INTRODUCTION
Gastrointestinal stromal tumors (GISTs), a rare type of tumor, are the
most frequent mesenchymal tumors arising from gastrointestinal
tract1. GISTs may occur anywhere in the digestive
tract and even outside the gastrointestinal tract occasionally, with the
stomach accounting for 60% and the small intestine
30%2. The morphology, immunohistochemistry, and
molecular markers are helpful to the diagnosis of GISTs. Surgical
resection is the standard treatment for resectable
GISTs3. Nowadays, novel small molecular tyrosine
kinase inhibitors, such as imatinib and sunitinib, have revolutionized
the integrated treatment of GISTs and greatly improved the long-term
prognosis of patients4.
Currently, some GIST-specific parameters based on postoperative
pathologies, such as tumor size, primary tumor location, mitotic index,
and tumor rupture, have been used to stratify the risk of recurrence for
GISTs2,5-7. Meanwhile, the recent effort has shed
light on the role of preoperative cancer-related inflammation and
nutrition status in cancer progression, such as gastric
cancer8, colorectal cancer9,
non-small lung cancer10, and gastrointestinal stromal
tumor11-16. Several preoperative
immuno-inflammatory-based prognostic scores, such as the preoperative
neutrophil to lymphocyte ratio (NLR), the lymphocyte to monocyte ratio
(LMR), and the platelet to lymphocyte ratio (PLR), reflect the
systematic inflammatory response, with some evidence revealing that they
are prognostic for GISTs13-17. Furthermore,
nutritional status, such as the prognostic nutritional index (PNI), has
also been shown to play an important role in GIST
progression10,11.
Recent studies have proposed a new combined index of
hemoglobin, albumin, lymphocyte, and
platelet (HALP), which is composed of hemoglobin, albumin, lymphocytes
and platelets, and can reflect systemic inflammation and nutritional
status simultaneously18. It has been reported to be
related to the prognosis of patients with pancreatic
cancer19, renal cancer20, gastric
cancer18, prostate cancer21, bladder
cancer22, esophageal cancer23 and
small cell lung cancer24. However, there are no
studies on the relationship between HALP and recurrence in GIST patients
with radical resection. Therefore, this study aimed to investigate the
prognostic value of preoperative HALP in resected GIST patients.
METHOD
Patient population
A flow diagram of the patient selection process is shown inFigure 1 . Data from consecutive,
previously untreated patients who underwent R0 resection for primary,
localized GISTs at West China Hospital between December 2008 and
December 2016 were included in this study. Patients younger than 18
years, without complete preoperative blood routine information or
medical history, with infectious diseases, WBC >10 ×
10^9/L, neutrophils > 8 × 10^9/L, or lymphocyte
> 5 × 10^9/L, with other tumors, with severe liver,
kidney, or heart diseases, with emergency surgery, and follow-up less
than 6 months were excluded. Finally, 591 GIST patients were enrolled
for the current analysis.
This study was reviewed and approved by the Ethics Committee of the West
China Hospital of Sichuan University. All patients provided written
informed consent.
Definition
RFS was defined as the time interval between the time of surgery and the
time of the first documented appearance of tumor after complete
resection. The HALP, PNI, NLR, PLR, and LMR were calculated using the
following formulas: hemoglobin level (g/L) × albumin level (g/L) ×
lymphocyte count (/L) / platelet count (/L)19, albumin
level (g/L) + 5 × lymphocyte count
(number/mm3)25, neutrophil count
(number/mm3)/ lymphocyte count
(number/mm3)15,16, platelet count
(number/mm3) / lymphocyte count
(number/mm3)14, lymphocyte count
(number/mm3) / monocyte count
(number/mm3)26, respectively.
Data collection
Clinicopathological data, postoperative treatment, and recurrence status
were recorded. The following data of each patient were retrieved from
the self-built GISTs database: demographic characteristics, tumor sites,
tumor size, mitotic index (mitosis / 50 high power field or mitosis / 50
mm2), morphology, immunohistochemistry, molecular
markers, preoperative hemoglobin, albumin, white blood cells count,
absolute neutrophil count, monocyte count, platelet count, and
lymphocyte count. Tumor risk stratification was determined based on
“the modified National Institutes of Health (NIH)
classification”27.
Perioperative Evaluation and
Follow-up
The laboratory tests were evaluated within 1 week before operation. The
parameters included complete blood cell count and serum albumin.
