Clinical Characteristics
A total of 4091 cancer patients were analyzed in the first step, among which 1303 were diagnosed with cachexia based on the 2011 international consensus of cachexia. The median age of patients with cachexia was 60 years (IQR [53.00–66.00]), and the proportion of males and females was 59.6% and 40.4%, respectively. The most frequent tumors were upper gastrointestinal tract (29.2%), lung (27.8%), colorectal (19.2%), hepatobiliary and pancreatic (8.6%), and breast (4.8%). Ninety-six patients (7.4%) had stage I cancer, 211 (16.2%) had stage II, 386 (29.6%) had stage III, and 610 (46.8%) had stage IV cancer. Cancer cachexia patients were more likely to be male, older, have a history of smoking and drinking, have advanced tumor stage, have NRS2002 ≥ 3, ECOG grade > 1, lower BMI, calf circumference and hand grip strength, increased NLR, and decreased albumin, prealbumin, and transferrin levels. A box plot was created to compare the levels of the three nutritional markers between patients with and without cachexia in different tumor types (Fig. 1). Detailed demographic information, tumor-related characteristics, and laboratory data are presented in Table 1. There was a moderate positive correlation between albumin and transferrin (male: R = 0.46, P < 0.001; female: R = 0.38, P < 0.001) and prealbumin (male: R = 0.44, P < 0.001; female: R = 0.42, P < 0.001) levels. A weak positive correlation was observed between prealbumin and transferrin levels (male: R = 0.33, P < 0.001; female: R = 0.20, P < 0.001) (Figure S2).
Table 1
Patients baseline characteristics
Variables | All patients (n = 4091) | Cachexia patients (n = 1303) | Non-cachexia patients (n = 2788) | P value |
Age, years | 59.00(51.00–65.00) | 60.00(53.00–66.00) | 59.00(50.00–65.00) | <0.001* |
Gender (Male/Female) | 2184/1907(53.4%/46.6%) | 777/526(59.6%/40.4%) | 1407/1381(50.5%/49.5%) | <0.001* |
Diabetes(Yes/No) | 351/3740(8.6%/91.4%) | 110/1193(8.4%/91.6%) | 241/2547(8.6%/91.4%) | 0.877 |
Hypertension(Yes/No) | 732/3359(17.9%/82.1%) | 234/1069(18.0%/82.0%) | 498/2290(17.9%/82.1%) | 0.975 |
Smoking(Yes/No) | 1714/2377(41.9%/58.1%) | 600/703(46.0%/54.0%) | 1114/1674(40.0%/60.0%) | <0.001* |
Drinking(Yes/No) | 898/3193(22.0%/78.0%) | 333/970(25.6%/74.4%) | 565/2223(20.3%/79.7%) | <0.001* |
Type of cancer | | | | <0.001* |
Lung | 1370(33.5%) | 362(27.8%) | 1008(36.2%) | |
Upper gastrointestinal | 752(18.4%) | 381(29.2%) | 371(13.3%) | |
Hepatobiliary and pancreatic | 181(4.4%) | 112(8.6%) | 69(2.5%) | |
Colorectal | 634(15.5%) | 250(19.2%) | 384(13.8%) | |
Breast | 690(16.9%) | 63(4.8%) | 627(22.5%) | |
Others | 464(11.3%) | 135(10.4%) | 329(11.8%) | |
TNM stages | | | | <0.001* |
Ⅰ | 417(10.2%) | 96(7.4%) | 321(11.5%) | |
Ⅱ | 842(20.6%) | 211(16.2%) | 631(22.6%) | |
Ⅲ | 1151(28.1%) | 386(29.6%) | 765(27.4%) | |
Ⅳ | 1681(41.1%) | 610(46.8%) | 1071(38.4%) | |
Surgery(Yes/No) | 2021/2070(49.4%/50.6%) | 647/656(49.7%/50.3%) | 1374/1414(49.3%/50.7%) | 0.851 |
Radiotherapy(Yes/No) | 507/3584(12.4%/87.6%) | 149/1154(11.4%/88.6%) | 358/2430(12.8%/87.2%) | 0.222 |
Chemotherapy(Yes/No) | 2516/1575(61.5%/38.5%) | 731/572(56.1%/43.9%) | 1785/1003(64.0%/36.0%) | <0.001* |
NRS2002(<3/≥3) | 2987/1104(73.0%/27.0%) | 504/799(38.7%/61.3%) | 2483/305(89.1%/10.9%) | <0.001* |
ECOG grade(≤ 1/>1) | 2063/2028(50.4%/49.6%) | 526/777(40.4%/59.6%) | 1537/1251(55.1%/44.9%) | <0.001* |
Body mass index, kg/m² | 22.58(20.20-24.82) | 20.40(18.55–22.89) | 23.37(21.23–25.46) | <0.001* |
Calf circumference, cm | 33.50(31.00–36.00) | 32.00(30.00-34.35) | 34.00(32.00-36.50) | <0.001* |
Hand grip strength, kg | 24.80(19.00-31.07) | 23.60(18.00-30.15) | 25.15(19.60–31.60) | <0.001* |
Neutrophil to lymphocyte ratio (NLR) | 2.36(1.58–3.75) | 2.74(1.68–4.60) | 2.24(1.54–3.42) | <0.001* |
Albumin, g/L | 40.00(36.60–42.90) | 38.60(34.90–42.10) | 40.50(37.40–43.40) | <0.001* |
Prealbumin, g/L | 0.22(0.17–0.26) | 0.20(0.15–0.24) | 0.23(0.18–0.27) | <0.001* |
Transferrin, g/L | 2.27(1.89–2.67) | 2.13(1.75–2.54) | 2.33(1.96–2.73) | <0.001* |
Abbreviations: TNM, tumor/node/metastasis; NRS 2002, Nutrition Risk Screen 2002; ECOG, Eastern Cooperative Oncology Group. |
Comparison between albumin, prealbumin and transferrin in predicting survival
During a median follow-up of 20.23 months, we recorded a total of 592 deaths in patients with cancer cachexia. The C-index for OS was the highest for albumin (0.608, IQR [0.584–0.633]), followed by transferrin (0.595, IQR [0.571–0.619]) and prealbumin (0.572, IQR [0.546–0.597]) (Table S1). The time-dependent ROC curve showed a similar trend: the 1-year AUC of albumin, transferrin, and prealbumin were 0.650, 0.633, and 0.600, respectively; and the 3-year AUC of albumin, transferrin, and prealbumin were 0.615, 0.598, and 0.571, respectively (Fig. 2).
