Impact of postoperative reduced skeletal muscle on prognosis after recurrence in gastric cancer

Preoperative computed tomography-determined sarcopenia is a reliable prognostic factor in patients with gastric cancer after radical gastrectomy: A sex-specific analysis

Background

The predictive role of sarcopenia in cancer prognosis is an area of increasing concern. However, the influence of sex difference on the predictive role of sarcopenia in cancer prognosis has not been clearly defined. This retrospective cohort study investigated the effect of preoperative sarcopenia on the long-term outcomes of patients with gastric cancer (GC) based on sexual dimorphism.

Methods

Preoperative abdominal computed tomography (CT) scans from 379 GC patients who underwent radical gastrectomy were carefully analyzed. The patients were categorized into sarcopenia and non-sarcopenia groups according to the L3 skeletal muscle index (L3 SMI) measured on CT scans. Moreover, other indexes which can be used to evaluate the muscle area or the muscle quality, including skeletal muscle area (SMA), visceral fat area (VFA), subcutaneous fat area (SFA), skeletal muscle radiation attenuation (SM-RA), visceral fat index (VFI), subcutaneous fat index (SFI), and subcutaneous and visceral ratio (SV), were obtained from CT scans.

Results

There were 254 men and 125 women included in our study. After calculation, we defined sex-specific SMI-related mortality cutoff as 39.73 and 32.97 cm²/m² for men and women. Univariable analysis showed that pathological tumor-node-metastasis (pTNM), depth of invasion, lymph node metastasis, differentiation degree, preoperative sarcopenia (for men), SMA (for men), L3 SMI, SFA (for women), SFI (for women), SV (for women), and SM-RA (especially for men) were significant independent predictors of overall survival (OS). Multivariable analysis showed that pTNM, depth of invasion, poor differentiation, and SM-RA were significantly associated with 5-year OS in GC patients. However, CT-determined sarcopenia was associated with significantly worse OS only in men, and SFA was significantly associated with 5-year OS only in women.

Conclusion

SM-RA is a reliable prognostic factor in patients with GC after radical gastrectomy. The impact of indexes mentioned above on survival outcomes is dependent on sex. CT-determined preoperative sarcopenia, a muscle-related indicator, was associated with outcomes in men. Adipose-related indicator (SFA), instead, was associated with outcomes in women.

Impact of skeletal muscle mass in patients with unresectable gastric cancer who received palliative first-line chemotherapy based on 5-fluorouracil

BACKGROUND

The mortality rate of patients with unresectable gastric cancer (UGC) has decreased with the development of chemotherapies and surgical techniques. However, the survival rate remains low. We retrospectively examined the prognostic significance of the pretreatment skeletal muscle mass index (SMI) and nutritional and inflammatory factors in patients with UGC.

METHODS

This study included 83 patients diagnosed with UGC at Tottori University Hospital who received palliative chemotherapy based on 5-fluorouracil. Pretreatment computed tomography (CT) measured overall skeletal muscle mass (SMM) and cross-sectional SMM at the third lumbar vertebra (L3). We focused on the neutrophil-to-lymphocyte ratio (NLR), C-reactive protein-to-albumin ratio (CAR), prognostic nutritional index (PNI), and platelet-to-lymphocyte ratio (PLR) as nutritional and inflammatory factors.

RESULTS

Receiver operating characteristic curve analysis was performed for median survival time (MST) after palliative chemotherapy. SMIs for males and females (43.9 cm2/m2 and 34.7 cm2/m2, respectively) were the cutoff values, and patients were divided into high (SMIHigh; n = 41) and low SMI groups (SMILow; n = 42). Body mass index (BMI) was significantly higher in patients in the SMIHigh group than in the SMILow group (p < 0.001). The number of patients who received third-line chemotherapy was significantly higher in the SMIHigh group than in the SMILow group (p = 0.037). The MST was significantly higher in the SMIHigh group than in the SMILow group (17.3 vs. 13.8 months; p = 0.008). The incidence of grade 3 or 4 side effects was significantly higher in patients with SMILow UGC (p = 0.028). NLR was significantly higher in patients with SMILow than it was in those with SMIHigh. (p = 0.047). In the univariate analysis, performance status, SMI, histological type, lines of chemotherapy, and NLR were prognostic indicators. The multivariate analysis identified SMI (p = 0.037), NLR (p = 0.002), and lines of chemotherapy (p < 0.001) as independent prognostic factors.

CONCLUSIONS

The SMILow group had significantly more grade 3 or 4 side effects, were related to high NLR, and had a significantly worse prognosis than the SMIHigh group.

TRIAL REGISTRATION

Retrospectively registerd.