Abdominal ultrasonography or computed tomography was performed every 3 -
6 months in the first 3 years after operation, and then every 6 - 12
months until 5 years after the operation, and then once a year until
recurrence. The recurrence status of patients was ascertained by
December 2020.
Statistical analysis
The optimal cutoff values for the HALP, PNI, NLR, PLR, and LMR were
determined by the x-Tile analysis at 31.5, 48.6, 2.60, 134.8, and 4.0,
respectively28. PSM was performed as 1:1 matching with
nearest neighbor matching and a 0.1 caliper based on the patient’s age,
tumor size, tumor site, mitosis, Ki67, intratumoral hemorrhage,
intratumoral necrosis and postoperative targeted therapy using nearest
neighbor matching with MatchIt R package. The categorical variables are
reported as numbers (%) and quantitative variables are reported as the
means ± SD or medians (range). Statistical significance of group
comparisons was analyzed via parametric and nonparametric tests for
continuous variables and via chi-square analysis or Fisher test for
categorical variables. Survival curves of the RFS were calculated by the
Kaplan-Meier methods and compared by log-rank tests. Hazard ratios for
recurrence were calculated by Cox regression analysis. Sensitivity and
specificity HALP, PNI, NLR, LMR, and PLR were defined using time
dependent receiver operating characteristics (ROC) curves, and areas
under the curve (AUC) were detected utilizing survivalROC R
package29. All statistical analyses were performed
using SPSS Statistics version 21 (SPSS 21.0; SPSS Inc) and GraphPad
Prism version 7.0 (GraphPad Software). Statistical significance was set
at P < 0.05 as two-sided.
RESULTS
Baseline characteristics
The demographic and clinicopathological characteristics of the 591 GIST
patients were listed in Table
1 . The study population consisted of 280 (46.8%) male and 311
(53.2%) female patients. The median (range) age was 57 (21 - 86) years.
The median follow-up time was 56 months (range, 4-138). The means ± SD
for the HALP, the PNI, the NLR, the PLR, and the LMR values were 45.81 ±
33.73, 49.04 ± 5.43, 2.64 ± 1.74, 152.8 ± 84.6 and 5.13 ± 3.00,
respectively. The means ± SD of tumor size was 6.16 ± 4.87 cm. 191
tumors (32.3%) had a mitotic index of > 5/50 high-power
field. A total of 34.0% (201/691) of the GIST patients received
adjuvant therapy with imatinib or sunitinib. According to NIH risk
classification, 72 (12.2%) patients were classified as very low risk,
178 (30.1%) patients were classified as low risk, 114 (19.3%) patients
were classified as intermediate risk, and 227 (38.4%) patients were
classified as high risk. Recurrence occurred in 62 GIST patients.
Association of HALP and clinicopathological
factors
The clinicopathological characteristics between the high and low groups
of HALP were categorized and analyzed inTable 1 . Together, 229 patients were
assigned to the low HALP group and 362 patients to the high HALP group.
The results demonstrated that tumor site, tumor size, mitotic index,
Ki67, intratumoral hemorrhage, intratumoral necrosis, NIH risk category,
and adjuvant therapy were associated with HALP (all p < 0.05).
PSM analysis was further carried out to avoid confounding variables that
might interfere with the association between RFS and HALP level. After
1:1 matching, PSM analysis identified 188 pairs of GIST patients. After
PSM, HALP were still associated with gender, histologic subtypes, NLR,
PLR, LMR, and PNI, but not with other clinicopathological
characteristics (Table 1 ).
Association of clinicopathological factors and
RFS
Before PSM, tumor site, tumor size, mitotic index, Ki67, intratumoral
hemorrhage, intratumoral necrosis, NIH risk category, albumin,
neutrophils, platelets, NLR, PLR, PNI, and HALP were associated with RFS
(all P < 0.05) (Table 2 ).
RFS in GIST patients with low HALP were significantly poor than patients
with high HALP (Figure 2 ). Cox
multiple regression analysis showed that HALP was an independent
prognostic factor for RFS in GIST patients before PSM (HR=0.506, 95%
CI: 0.291-0.879, P=0.016).