Restricted cubic spline plots showed an association between serum nutritional markers and the HR for all-cause mortality in cancer patients with cachexia (Fig. 3). The risk of cancer-related mortality increased as serum albumin and transferrin levels decreased, with adjusted P values of 0.015 and 0.018, respectively. After adjusting for confounding factors, a significant nonlinear correlation was observed between prealbumin and mortality (P = 0.012). The optimal cutoff value of albumin, prealbumin, and transferrin for cancer cachexia patients in our study was 38.7 g/L, 0.17 g/L, and 2.29 g/L, respectively, as calculated by standardized log-rank statistics (Figure S3).
Survival analysis of albumin, prealbumin, and transferrin in cancer cachexia patients
Kaplan-Meier curves showed that patients in the low albumin, prealbumin, and transferrin groups had markedly poorer prognoses than those in the high serum nutritional marker group (Fig. 4). After adjusting for age, sex, smoking, drinking, BMI, HGS, CC, tumor type, tumor stage, surgery, chemotherapy, NRS2002, ECOG grade, and NLR, multivariate Cox proportional risk regression analysis showed that low albumin (HR = 1.55, 95%CI = 1.31–1.84, P < 0.001), prealbumin (HR = 1.33, 95%CI = 1.11–1.59, P = 0.002), and transferrin (HR = 1.46, 95%CI = 1.22–1.74, P < 0.001) were independent risk factors for prognosis (Table 2). We also performed two sensitivity analyses to confirm the prognostic value in patients with cachexia (Figure S4). First, we excluded 88 patients with liver diseases such as chronic hepatitis, cirrhosis, and liver cancer. Low albumin (adjusted HR = 1.54, 95%CI [1.30–1.84], P < 0.001), prealbumin (adjusted HR = 1.25, 95%CI [1.04–1.51], P = 0.016), and transferrin (adjusted HR = 1.51, 95%CI [1.26–1.82], P < 0.001) levels were still associated with shorter OS and were independently unfavorable factors for prognosis. Secondly, 175 patients who died within 6 months after the beginning of this study were also excluded, the overall result was unchanged, with adjusted HR of albumin, prealbumin and transferrin of 1.41 (95%CI [1.17–1.71], P < 0.001), 1.28 (95%CI [1.04–1.57], P = 0.019) and 1.36 (95%CI [1.11–1.66], P = 0.003).
