Real world evidence study on treatment patterns and health resource utilization in patients with HR+/HER2- locally advanced or metastatic breast cancer in Korea

Figures & data

Table 1. Patient characteristics.

Characteristics	Total (N = 109)	Patients progressed with ET (N = 33)	Patients with no prior systemic treatment (N = 52)	Other patients (N = 24)
Age (years)^a
Mean (SD)	57.5 (9.39)	60.5 (10.26)	58.4 (5.80)	51.5 (11.88)
Range	40–81	41–77	41–72	40–81
Alive at time of data abstraction, n (%)	109 (100.0%)	33 (100.0%)	52 (100.0%)	24 (100.0%)
Not employed (student, retired, other)	96 (94.1%)	32 (97.0%)	45 (100.0%)	19 (79.2%)
Comorbidities,^b,c n (%)
Hypertension	52 (47.7%)	22 (66.7%)	25 (48.1%)	5 (20.8%)
Arthritis	0 (0.0%)	0 (0.0%)	0 (0.0%)	0 (0.0%)
Thyroid problem	0 (0.0%)	0 (0.0%)	0 (0.0%)	0 (0.0%)
Hyperlipidemia	21 (19.3%)	7 (21.2%)	9 (17.3%)	5 (20.8%)
Hypercholesterolemia	7 (6.4%)	3 (9.1%)	4 (7.7%)	0 (0.0%)
Diabetes	16 (14.7%)	5 (15.2%)	11 (21.2%)	0 (0.0%)
GI disorders or GERD (gastroesophageal reflux disease)	0 (0.0%)	0 (0.0%)	0 (0.0%)	0 (0.0%)
Heart Disease	0 (0.0%)	0 (0.0%)	0 (0.0%)	0 (0.0%)
Respiratory Disease	5 (4.6%)	0 (0.0%)	0 (0.0%)	5 (20.8%)
Depression	9 (8.3%)	2 (6.1%)	2 (3.8%)	5 (20.8%)
Other	33 (30.3%)	7 (21.2%)	13 (25.0%)	13 (54.2%)
Hormone receptor status^c n (%)
Estrogen receptor positive (ER+)	109 (100.0%)	33 (100.0%)	52 (100.0%)	24 (100.0%)
Progestrone receptor positive (PR+)	98 (89.9%)	32 (97.0%)	42 (80.8%)	24 (100.0%)
Both ER + and PR+	98 (89.9%)	32 (97.0%)	42 (80.8%)	24 (100.0%)
ECOG score, n (%)
0	27 (24.8%)	7 (21.2%)	19 (36.5%)	1 (4.2%)
1	78 (71.6%)	26 (78.8%)	33 (63.5%)	19 (79.2%)
2+	4 (3.7%)	0 (0.0%)	0 (0.0%)	4 (16.7%)
Pre- or perimenopause	25 (22.9%)	7 (21.2%)	0 (0.0%)	18 (75.0%)
Number of metastatic sites (number of organs involved)
Mean (SD)	1.8 (1.05)	1.4 (0.66)	1.6 (0.79)	2.5 (1.56)
Range	1–7	1–3	1–4	1–7
Brain metastasis, n (%)	3 (2.8%)	0 (0.0%)	0 (0.0%)	3 (12.5%)
Bone and bone marrow metastasis, n (%)	68 (62.4%)	18 (54.5%)	29 (55.8%)	21 (87.5%)
Any visceral disease,^c n (%)	42 (38.5%)	8 (24.2%)	23 (44.2%)	11 (45.8%)

Abbreviations. ECOG, Eastern Cooperation Oncology Group; n, number of patients; SD, standard deviation.

Notes: Patients who progressed with ET include patients who had disease progression while receiving endocrine monotherapy as first-line therapy post ABC diagnosis. Patients with no prior systemic treatment includes postmenopausal women who are not in the patient population who progressed with ET after first-line therapy. The 24 patients who do not meet the criteria for either “progressed with ET” or “no prior systemic treatment” are included in the “Other patients” population. Total includes all patients in the study.

^aAge is measured as at date of data collection or at death.

^bComorbidities were measured as at date ABC diagnosis.

^cPercentages may add to more than 100% as patients may be counted in more than one category.

Table 2. Most common treatments (>10% of patients) after diagnosis of ABC.

