Abstract
The standard treatment for gastric cancer is surgical resection and perioperative adjuvant treatment. Multidisciplinary treatment for gastric cancer leads to nutritional and inflammatory changes. Nutritional and inflammatory changes during multidisciplinary treatment can lead to poor physical activity, severe toxicity in patients receiving chemotherapy or radiation therapy, and poor oncological outcomes. Evaluation of the perioperative nutritional and inflammatory status during treatment is necessary in order to utilize and optimize multidisciplinary therapy for gastric cancer. If physicians were able to detect the perioperative nutritional and inflammatory status before and during gastric cancer treatment, they would be able to select the optimal treatment and perioperative nutritional treatment. Recently, various types of nutrition and inflammation assessment tools were developed and reported for gastric cancer. These nutrition and inflammation assessment tools have some clinical advantages, such as ease of implementation, perioperative accessibility, and low cost. On the other hand, each tool has its own clinical characteristics, which must be understood before using it in the clinical practice. This review summarizes the background, current status, and future perspectives on the application of nutrition and inflammation assessment tools in gastric cancer treatment.
An estimated 19.3 million new cancer cases and 10.0 million cancer deaths occurred worldwide in 2020 (1, 2). Among them, gastric cancer is one of the most frequent types of cancer. Curative resection and perioperative adjuvant treatment is the standard treatment for gastric cancer (3-5). Although the prognosis of patients with gastric cancer is gradually improving, more than half of patients develop recurrent disease, even after curative treatment (6, 7). Thus, in order to improve the prognosis of gastric cancer, it is necessary to identify useful prognostic factors.
Thus far, the perioperative nutritional status and the inflammatory status have been shown to affect short-term oncological outcomes, including postoperative surgical complications, continuation of adjuvant treatment, and adverse events of adjuvant treatment (8-12). In addition, the perioperative nutritional status and inflammatory status affect the long-term oncological outcomes (13, 14). The evaluation of the perioperative nutritional status and the inflammatory status during treatment is necessary for utilizing and optimizing multidisciplinary therapy for gastric cancer. If physicians were able to detect the perioperative nutritional status and inflammatory status before and during gastric cancer treatment, they would be select optimal treatment and perioperative nutritional treatment. Recently, various types of nutrition and inflammation assessment tools for patients with gastric cancer have been developed and reported. The perioperative nutritional assessment of gastric cancer has been based on changes in body composition, blood biochemistry, or a combination of both. These nutrition and inflammation assessment tools have some clinical advantages, including ease of implementation, perioperative accessibility, and low cost. On the other hand, each tool has its own clinical characteristics, therefore it is necessary to understand the characteristics of each nutrition and inflammation assessment tool before using it in clinical practice.
This review summarizes the background, current status, and future perspectives of nutrition and inflammation assessment tools for gastric cancer treatment.
Clinical Use of the Glasgow Prognostic Score and Modified Glasgow Prognostic Score in Gastric Cancer Treatment
The Glasgow Prognostic Score (GPS) was first reported by Forrest and McMillan (15). The GPS is determined from the serum C-reactive protein level (CRP) and serum albumin level. The CRP level reflects the systemic inflammation status and the albumin level reflect the nutritional status. Therefore, the GPS can assess both the inflammatory and nutritional status associated with malignancy. The GPS is determined as follows: Cases with both elevated CRP (>10 mg/l) and low albumin (<35 g/l) are scored as 2; cases with only one of these biochemical abnormalities are scored as 1; and cases with neither of these abnormalities are scored as 0. After further investigation, the GPS was modified. The mGPS is scored as follows: Cases with both elevated CRP (>10 mg/l) and low albumin (<35 g/l) are scored as 2; cases with elevated CRP are scored as 1; and cases with neither elevated CRP nor low albumin are scored as 0. A total of 17 studies have evaluated the clinical impact of the GPS/mGPS in gastric cancer. Table I summarizes each study (16-32). In previous studies, the cut-off value of the GPS/mGPS was 1 or 2. Among them, 10 studies evaluated resectable gastric cancer and seven evaluated unresectable gastric cancer. In both the resectable and unresectable settings, a high GPS/mGPS (more than 1 or 2) was associated with a poor prognosis. The hazard ratio (HR) of GPS/mGPS for overall survival (OS) was 1.042-5.07 in the resectable setting and 1.621-5.89 in the unresectable setting. In addition, two studies showed that a high GPS/mGPS was associated with the occurrence of postoperative surgical complications. Accordingly, GPS and mGPS have clinical impact in relation to both the short- and long-term oncological outcomes in gastric cancer.
Literature investigating the utility of the Glasgow Prognostic Score (GPS)/modified Glasgow Prognostic Score (mGPS) in patients with gastric cancer.
