Abstract P5-14-02: Clinical predictors of benefit from fulvestrant in advanced breast cancer: A meta-analysis of randomized controlled trials

Background: While fulvestrant is approved by the United Stated Food and Drug Administration as an alternate endocrine therapy for treatment of advanced breast cancer, data on its efficacy compared to other endocrine treatments are inconsistent. Clinical markers predictive of greater benefit from fulvestrant compared to the alternate endocrine agents have not been identified.

Methods: We searched the literature from inception to May, 2015 from MEDLINE, EMBASE, and major conference proceedings. We included randomized controlled trials that evaluated Fulvestrant compared to either tamoxifen or an AI. We collected the efficacy data reported as Time to Progression (TTP) or Progression Free Survival (PFS) on 7 distinct subgroup of patients from the RCTs defined by: age, time to cancer reoccurrence from primary diagnosis, presence of visceral metastasis, previous chemotherapy exposure, presence of measurable disease, hormone receptor status and, HER-2 status. Data on rates of occurrences of 9 most frequently reported adverse events were also collected from both arms of the studies. Data on both efficacy and toxicity were then weighted using generic inverse variance approach and pooled in a meta-analysis using RevMan 5.3 software.

Results: We identified 8 RCTs that fulfilled our criteria and involved 4,024 patients (2,032 on fulvestrant and 1,992 on control arms). TTP/PFS was the primary endpoint in 7 out of 8 RCTs and secondary endpoint in one. Compared to an AI or tamoxifen, there was a statistically significant improvement in TTP favoring fulvestrant in patients who had visceral metastasis [Hazards Ratio (HR) 0.86; 95% Confidence Interval (CI) 0.77 to 0.96, p<0.01], measurable disease [HR 0.74; 95% CI 0.58 to 0.93, p=0.01], and HER-2 overexpression [HR 0.43; 95% CI 0.27 to 0.70, p<0.001]. Similar effect sizes were observed in a sensitivity analysis excluding the trials of combinations of fulvestrant and AI in the experimental arm. Rates of occurrences of adverse events were similar between fulvestrant and other endocrine agents.

Conclusion: Patients with advanced breast cancer that have visceral disease, measurable disease, or HER-2 driven disease are likely to derive higher benefits from treatment with fulvestrant compared to tamoxifen or an AI. These results may have implications for selection of patients in the design of future clinical trials and to inform treatment decisions in clinical practice.

Citation Format: Niraula S, Pitz M, Gordon V, Grenier D, Amir E, Brandes L. Clinical predictors of benefit from fulvestrant in advanced breast cancer: A meta-analysis of randomized controlled trials. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-14-02.

Abstract P2-02-12: Association of inflammatory and tumor markers with circulating tumor cells in metastatic breast cancer

Background: Circulating tumor cells (CTCs) are associated with prognosis in metastatic breast cancer (BC). We evaluated the association of inflammatory/tumor markers and CTCs in women with progressing metastatic breast cancer prior to commencing a new line of systemic therapy.

Methods: From February 2013 to April 2015, 96 patients with metastatic BC about to start a new treatment (due to progression), without current diabetes or use of anti-inflammatory agents, were recruited from four Ontario cancer hospitals. Women provided fasting blood for inflammatory and tumor markers and CTC measurement; CTCs were assayed within 72 hours of collection using CellSearch. Blood was frozen at -80C until assays were performed in a single batch (C-reactive protein (CRP), IL-6, PAI-1, Ca15-3, Ca125, VEGF, TNFa). Associations of CTCs with blood factors were evaluated using Pearson correlation coefficients after transforming the variables to normality. For CTCs the transformation log(x+0.5) was used. Associations with categorical variables were tested using one-way analysis of variance. P values <0.05 were significant.

