Survival of HER2-positive primary breast cancer patients treated by neoadjuvant chemotherapy plus trastuzumab: a multicenter retrospective observational study (JBCRG-C03 study)

We investigated the disease-free survival (DFS) of HER2-positive primary breast cancer patients treated with neoadjuvant chemotherapy plus trastuzumab, as well as predictive factors for DFS and pathologic response. Data from 829 female patients treated between 2001 and 2010 were collected from 38 institutions in Japan. Predictive factors were evaluated using multivariate analyses. The 3-year DFS rate was 87 % [95 % confidence interval (CI) 85-90]. The pathologic complete response (pCR: ypT0/is + ypN0) rate was 51 %. The pCR rate was higher in the ER/PgR-negative patients than in the ER/PgR-positive patients (64 vs. 36 %, P < 0.001). Patients with pCR showed a higher DFS rate than patients without pCR (93 vs. 82 %, P < 0.001). Multivariate analysis revealed three independent predictors for poorer DFS: advanced nodal stage [hazard ratio (HR) 2.63, 95 % CI 1.36-5.21, P = 0.004 for cN2-3 vs. cN0], histological/nuclear grade 3 (HR 1.81, 95 % CI 1.15-2.91, P = 0.011), and non-pCR (HR 1.98, 95 % CI 1.22-3.24, P = 0.005). In the ER/PgR-negative dataset, non-pCR (HR 2.63, 95 % CI 1.43-4.90, P = 0.002) and clinical tumor stage (HR 2.20, 95 % CI 1.16-4.20, P = 0.017 for cT3-4 vs. cT1-2) were independent predictors for DFS, and in the ER/PgR-positive dataset, histological grade of 3 (HR 3.09, 95 % CI 1.48-6.62, P = 0.003), clinical nodal stage (HR 4.26, 95 % CI 1.53-13.14, P = 0.005 for cN2-3 vs. cN0), and young age (HR 2.40, 95 % CI 1.12-4.94, P = 0.026 for ≤40 vs. >40) were negative predictors for DFS. Strict pCR (ypT0 + ypN0) was an independent predictor for DFS in both the ER/PgR-negative and -positive datasets (HR 2.66, 95 % CI 1.31-5.97, P = 0.006 and HR 3.86, 95 % CI 1.13-24.21, P = 0.029, respectively). These results may help assure a more accurate prognosis and personalized treatment for HER2-positive breast cancer patients.

Abstract P3-12-03: Adjuvant capecitabine in breast cancer patients with pathologic residual disease after neoadjuvant chemotherapy: First safety analysis of CREATE-X (JBCRG-04)

Background

Patients (pts) without pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) have a poor prognosis compared with pts achieving a pCR with NAC. It is not clear whether further systemic chemotherapy is beneficial for pts with no pCR. CREATE-X (UMIN000000843) is an ongoing collaborative Korean (KRN)/Japanese (JPN) prospective multicenter open-label randomized phase III trial evaluating this clinical question using capecitabine (X) in pts with no pCR after NAC. We report first safety results, focusing on hand-foot syndrome (HFS), the timing of radiotherapy (RT) and hormone therapy (HT), and differences between KRN and JPN pts.

Methods

Pts with residual invasive cancer after anthracycline- and/or taxane-containing NAC were randomized to standard post-surgical treatment (RT, HT as appropriate) with or without 8 cycles of X (1250 mg/m2 bid, days 1–14 q3w). RT was given before or after X. Pts with hormone receptor (HR)-positive disease received HT either with or after X, according to each center's prespecified standard practice. After evaluation of the tolerability of 6 cycles of X in the first 50 pts, the independent data monitoring committee recommended extending X to 8 cycles.

