Adjuvant carboplatin and paclitaxel with "sandwich" method radiotherapy for stage III or IV endometrial cancer: long-term follow-up at a single-institution

OBJECTIVE

To evaluate disease-free survival (DFS) and overall survival (OS) associated with adjuvant carboplatin and paclitaxel chemotherapy interposed with radiation for advanced endometrial cancer.

METHODS

This is a cohort study of adult women with stage III or IV endometrial cancer treated at a single institution, between April 2002 and October 2017. Tumor and treatment characteristics were recorded. Treatment consisted of 4 cycles of intravenous paclitaxel and carboplatin every 3 weeks, followed by external beam radiotherapy to the pelvis (45-50 Gy), and another 2 cycles of chemotherapy. One cohort of patients were prospectively enrolled from 2002 through 2006 and an additional cohort from 2007 to 2017, which was retrospectively analyzed. Primary endpoints for this study were DFS and OS rates which were calculated using Cox regression models.

RESULTS

Eighty-two patients with a median age of 66.5 years (range, 35-83 years) were included. Median follow-up was 46 months (range, 9-196 months). Most patients had stage IIIC disease (62.2%) and serous carcinoma histology (46.3%). Median OS was 146 months and median DFS was 71 months. A 5-year OS and DFS were 64.9% and 55.7%, respectively. Age >60 years subgroup was at a significantly higher risk of DFS event or death. Histological subtype, location of positive nodes, and cancer stage (IIIa vs. higher stage) did not correlate to a higher risk of recurrence or death.

CONCLUSION

Long term follow-up and a larger population confirm that the chemoradiotherapy sandwich method yields favorable outcomes in patients with high-risk endometrial cancer.

Antibody-Drug Conjugates in Breast Cancer: Ascent to Destiny and Beyond-A 2023 Review

Antibody-drug conjugates (ADCs) are revolutionizing cancer treatment, adding another important new class of systemic therapy. ADCs are a specially designed class of therapeutics that target cells expressing specific cancer antigens using directed antibody-drug delivery and release a cytotoxic chemotherapeutic payload. Over the past two decades, improvements in ADC design, development, and research, particularly in breast cancer, have led to several recent landmark publications. These advances have significantly changed various treatment paradigms and revamped traditional classifications of breast cancer with the introduction of a potential new subtype: "HER2-low". This review will focus on several ADCs developed for breast cancer treatment, including trastuzumab emtansine (T-DM1), trastuzumab deruxtecan (T-DXd), sacituzumab govitecan (SG) and other newer emerging agents. It will provide an overview of the role of ADCs in breast cancer and discuss the opportunities and challenges they present. Additionally, our review will discuss future research directions to improve the selection of targets, combination therapies, and aim to improve drug safety. Important first-line metastatic and adjuvant clinical trials are underway, which may expand the role of ADC therapy in breast cancer. We foresee ADCs driving a new era of breast cancer treatment, adding to the steady incremental survival advantage observed in recent years.

Body composition and endometrial cancer outcomes

BACKGROUND

Obesity is a known risk factor for developing endometrial cancer. However, the association of obesity with endometrial cancer (EC) outcomes has not been clearly established. This study examined how outcomes in women with early stage EC vary with body composition measured via computed tomography (CT).

METHODS

In this retrospective study, patients diagnosed with EC international Federation of Gynecology and Obstetrics stages I-III and available CT scans were included. Automatica software was used to assess the areas of visceral adipose tissue, subcutaneous adipose tissue (SAT), and intermuscular adipose tissue (IMAT) and skeletal muscle area.

RESULTS

Of 293 patient charts assessed, 199 met eligibility criteria. Median body mass index (BMI) was 32.8 kg/m2 (interquartile range [IQ] = 26.8-38.9); 61.8% had histologic subtype endometrioid carcinoma. Adjusted for age, international Federation of Gynecology and Obstetrics stage, and histologic subtype, a BMI of at least 30 vs less than 30 kg/m2 was associated with lower endometrial cancer-specific survival (ECSS) (hazard ratio [HR] = 2.32, 95% confidence interval [CI] = 1.27 to 4.25) and overall survival (OS) (HR = 2.7, 95% CI = 1.35 to 5.39). Higher IMAT 75th vs 25th percentile and SAT of at least 225.6 vs less than 225.6 cm2 were associated with lower ECSS (HR = 1.53, 95% CI = 1.1 to 2.13, and HR = 2.57, 95% CI = 1.13 to 5.88) and OS (HR = 1.50, 95% CI = 1.11 to 2.02, and HR = 2.46, 95% CI = 1.2 to 5.01), respectively. The association of visceral adipose tissue (75th vs 25th percentile) with ECSS and OS was not statistically significant (HR = 1.42, 95% CI = 0.91 to 2.22, and HR = 1.24, 95% CI = 0.81 to 1.89).