The C-Reactive Protein-to Albumin-Ratio in Gastric Cancer Treatment
The C-reactive protein to albumin ratio (CRP/Alb) is derived from laboratory tests. The CRP/Alb is determined by dividing the serum CRP level by the albumin level. CRP is an acute-phase response protein synthesized by liver cells and is one of the most sensitive indicators of inflammation. Albumin is synthesized by the liver and is the main component of human serum total protein. Albumin plays an important role in maintaining blood colloid osmotic pressure, transporting metabolites, and reflects the nutritional status. Therefore, the CRP/Alb ratio reflects both the inflammation status and the nutrition status. Thus far, 11 studies have evaluated the clinical impact of CRP/Alb in gastric cancer. Table II summarizes each study (33-43). Among them, nine studies evaluated CRP/Alb as a prognostic factor, while two studies evaluated it as a predictive factor for postoperative surgical complications. The cut-off CRP/Alb value was reported to range from 0.025 to 0.3778 as a prognostic factor in the previous studies. In the evaluation as a prognostic factor, a high CRP/Alb value was associated with a poor prognosis. The hazard ratio (HR) of the CRP/Alb value for OS was 1.626-2.844. In addition, two studies showed that a high CRP/Alb value was associated with the occurrence of postoperative surgical complications. Accordingly, the CRP/Alb value is considered to have a clinical impact on both the short- and long-term oncological outcomes. Further studies are needed to clarify whether CRP/Alb is an optimal tool for unresectable gastric cancer. In other malignancies, recent studies showed that the CRP/Alb ratio is a promising marker for selecting patients who are eligible for chemotherapy or as a predictor of adverse events of chemotherapy. These issues need to be clarified in gastric cancer.
Literature investigating the utility of the C-reactive protein-to albumin-ratio in patients with gastric cancer.
The Neutrophil-to-Lymphocyte Ratio in Gastric Cancer Treatment
The neutrophil-lymphocyte ratio (NLR) was first recognized for its association with systemic inflammation in the critically ill, and meta-analyses on the association between an elevated NLR and a poor prognosis have been reported for various malignancies. The NLR is determined by dividing the absolute neutrophil count by the absolute lymphocyte count. The NLR can easily be calculated from parameters that are obtained in routine blood cell counts. The close association between inflammation and cancer progression hints at the potential application of elevated tumor-associated neutrophils, or neutrophils that infiltrate tumors, as a prognostic biomarker. Thus far, 63 studies have evaluated the clinical impact of NLR in gastric cancer. Table III summarizes each study (18, 44-97). Among them, 60 studies evaluated the NLR as a prognostic factor, three evaluated the NLR as a predictive factor for postoperative surgical complications. Among 60 studies that evaluated the NLR as a prognostic factor, 34 evaluated its role in resectable gastric cancer and 26 studies evaluated unresectable gastric cancer. In both the resectable and unresectable settings, a high NLR was associated with a poor prognosis. The HR of NLR for OS was 1.1-14.621 in the resectable setting and 1.116-11.41 in the unresectable setting. The cut-off value of the NLR was reported to be 1.7-5 in the resectable setting and 1.5-5 in the unresectable setting. In addition, three studies showed that a high NLR was associated with the occurrence of postoperative surgical complications. Accordingly, the NLR had clinical impact in both short- and long-term oncological outcomes in resectable and unresectable settings. Recently, changes of the NLR during treatment have been reported to be associated with gastric cancer survival. Further studies are needed to clarify this issue.
Literature investigating the utility of the neutrophil-to-lymphocyte ratio in patients with gastric cancer.
The Platelet-to-Lymphocyte Ratio in Gastric Cancer Treatment
Recently, the platelet-to-lymphocyte ratio (PLR) was developed and reported as a promising prognostic factor for gastrointestinal malignancies. The PLR is particularly promising as it can potentially provide insight into both cancer-related inflammation and cancer-related thrombotic/hemostatic mechanisms in various malignancies. Five studies have evaluated the clinical impact of the PLR in gastric cancer. Table IV summarizes each study (39, 48, 98-100). Among them, four studies evaluated the PLR as a prognostic factor, while one study evaluated the PLR as a predictive factor for postoperative surgical complications. The cut-off value of the PLR as a prognostic factor was reported to be 159-191 in the previous studies. In evaluation as a prognostic factor, a high PLR was associated with a poor prognosis. The HR of the PLR for OS was 1.552-2.47. Although almost 30 studies have assessed the prognostic value of the PLR in gastric cancer, limited studies showed that the PLR had a significant impact for OS in gastric cancer. Therefore, further studies are needed to clarify the clinical impact of the PLR in gastric cancer treatment.
Literature investigating the utility of the platelet-to-lymphocyte ratio in patients with gastric cancer.
The Prognostic Nutritional Index in Gastric Cancer Treatment
The prognostic nutritional index (PNI) is a novel method to assess the immune and nutritional status based on the serum lymphocyte count and albumin level. Twenty-six studies have evaluated the clinical impact of the PNI in gastric cancer. Table V summarizes each study (77, 101-124). Among the 26 studies that evaluated the PNI as a prognostic factor, 24 evaluated resectable gastric cancer and two evaluated unresectable gastric cancer. In both the resectable and unresectable settings, a high PNI was associated with a poor prognosis. The HR of the PNI for OS was 1.287-12.933 in the resectable setting. The cut-off value of the PNI was reported to be 41-50 in the resectable setting and 40 in the unresectable setting. Recent studies have reported that the immune status and nutritional status affect the continuation of chemotherapy and the occurrence of adverse events of chemotherapy. Therefore, the PNI may have some clinical impact in patients with unresectable gastric cancer who receive chemotherapy. Further studies are needed to clarify this issue.
