Key words
geriatric nutritional risk index - non-small cell lung cancer - survival - predict - meta-analysis
Introduction
Currently, lung cancer has become the leading cause of cancer-related mortality of
global population, and more than 1.7 million people died of lung cancer in each year
[1]
[2]. Pathologically, lung cancer could be classified as small cell lung
cancer and non-small cell lung cancer (NSCLC), and the latter accounts for about
85% of all the patients with lung cancer [3]. Current treatment for patients with NSCLC involves multiple
anticancer modalities such as surgical resection, chemotherapy, radiotherapy,
targeted therapy, and immunotherapy [3].
However, survival of patients with NSCLC remains poor, particularly for patients
with advanced NSCLC, which highlights the importance of prognostic evaluation for
these patients [4].
Accumulating evidence suggests that pretreatment nutritional status is an important
determinant of survival in patients with various malignancies [5]. Indeed, surgeries and chemotherapy are more
likely to be tolerated in patients with good pretreatment nutritional status [6]
[7].
Besides, nutritional and inflammatory status may also affect the responses of
patients to immunotherapies [8]. Collectively,
it has been suggested that malnutrition negatively affects several aspects of cancer
treatment and outcome, which involve reducing the intensity of treatment, increasing
its toxicities, impairing quality of life, and ultimately worsening survival [9]. Geriatric nutritional risk index (GNRI) is
a newly developed indicator of nutritional status which is calculated by serum
albumin concentration and ideal body weight [10]. Compared to other scoring systems for nutritional analysis such as
the malnutrition inflammation score [11], the
P-POSSUM score [12], the subjective global
assessment [13], the Mini Nutritional
Assessment (MNA) [14], and the Nutritional
Risk Score 2002 (NRS-2002) [15], the GNRI is a
simple, objective, and less time-consuming tool, which could also be readily
determined from routinely collected laboratory data. Previous studies showed that
GNRI may be a prognostic factor of patients with various malignancies, such as those
with esophageal cancer [16] and renal cell
carcinomas [17]. However, the influences of
GNRI on survival outcomes in patients with NSCLC remain to be determined. Moreover,
it remains unknown whether differences in anticancer treatments may affect the
potential association between GNRI and survival outcomes of NSCLC patients.
Therefore, we performed a meta-analysis to systematically evaluate the prognostic
role of GNRI in patients with NSCLC.
Materials and Methods
The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA)
statement [18]
[19] was followed in conceiving, conducting, and reporting of the study,
and the methodology of the meta-analysis was in accordance with the recommendations
of the Cochrane’s Handbook [20]
guideline.
Literature retrieving
Studies that evaluated the association between GNRI and survival in patients with
NSCLC were retrieved by search of the electronic database including PubMed,
Embase, and Web of Science, from inception of the databases to January 12, 2022.
A search strategy with combined search terms were used, and listed as
(“geriatric nutritional risk index” OR “GNRI”)
AND “lung” AND (“neoplasms” OR
“carcinoma” OR “cancer” OR
“tumor” OR “malignancy” OR
“adenoma”). Only human studies published as full-length articles
were considered. No restriction was applied regarding the language of
publication. As a supplementation, we manually checked the citations of the
relevant original and review articles for possible relevant studies.
Study selection
The PICOS criteria were used to determine the inclusion criteria of the
meta-analysis.
P (patients): Adult patients with NSCLC, regardless of the cancer stage or
treatments;
I (exposure): patients with malnutrition as evidenced by the lower GNRI at
baseline;
C (control): patients without malnutrition as evidenced by the higher GNRI
at baseline. GNRI was as previously defined: GNRI=[1.489 × serum
albumin (g/dl)]+[41.7 × actual weight/ideal
weight] [10]. Ideal weight was calculated
using body mass index (BMI): ideal weight=22×[height
(m)2] The cutoffs for defining of patients with higher versus
lower GNRI were in accordance with the values applied in the original
studies.
O (outcomes): the primary outcome was overall survival (OS), and the
secondary outcomes were progression-free survival (PFS) and cancer-specific
survival (CSS), compared between NSCLC patients with lower versus higher GNRI.
Generally, OS was defined as the time elapsed from treatment and to the date of
death from any cause, PFS was defined as the interval between initiation of the
treatment and the first recurrence or progression event, and CSS was defined as
the time elapsed from initiation of the treatment to the date of lung cancer
related-death [21]
[22].
S (study design): cohort studies, including prospective and retrospective
cohorts.