After PSM, tumor site, tumor size, mitotic index, Ki67, intratumoral
hemorrhage, intratumoral necrosis, NIH risk category, albumin,
neutrophils, PNI, and HALP were still related to RFS (all P <
0.05) (Table 2 ). RFS was also
significantly poor in GIST patients with low HALP than patients with
high HALP. (Figure 2 ). Furthermore,
Cox multiple regression analysis showed that HALP was an independent
prognostic factor for RFS in GIST patients (HR=0.585, 95% CI: 0.316 -
0.972, P=0.042).
Subgroup analysis
The clinicopathological characteristics of high-risk GIST patients
between the high and low groups of HALP were categorized inTable S1 . Together, 125 patients
were assigned to the low HALP group and 102 patients to the high HALP
group. The results demonstrated that gender, Ki67, intratumoral
hemorrhage, intratumoral necrosis were associated with HALP (all p
< 0.05). Not surprisingly, patients in the low HALP group had
significantly worse survival than patients in the high HALP group
(Figure 2 ). Furthermore, Cox
multiple regression analysis indicated that HALP was an independent
prognostic factor for RFS in GIST patients (HR=0.469, 95% CI:
0.245-0.896, P=0.022) (Table S2 ).
Sensitivity analysis
As sensitivity analysis, time dependent ROC was generated for HALP, PNI,
NLR, LMR, and PLR to predict five-year RFS. According to the results,
HALP had the highest sensitivity and accuracy (AUC=0.661) in predicting
five-year RFS, while the AUC of PNI, NLR, LMR, and PLR were 0.622,
0.591, 0.505, and 0.627, respectively
(Figure 3 ).
In addition, to assess consistency of HALP prediction, Cox multiple
regression analysis in GIST patients before PSM, after PSM and in
high-risk subgroups were performed to better assess the impact of each
type of covariates on the association between HALP and RFS. In the three
models, tumor site, mitotic index, Ki67, adjuvant therapy, and HALP were
all proved as independent prognostic factors for poor RFS, but tumor
size was not in high-risk GIST patients
(Table 2 &Table S2 ).
DISCUSSION
There is growing evidence that preoperative nutritional status and
inflammatory response may be a potentially powerful predictor of the
prognosis of cancer patients. Consistent with previous research,
preoperative inflammation scores, such as NLR and PLR, were associated
with the prognosis of GIST patients before PSM and after PSM in the
present study14,16,30,31. However, LMR seemed to be
irrelevant to the RFS of GIST patients, which is different from previous
studies14. In addition, the PNI, a nutritional score
based on albumin levels and lymphocytes, was also related to RFS of GIST
patients before PSM and after PSM in present
study11,12 (Figure
S1 ).
In this study, we found that preoperative HALP was significantly
correlated with tumor site, tumor size, mitosis, Ki67, intratumoral
hemorrhage, intratumoral necrosis, NIH risk category and adjuvant
therapy. Anemia is one of the most common symptoms of GIST, which may be
caused by gastrointestinal bleeding and intratumoral
bleeding32. Additionally, since tumor cells synthesize
proteins with albumin, this will result in hypoalbuminemia in GIST
patients. As a result, it is unsurprising that HALP, which is composed
of hemoglobin and albumin, is associated with parameters indicating the
degree of malignancy in GIST.
To avoid the impact of these biases on RFS, we utilized the PSM method
to balance tumor site, tumor size, mitosis, Ki67, intratumoral
hemorrhage, intratumoral necrosis, and adjuvant therapy. After PSM,
gender, histologic subtypes, PNI, NLR, LMR, and PLR were still
associated with HALP. Importantly, there were no difference in risk
factors (tumor site, tumor size, mitosis, Ki67, NIH risk category, and
adjuvant therapy) in the low/high HALP group. Given that HALP shared the
same parameters with PNI, NLR, LMR, and PLR, their statistically
significant correlation is unsurprising. The correlation between HALP
and gender mainly attributed to the difference of hemoglobin level
between male and female patients (123.22 ± 2.08 g/L for male and 105.46
± 1.84 g/L for female, P < 0.001). Additionally, the
correlation between HALP and histologic subtypes mainly attributed to
insufficient sample size in epithelioid subgroup, where the patients of
low HALP group was 0, while patient of the high HALP group was eight.
Notably, neither gender nor histologic subtype was associated with
recurrence (Table S1 ). Subgroup
analysis based on gender demonstrated that a low level of HALP was
associated with recurrence in female patients but not in male patients.
However, there was still a trend of poor prognosis in male patients with
lower HALP (Figure S2 ). The reason
for this phenomenon might be the insufficient sample size, but further
research was needed.