Results

Between Feb 2007 and Jul 2012, 910 pts were enrolled (304 in Korea, 606 in Japan). At the time of data cut-off (May 20, 2013), data were available from 866 pts. Median age was 48 years in both arms. In the investigational arm, RT was given before X in 260 pts and after X in 33 pts; 73 pts received prophylactic vitamin B6 (VB6). In HR-positive pts HT was given with X in 200 pts and after X in 24 pts. The relative dose intensity of X was 85.7% in JPN pts and 95.2% in KRN pts. Grade (G) 3/4 neutropenia, HFS (G3 only), fatigue, and diarrhea were significantly (p&lt;0.05) more common with X than no X. G3 HFS occurred in 11.1% of pts receiving X, and was significantly more common in JPN vs KRN pts (p = 0.016). No significant difference in HFS was observed between pts who received vs did not receive VB6 (p = 0.392). G3/4 alanine aminotransferase (ALT) abnormalities were significantly more common in pts receiving RT after vs before X (p&lt;0.001) and in pts receiving HT after vs concurrently with X (p&lt;0.001).

 n/N(%) Investigational armControl arm (n = 430)(n = 436)HR status Positive275/430(64)275/436(63)Negative141/430(33)143/436(33)Unknown14/430(3)18/436(4)G 3/4 toxicity Neutropenia36/385(9)5/326(2)Fatigue6/426(1)0/417(0)Diarrhea12/426(3)1/417(&lt;1)HFS(G3)47/424(11)0 JPN40/296(14)0 KRN7/128(5)0 VB66/73(8)- No VB641/351(12)-ALT abnormality10/409(2)3/391(&lt;1) with RT8/285(3)1/280(&lt;1) X → RT8/31(26)- RT → X0/254(0)- without RT2/124(2)2/111(2) with HT2/214(1)1/267(&lt;1) X + HT0/190(0)- X → HT2/24(8)- wothout HT8/195(4)2/124(2)

Conclusions

Addition of 8 cycles of X to standard adjuvant therapy is feasible and tolerable, resulting in a modest yet acceptable increase in toxicities. The timing of RT and HT administration relative to X influenced the incidence of adverse events. HFS was more common in JPN than KRN pts, although further investigation of the potential cause of this difference is required. These findings should be interpreted in light of efficacy data, expected in 2015.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-12-03.

Abstract P6-06-20: Predictive factors for pathologic complete response and disease-free survival after neoadjuvant chemotherapy with trastuzumab: A multicenter retrospective observational study in patients with HER2-positive primary breast cancer (JBCRG-C03 study)

BACKGROUND:

Addition of trastuzumab to neoadjuvant chemotherapy (NAC) improved pathologic complete response (pCR) rate in HER2-positive breast cancer. Although recent trials have shown favorable prognosis with NAC plus trastuzumab, clinicopathological factors to predict the outcome have not been fully understood. The aim of this study was to investigate the survival after NAC with trastuzumab and to explore the predictive factors.

PATIENTS AND METHODS:

This is a multicenter retrospective observational study. Patients with HER2-positive primary breast cancer treated with NAC plus trastuzumab from 2001 to 2010 were identified from the institutional database. Primary end point was disease-free survival (DFS). pCR was defined as ypT0/is+ypN0. Kaplan-Meier method was used to estimate DFS. Logistic regression and proportional hazard analysis were used to identify clinicopathological factors to predict pCR and DFS, respectively.

RESULTS:

733 patients were included in the analysis (whole dataset). 425 were ER/PgR-negative (HR- dataset) and 306 were ER/PgR-positive (HR+ dataset). Radiation therapy was performed in 90% of lumpectomy and 31% of mastectomy. Hormonal therapy was performed in 84% of HR+ dataset. pCR rate was 45% in whole dataset, 60% in HR- dataset, and 34% in HR+ dataset. Table 1 showed the result of multivariate analysis for pCR in whole dataset. When HR+ and HR- dataset were analyzed separately, no definitive predictors for pCR were identified in multivariate analysis. Although the patients with pCR showed a significantly favorable prognosis than those without pCR at 3 years DFS, in whole dataset (93% vs 83%, p&lt;0.0001) and HR- dataset (94% vs 80%, p&lt;0.0001), there was no significant difference in HR+ dataset (89% vs 86%, p = 0.10). Different predictors were selected for DFS when multivariate analysis was conducted separately between HR- and HR+ dataset (Table 2).

CONCLUSIONS:

In this observational study, we clarified predictors for pCR and DFS in HER2-positive patients treated with neoadjuvant trastuzumab containing therapy based on tumor subtype. Our results may help us to predict the prognosis more precisely and to simulate the disease course.