Reviews, preclinical studies, studies including non-NSCLC patients, studies that
did not evaluate GNRI, or studies that did not report the survival outcomes were
removed.
Data collection and quality assessment
Two independent authors conducted literature search and analysis, data
collection, and study quality assessment separately. If discrepancies occurred,
the corresponding author joined the discussion for reaching a final consensus.
Data regarding study information, patient demographic factors, cancer stage and
treatment, GNRI cutoffs, and outcomes reported were collected. Study quality
assessment was achieved via the Newcastle-Ottawa Scale [23] with scoring systems on the basis of
participant selection, comparability of the groups, and the validity of the
outcomes. The scale ranged between 1–9 stars, with more stars presenting
higher study quality.
Statistical analyses
The main objective of the meta-analysis was to determine the relative risk for
OS, PFS, and CSS between NSCLC patients with higher versus lower GNRI at
baseline. The relative risks for the outcomes were presented as hazard ratios
(HRs) and confidence intervals (CIs). Using the 95% CIs or p-values,
data of HRs and the standard errors (SEs) were calculated, and a subsequent
logarithmical transformation was conducted to keep stabilized variance and
normalized distribution. Between study heterogeneity was estimated using the
Cochrane’s Q test and the I2 statistic [24]. An I2>50%
suggests significant heterogeneity. A random-effect model was applied to combine
the results by incorporating the influence of heterogeneity [20]. Sensitivity analyses which omitted one
study at a time was performed to evaluate the influence of individual study on
the results of the overall meta-analysis [25]. For primary outcome of OS, subgroup analyses were also performed
to explore the influences of various study characteristics on the outcome. By
construction of the funnel plots, the publication bias of the meta-analysis was
estimated based on the visual judgement of the symmetry of the plots,
supplemented with the Egger’s regression asymmetry test [26]. The RevMan (Version 5.1; Cochrane
Collaboration, Oxford, UK) and Stata (Version 17.0; Stata Corporation, College
Station, TX, USA) software packages were applied for the statistical
analyses.
Results
Studies obtained
[Fig. 1] shows the process of literature
analysis. In brief, the initial search of the databases retrieved 613 articles
after removing of the duplicated records. Then, additional 590 articles were
excluded via screening of the titles and abstracts because they were not
relevant to the meta-analysis. A total of 23 studies underwent the full-text
review. After excluding 12 studies through full-text review, 11 cohort studies
[27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
[36]
[37] were included. Reasons for removing of the 12 studies are also
presented in [Fig. 1].
Fig. 1 Summarized process of literature search and study
retrieving.
Characteristics of the included studies
As shown in [Table 1], 11 cohort studies
[27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
[36]
[37] involving 2865 patients with NSCLC contributed to the
meta-analysis. Two of them were prospective [33]
[37], while the remaining
studies were retrospective [27]
[28]
[29]
[30]
[31]
[32]
[34]
[35]
[36]. These studies were published between 2017 and 2022, and
performed in Japan [27]
[28]
[29]
[30]
[31]
[32]
[34]
[35]
[37] and China [33]
[36]. The cancer stage of the included
patients varied from stage I to stage IV, and the treatments included surgical
resection, chemotherapy, and immunotherapy. The cutoffs for defining of the
lower versus higher GNRI were also varied among the included studies. All of the
11 cohort studies [27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
[36]
[37] reported the outcome of OS, seven [27]
[30]
[31]
[32]
[34]
[35]
[37] reported PFS, and two studies [27]
[29] reported CSS. Multivariate analyses were applied to analyze the
association between GNRI and survival of NSCLC in all of the included studies,
and confounding factors including age, sex, performance status, cancer
histological type, stage, and treatment etc. were adjusted among the original
studies. The NOS of the included studies were 8 to 9 stars, suggesting generally
good study quality ([Table 2]).
Table 1 Characteristics of the included cohort
studies.