Treatment	Total	Patients progressed with ET	Patients with no prior systemic treatment	Other patients
First-line Therapy, n (%)	(N = 109)	(N = 33)	(N = 52)	(N = 24)
Letrozole ± Palbociclib	56 (51.4%)	27 (81.8%)	28 (53.8%)	1 (4.2%)
ET monotherapy: Letrozole	34 (31.2%)	27 (81.8%)	6 (11.5%)	1 (4.2%)
ET + CDK: Letrozole + Palbociclib	22 (20.2%)	0 (0.0%)	22 (42.3%)	0 (0.0%)
ChT combinations	25 (22.9%)	0 (0.0%)	9 (17.3%)	16 (66.7%)
Cyclophosphamide + Doxorubicin	11 (10.1%)	0 (0.0%)	7 (13.5%)	4 (16.7%)
Second-line Therapy, n (%)	(N = 72)	(N = 30)	(N = 20)	(N = 22)
ET ± Everolimus	30 (41.6%)	16 (48.5%)	9 (45.0%)	5 (22.7%)
ET monotherapy	18 (25.0%)	7 (23.3%)	8 (40.0%)	3 (13.6%)
ET combination	2 (2.8%)	0 (0.0%)	1 (5.0%)	1 (4.5%)
ET + mTOR: Exemestane + Everolimus	10 (13.9%)	9 (30.0%)	0 (0.0%)	1 (4.5%)
ChT	28 (38.9%)	9 (30.0%)	8 (40.0%)	11 (45.8%)
ChT monotherapy: Docetaxel	9 (12.5%)	5 (16.7%)	3 (15.0%)	1 (4.5%)
ChT monotherapy: Other agent	1 (1.4%)	0 (0.0%)	1 (5.0%)	0 (0.0%)
ChT combinations	18 (25.0%)	4 (13.3%)	4 (17.3%)	10 (45.5%)
Ovarian suppression monotherapy	5 (6.9%)	4 (13.3%)	1 (5.0%)	0 (0.0%)
Third-line Therapy, n (%)	(N = 25)	(N = 8)	(N = 4)	(N = 13)
ChT	17 (68.0%)	7 (87.5%)	3 (75.0%)	7 (53.8%)
ChT monotherapy	11 (44.0%)	6 (75.0%)	2 (50.0%)	3 (23.1%)
ChT Combinations: Docetaxel + Epirubicin	5 (20.0%)	0 (0.0%)	1 (25.0%)	4 (30.8%)
ChT Combinations: Cyclophosphamide + Doxorubicin	1 (4.0%)	1 (12.5%)	0 (0.0%)	0 (0.0%)
ET + Ovarian suppression: Tamoxifen + Goserelin	5 (20.0%)	0 (0.0%)	0 (0.0%)	5 (38.5%)

Abbreviations. ABC, locally advanced or metastatic breast cancer; CDK, cyclin dependent kinase; ChT, chemotherapy; ET, endocrine therapy; mTOR, mechanistic target of rapamycin.

Notes: Patients who progressed with ET includes patients who had disease progression while receiving endocrine monotherapy as first line therapy post ABC diagnosis. Patients with no prior systemic treatment includes postmenopausal women who are not in the patient population who progressed with ET after first- line therapy. The 24 patients who do not meet the criteria for either “progressed on ET” or “no prior systemic treatment” are included in the “Other patients” population. Total includes all patients in the study.

Figure 1. (A) Most common severe adverse events (>10% of patients) during treatment in patients on endocrine based therapy. Notes: Percentages may add to more than 100% as patients may be counted in more than one category. Abbreviation. SAE, severe adverse event (grade 3 or higher). ^a)Leukopenia was not necessarily reported separately if neutropenia or febrile neutropenia is also reported. (B) Most common severe adverse events (>10% of patients) during treatment in patients on chemotherapy based regimen. Notes: Percentages may add to more than 100% as patients may be counted in more than one category. Abbreviation. SAE, severe adverse event (grade 3 or higher). ^a)Leukopenia was not necessarily reported separately if neutropenia or febrile neutropenia is also reported.

Table 3. Health care resource utilization after diagnosis of ABC.