Table 1) Multivariate logistic regression analysis for pCR in whole datasetFactorsOR95%CIp-valuePost- vs Pre-menopause1.50(1.05-2.15)0.026*cT1-2 vs cT3-41.72(1.16-2.59)0.008*ER/PgR-negative vs ER/PgR-positive3.32(2.30-4.82)&lt;0.0001*Grade 3 vs 1-21.28(0.89-1.84)0.183

Table 2) Multivariate proportional hazard analysis for DFSFactors†HR95%CIp-valueWhole dataset   Pre- vs Post-menopause1.61(1.04-2.52)0.033*cN2-3 vs cN03.06(1.58-6.24)0.001*cN1 vs cN02.26(1.23-4.41)0.007*Grade 3 vs 1-21.87(1.20-2.97)0.006*non-pCR vs pCR1.90(1.18-3.13)0.008*HR- dataset   Pre- vs Post-menopause1.70(1.01-2.85)0.046*cT3-4 vs cT1-21.86(1.09-3.17)0.024*non-pCR vs pCR3.28(1.90-5.87)&lt;0.0001*HR+ dataset   cN2-3 vs cN05.01(1.79-16.19)0.002*cN1 vs cN03.50(1.40-10.61)0.006*Grade 3 vs 1-22.95(1.52-5.87)0.001*†Only factors with statistical significance

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-20.

Abstract P6-07-39: Prognostic Value of Body Mass Index in Japanese Breast Cancer Patients: A Collaborative Study by the Kobe Breast Cancer Oncology Group and Hokkaido Cancer Center

Background: Many recent clinical trials conducted in Western populations suggest that obesity is a prognostic factor after primary treatment in postmenopausal breast cancer patients. However, the incidence of obesity differs substantially between Asian and Western breast cancer patients. Moreover, few studies have reported the relationship between body mass index (BMI) and postsurgical prognosis in Asian breast cancer patients. A previous retrospective analysis of Japanese populations revealed that obesity might be a prognostic risk factor in Japanese breast cancer patients.

Methods: We retrospectively analyzed BMI and clinical outcomes after primary treatment in Japanese breast cancer patients of Hanshin and Hokkaido areas. We reviewed the clinical data (height, weight, BMI, estrogen receptor [ER] status, progesterone receptor status [PgR], human epidermal growth factor receptor 2 [HER2] status, and outcome) of 1,222 primary breast cancer patients with clinical stage I-III disease who were operated on between Jan 2004 and Dec 2005 at Kobe Breast Cancer Oncology Group (KBCOG) and Hokkaido Cancer Center (median follow-up period, 74 months). The patients were categorized into 4 groups: underweight (BMI, &lt;18.5 kg/m2), normal (18.5–24.9 kg/m2), overweight (25–29.9 kg/m2), and obesity (&gt;30.0 kg/m2). Patient characteristics, excluding age and menopausal status, were well-balanced across groups. The correlations of BMI with disease-free survival (DFS) and overall survival (OS) were analyzed using the Cox hazards model.

Results: The normal, underweight, overweight, and obesity groups contained 832 (68.1%), 92 (7.5%), 253 (20.7%), and 45 (3.7%) patients, respectively. Breast cancer recurred in 184 patients (15.0%); 75 patients died due to breast cancer recurrence, 29 died of other diseases, and 6 died of unknown causes. The univariate hazard ratio (HR) values for disease-free survival and overall survival in the overweight group were significantly lower than those in the normal group. However, there were no statistical significant differences among four groups by the multivariate analysis. We added subgroup analysis with classifications by ER and PgR status to speculate the cause for these unexpected results. Although there were no statistically significant differences, HRs for DFS and OS in the obesity group were higher than those in the normal group among ER− and/or PgR-positive patients. However, HRs for DFS and OS tended to be higher in the underweight groups and lower in the overweight groups in ER− and PgR-negative populations.

Conclusions: The incidence of obesity in the Japanese population is much lower than that in the Western population. Although results of this study were slightly different from recent findings, obesity might be a risk factor for DFS and OS in ER-positive Japanese breast cancer patients, similar to that in Western countries. In underweight patients, ER− and PgR-negative status might indicate poor prognosis. However, this study was a retrospective analysis of a limited, heterogeneous patient group. A large-scale cohort study in the Japanese population is, therefore, recommended.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-07-39.

