Microwave ablation without subsequent lumpectomy versus breast-conserving surgery for early breast cancer: a propensity score matching study

Figures & data

Figure 1. Flowchart shows participants in microwave ablation (MWA) and breast conserving surgery (BCS) group.

Figure 2. Distribution of the propensity score in patients who underwent MWA or BCS in the PSM population.

Table 1. Baseline Characteristics for the Total Study Cohort and Propensity Score–matched Cohort.

	Total Study Cohort			Propensity Score–matched Cohort
Parameter	MWA Group (n = 21)	BCS Group (n = 85)	p Value	MWA Group (n = 21)	BCS Group (n = 21)	p Value
Age (yr)^a			0.00			>0.99
<50	2 (9.5)	51 (60.0)		2 (9.5)	2 (9.5)
≥50	19 (90.5)	34 (40.0)		19 (90.5)	19 (90.5)
Body mass index (kg/m²)^a	26.4 ± 4.1 (20.8-34.9)	23.4 ± 2.6 (17.6–31.2)	0.00	26.4 ± 4.1 (20.8–34.9)	24.4 ± 3.2 (1.6–31.2)	0.08
Postmenopausal	18 (85.7)	25 (29.4)	0.00	18 (85.7)	14 (66.7)	0.28
Mean max size (cm)^a
<2.0	9 (42.9)	63 (74.1)	0.01	9 (42.9)	15 (71.4)	0.32
2.1-3.0	5 (23.8)	16 (18.8)		5 (23.8)	3 (14.3)
3.1-4.0	4 (19.0)	4 (4.7)		4 (19.0)	2 (9.5)
4.1-5.0	3 (14.3)	2 (2.4)		3 (14.3)	1 (4.8)
Tumor Number			0.00			0.22
1	16 (76.2)	84 (98.8)		16 (76.2)	20 (95.2)
2	3 (14.3)	1 (1.2)		3 (14.3)	1 (4.8)
3	2 (9.5)	0 (0.0)		2 (9.5)	0 (0.0)
Tumor Location			0.71			0.76
left	11 (52.4)	39 (45.9)		11 (52.4)	9 (42.9)
right	10 (47.6)	45 (52.9)		10 (47.6)	11 (52.4)
Bilateral	0 (0.0)	1 (1.2)		0 (0.0)	1 (4.8)
Tumor size			0.02			1.00
T1	9 (42.9)	59 (69.4)		9 (42.9)	10 (47.6)
T2	12 (57.1)	26 (30.6)		12 (57.1)	11 (52.4)
Nodal status			0.45			0.69
N0	16 (76.2)	73 (85.9)		16 (76.2)	18 (85.7)
N1	5 (23.8)	12 (14.1)		5 (23.8)	3 (14.3)
Tumor stage			0.12			0.85
T1N0M0	9 (42.9)	55 (64.7)		9 (42.9)	10 (47.6)
T1N1M0	0 (0.0)	4 (4.7)		0 (0.0)	0 (0.0)
T2N0M0	7 (33.3)	18 (21.2)		7 (33.3)	8 (38.1)
T2N1M0	5 (23.8)	8 (9.4)		5 (23.8)	3 (14.3)
Subrogate molecular subtype^b			0.74			0.23
Luminal A	5 (23.8)	30 (35.3)		5 (23.8)	9 (42.9)
Luminal B
HER2 positive	9 (42.9)	27 (31.8)		9 (42.9)	6 (28.6)
HER2 negative	1 (4.8)	6 (7.1)		1 (4.8)	1 (4.8)
HER2 enriched (nonluminal)	0 (0.0)	3 (3.5)		0 (0.0)	2 (9.5)
Triple negative	1 (4.8)	7 (8.2)		1 (4.8)	2 (9.5)
Undefined	5 (23.8)	12 (14.1)		5 (23.8)	1 (4.8)

Note.—Except where indicated, data are numbers of participants, with percentages in parentheses. MWA: microwave ablation; BCS: breast conserving surgery.

^aNumbers in parentheses are the range.

^bLuminal A: estrogen receptor (ER) and progesterone receptor (PR) positive, Ki67 level less than 20%, and human epidermal growth factor receptor type 2 (HER2) negative. Luminal B (HER2 negative): ER positive and HER2 negative (PR <20% or Ki67 ≥ 20%). Luminal B (HER2 positive): ER and HER2 positive (PR <20% or Ki67 ≥ 20%). HER2 enriched (nonluminal): ER and PR negative and HER2 positive. T riple negative: ER, PR, and HER2 negative.

Table 2. Hospital Information and Adjuvant Therapy for the Total Study Cohort and Propensity Score–matched Cohort.