Literature investigating the utility of the Prognostic Nutritional Index in patients with gastric cancer.
Controlling Nutritional Status in Gastric Cancer Treatment
The controlling nutritional status (CONUT) score was developed as an accessible nutritional screening tool for evaluating a patient’s nutritional status. The CONUT score is calculated from the serum albumin level, the total cholesterol level, and the total lymphocyte count. The clinical impact of the CONUT score on the outcomes of gastric cancer was first reported in 2018. Twenty-six studies have evaluated the clinical impact of the PNI in gastric cancer. Table VI summarizes each study (125-137). Among 11 studies that evaluated the CONUT score as a prognostic factor, 10 evaluated patients with resectable gastric cancer and one evaluated those with unresectable gastric cancer. In both settings, a high CONUT score was associated with a poor prognosis. The HR of the CONUT score for OS was 1.553-3.707 in the resectable setting. The cut-off value of the CONUT score was reported to be 0-5. In addition, four studies evaluated the CONUT score as a predictive factor for postoperative surgical complications. These studies showed that a high CONUT score was associated with postoperative surgical complications.
Literature investigating the utility of the Controlling Nutritional Status in patients with gastric cancer.
The Albumin-to-Globulin Ratio and the Lymphocyte-to-C-Reactive Protein Ratio in Gastric Cancer Treatment
Recently, the clinical utilities of albumin and globulin as tumor prognostic markers have aroused great interest. The albumin-to-globulin ratio (AGR), which is calculated as AGR=albumin/(total protein−albumin) has been considered a possible effective combination of two prognostic indicators. In addition, the lymphocyte-to-C-reactive protein ratio (LCR) is a particularly promising marker of systemic inflammation in the perioperative period. Table VII (112, 138) and Table VIII (139-141) showed the clinical impacts of the AGR and LCR in gastric cancer treatment. However, limited studies have shown its significance as a prognostic factor in gastric cancer treatment. Additional studies are needed to clarify the clinical impact of the AGR and LCR in gastric cancer treatment.
Literature investigating the utility of the albumin-to-globulin ratio in patients with gastric cancer.
Literature investigating the utility of the lymphocyte-to-C-reactive protein ratio in patients with gastric cancer.
Future Prospects for Nutrition and Inflammation Assessment Tools for Gastric Cancer Treatment
Thus far, various nutrition and inflammation assessment tools have been applied in gastric cancer treatment. To utilize the nutrition and inflammation assessment tools in gastric cancer treatment, the following points should be clarified. Firstly, it is necessary to set the optimal cut-off value for each nutrition and inflammation assessment tool. In the previous studies, patient background factors and treatment methods were heterogeneous. In addition, the sample sizes of the previous studies were relatively small and the studies were retrospective in nature. Therefore, these differences may have affected the cut-off values used for each tool. In addition, the timing of the application of these tools is also unclear. Previous studies assessed each tool at the preoperative, postoperative, and pretreatment of chemotherapy. It is necessary to establish the optimal timing for assessment by these tools. Secondly, the mechanisms through which nutrition and inflammation affect the prognosis of gastric cancer are unclear. Recently, the nutrition and inflammation status has been reported to affect postoperative surgical complications, the introduction of chemotherapy, and adverse events of chemotherapy. Previous studies demonstrated that postoperative surgical complications and the management of chemotherapy affect survival of patients with gastric cancer. However, the precise mechanism through which the nutritional and inflammatory status – as assessed by these tools – influences gastric cancer prognosis is unclear. Thirdly, it is unclear whether nutrition and inflammation assessment using these tools will become promising aids for defining treatment approaches targeting nutrition/inflammation in gastric cancer. Recent studies have focused on introducing perioperative oral nutritional treatment for patients with gastrointestinal cancer. The clinical relationship between changes in the nutritional and inflammatory status and perioperative oral nutritional treatment still needs to be clarified.
Conclusion
The nutritional and inflammatory status—as assessed by nutrition and inflammation assessment tools—may have some clinical influence on both the short- and long-term oncological outcomes in patients with gastric cancer. However, the optimal cut-off values for each tool have not been established and the mechanism through which these parameters influence prognosis is unclear. To optimize the nutrition and inflammation assessment tools for gastric cancer, it is necessary to clarify these points in further studies.
Acknowledgements
This work was supported by JSPS KAKENHI Grant Number 21K08688.
Footnotes
↵* These Authors contributed equally to this article.
Authors’ Contributions
TA and KH made substantial contributions to the concept and design. TA, YM, KH, and KK made substantial contributions to the acquisition of data and the analysis and interpretation of the data. TA and YM were involved in drafting the article or revising it critically for important intellectual content. TA, and KH gave their final approval of the version to be published.
Conflicts of interest
None.
- Received September 6, 2022.
- Revision received September 23, 2022.
- Accepted September 28, 2022.
- Copyright © 2022 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.
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