MUC1 enhances hypoxia-driven angiogenesis through the regulation of multiple proangiogenic factors

Pancreatic cancer is one of the most lethal malignancies due to its aggressive growth and rapid development of distant metastases. In this context, mucin 1 (MUC1) overexpression and hypoxia are frequently observed events. However, their functional relationship remains largely unknown. This study provides evidence that MUC1 is overexpressed by hypoxia and contributes to hypoxia-driven angiogenesis. Using the conditioned medium obtained from hypoxia-stressed AsPC1 cells treated with MUC1 siRNAs, we demonstrated that MUC1 enhanced the endothelial tube formation, proliferation and migration ability, which induced by hypoxia-conditioned medium (HCM). In addition, MUC1 was significantly induced by hypoxia, especially in the pancreatic cancer cells derived from metastatic tumors (AsPC1, HPAF2 or Capan1), and MUC1-cytoplasmic tail (MUC1-CT) accumulated in the nucleus under hypoxia. As noted in a previous report, MUC1-CT was recruited to genomic regions upstream of the connective tissue growth factor (CTGF) accompanied with β-catenin and p53, resulting in the hypoxic induction of CTGF. Moreover, hypoxia-induced MUC1 partially regulated two other hypoxia-inducible proangiogenic factors including vascular endothelial growth factor-A and platelet-derived growth factor-B. The neutralization assay revealed that endothelial tube formation induced by HCM was clearly suppressed by antibodies against these three factors, suggesting the importance of these factors in hypoxia-driven angiogenesis. In summary, this is the first report demonstrating a pivotal role of MUC1 in controlling the hypoxia-driven angiogenesis through the regulation of multiple proangiogenic factors in pancreatic cancer. Our findings provide the novel insights into the understanding of complex interactions between pancreatic cancer cells and tumor microenvironments.

MO-F-213AB-04: Biological Effect of Dose Shadowing by Fiducial Markers in Spot Scanning Proton Therapy with a Limited Number of Fields

PURPOSE

In spot scanning proton therapy, accurate patient positioning before and during treatment is essential. A small gold ball marker is suitable as a fiducial for prostate treatment. However, it has been pointed out that the marker causes dose shadowing because the protons are scattered with their energy quickly diminished. In this research we explore the possibility that the biological effect of dose shadowing can be mitigated with a limited number of fields.

METHODS

The proton dose distribution in prostate was simulated using Geant4. The simulations include the Hokkaido University spot scanning nozzle and a water phantom positioned isocentrically. The PTV was delineated at the center of the phantom and a gold ball of 2 mm in diameter was placed at the middle of the PTV. The plan was created by single-field optimization and each of the following beam arrangements was investigated; (1) single lateral field (2) two lateral fields (3) two lateral + one anterior fields (4) four-field box. The dose prescription was D95 = 74 GyE (37 fr). The minimum dose and tumor control probability (TCP) were compared for the four beam arrangements.

RESULTS

For (1)-(4), the minimum dose values were 55%, 77%, 78%, and 84% of the prescribed dose, respectively. The reduction of the TCP values from those in the absence of the gold marker were 50%, 2%, 1.1%, and 0.7%, using the TCP model by Wang et al. (Int.J.Radiat.Oncol.Biol.Phys. 55, 2003) and 2%, 0.7%, 0.5%, and 0.4%, using the biological parameters in Levegrün et al. (Int.J.RadiatOncol.Biol.Phys. 51, 2001), respectively.

CONCLUSIONS

Although dose shadowing by the gold marker is locally non-negligible, the size of the affected domain is tiny. It was found that with a minimum number of fields, the TCP nearly recovers to the value without the gold marker.

Prospective Study of Ice Gel Pack as Less Expensive Alternative for Prevention of Skin and Nail Toxicity in Patients with Breast Cancer Receiving Docetaxel

