The Breast Journal

Research Article

Exploring the Value of Additional Primary Tumour Excision Combined with Systemic Therapy Administered in Different Sequences for Patients with de Novo Metastatic Breast Cancer

Table 4

Multivariate analysis of BCSD according to the metastatic site in patients with single-organ involvement.


	Bone-only metastasis (N = 6214)		Lung-only metastasis (N = 1725)		Liver-only metastasis (N = 1300)		Brain-only metastasis (N = 208)
	SHR (95% CI)	-value	SHR (95% CI)	-value	SHR (95% CI)	-value	SHR (95% CI)	-value

Treatment modality in model 1
Systemic therapy without primary surgery	1 [Reference]	NA	1 [Reference]	NA	1 [Reference]	NA	1 [Reference]	NA
Systemic therapy after primary surgery	0.66 (0.60–0.74)	<0.001	0.81 (0.68–0.97)	0.02	0.79 (0.64–0.97)	0.03	0.89 (0.57–1.39)	0.61
Systemic therapy before primary surgery	0.61 (0.53–0.69)	<0.001	0.58 (0.46–0.72)	<0.001	0.62 (0.47–0.83)	<0.001	0.64 (0.33–1.26)	0.20
Treatment modality in model 2
Systemic therapy without primary surgery	—	—	—	—	—	—	—	—
Systemic therapy after primary surgery	1 [Reference]	NA	1 [Reference]	NA	1 [Reference]	NA	1 [Reference]	NA
Systemic therapy before primary surgery	0.92 (0.80–1.06)	0.23	0.71 (0.56–0.90)	0.005	0.79 (0.58–1.08)	0.13	0.72 (0.37–1.41)	0.34
Non-primary surgical procedure to distant site
No	1 [Reference]	NA	1 [Reference]	NA	1 [Reference]	NA	1 [Reference]	NA
Yes	0.96 (0.75–1.22)	0.72	0.61 (0.36–1.03)	0.07	0.78 (0.46–1.33)	0.36	0.90 (0.55–1.46)	0.67
Unknown	1.34 (0.95–1.87)	0.09	0.46 (0.21–1.00)	0.05	0.55 (0.18–1.69)	0.30	0.94 (0.34–2.60)	0.90

The reference category of treatment modality on primary site varied within different models (“systemic therapy without primary surgery” for model 1 and “systemic therapy after primary surgery” for model 2). The competing risk model was adjusted for age, race, marital status, year of diagnosis, histologic type, grade, molecular subtype, AJCC T category, AJCC N category, receipt of radiotherapy, and non-primary surgical procedure to distant site. Abbreviations: SHR, subdistribution hazard ratio; CI, confidence interval; NA, not applicable.