Patient characteristics
Table 1 shows the characteristics of the 100 patients. The median age was 66 (range, 43–78) years and 82 patients (82%) were males. The median BMI was 20.4 (range, 14.6–28.5) kg/m2. Of these patients, 3 (3%), 38 (38%), 28 (28%), and 31 (31%) had cStage Ⅱ, Ⅲ, Ⅳa, and Ⅳb, respectively. The initial full dose of DCF chemotherapy for cycle 1 was given to 49 patients (49%). In patients with prior neoadjuvant chemotherapy, 15 (15%) received 1 cycle of CF, 3 (3%) received 2 cycles of CF, and 2 (2%) received 1 cycle of SP.
Outcome
The incidence of FN in cycle 1 was 21%. Additionally, 47 patients (52%) had grade 3 or 4 neutropenia and of these 27 patients (30%) had grade 4 neutropenia. The median time of administered pegfilgrastim was 7 (range, 7–9) days, and the median incidence of FN was 9 (range, 8–10) days.
Univariate analysis
In the FN group, age ≥ 65 (76.2% vs. 49.4%, P = 0.028), neutrophil counts < 2000/mm3 (23.8% vs. 2.6%, P = 0.004), anemia (47.6% vs. 25.3%, P = 0.047), Alb < 3.5 g/dL (28.6% vs. 7.6%, P = 0.017), T-cho < 180 mg/dL (57.1% vs. 33.3%, P = 0.048), PNI < 45 (47.6% vs. 20.3%, P = 0.011), GNRI < 92 (52.4% vs. 8.9%, P < 0.001), CONUT score ≥ 4 (23.8% vs. 4.0%, P = 0.012), and COP-NLR score of 0 (52.4% vs. 24.4%, P = 0.013) were significantly higher than those of the non-FN group (Table 2).
Multivariate analysis
In the multivariate analysis, GNRI < 92 (odds ratio [OR] 13.162, P < 0.001) and COP-NLR score of 0 (OR 4.619, P = 0.012) were independent significant predictors of FN in cycle 1 (Table 3).
Changes in neutrophil counts
Fig. 1 shows changes in neutrophil counts between the FN and non-FN groups. In the FN group, day 7–10 neutrophil counts were significantly lower than those in the non-FN group (median neutrophil counts (mm3): day 7, 805 vs. 1,340, P = 0.002; day 8, 350 vs. 1,240, P = 0.001; day 9, 255 vs. 530, P = 0.001; day 10, 730 vs. 3,485, P = 0.004). In the FN group, neutrophil counts on day 11–21 were not significantly different from those of the non-FN group.
RDI
Table 4 shows the completion rate, % dose, duration of administration, and RDI of DCF chemotherapy. Notably, 77 patients (77%) received 3 cycles completely. The completion rate of DCF chemotherapy in the FN group were not significantly different from that in the non-FN group.
The % dose of DCF chemotherapy in the FN group was significantly lower in cycles 2 and 3 than that in the non-FN group. The duration of administration of DCF chemotherapy in the FN group was significantly delayed in cycle 1 than in the non-FN group. The adverse events that caused dose reduction in the next cycle of DCF chemotherapy in the FN group was the development of FN (100%), whereas in the non-FN group was the development of anorexia (8.9%), diarrhea (5.1%), enteritis (2.5%), and drug-induced liver injury (1.3%). The median of the total RDI in all patients was 90.0% (range, 30–100). The RDI of all cycles in the FN group was significantly lower than those in the non-FN group.
The proportion of patients with total RDI ≥ 85%
Fig. 2 shows the proportion of patients with total RDI ≥ 85% of DCF chemotherapy in all cycles. The proportion of patients with total RDI ≥ 85% in the FN group was significantly lower than those in the non-FN group (cycle 1, 33.3% vs. 74.7%, P < 0.001; cycle 2, 17.6% vs. 77.0%, P < 0.001; cycle 3, 20.0% vs. 79.0%, P < 0.001). Additionally, the proportion of patients with total RDI ≥ 85% in all cycles in the FN group was significantly lower than those in the non-FN group.