Background: Docetaxel (DTX)-induced nail and skin toxicity can be prevented by frozen glove. We investigate whether we can use cooling gel pad (CGP), which is available less than 10 dollars in Japan, as less expensive alternative.Method: Patients (pts) with breast cancer receiving DTX as preoperative or post operative chemotherapy were eligible for this study. Two CGPs, which were refrigerated for eight hours beforehand, were used to cover patient's hand from 15 minutes before to 15minutes after DTX administration. To reduce discomfort from icing, pts were wearing cotton glove during CGP usage. If pts felt CGP as too cold during the cooling process, they were allowed to remove CGP tentatively until they felt comfort. Another hand was not covered as the control. Nail and skin toxicity were assessed at each cycle by CTCAEver.3.0 and documented by photography. Fisher's exact probability test was used. Satisfaction and discomfort of CGP covering was assessed by pts using two item questionnaires. All patients gave written informed consent. The protocol was approved by institutional review board.Result: From October 2006 to September 2008, 50 pts were enrolled to this study. All the patients were female, and received DTX 75mg/m2 in every three weeks schedule for four cycles. Most of patients received DTX after anthracycline-containing regimen. Both nail (10% v 66%, p&lt;0.0001) and skin (0% v 34%, p&lt;0.0001) toxicity was reduced in CGP covered hands. Nail toxicity was grade (G) 0 in 90% v 34%, G1 in 10% v 42%, G2 in 0% v 22%, and G3 in 0% v 2%, for CGP covered and the control hand, respectively. Skin toxicity was G0 in 100% v 66%, G1 in 0% v 4%, G2 in 0% v 30% in CGP covered hand and the control hand, respectively. About the timing of toxicity occurrence, “after the first cycle” was most common, 13 pts (39%) in nail change and 7 pts (41%) in skin toxicity. In the questionnaires, 94% were satisfied with CGP covering.Discussion: The iced CGP cover method reduced the incidence and severity of nail and skin toxicity associated with DTX, even if patients wear cotton glove and remove CGP for a while, in case of excess coldness. This method has no adverse effect, and patients were satisfied with the effect. The iced CGP may be considered as a new, effective and less expensive method for prevention of nail and skin toxicity caused by DTX.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1114.

Induction of primary systemic therapy by weekly paclitaxel: Predictive value of hormone receptors, HER-2, topoisomerase II- alpha, and other biological markers in relation to pathological complete response

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Background: Randomized phase II study of epirubicin(E) plus cyclophosphamide (C) vs. weekly paclitaxel (P) as primary systemic therapy (PST) in stage II and III breast cancer(BC) have shown that there was no significant difference in the pathological complete response (pCR) rate between the EC and P groups (#568 ASCO 2008). The aim of this study is to evaluate the predictive value of hormone receptors, HER2, topoisomerase IIα(TOP II) and other biological markers in the EC and P groups as PST. Methods: Tissue samples were obtained before PST from pts who were randomized to either Arm A (EC: E 75 mg/m2 and C 600 mg/m2 every 3 W for 4 cycles) or Arm B (weekly P: P 80 mg/m2 weekly for 12 w). Pts received PST for 12 w, then underwent surgery. All pts received a crossover regimen as adjuvant chemotherapy.The pretreatment expression of estrogen receptor (ER), progesterone receptor(PgR), HER2, P53, Ki67, P21 and CD31 were analized by immunohistochemical staining. The status of TOP II gene was evaluated by FISH. Results: One-hundred- sixty pts (Arm A: n=82, Arm B: n=78 ) were estimable. The pCR rates were 13.4% in Arm A and 17.9% in Arm B(p=0.43). In both arms, pCR rate was significantly higher for pts whose tumors did not express ER nor PgR(ER/PgR-) compared with the receptor positive(ER/PgR+) pts. Pts with HER2 positive tumors tend to have higher pCR rate in Arm B compared with Arm A (32.2% vs. 12.5%;p=0.11). The pCR rate for pts with HER2 negative BC were not different in both Arms(A:14.0% vs. B:8.5%). Pts with triple negative (TN) (ER/PgR, HER2-) BC achieved almost same pCR in both Arms (A:25.0% vs. B:23.1%). However, the pCR rate for pts with nonTN BC was significantly higher in ArmB compared to Arm A (16.9% vs. 8.6%, p<0.001). The deletion and amplification of TOP II gene were not predictive of higher pCR rate to ArmA than to Arm B. The pretreatment expression of P53, Ki67, P21 and CD31 was unlikely to predict the higher response of any Arm. Conclusions: Althogh valuable predictive factor of pCR were not detected between EC and weekly P group, the efficacy of weekly P therapy as PST were equal to EC therapy regardless of HR,HER2 and TOP II gene status. Therefore, induction of PST by weekly P therapy seems to be promising.

No significant financial relationships to disclose.