	Annual Rate (95% CI)^a
	Total (N = 109)	ET-based line-1 therapy (N = 74)	ChT-based line-1 therapy (N = 29)
Diagnostic and monitoring tests
Chest X-ray	3.94 (3.68, 4.21)	3.28 (2.99, 3.59)	5.96 (5.36, 6.63)
CT	2.99 (2.76, 3.23)	2.35 (2.11, 2.61)	4.63 (4.11, 5.23)
Tumor markers	2.70 (2.49, 2.93)	2.73 (2.47, 3.02)	2.93 (2.52, 3.41)
Bone scan	2.23 (2.04, 2.44)	2.00 (1.78, 2.25)	3.02 (2.60, 3.50)
Ultrasound	0.99 (0.86, 1.13)	0.77 (0.63, 0.93)	1.74 (1.43, 2.12)
MRI	0.90 (0.78, 1.04)	0.66 (0.54, 0.81)	1.68 (1.38, 2.06)
PET	0.58 (0.49, 0.69)	0.62 (0.51, 0.77)	0.51 (0.35, 0.73)
Office Visits
Oncologist	9.27 (8.87, 9.69)	8.55 (8.08, 9.04)	11.70 (10.85, 12.62)
Surgeon	0.62 (0.52, 0.74)	0.38 (0.29, 0.49)	1.35 (1.08, 1.69)
Other specialist physician	0.38 (0.31, 0.48)	0.36 (0.27, 0.48)	0.54 (0.38, 0.77)
Accident and emergency visits	0.07 (0.04, 0.12)	0.01 (0.00, 0.06)	0.23 (0.13, 0.39)
Hospitalization	0.44 (0.36, 0.54)	0.04 (0.02, 0.09)	1.47 (1.19, 1.83)
Length of stay per hospitalization (days)^b
Mean (SD)	14.3 (10.32)	9.3 (3.20)	15.2 (10.97)

Abbreviations. ABC, locally advanced or metastatic breast cancer; ChT, chemotherapy; CI, confidence interval; CT, computed tomography; ET, endocrine therapy; MRI, magnetic resonance imaging; PET, positron emission tomography; SD, standard deviation.

^aRates are reported as per person and per year with the 95%CI estimated from the Poisson model with an offset for patient observation time.

^bInformation collected on most recent 5 hospitalizations per person only.

Table 4. Palliative and supportive care treatments after diagnosis of ABC.

Treatment	Total (N = 109)	Patients progressed with ET (N = 33)	Patients with no prior systemic treatment (N = 52)	Other patients (N = 24)
Patients
Antiemetic drugs, n (%)	56 (51.4%)	14 (42.4%)	21 (40.4%)	21 (87.5%)
Pain medications (opiate and non-opiate), n (%)	46 (42.2%)	16 (48.5%)	17 (32.7%)	13 (54.2%)
Antibiotics, n (%)	31 (28.4%)	9 (27.3%)	11 (21.2%)	11 (45.8%)
Bone-modifying agents, n (%)	28 (25.7%)	12 (36.4%)	12 (23.1%)	4 (16.7%)
Growth factors, n (%)	25 (22.9%)	4 (12.1%)	11 (21.2%)	10 (41.7%)
Corticosteroids, n (%)	13 (11.9%)	7 (21.2%)	2 (3.8%)	4 (16.7%)
Antidepressant/anxiolytic agents, n (%)	12 (11.0%)	0 (0.0%)	4 (7.7%)	8 (33.3%)
Antidiarrheal agents, n (%)	7 (6.4%)	6 (18.2%)	1 (1.9%)	0 (0.0%)
Iron supplements, n (%)	6 (5.5%)	4 (12.1%)	2 (3.8%)	0 (0.0%)
Nutritional support^a, n (%)	5 (4.6%)	0 (0.0%)	1 (1.9%)	4 (16.7%)
Oxygen, n (%)	4 (3.7%)	0 (0.0%)	0 (0.0%)	4 (16.7%)

Notes: Percentages may add to more than 100% as patients may be counted in more than one category.

Patients who progressed with ET includes patients who had disease progression while receiving endocrine monotherapy as first-line therapy post ABC diagnosis. Patients with no prior systemic treatment includes postmenopausal women who are not in the patient population who progressed with ET after first- line therapy. The 24 patients who do not meet the criteria for either “progressed on ET” or “no prior systemic treatment” are included in the “Other patients” population. Total includes all patients in the study.

^aNutritional support consisting of interventions, such as enteral nutrition, parenteral nutrition, home artificial nutrition.