Results: Median age of patients was 60.5 years, 87 (90.6%) were post-menopausal, 83 (86.5%) had hormone receptor positive BC, 16 (16.7%) HER2 positive BC, 10 (10.4%) triple negative; 75 (78.1%) grade II/III. At the time of CTC measurement, bone, lung, liver and brain metastases were present in 79%, 44%, 40% and 6% of patients respectively, with 54%, 37%, 35% and 3% having progression at these sites respectively. PAI-1 and CA15-3 exceeded the limit of the assay in 11 and 5 cases respectively (the upper limit of the assay was used in the analysis). 33.4% of patients were starting first line therapy, 25% second line and 16.7% third line. CTC counts (per 7.5cc) ranged from 0 to 1238 (median 2, geometric mean 3.63); none were detected in 29 (30.2%) patients, 1 to 4 in 25 (26%) and 5 or more in 42 (43.8%) patients. CTCs were not associated with age, estrogen receptor, progesterone receptor, HER2, line of treatment, lymph-vascular invasion or tumor grade. Compared to metastatic disease at other sites, CTCs were higher in the presence of bone (p=0.027) and liver metastases (p=0.002) and with progressing bone (p=0.018) and liver (p=0.012) metastases. CTCs were significantly associated with CRP (R =0.25, p=0.014), IL-6 (R=0.31, p=0.002), PAI-1 (R=0.31, p=0.002), Ca15-3 (R=0.44, p=<0.0001) and Ca 125 (R=0.21, p=0.04) but not with VEGF and TNFa (R = 0.11, p= 0.29 and R = 0.16, p=0.11, respectively).

Conclusion: CTCs were associated with bone and liver metastases and with higher levels of inflammatory and tumor markers, potentially reflecting tumor burden. Additional inflammatory marker assays are underway. Future studies are warranted to confirm these findings.

Citation Format: Lohmann AE, Chang M, Dowling RJO, Ennis M, Amir E, Elser C, Brezden-Masley C, Vandenberg T, Lee E, Fazae K, Stambolic V, Goodwin PJ. Association of inflammatory and tumor markers with circulating tumor cells in metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-02-12.

Abstract P2-02-09: Obesity associated factors are inversely associated with circulating tumor cells in metastatic breast cancer

Background: Elevated levels of circulating tumor cells (CTCs) are associated with adverse outcomes in metastatic breast cancer (BC). However, relationships between CTCs and various patient-related factors that may impact outcome remain undefined. Consequently, associations of CTC counts with obesity and metabolic factors were evaluated in order to gain insight into potential interactions between patient physiology and disease burden. We hypothesized that obesity and associated metabolic factors would be associated with higher CTC counts.

Methods: Non-diabetic women with metastatic BC beginning a new line of treatment due to progressive disease were recruited from four Ontario cancer hospitals between February 2013 and April 2015. Patients provided blood for CTC analysis, which was completed within 72 hours of collection using the Janssen CellSearch platform. Fasting serum was also collected for assessment of metabolic factors including glucose (mmol/L), insulin (pmol/L), leptin (ng/mL) and adiponectin (ng/mL). Associations of CTC counts with these factors, as well as anthropometric measurements (height (cm), weight (kg), BMI (kg/m2)) were evaluated using Pearson correlation coefficients after transforming the variables involved to normality. For CTC counts, the log transformation with half integer correction was used.

Results: 96 patients with a median age of 60.5 years completed the study. Most were post-menopausal (87, 90.6%) and exhibited grade II/III tumors (75, 78.1%). The majority of patients had hormone receptor positive disease (83, 86.5%), but 16.7% (16) were HER2 positive and 10.4% (10) were triple negative. The number of CTCs observed ranged from 0 to 1238 (median 2, geometric mean 3.63). No CTCs were detected in 29 patients (30.2%), whereas 25 patients (26 %) exhibited counts of 1 to 4 CTCs and 42 (43.8%) had 5 or more CTCs. CTCs were not significantly associated with tumor characteristics including ER/PgR, HER2, grade, stage (T/N) or lymphovascular invasion. The number of CTCs inversely correlated with BMI (r=-0.26, p=0.01), leptin (r=-0.29, p=0.004), and leptin-adiponectin ratio (r=-0.3, p=0.004). A similar trend that approached significance was noted for body weight (r=-0.19, p=0.07), insulin (r=-0.19, p=0.06) and homeostatic model assessment (HOMA, an estimate of insulin resistance, r=-0.2, p=0.055). Conversely, adiponectin (r=0.18, p=0.07) and height (r=0.18, p=0.07) were positively associated with CTC counts in correlations that neared significance. No associations were observed for age (r=0.09, p=0.4) or glucose (r=-0.09, p=0.4).

Conclusions: Obesity associated metabolic factors including weight, BMI, insulin, HOMA and leptin were inversely associated (and adiponectin and height positively associated) with CTC counts. These patterns are consistent with weight loss and/or cachexia in women with elevated CTC counts who have higher disease burden. Additional analyses are underway to further characterize these associations and include assessment of serum albumin, free fatty acids, creatine kinase and hepcidin.

