Table 3. Univariate and multivariate analysis of factors associated with discontinuity in endocrine therapy in women with breast cancer.
| Variables | Univariate analysis | Multivariate analysis | ||||||
|---|---|---|---|---|---|---|---|---|
| Value | HR | 95%CI | P value | HR | 95%CI | P value | ||
| Age at biopsy | (ref = ≤ 50) | > 50 | 1.26 | 0.72-2.34 | 0.43 | |||
| Histological grade | (ref = 1,2) | 3 | 0.96 | 0.52-1.69 | 0.91 | |||
| ER (IHC) | (ref = median) | ≥ 90% | 1.28 | 0.77-2.10 | 0.34 | |||
| PgR (IHC) | (ref = median) | ≥ 30% | 0.99 | 0.61-1.60 | 0.97 | |||
| Visceral involvement | (ref = No) | Yes | 1.04 | 0.61-1.84 | 0.90 | |||
| Bone involvement | (ref = No) | Yes | 1.22 | 0.76-1.99 | 0.41 | |||
| Number of metastatic lesions | (ref = 1, 2) | ≥ 3 | 1.20 | 0.74-1.94 | 0.46 | |||
| Prior endocrine therapy | ||||||||
| SERM | (ref = No) | Yes | 2.30 | 1.39-3.87 | 0.0011 a | 0.70 | 0.16-2.3 | 0.59 |
| AI | (ref = No) | Yes | 2.02 | 1.14-3.81 | 0.015 a | 1.0 | 0.46-2.3 | 0.99 |
| Both AI and SERM | (ref = No) | Yes | 2.89 | 1.73-4.92 | < 0.0001 a | 2.96 | 0.75-15.1 | 0.13 |
| ESR1 genomic state | (ref = WT) | Mut | 3.2 | 1.76-5.71 | 0.0002 a | 2.04 | 1.08-3.83 | 0.029 a |
| ESR1 MAF (%) | (ref = < Median) | Median > | 0.73 | 0.30-1.82 | 0.51 | |||
| PIK3CA genomic state | (ref = WT) | Mut | 2.25 | 1.24-3.94 | 0.0091 a | 1.78 | 0.96-3.18 | 0.066 |
| PIK3CA MAF (%) | (ref = < Median) | Median > | 0.76 | 0.29-2.04 | 0.58a | |||
(Cox proportional hazards model)
Abbreviations: HR, hazard ratio; 95%CI, 95% confidence interval; ER, estrogen receptor; IHC, immunohistochemistry; PgR, progesterone receptor; SERM, selective estrogen receptor modulator; AI, aromatase Inhibitor; MAF, mutant allele frequency; Mut, mutation.
a Factor showing statistical significance.