115.71
(90.83,
146.15) | -31.93
(71.59) | 0.004 | 0.009 |
| SII (×10⁹/L) | 41 | 729.64
(504.43,
986.00) | 253.00
(168.00,
403.98) | -445.71
(-717.98,
-249.43) | <0.001 | 45 | 386.69
(272.00,
687.69) | 306.25
(228.57,
370.96) | -94.38
(-368.71,0.00) | <0.001 | <0.001 |
| PNI (points) | 41 | 49.10
(45.55,50.70) | 48.50
(45.50,
52.40) | 1.00
(-3.05,4.25) | 0.411 | 45 | 49.50
(46.80,51.70) | 49.60
(47.30,52.80) | -0.30
(-1.60,1.20) | 0.982 | 0.369 |
Table 2: Comparison of clinical variables between the control and ONS groups at baseline and after the 3-week observation period. The control group included 41 patients who received dietary counseling alone, whereas the ONS group included 46 patients who received omega-3 PUFA-enriched ONS plus dietary counseling. Baseline refers to the beginning of the observation period, and final refers to the assessment performed after 3 weeks. Data are presented as mean ± SD for normally distributed variables or median (IQR) for non-normally distributed variables. Change scores (Δ) were calculated for each patient as the week-3 value minus the baseline value and are presented as mean (SD) or median (IQR), depending on the distribution of patient-level change values. Within-group comparisons were performed using paired t-tests or Wilcoxon signed-rank tests. Between-group comparisons of Δ values were performed using independent-samples t-tests or Mann-Whitney U tests. "P for Δ" represents the P value for the comparison of change scores between the ONS and control groups. All P values are two-sided, and P < 0.05 was considered statistically significant. Abbreviations: ONS = oral nutritional supplement; BMI = body mass index; WBC = white blood cell count; NE = neutrophil count; PLT = platelet count; LY = lymphocyte count; CRP = C-reactive protein; TC = total cholesterol; TG = triglycerides; TP = total protein; ALB = albumin; NLR = neutrophil-to-lymphocyte ratio; PLR = platelet-to-lymphocyte ratio; SII = systemic immune-inflammation index; PNI = prognostic nutritional index; SD = standard deviation; IQR = interquartile range.
| Outcome Variable | Coefficient | 95% CI | P |
| Weight (kg) | 1.49 | 0.579, 2.393 | 0.002 |
| BMI (kg/m²) | 0.51 | 0.190, 1.015 | 0.002 |
| WBC (×10⁹/L) | 1.08 | 0.244, 1.919 | 0.012 |
| NE (×10⁹/L) | 0.97 | 0.304, 1.637 | 0.005 |
| PLT (×10⁹/L) | 18.20 | -23.202, 59.608 | 0.384 |
| LY (×10⁹/L) | 0.07 | -0.187,0.323 | 0.597 |
| CRP (mg/L) | 3.17 | -0.476, 6.819 | 0.087 |
| Hemoglobin(g/L) | 2.15 | -4.335, 8.632 | 0.511 |
| TC (mmol/L) | 0.13 | -0.243, 0.493 | 0.499 |
| TG (mmol/L) | -0.03 | -0.496, 0.445 | 0.914 |
| TP (g/L) | -0.33 | -3.066, 2.412 | 0.813 |
| ALB (g/L) | 1.81 | -0.192, 3.802 | 0.076 |
| Creatinine (µmol/L) | -2.89 | -8.252, 2.469 | 0.286 |
| Uric acid (µmol/L) | 2.63 | -40.019, 45.284 | 0.903 |
| NLR | 0.60 | 0.066, 1.131 | 0.028 |
| PLR | 9.71 | -15.517, 34.937 | 0.446 |
| SII (×10⁹/L) | 116.59 | -13.811, 246.991 | 0.079 |
| PNI (points) | 2.18 | -0.483, 4.833 | 0.107 |
Table 3: Adjusted between-group differences in hematological, nutritional, metabolic, and immune-inflammatory outcomes at week 3. Adjusted between-group differences were estimated separately for each outcome using multivariable linear regression models. The week-3 value was entered as the dependent variable, and the study group was entered as the primary independent variable. Each model was adjusted for the corresponding baseline value, tumor site, and baseline weight-loss status. The control group served as the reference category, and robust standard errors were applied. Regression coefficients represent the adjusted differences in week-3 values between the ONS and control groups in the original units of each outcome. Positive coefficients indicate higher adjusted values in the ONS group, whereas negative coefficients indicate lower adjusted values. Results are presented as adjusted regression coefficients with 95% confidence intervals (CIs). All P values are two-sided, and P < 0.05 was considered statistically significant. Abbreviations: ONS = oral nutritional supplement; BMI = body mass index; WBC = white blood cell count; NE = neutrophil count; PLT = platelet count; LY = lymphocyte count; CRP = C-reactive protein; TC = total cholesterol; TG = triglycerides; TP = total protein; ALB = albumin; NLR = neutrophil-to-lymphocyte ratio; PLR = platelet-to-lymphocyte ratio; SII = systemic immune-inflammation index; PNI = prognostic nutritional index; CI = confidence interval.
Supplementary Table 1: Individual-level oncological treatment regimens and supportive treatments during the 3-week observation period. This table presents the treatment group, categorized oncological treatment, specific treatment regimen, and supportive treatment recorded for each patient during the 3-week observation period. Abbreviations: ONS = oral nutritional supplement; FOLFOX = folinic acid, fluorouracil, and oxaliplatin; TOMOX = raltitrexed and oxaliplatin; XELOX = capecitabine and oxaliplatin; SOX = S-1 and oxaliplatin; FOLFIRI = folinic acid, fluorouracil, and irinotecan.Please click here to download this file.
Supplementary Table 2: De-identified individual-level data. This table provides the de-identified individual-level data used in the statistical analyses, including demographic and clinical characteristics, treatment group, anthropometric measurements, hematological parameters, biochemical and nutritional markers, and immune-inflammatory indices measured at baseline and week 3. Measurement units are specified in the corresponding column headings. Abbreviations: ONS = oral nutritional supplement; BMI = body mass index; WBC = white blood cell count; NE = neutrophil count; PLT = platelet count; LY = lymphocyte count; CRP = C-reactive protein; TC = total cholesterol; TG = triglycerides; TP = total protein; ALB = albumin; PNI = prognostic nutritional index; NLR = neutrophil-to-lymphocyte ratio; PLR = platelet-to-lymphocyte ratio; SII = systemic immune-inflammation index.Please click here to download this file.