	Total Study Cohort			Propensity Score–matched Cohort
Parameter	MWA Group (n = 21)	BCS Group (n = 85)	p Value	MWA Group (n = 21)	BCS Group (n = 21)	p Value
Hospital days (days)^a	8 (2–21)	9 (2–30)	0.47	8 (2–21)	8.8 (2-30)	0.58
Postoperative hospitalization time (days)^a	3.43 (1–15)	3.60 (1–8)	0.81	3.43 (1–15)	3.3 (1–6)	0.90
Anesthesia methods	local anesthesia	general anesthesia		local anesthesia	general anesthesia
Operative time (mins^a	60.0 (27–120)	101.0 (33–295)	0.00	60.0 (27–120)	105.3 (50–188)	0.00
Estimated blood loss (ml)^a	3.19 (1–5)	33.7 (5–400)	0.00	3.19 (1–5)	24.3 (10–50)	0.00
Management of axillary lymph nodes	6 (28.6)	20 (23.5)	0.631	6 (28.6)	5 (23.8)	0.513
Contrast-enhanced evaluation
CEMRI before treatment	14 (66.7)	7 (8.2)	0.00	14 (66.7)	2 (9.5)	0.00
CEMRI after treatment	15 (71.4)	3 (3.5)	0.00	15 (71.4)	0 (0.0)	0.00
CEUS before treatment	19 (90.5)	0 (0.0)	0.00	19 (90.5)	0 (0.0)	0.00
CEUS after treatment	6 (28.6)	0 (0.0)	0.00	6 (28.6)	0 (0.0)	0.03
Costs (RMB)^a	27406.25 (17663.72–50090.4)	19874.71 (10414.49–52469.48)	0.00	27406.25 (17663.72–50090.4)	19592.28 (10414.49–52469.48)	0.02
Adjuvant systematic therapy
Actual endocrine therapy	12 (57.1)	46 (54.1)	0.80	12 (57.1)	11 (52.4)	>0.99
Recommended endocrine therapy	15 (71.4)	66 (77.6)	0.753	15 (71.4)	18 (85.7)	0.452
Actual chemotherapy	3 (14.3)	53 (62.4)	0.004	3 (14.3)	10 (47.6)	0.04
Recommended chemotherapy	17 (81.0)	53 (62.4)	0.157	17 (81.0)	13 (61.9)	0.172
Actual radiation therapy	3 (14.3)	75 (88.2)	0.00	3 (14.3)	17 (81.0)	0.00
Recommended radiation therapy	21 (100.0)	85 (100.0)	>0.99	21 (100.0)	85 (100.0)	>0.99

Note.—Except where indicated, data are numbers of participants, with percentages in parentheses. MWA: microwave ablation; BCS: breast conserving surgery. CEMRI: contrast-enhanced magnetic resonance image. CEUS: contrast-enhanced ultrasound.

^aNumbers in parentheses are the range.

Table 3. Follow-up Information and Complication for the Total Study Cohort and Propensity Score–matched Cohort.

	Total Study Cohort			Propensity Score–matched Cohort
Parameter	MWA Group (n = 21)	BCS Group (n = 85)	p Value	MWA Group (n = 21)	BCS Group (n = 21)	p Value
Minor complication	0 (0.0)	14 (16.5)	0.10	0 (0.0)	4 (19.0)	0.58
Breast hematoma	0 (0.0)	6 (7.1)	0.47	0 (0.0)	1 (4.8)	0.29
Breast inflammation	0 (0.0)	1 (1.2)	>0.99	0 (0.0)	1 (4.8)	0.29
Chronic pain	0 (0.0)	7 (8.2)	0.38	0 (0.0)	2 (9.5)	0.08
Follow-up (mons)^a	38 (16-59)	44 (15–89)	0.44	38 (16–59)	33 (15–81)	0.13
Tumor progression	2 (9.5)	2 (2.4)	0.18	2 (9.5)	0 (0.0)	0.48
Local tumor recurrence	1 (4.8)	0 (0.0)	0.20	1 (4.8)	0 (0.0)	>0.99
Ipsilateral breast progression	1 (4.8)	1 (1.2)	0.36	1 (4.8)	0 (0.0)	>0.99
Contralateral breast progression	0 (0.0)	0 (0.0)	>0.99	0 (0.0)	0 (0.0)	>0.99
Systematic metastasis	0 (0.0)	1 (1.2)	>0.99	0 (0.0)	0 (0.0)	>0.99
OS	20 (95.5)	84 (98.8)	0.36	20 (95.5)	21 (100.0)	>0.99
DSS	21 (100.0)	84 (98.8)	>0.99	21 (100.0)	21 (100.0)	>0.99

Note.—Except where indicated, data are numbers of participants, with percentages in parentheses. MWA: microwave ablation; BCS: breast conserving surgery; OS:overall survival; DSS: disease-specific survival.

^aNumbers in parentheses are the range.

Figure 3. Cosmetic results and reasons for without excellent evaluation between ESBC patients who underwent MWA and BCS. (A) Cosmetic Results in Total cohort. (B) Cosmetic Results in PSM cohort.

Table 4. Cosmetic Results of Total Study cohort and Matched Patients between the MWA and BCS Groups.

	Total Study cohort Patients			Propensity Score–matched Patients
Parameter	MWA Group (n = 21)	BCS Group (n = 85)	p value	MWA Group (n = 21)	BCS Group (n = 21)	p value
Cosmetic results			0.01			0.01
Bad	0 (0.0)	0 (0.0)		0 (0.0)	0 (0.0)
Fair	0 (0.0)	3 (3.5)		0 (0.0)	1 (4.8)
Good	0 (0.0)	21 (24.7)		0 (0.0)	5 (23.8)
Excellent	21 (100%)	61 (71.8)		21 (100%)	15 (71.4)

Note.—Except where indicated, data are numbers of participants, with percentages in parentheses. MWA: microwave ablation; BCS: breast conserving surgery.

Data availability statement

We understand the terms of the share upon reasonable request data policy and our data generated or analyzed during the study are available from the corresponding author by request.