Study [Ref]
|
Country
|
Design
|
Sample size
|
Mean age (years)
|
Men (%)
|
Cancer stage
|
Treatment
|
GNRI cutoff
|
Median follow-up (months)
|
Outcomes reported
|
Variables adjusted
|
Shoji 2017a [27]
|
Japan
|
RC
|
141
|
68
|
43.3
|
I
|
Surgery
|
<98 vs.≥98
|
58
|
OS, PFS, CSS
|
Age, sex, smoking, tumor biomarkers, tumor size, histological
type, procedure and chemotherapy
|
Shoji 2017b [28]
|
Japan
|
RC
|
272
|
78
|
57
|
I–III
|
Surgery
|
<98 vs.≥98
|
51
|
OS
|
Age, sex, smoking, stage, histological type, and
procedures
|
Hino 2020 [29]
|
Japan
|
RC
|
739
|
70
|
61.6
|
I–III
|
Surgery
|
<98 vs.≥98
|
41
|
OS
|
Age, sex, BMI, pulmonary function, CCI, tumor stage,
histological type, and procedure
|
Asakawa 2021 [30]
|
Japan
|
RC
|
286
|
NR
|
63.1
|
I–IIA
|
Surgery
|
<102 vs.≥111 (Q4 vs. Q1)
|
>60 months
|
OS and PFS
|
Age, sex, BMI, complication, tumor stage, histological type,
pulmonary function, surgery and smoking status
|
Karayama 2021 [31]
|
Japan
|
RC
|
148
|
65
|
73.6
|
IIIB–IV
|
Platinum-based chemotherapy
|
<92 vs.≥92
|
24
|
OS and PFS
|
Age, sex, smoking, PS, CCI, histological type, and tumor
stage
|
Takahashi 2021 [35]
|
Japan
|
RC
|
475
|
70
|
62.1
|
I–III
|
Surgery
|
<101 vs.≥101 (ROC derived)
|
46
|
OS and PFS
|
Age, sex, smoking, tumor biomarkers, and procedure
|
Matsuura 2021 [32]
|
Japan
|
RC
|
160
|
70
|
85.6
|
IIIC–IV
|
Chemotherapy and/or immunotherapy
|
<93.6 vs.≥93.6 (ROC derived)
|
28
|
OS and PFS
|
Age, sex, smoking, PS, tumor stage, and first-line
therapy
|
Peng 2021 [33]
|
China
|
PC
|
257
|
62.6
|
61.9
|
IIIB–IV
|
Chemotherapy or supportive care
|
<92 vs.≥98
|
28
|
OS
|
Age, sex, smoking, BMI, comorbidities, histological type,
tumor stage, and therapy
|
Tang 2021 [36]
|
China
|
RC
|
144
|
NR
|
53.5
|
IV
|
Chemotherapy or supportive care
|
<97 vs.≥97 (ROC derived)
|
17
|
OS
|
Age, sex, BMI, metastatic status, EGFR mutation, and PS
|
Sonehara 2021 [34]
|
Japan
|
RC
|
85
|
NR
|
80
|
IIIB–IV
|
Immunotherapy
|
<89.5 vs.≥89.5 (ROC derived)
|
20
|
OS and PFS
|
Age, sex, PS, smoking, and lines of chemotherapy
|
Karayama 2022 [37]
|
Japan
|
PC
|
158
|
69
|
81.6
|
IIIB–IV
|
Immunotherapy
|
<92 vs.≥98
|
24
|
OS and PFS
|
Age, sex, smoking, PS, histological type, tumor stage, PD-LI
expression, and treatment line
|
GNRI: Geriatric nutritional risk index; RC: Retrospective cohort; PC:
Prospective cohort; NR: Not reported; Q: Quartile; ROC: Receiver
Operating Characteristic Curve; OS: Overall survival; PFS:
Progression-free survival; CSS: Cancer-specific survival; BMI: Body mass
index; CCI: Charlson Comorbidity Index; PS: Performance status; EGFR:
Epidermal growth factor receptor; PD-L1: Programmed cell death ligand
1.
Table 2 Details of study quality evaluation via the
Newcastle-Ottawa Scale.
Study [Ref]
|
Representativeness of the exposed cohort
|
Selection of the non-exposed cohort
|
Ascertainment of exposure
|
Outcome not present at baseline
|
Control for age
|
Control for other confounding factors
|
Assessment of outcome
|
Enough long follow-up duration
|
Adequacy of follow-up of cohorts
|
Total
|
Shoji 2017a [27]
|
0
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
8
|
Shoji 2017b [28]
|
0
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
8
|
Hino 2020 [29]
|
0
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
8
|
Asakawa 2021 [30]
|
0
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
8
|
Karayama 2021 [31]
|
0
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
8
|
Takahashi 2021 [35]
|
0
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
8
|
Matsuura 2021 [32]
|
0
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
8
|
Peng 2021 [33]
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
9
|
Tang 2021 [36]
|
0
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
8
|
Sonehara 2021 [34]
|
0
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
8
|
Karayama 2022 [37]
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
1
|
9
|
Meta-analysis results
Pooled results with 11 cohort studies [27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
[36]
[37] showed that compared to
those with higher GNRI, NSCLC patients with lower GNRI had poorer OS (HR: 2.39,
95% CI: 1.97 to 2.91, p<0.001; [Fig. 2a]) with moderate heterogeneity
(I2=29%). Subsequent sensitivity analysis by
excluding one study at a time did not significantly change the results (HR: 2.26
to 2.51, p all<0.05). Subgroup analyses showed that the association
between lower GNRI and worse OS in patients with NSCLC was not affected by study
characteristics including study location, design, cancer stage, treatment, or
follow-up durations (p for subgroup effects all<0.001; [Table 3]). Further meta-analyses with
seven [27]
[30]
[31]
[32]
[34]
[35]
[37] and two studies [27]
[29] showed that NSCLC patients with lower GNRI also had poorer PFS
(HR: 1.94, 95% CI: 1.52 to 2.47, p<0.001;
I2=29%; [Fig.
