Factors Associated with the Selection of First-line Bevacizumab plus Chemotherapy and Clinical Response in HER2-negative Metastatic Breast Cancer: ONCOSUR AVALOX Study

AIM

To evaluate factors associated with the selection of first-line bevacizumab plus chemotherapy and clinical response in HER2-negative metastatic breast cancer (MBC) in clinical practice in Spain.

PATIENTS AND METHODS

All consecutive adult female patients with HER2-negative MBC who had received first-line bevacizumab plus chemotherapy for at least 3 months were enrolled in the present study.

RESULTS

A total of 292 evaluable patients were included; 25% had triple-negative breast cancer (TNBC) and 75% had hormone receptor-positive breast cancer (HRPBC). Nearly 40% of patients had ≥3 metastatic sites, mainly located in the bone (48%) and liver (40%). Bevacizumab was mostly combined with paclitaxel (67.1%). ER-positive tumors were only identified as an independent factor associated with the choice of treatment (odds ratio (OR): 0.538; p=0.02). The overall response rate (ORR) was 63.7% (TNBC: 57.5%; HRPBC: 65.9%). Patients aged 36-50 years (OR: 3.03; p=0.028) and those with metastases at sites other than the bone (OR: 0.38; p=0.001) and ≥3 metastatic sites (OR: 1.41; p=0.018) were more likely to achieve objective responses.

CONCLUSION

First-line bevacizumab plus chemotherapy, mainly paclitaxel, is an effective and well-tolerated treatment option for HER2-negative MBC, particularly in more aggressive disease.

Prognostic factors influencing the selection of bevacizumab combined with chemotherapy in patients with HER2-negative metastatic breast cancer in routine clinical practice: Oncosur-Avalox—Observational cross-sectional study

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Background: Combining bevacizumab (BEV) with chemotherapy (CT) improves survival in HER2-negative metastatic breast cancer (MBC). We investigated the influence of age, ECOG, hormonal status, number of sites, location of metastases and patient decision on the selection of BEV combined with CT in MBC. Methods: Observational cross-sectional multicenter study in patients with HER2- negative MBC who have received first-line CT with BEV. Results: 219 patients were included: median age 51(44-63) yr; ECOG: 0=53%; 60.4% pre-menopausic; 23.9% triple-negative (TN);76.2 % hormone receptor positive (HR+).Metastatic disease: ≥3 sites=39.2% (TN: 22%; HR+: 43.9%); location: 45.2% bone, 37.4% liver, 30.1% lung. Most frequent BEV combinations were paclitaxel/BEV(60.7%) and docetaxel/BEV(12.8%); median no. of CT cycles: 6 (5- 8). A disease-free survival (DFS) ≥12 months was achieved by 82.8%; TN: 78.9%; HR+: 83.3%. Overall response rate (ORR) was 62.7%: 53.6% partial response (PR), 9.1% complete response (CR); 25.4% stable disease (SD) and 7.2% disease progression (4.8% non evaluated). TN:ORR 54.2% (47.9% PR), clinical benefit 80% (27.1% SD); HR+:ORR 65.8% (55.7% PR), clinical benefit 89.9% (24.1% SD). 66.2% presented at least one toxicity, mainly grade 1-2; 32% BEV-related: only 3 grade 3 toxicities; no grade 4. Receiving adjuvant hormonal therapy was associated to DFS ≥12 months (p<0.05). ER+ tumors (OR:0.326;95%CI:0.16-0.65;p=0.002) and patient decision after consider doctor opinion (OR:0.026;95%CI:0.01-0.74; p=0.085) were independent factors associated with the selection of paclitaxel-BEV in the overall population (TN or HR+). Liver metastases were significantly related to paclitaxel-BEV administration (p<0.01). Conclusions: First-line CT with BEV is an effective and safe scheme for patients with TN and HR+ MBC. ER+ tumors and patient decision after consider doctor opinion were identified as independent factors for the selection of paclitaxel-BEV therapy. The presence of liver metastases was significantly associated to the administration of a paclitaxel-BEV regimen.

Observational cross-sectional study to evaluate the prognostic factors influencing the selection of bevacizumab combined with chemotherapy in patients with HER2-negative metastatic breast cancer in routine clinical practice. ONCOSUR-AVALOX study

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Background: Combining bevacizumab (BEV) with chemotherapy (CT) improves survival in HER2-negative metastatic breast cancer (MBC). We investigated the influence of age, ECOG, hormonal status, number of sites and location of metastases and patient decision on the selection of BEV combined with CT in MBC. Methods: Observational cross-sectional multicenter study in pts with HER2-negative MBC who have received first-line CT with BEV. Results: From November 2010 to November 2011, 124 pts were included: median age 51 (45-64) yr; ECOG: 0=50%; 60% pre-menopausic; 23% triple-negative (TN); 77% hormone receptor-positive (HR+). Metastatic disease: ≥3 sites=42% (TN: 32%; HR+: 45%); location: 44% bone, 35% lung, 30% liver. Most frequent BEV-based combinations were paclitaxel/BEV (53%) and docetaxel/BEV (14.5%); median no. of CT cycles: 6 (5-8). A disease-free survival (DFS) ≥12 months was achieved by 73%; TN: 68%; HR+: 76%. Overall response rate (ORR) was 58%: 51% partial response (PR), 7% complete response (CR); 28% stable disease (SD) and 10% disease progression. TN: ORR 44% (40% PR), clinical benefit 80% (36% SD); HR+: ORR 62% (54% PR), clinical benefit 87% (25% SD). 58% presented at least one toxicity, mainly grade 1-2; 26% BEV-related: only 3 (2.4%) grade 3 toxicities; no grade 4. Receiving adjuvant hormonal therapy was associated to DFS ≥12 months (p<0.05). ER+ tumors (OR: 0.215; 95% CI: 0.08-0.56; p=0.002) and one metastatic site, vs. ≥3 sites (OR: 0.309; 95% CI: 0.12-0.83; p=0,020) were independent factors associated with the selection of paclitaxel-BEV therapy in the overall population (TN or HR+). Metastases in the liver were significantly related to paclitaxel-BEV administration (p<0.01). Conclusions: Our findings suggest that first-line CT with BEV is an active and tolerable treatment option for pts with TN and HR+ MBC. ER+ tumors and a single metastatic site were identified as independent factors for the selection of a paclitaxel-BEV therapy. The presence of metastases in the liver was significantly associated to the administration of a paclitaxel-BEV regimen.