Evaluation of tumour heterogeneity by 18F-fluoroestradiol PET as a predictive measure in breast cancer patients receiving palbociclib combined with endocrine treatment

Table 3 Univariate and multivariate Cox regression analyses for prediction of PFS in the subgroup of patients with only FES-positive sites

Parameters	No	Event	Median PFS	Log-rank	Univariate analysis		Multivariate analysis
Parameters	No	Event	(95% CI)	P value	HR (95% CI)	P value	HR (95% CI)	P value
FES SUVmax
≥ 6.5	23	14	21.6(13.5–29.6)	0.258	0.63(0.28–1.42)	0.262	NA
< 6.5	23	10	29.4(13.4–45.4)	0.258	0.63(0.28–1.42)	0.262	NA
FES Hot5 lesions
≥ 8.1	23	13	23.6(14.3–32.8)	0.575	0.79(0.35–1.79)	0.576	NA
< 8.1	23	11	23.9(9.3–38.5)	0.575	0.79(0.35–1.79)	0.576	NA
FES HI ^a
≥ 1.50	23	14	16.5(4.4–28.6)	0.004*	0.27(0.10–0.70)	0.007*	NA
< 1.50	23	10	26.5(21.8–32.2)	0.004*	0.27(0.10–0.70)	0.007*	NA

PFS Progression-free survival; CI Confidence interval; HR Hazard ratio; SUVmax Maximum standard uptake value; SUVmean Mean standard uptake value; HI Heterogeneity index
^a HI = SUVmax/SUVmean; * Indicates statistically significant differences (P < 0.05)

ISSN: 1465-542X