Table 2
Cox proportional hazard regression analyses of albumin, prealbumin and transferrin
Groups | No. of patients | Crude model | | Adjusted Model * | | Adjusted Model** |
HR(95%CI) | P-value | | HR(95%CI) | P-value | | HR(95%CI) | P-value |
Albumin | | | | | | | | | |
By per SD | | 1.34(1.25–1.45) | <0.001* | | 1.24(1.15–1.34) | <0.001* | | 1.19(1.09–1.29) | <0.001* |
≥38.7g/L | 650 | Reference | | | Reference | | | Reference | |
<38.7g/L | 653 | 1.87(1.59–2.20) | <0.001* | | 1.61(1.37–1.91) | <0.001* | | 1.55(1.31–1.84) | <0.001* |
Prealbumin | | | | | | | | | |
By per SD | | 1.21(1.11–1.31) | <0.001* | | 1.18(1.08–1.28) | <0.001* | | 1.12(1.03–1.22) | 0.011* |
≥0.17g/L | 846 | Reference | | | Reference | | | Reference | |
<0.17g/L | 457 | 1.58(1.35–1.86) | <0.001* | | 1.40(1.19–1.66) | <0.001* | | 1.33(1.11–1.59) | 0.002* |
Transferrin | | | | | | | | | |
By per SD | | 1.30(1.20–1.42) | <0.001* | | 1.16(1.07–1.27) | <0.001* | | 1.13(1.04–1.24) | 0.006* |
≥2.29g/L | 527 | Reference | | | Reference | | | Reference | |
<2.29g/L | 776 | 1.73(1.46–2.05) | <0.001* | | 1.49(1.25–1.77) | <0.001* | | 1.46(1.22–1.74) | <0.001* |
Abbreviation: HR, hazard ratio; CI, confidence interval; SD, standard deviation . |
*Adjusted for age, sex, tumor type and TNM stage. |
**Adjusted for variables found significant at P < 0.05 in the univariate analyses, including age, sex, drinking, smoking, tumor type, TNM stage, surgery, chemotherapy, NRS2002, ECOG, BMI, HGS, CC and NLR. |
Subgroup analysis
We performed subgroup analyses based on various clinicopathological characteristics including age, sex, tumor type, TNM stage and ECOG grade (Fig. 5). Low albumin and prealbumin levels were independent risk factors for survival in all age, sex, and ECOG grade groups. However, the prognostic performance of transferrin in patients aged 65 years was not statistically significant. Low albumin levels were associated with high-risk mortality in patients with upper gastrointestinal cancer, hepatobiliary and pancreatic cancer, and colorectal cancer. The predictive ability of low prealbumin levels for survival was significant in patients with colorectal cancer. Low transferrin levels were confirmed as a prognostic predictor in patients with upper gastrointestinal cancer and colorectal cancer. Notably, the prognostic value of the three nutritional markers was significant in patients with advanced TNM stage (stage III and IV).
Association between nutritional markers with short-term survival and QoL
We performed a multivariate logistic regression analysis to investigate the impact of serum nutritional markers on short-term survival. As the values of albumin and transferrin decreased per standard deviation, the risk of mortality within 90 days rose to 1.87 (95%CI = 1.50–2.35, P < 0.001) and 1.55 (95%CI = 1.19–2.05, P = 0.001), respectively, after adjusting for confounding factors (Table 3). A similar trend was observed for prealbumin; however, it was not statistically significant as a continuous variable. When classified by cut-off value, we found that low albumin (OR = 3.90, 95%CI = 2.27–7.06, P < 0.001), prealbumin (OR = 1.63, 95%CI = 1.01–2.64, P = 0.044), and transferrin (OR = 1.98, 95%CI = 1.17–3.48, P = 0.013) were all independent risk factors for short-term survival. Moreover, patients with low levels of serum nutritional markers were more likely to have poorer QoL (Table S2). The median summary score of QoL in the low albumin population was 83.72 (IQR [70.94–92.78]), notably lower than that in patients with high albumin (88.35, IQR [77.46–95.90], P < 0.001). Low transferrin level was also an adverse factor of QoL, with a summary score of 84.62 in the low transferrin group and 87.78 in the high transferrin group (P = 0.002). Similarly, patients with low prealbumin levels had significantly poorer QoL than those with high prealbumin levels. Notably, prealbumin had an effective stratification value in each domain of the QLQ-C3 in patients with cancer cachexia.
Table 3
Logistic regression analyses of nutritional marker associated with short-term survival
Groups | No. of patients | Crude model | | Adjusted Model * | | Adjusted Model** |
OR(95%CI) | P-value | | OR(95%CI) | P-value | | OR(95%CI) | P-value |
Albumin | | | | | | | | | |
By per SD | | 1.92(1.56–2.37) | <0.001* | | 1.90(1.54–2.37) | <0.001* | | 1.87(1.50–2.35) | <0.001* |
≥38.7g/L | 650 | Reference | | | Reference | | | Reference | |
<38.7g/L | 653 | 4.19(2.49–7.44) | <0.001* | | 4.18(2.44–7.53) | <0.001* | | 3.90(2.27–7.06) | <0.001* |
Prealbumin | | | | | | | | | |
By per SD | | 1.18(0.94–1.49) | 0.149 | | 1.14(0.91–1.45) | 0.261 | | 1.10(0.88–1.38) | 0.424 |
≥0.17g/L | 846 | Reference | | | Reference | | | Reference | |
<0.17g/L | 457 | 1.89(1.21–2.95) | 0.005* | | 1.81(1.14–2.89) | 0.012* | | 1.63(1.01–2.64) | 0.044* |
Transferrin | | | | | | | | | |
By per SD | | 1.61(1.26–2.08) | <0.001* | | 1.56(1.21–2.03) | <0.001* | | 1.55(1.19–2.05) | 0.001* |
≥2.29g/L | 527 | Reference | | | Reference | | | Reference | |
<2.29g/L | 776 | 2.24(1.36–3.84) | 0.002* | | 2.10(1.25–3.66) | 0.006* | | 1.98(1.17–3.48) | 0.013* |
Abbreviation: OR, odds ratio; CI, confidence interval; SD, standard deviation. |
*Adjusted for age, sex, tumor type and TNM stage. |
**Adjusted for age, sex, drinking, smoking, tumor type, TNM stage, surgery, chemotherapy, NRS2002, ECOG. |