Finally, consistent with previous research on HALP in other
tumor18-24, our findings revealed prognostic value of
HALP in GIST. HALP was an independent risk factor for GIST patients
before PSM, after PSM, and in high-risk subgroups. GIST patients with
low HALP before PSM, after PSM, and in high-risk subgroups all had a
poor prognosis. Thus, HALP can be used not only to evaluate the
postoperative risk classification of GIST patients prior to surgery, but
also to assess their prognosis. Notably, the HALP index can be
conveniently and inexpensively applied to predict the prognosis of
patients.
Although the underlying mechanism of systemic inflammation in
tumorigenesis, progression and metastasis remains obscure, there are
some theories that it stimulates angiogenesis, immunosuppression and the
formation of supporting microenvironment. It is well known that
lymphocytes play an important role in inhibiting tumor
growth33-35. A higher lymphocyte signature was
associated with improved prognosis in a variety of
tumors35. Whereas, platelets could infiltrate into the
tumor microenvironment and interact with cancer cells directly, helping
circulating tumor cell attach to endothelial cells and providing signals
to establish a niche environment before
metastasis36-42
Zheng-Yang Yang et al. found that GIST with gastrointestinal bleeding
was independent prognostic predictors for poor RFS43.
Some studies have shown that low hemoglobin can lead to tumor hypoxia,
which has a higher risk of local failure and distant
metastasis31,44. Furthermore, a hypoxic tumor
environment could induce limited accumulation of drugs and hinder the
efficacy of drugs45. Additionally, one of the primary
adverse effects of imatinib is anemia46, which may be
prevented by a normal preoperative hemoglobin levels, thus improving
imatinib treatment compliance.
Low levels of serum albumin were also associated with poor long-term
survival in GIST patients44,45, which was consistent
with our findings. Serum albumin is generally considered to be
associated with nutritional status and liver or renal function, both of
which may affect patients’ compliance with imatinib therapy, similar to
hemoglobin. Moreover, about 95% of imatinib is bound to serum proteins,
mainly albumin and 1-acid glycoprotein47. Tumors
tissues have abnormal vascular endothelial gaps and lack effective
lymphatic drainage, allowing macromolecules more likely to accumulate in
the tumor tissue than normal tissue48,49. This effect
is referred to as the enhanced permeability and retention effect.
Albumin exerts this effect as a result of its unique molecular size,
which may facilitate drug accumulation in tumors and improve therapeutic
effect50.
There are some limitations to this study. Firstly, this study is a
retrospective study, so there may be biases in the process of data
collection. Secondly, our cases were collected from 2008 to 2016, during
which time imatinib has been used in the adjuvant treatment of GIST in
China. Despite the adverse reaction and higher costs, 201/591(34.0%) of
GIST patients still received adjuvant imatinib therapy. As an important
treatment after GIST, adjuvant imatinib therapy can significantly
improve the prognosis of GIST patients51, and its
benefits are also shown in present study. However, there was no adequate
collection and analysis of the time, dose and adverse reactions of
patients with imatinib or sunitinib therapy, which may be also related
to HALP. Moreover, this study also did not evaluate other
clinicopathological factors, especially gene mutation status, which also
relate to prognosis. Most importantly, nutritional status may be
associated with the economic status, which is a critical factor
influencing medication compliance and prognosis. Furthermore, the effect
of preoperative or postoperative improvement of nutritional status or
inflammation response on the prognosis of GIST remained obscure, which
needed to be further confirmed in clinical studies.
CONCLUSION
A low level of HALP was related to tumor site, tumor size, mitosis,
Ki67, NIH risk category and adjuvant therapy. A low level of HALP was
considered to be an important risk factor for RFS in GIST patients with
R0 resection.
FUNDING INFORMATION
This study was funded by the
National Natural Science Foundation of China (Grant No. 81572931) and
1.3.5 project for disciplines of excellence, West China Hospital,
Sichuan University (ZYJC18034).
CONFLICT OF INTEREST
None declared.
AUTHOR CONTRIBUTION
Zhou Zhao: wrote the manuscript and followed up.
Xiaonan Yin: collected the clinicopathological data.
Jian Wang: performed statistical analysis.
Xin Chen: collected the clinicopathological data and followed up.
Zhaolun Cai: supervised the resolved disputes in the data collection.
Bo Zhang: supervised and revised the report