2b]) and CSS (HR: 2.59, 95% CI: 1.55 to 4.35, p<0.001;
I2=0%; [Fig.
2c]).
Fig. 2 Forest plots for the meta-analysis of the association
between GNRI and survival in patients with NSCLC. a: forest plots
for the association between GNRI and OS; b: forest plots for the
association between GNRI and PFS; and c: forest plots for the
association between GNRI and CSS.
Table 3 Results of subgroup analyses for the association
between GNRI and OS.
Study characteristics
|
Datasets number
|
HR (95% CI)
|
I2
|
p for subgroup effect
|
p for subgroup difference
|
Country
|
|
|
|
|
|
China
|
2
|
2.57 [1.76, 3.76]
|
7%
|
<0.001
|
|
Japan
|
9
|
2.36 [1.86, 2.98]
|
38%
|
<0.001
|
0.70
|
Design
|
|
|
|
|
|
PC
|
2
|
3.52 [2.23, 5.54]
|
0%
|
<0.001
|
|
RC
|
9
|
2.24 [1.82, 2.74]
|
25%
|
<0.001
|
0.07
|
Cancer stage
|
|
|
|
|
|
I–III
|
5
|
2.57 [1.76, 3.75]
|
53%
|
<0.001
|
|
III–IV
|
6
|
2.26 [1.81, 2.83]
|
6%
|
<0.001
|
0.58
|
Treatment
|
|
|
|
|
|
Surgery
|
5
|
2.57 [1.76, 3.75]
|
53%
|
<0.001
|
|
Chemotherapy
|
3
|
2.36 [1.74, 3.19]
|
0%
|
<0.001
|
|
Immunotherapy
|
3
|
2.24 [1.47, 3.43]
|
42%
|
<0.001
|
0.89
|
Follow-up duration
|
|
|
|
|
|
≤24 months
|
4
|
2.31 [1.75, 3.04]
|
0%
|
<0.001
|
|
>24 months
|
7
|
2.47 [1.85, 3.30]
|
48%
|
<0.001
|
0.73
|
GNRI: Geriatric nutritional risk index; OS: Overall survival; HR: Hazard
ratio; CI: Confidence interval; PC:Prospective cohort; RC: Retrospective
cohort.
Publication bias
[Fig. 3a] and [3b] display the funnel plots for the
outcomes of OS and PFS. Visual inspection showed symmetry of the plots,
suggesting low risks of publication biases. The Egger’s regression tests
also indicated low risk of publication biases (p=0.28 and 0.19,
respectively). Publication bias regarding the meta-analysis for CSS was
difficult to estimate because only two studies were included.
Fig. 3 Funnel plots for the publication bias underlying the
meta-analyses. a: funnel plots for the meta-analysis of OS; and
b: funnel plots for the meta-analysis of PFS.
Discussion
The GNRI was first proposed by Bouillanne et al. in 2005 [10] and validated as a reliable prognostic
nutritional index for elderly patients with various clinical conditions, such as
those admitted to a geriatric rehabilitation care unit [10], with acute ischemic stroke [38], heart failure [39], respiratory failure [40], after emergency surgeries [41]. Further studies in oncology showed that
GNRI may also be applied as an effective prognostic index in patients with various
malignancies, which was also not limited to elderly patients [42]. In this meta-analysis, we pooled the
results of eleven cohort studies including patients with NSCLC, and the results
showed that a lower GNRI at baseline was associated with poor OS, PFS, and CSS in
these patients. The association between lower GNRI and poor OS in patients with
NSCLC was consistent in sensitivity analysis by excluding one study at a time,
suggesting that the association was not primarily driven by either of the included
study. Further subgroup analysis showed that the significant association between
lower GNRI and worse OS in patients with NSCLC was not affected by study
characteristics including study location, design, cancer stage, treatment, or
follow-up durations. Moreover, since multivariate model was applied in all of the
included studies after adjustment of the demographic factors and characteristics of
cancers, the findings are likely to indicate that a lower GNRI at baseline is an
independent risk factor of poor survival in patients with NSCLC.