Citation Format: Dowling RJO, Chang MC, Lohmann AE, Ennis M, Amir E, Elser C, Brezden-Masley C, Vandenberg T, Lee E, Fazaee K, Stambolic V, Goodwin PJ. Obesity associated factors are inversely associated with circulating tumor cells in metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-02-09.

Abstract P6-12-02: Association between a dedicated program for young breast cancer patients and discussion about fertility preservation

Purpose: To assess whether a dedicated program, including a nurse navigator, improves the frequency of: a) documentation of fertility discussion and b) referrals for fertility preservation (FP).

Methods: A retrospective chart review and prospective survey were undertaken of a cohort of young breast cancer patients diagnosed between 2011-2013 at two academic centres in Toronto, Ontario. The Odette Cancer Center (OCC) has a dedicated program for young breast cancer patients while Princess Margaret Cancer Centre (PM) does not. Documentation of fertility discussion prior to receipt of systemic therapy was extracted from patient records. Prospective surveys were administered to the same cohort to corroborate data collected. Descriptive statistics were used to characterize baseline patient variables. Chi-squared was used to compare categorical variables and t-tests for continuous variables between the two cancer centres. Statistical significance was defined as p<0.05.

Results: At OCC and PM respectively, 91 and 81 patient charts were reviewed while 54 and 49 women returned surveys for response rates of 59% and 60% . Chart reviews demonstrated no difference in the frequency of documentation of fertility discussion (80% versus 75% for OCC and PM, p=0.44); however, surveys demonstrated higher recall of fertility discussion rates at OCC (96% versus 83%, p=0.046). A greater proportion of women were offered FP referrals at OCC, as observed in both chart reviews (53% versus 41%, p=0.18) and surveys (70% versus 46%, p=0.02). Time to initiation of chemotherapy did not significantly differ between women who underwent FP and those who did not.

Conclusion: A dedicated program for young women with breast cancer including a nurse navigator is associated with a higher frequency of FP referrals without delaying systemic therapy.

Citation Format: Srikanthan A, Amir E, Warner E. Association between a dedicated program for young breast cancer patients and discussion about fertility preservation. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-12-02.

Abstract P2-08-05: Association between the neutrophil-to-lymphocyte ratio (NLR) and the 21-gene recurrence score

Introduction: A high neutrophil-to-lymphocyte ratio (NLR) has been reported to be a poor prognostic indicator in several malignancies including breast cancer. It is unknown whether the prognosis associated with high NLR can be explained by other prognostic factors such as proliferation or estrogen receptor signalling. Here we explore the association between NLR and the 21-gene recurrence score (RS).

Methods: The associations between RS, NLR, tumor size, histologic grade, and estrogen receptor (ER) and progesterone receptor (PgR) expression (assessed by immunohistochemistry) were explored in sequential women with early-stage, lymph node-negative (or with lymph node micrometastases), ER-positive and HER2-negative breast cancer treated at Princess Margaret Cancer Centre in Toronto, Canada and in whom results of the RS were available. NLR was measured prior to surgery. Patients with a documented history of pre-existing infectious/inflammatory condition were excluded. Associations were explored using simple linear regression and statistical significance was defined as p<0.05.

Results: A total of 130 women diagnosed between January 2006 and April 2015 were included in the analysis. Median age was 55 (range 32-79), 87% were lymph node negative and 13% had nodal micrometastases. The median NLR was 2.2 (range 0.9-9.1) and was collected at a median of 12 days prior to surgery (range 0-60). The median RS was 18 (range 0-41). There was no association between RS and NLR (R=-0.10, p=0.31), grade (R=0.13, p=0.15), age (R=-0.05, p=0.58) or tumor size (R=0.06, p=0.48). RS was negatively associated with the magnitude of expression of both ER (R=-0.22, p=0.01) and PgR (R=-0.44, p<0.001). There was no association between NLR and grade (R=0.20, p=0.15), age (R=-0.13, p=0.17), tumor size (R=0.14, p=0.93), ER (R=0.01, p=0.94) or PgR (R=0.13, p=0.23)

Conclusion: The poor outcomes associated with high NLR are unlikely explained by proliferation of estrogen receptor signalling.

