Based on the inclusion and exclusion criteria, 598 patients were included in our study. Our study included 170 recurrent GC patients and 428 metastatic GC patients. The general characteristics of all enrolled patients are listed in Table 1. The age and gender proportions and surgical and pathological factors of the patient population were similar to those observed in other studies .
Follow-up and survival
Of the 598 GC patients, the median follow-up time was 11.60 months (range 0-76), and the median OS after chemotherapy was 12 months (95 % CI 11.221–12.779), with 1-, 3-, and 5-year OS rates of 45.40%, 3.80%, and 0.90 %, respectively.
The 598 patients were divided into the HBini≤ 80 g/L cohort and the HBini level > 80 g/L cohort. Our study included 40 patients in the HBini≤ 80 g/L cohort and 558 patients in the HBini level > 80 g/L cohort.
For the HBini≤ 80 g/L cohort, the median OS was 10 months with 1-, 3-, and 5-year survival rates of 35.40%, 0%, and 0%, respectively, while in the HBini level > 80 g/L cohort, the median OS was 12 months with 1-, 3-, and 5-year survival rates of 46.10%, 4.10%, and 3.00%, respectively. The OS of the HBini≤ 80 g/L cohort was significantly worse than that of the HBini level > 80 g/L cohort (p=0.009, Table 2).
Kaplan-Meier analysis was also used to analyse the correlation between HBini level and PFS. Our results revealed that patients with HBini levels ≤ 80 g/L also had a trend toward a shortened median PFS (p=0.049, Table 2). Interestingly, we found that HBdec ≥30 g/L was associated with a significantly shortened median PFS (p=0.001), and a similar relationship was found with decreased median OS (p=0.039, Table 2).
Red blood cell (RBC) transfusion is an important treatment modality, while chemotherapy is beneficial for improving the prognosis of recurrent and metastatic GC patients. Thus, we analysed the different treatment modalities and clinicopathological parameters for the OS and PFS in our patients.
Using univariate analysis, we found that RBC transfusion was associated with neither median OS nor median PFS (Table 2 and Table 3). The factors that significantly influenced OS were HBini level, HBini ≤80 g/L, metastatic sites ≥3, liver metastases, bone metastases, paclitaxel-based combination of three regimens, the number of chemotherapy cycles, treatment response, and HBdec ≥30 g/L (p<0.05). Additionally, HBini level, the lowest haemoglobin level, metastatic sites ≥3, liver metastases, bone metastases, number of chemotherapy cycles, chemotherapy including paclitaxel, treatment response and HBdec ≥30 g/L were significantly associated with PFS (p<0.05) (Table 3).
Multivariate analysis showed that HBini level ≤80 g/L (HR=1.879, 95% CI=1.301-2.767, p=0.001), liver metastases (HR=1.234, 95% CI=1.022-1.490, p=0.029), chemotherapy including paclitaxel (HR=1.225, 95% CI=1.013-1.481, p=0.036), treatment response (HR=1.457, 95% CI=1.173-1.808, p=0.001), and HBdec ≥30 g/L (HR=1.536, 95% CI=1.206 -1.957, p=0.001) were significant adverse prognosis factors of OS (Table 4). More importantly, the number of chemotherapy cycles was also significantly correlated with improved OS (HR=0.879, 95% CI=0.855-0.904, p <0.001) (Table 4).
For PFS, HBini level ≤80 g/L (HR=1.516, 95% CI=1.082-2.126, p=0.016), chemotherapy including paclitaxel (HR=1.273, 95% CI=1.068-1.517, p=0.007), treatment response (HR=2.235, 95% CI=1.818-2.747, p<0.001), the number of chemotherapy cycles (HR=0.922, 95% CI=0.899-0.945, p<0.001), and HBdec ≥30 g/L (HR=1.543, 95% CI=1.233-1.932, p<0.001) were independent prognostic factors.
Relationship between the degree of decrease in haemoglobin levels and the clinicopathological parameters of our patients
We then investigated whether we could identify correlations between the degree of decrease in haemoglobin levels and the clinicopathological parameters of our GC patients. Our results suggested that bone metastases, chemotherapy including platinum, the number of chemotherapy cycles, and treatment response were associated with the degree of haemoglobin decrease (p<0.05) (Table 5). Multivariate analyses revealed that the number of chemotherapy cycles and chemotherapy including platinum were significantly correlated with improved HBdec (p<0.001 and p=0.019, respectively) (Table 6).