Although several meta-analyses have evaluated the role of GNRI as a prognostic factor
for patients with various malignancies [42],
meta-analysis focusing on patients with NSCLC is rare. This is necessary because the
course and the treatment of the malignancy could be very different in patients with
different cancers, which may cause significant heterogeneity. During the preparation
of our manuscript, two mea-analyses regarding the association between GNRI and
outcomes of patients with lung cancer were published [43]
[44].
One study included eight retrospective cohort studies in NSCLC patients and showed
that GNRI may be a prognostic factor of NSCLC [43]. However, probably due to the relative number of studies included, no
subgroup analyses were performed according to the therapy of the patients (surgery,
chemotherapy, or immunotherapy) [43]. The
other meta-analysis included patients with NSCLC and SCLC [44]. As mentioned previously, the differences
in the disease course and treatments of the two subtypes of lung cancer may affect
the association between GNRI and outcomes of the patients [44]. In our study, a lower GNRI has been
related to a poor survival in patients with NSCLC, and subgroup analysis showed
consistent association in patients after surgical resection, and in those treated
with chemotherapy or immunotherapy. Clinically, GNRI could be conveniently
calculated based on the serum albumin, height, and body weight of the patients,
which is highly practicable in real-world clinical practice.
Currently, the mechanisms underlying the association between GNRI and survival in
patients with NSCLC may be explained by the roles of the components of the
parameters in patients with cancers. Both serum albumin [45] and body weight [46] has been recognized as possible predictive
factors for poor survival in patients with cancer. Biologically, albumin plays key
roles in maintaining osmotic pressure [47],
delivering bioactive anticancer molecules [48], inhibition of overactivated inflammation [49], modulation of immune response [50], and anti-oxidative stress [51], all of which are important for the
exerting the anticancer efficacies of the body and various treatments. On the other
hand, the obesity paradox, which implies that ideal or high body weight may be
associated with survival benefits in patients with cancer, has also been observed in
patients with NSCLC [52]. Although the
mechanisms remain to be clarified, an ideal or high body weight of a patient with
cancer may reflect that the cancer is less invasive than those who are underweight.
In addition, multiple anticancer treatments may be more tolerable to cancer patients
with ideal or high body weight, which may also explain the better survival in these
patients [52].
Collectively, results of the meta-analysis support that GNRI is a reliable prognostic
parameter in patients with NSCLC, which may be useful in risk stratification and
prognosis evaluation in these patients. Additionally, the results indicate that
nutritional support is also essential as a direct consequence of malnutrition
assessments. If it is determined that patients have a low GNRI, nutritional support
should be provided immediately. In fact, early nutritional support has been
recommended as a complementary treatment to active treatment in cancer patients
[53]
[54]. It has been shown that adequate nutritional support can positively
influence tolerance to therapies, continuity of treatment, quality of life, and
survival outcomes [55].
The limitations of the study include the following. First, all the studies were from
Japan and China, and results of the meta-analysis should be validated in studies
from other countries. In addition, the optimal cutoff value for the predictive
efficacy of GNRI in patients with NSCLC remains to be determined, and a
dose-response relationship between GNRI and NSCLC remains to be established. Large
prospective cohort studies are needed in this regard. Besides, only studies
published as full-length articles were included in the meta-analysis. Grey
literatures, such as conference abstracts and unpublished data were not considered
because these literatures were generally not peer-reviewed, and including these
studies may impair the reliability of the findings. However, excluding these grey
literatures may increase the risk of publication bias. Moreover, GNRI was only
evaluated for once among the included studies. Studies may be considered in the
future to determine whether repeated evaluation via GNRI could improve the
prognostic efficacy of the parameter in patients with NSCLC. Finally, as a
meta-analysis of observational studies, we could not exclude other factors that may
affect the association between GNRI and survival outcomes in patients with NSCLC,
such as some dietary or nutritional interventions that may affect serum albumin.
Conclusions
To sum up, results of the meta-analysis suggest that a lower GNRI at baseline may be
an independent predictor of poor survival in patients with NSCLC. Considering the
cost-effectiveness of the parameter, nutritional status indicated by GNRI may be
practical and important for the prognostic evaluation for patients with NSCLC.