Citation Format: Srikanthan A, Bedard PL, Goldstein S, Templeton A, Amir E. Association between the neutrophil-to-lymphocyte ratio (NLR) and the 21-gene recurrence score. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-05.

Economic evaluation of hormonal therapies for postmenopausal women with estrogen receptor-positive early breast cancer in Canada

BACKGROUND

Aromatase inhibitor (ai) therapy has been subjected to numerous cost-effectiveness analyses. However, with most ais having reached the end of patent protection and with maturation of the clinical trials data, a re-analysis of ai cost-effectiveness and a consideration of ai use as part of sequential therapy is desirable. Our objective was to assess the cost-effectiveness of the 5-year upfront and sequential tamoxifen (tam) and ai hormonal strategies currently used for treating patients with estrogen receptor (er)-positive early breast cancer.

METHODS

The cost-effectiveness analysis used a Markov model that took a Canadian health system perspective with a lifetime time horizon. The base case involved 65-year-old women with er-positive early breast cancer. Probabilistic sensitivity analyses were used to incorporate parameter uncertainties. An expected-value-of-perfect-information test was performed to identify future research directions. Outcomes were quality-adjusted life-years (qalys) and costs.

RESULTS

The sequential tam-ai strategy was less costly than the other strategies, but less effective than upfront ai and more effective than upfront tam. Upfront ai was more effective and less costly than upfront tam because of less breast cancer recurrence and differences in adverse events. In an exploratory analysis that included a sequential ai-tam strategy, ai-tam dominated based on small numerical differences unlikely to be clinically significant; that strategy was thus not used in the base-case analysis.

CONCLUSIONS

In postmenopausal women with er-positive early breast cancer, strategies using ais appear to provide more benefit than strategies using tam alone. Among the ai-containing strategies, sequential strategies using tam and an ai appear to provide benefits similar to those provided by upfront ai, but at a lower cost.

Neutrophil/lymphocyte ratio as a prognostic factor in biliary tract cancer

BACKGROUND

Biliary tract cancers (BTCs) include intrahepatic (IHC), hilar, distal bile duct (DBD) and gallbladder carcinoma (GBC). Neutrophil/lymphocyte ratio (NLR), a marker of host inflammation, is prognostic in several cancers but has not been reviewed in large BTC series, or advanced BTC (ABTC) at diagnosis.

PATIENTS AND METHODS

Baseline demographics and NLR at diagnosis were retrospectively evaluated in 864 consecutive patients with BTC treated from January 1987 to December 2012. The association between NLR and overall survival (OS) was determined using a multivariable Cox proportional hazards model.

RESULTS

Eight hundred and sixty-four patients were included in the analysis, of which 62% had ABTC and 38% had surgery with curative intent. Median age was 65 years, 444 (51%) were male and 727 (84%) had performance status (PS) ⩽ 2. A NLR ⩾ 3.0, PS >2, IHC primary, stage, lack of surgery, haemoglobin <110 g/L and albumin <40 g/L were associated with significantly worse OS on multivariable analysis. A NLR ⩾ 3.0 was an independent prognostic factor for OS for the entire cohort; median OS was 21.6 months versus 12.0 months for patients with NLR <3.0 versus NLR ⩾ 3.0 respectively (adjusted hazard ratio (HR)-1.26, 95% confidence interval (CI); 1.06-1.50, P = 0.01). NLR was also prognostic in patients with ABTC (HR-1.26, 95% CI; 1.02-1.56, P = 0.035) and hilar cancer: overall group (N = 149) (HR-1.70, 95% CI; 1.10-2.50, P = 0.01) and advanced group (N = 111) (HR-1.57, 95% CI; 1.04-2.44, P = 0.048).

CONCLUSION

Baseline NLR is a readily available and inexpensive prognostic biomarker in patients with BTC and likely warrants validation in large prospective clinical trials.

Abstract P6-06-12: Prognostic significance of pretreatment neutrophil/-lymphocyte ratio in breast cancer: A meta-analysis

Background: There is an increasing body of evidence that the host inflammatory response plays an important prognostic role in cancer. High level of the neutrophil/lymphocyte ratio (NLR) has been associated with poor prognosis in many cancers. The association of NLR with survival in breast cancer and its different subtypes remains unclear.

Methods: A literature review of electronic databases was conducted to identify studies exploring the prognostic role of NLR in breast cancer. Data were extracted from individual publications or estimated from associated figures. Where possible, data were included in a meta-analysis. The association of high NLR with other classical prognostic factors (e.g. tumor size, histological grade, nodal metastasis, and estrogen receptor or HER2/neu expression) was evaluated using the Mantel-Haenszel odds ratio (OR). Both univariable and multivariable analyses of NLR with overall survival (OS) were assessed using generic inverse variance. Subgroup analysis was conducted to assess the effect of different cut-offs to define high versus low NLR. Breast cancer-specific survival was assumed to be equivalent to OS if non-breast cancer deaths contributed to &lt;5% of evaluable patients.

Results: The analysis included a total of 5 retrospective studies comprising of 3,449, predominantly early-stage, breast cancer patients. Three studies defined high NLR based on the most discriminating cut-off evaluated by receiver operator characteristic (ROC) analysis, while two studies compared upper to lower quartiles for NLR. The mean age was 56.9 and there were no differences in age between those with high and low NLR (mean difference +1.54 years, 95% confidence intervals [CI] -0.17-3.24, P = 0.08). Compared with low NLR, patients with high NLR were more likely to have tumors larger than 2cm (OR 1.69, 95% CI 1.23-2.32, P = 0.001), nodal metastases (OR 1.65, 95% CI 1.21-2.23, P = 0.001) and HER2/neu overexpression or amplification (OR 1.77, 95% CI 1.20-2.62, P = 0.004). There were no differences in the proportion of tumors that were high grade (OR 1.27, 95% CI 0.90-1.79, P = 0.18) or estrogen receptor positive (OR 0.76, 95% CI 0.54-1.09, P = 0.13) between those with high and low NLR. High NLR showed an association with worse OS (univariable hazard ratio [HR] 3.42, 95% CI 2.75-4.24, P&lt;0.001). This association was retained in multivariable analyses (HR 3.16, 95% CI 2.13-4.68, P&lt;0.001). There was no difference in this association with worse survival when NLR was assessed based on a single cut-off or when compared between upper and lower quartiles (subgroup difference P = 0.68, table).

Conclusion: High NLR is associated with various poor prognostic factors, but despite this appears to be an independent factor for worse survival from breast cancer. These findings may be explained by an adverse host response to cancer.

SubgroupNumber of studiesHR for OS95% CIPCut-off determined by ROC analysis33.362.64-4.29&lt;0.001Upper versus lower quartile23.872.08-7.23&lt;0.001

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-12.

Translating clinical trials to clinical practice: outcomes of men with metastatic castration resistant prostate cancer treated with docetaxel and prednisone in and out of clinical trials

BACKGROUND

Multiple factors can influence outcomes of patients receiving identical interventions in clinical trials and in routine practice. Here, we compare outcomes of men with metastatic castrate-resistant prostate cancer (mCRPC) treated with docetaxel and prednisone in routine practice and in clinical trials.

PATIENTS AND METHODS

We reviewed patients with mCRPC treated with docetaxel at Princess Margaret Cancer Centre. Primary outcomes were overall survival and PSA response rate. Secondary outcomes were reasons for discontinuation and febrile neutropenia. Outcomes were compared for men treated in routine practice and in clinical trials, and with data from the TAX 327 study.

RESULTS

From 2001 to 2011, 438 men were treated, of whom 357 received 3-weekly docetaxel as first-line chemotherapy: 314 in routine practice and 43 in clinical trials. Trial patients were younger and had better performance status. Median survival was 13.6 months [95% confidence interval (95% CI) 12.1-15.1 months] in routine practice and 20.4 months (95% CI 17.4-23.4 months, P = 0.007) within clinical trials, compared with 19.3 months (95% CI 17.6-21.3 months, P < 0.001) in the TAX 327 study. PSA response rates were 45%, 54%, and 53%, respectively (P = NS). Reasons for treatment discontinuation were similar although trial patients received more cycles (median: 6 versus 8 versus 9.5, P < 0.001). Rates of febrile neutropenia were 9.6, 0, and 3% (P < 0.001) while rates of death within 30 days of last dose were 4%, 0%, and 3%, respectively (P = NS).

CONCLUSIONS

Survival of patients with mCRPC treated with docetaxel in routine practice is shorter than for men included in trials and is associated with more toxicity.