CONCLUSION

Higher BMI, IMAT, and SAT were associated with higher mortality from EC and lower OS. A better understanding of the mechanisms underlying these relationships could inform strategies to improve patient outcomes.

Imaging modalities for measuring body composition in patients with cancer: opportunities and challenges

Body composition assessment (ie, the measurement of muscle and adiposity) impacts several cancer-related outcomes including treatment-related toxicities, treatment responses, complications, and prognosis. Traditional modalities for body composition measurement include body mass index, body circumference, skinfold thickness, and bioelectrical impedance analysis; advanced imaging modalities include dual energy x-ray absorptiometry, computerized tomography, magnetic resonance imaging, and positron emission tomography. Each modality has its advantages and disadvantages, thus requiring an individualized approach in identifying the most appropriate measure for specific clinical or research situations. Advancements in imaging approaches have led to an abundance of available data, however, the lack of standardized thresholds for classification of abnormal muscle mass or adiposity has been a barrier to adopting these measurements widely in research and clinical care. In this review, we discuss the different modalities in detail and provide guidance on their unique opportunities and challenges.

Abstract P6-01-17: A single-center prospective cohort study to evaluate circulating tumor cells as a monitoring tool in women with breast cancer treated with neoadjuvant chemotherapy

Background The presence of circulating tumor cells (CTCs) among women before and/or after completion of neoadjuvant chemotherapy (NAC) for breast cancer may be associated with an increased risk of recurrence, but limited data is available. Objectives To use the Epic Sciences platform to detect and enumerate CTCs in blood samples from women with a new diagnosis of non-metastatic breast cancer of any subtype both i) prior to commencing NAC, and ii) after completion of NAC and surgery. Methods Inclusion criteria included women of any age with non-metastatic breast cancer of any subtype who have not yet commenced NAC. Those diagnosed with prior invasive cancer at any site (apart from non-melanoma skin cancer diagnosed more than five years prior to enrollment) were excluded. Blood samples were obtained to measure CTCs prior to NAC and after NAC and surgery, respectively. CTC identification was based on immunofluorescence analysis using Epic Sciences platform as previously described (Ueno et al 2017). The presence of CTCs was correlated with clinical/pathological data and treatment response, which were abstracted from patients’ medical records. The association between the presence of CTCs and clinical/pathologic characteristics was tested using Fisher’s exact test for categorical variables and t-test or Wilcoxon rank sum tests for numerical variables. All analyses were performed using the R software package. An ad-hoc preliminary analysis was conducted among the first 34 of 50 participants. Results 41 patients (out of an intended 50) have been recruited to-date. 34 participants have a pre- and/or post-treatment CTC measurement available, but 1 was excluded because it was identified to have metastatic disease shortly after enrollment. Among 33 evaluable patients without metastatic disease, 6 (19%) had triple negative breast cancer (TNBC), 13 (39%) had HER2+ and 13 (39%) had hormone receptor (HR)+/HER2- breast cancer. Most (94%) received anthracycline and taxane-based NAC. The median age of breast cancer diagnosis was 50 (29-75). A total of 53 samples were tested for CTC enumeration (5 mL per sample) including 33 pre-treatment and 20 post-treatment samples. CTCs were detected in 32 samples (n=32/53, 60%), including 24 pre-NAC (n=24/33, 73%) with a median of 0.9 CTCs per mL (0.2-19) and 8 post-NAC and surgery (n= 8/20, 40%) with a median of 0.6 CTCs per mL (0.3-3.3). Among the 24 patients (73%) who had detectable CTCs pre-NAC, 10 had HR+/HER2- (41.7%), 9 had HER2+ (37.5%) and 4 (16.7%) had triple negative disease. Among the 20 patients for whom matched pre- and post-treatment CTC results were available, 16 (80%) had detectable CTCs pre-treatment and 8 (40%) had detectable levels post-NAC and surgery. Among the 8 patients (40%) for whom CTCs were detectable post NAC and surgery, 4 (50%) had HR+/HER2-, 2 had HER2+ (25%) and 2 (25%) had triple negative disease. 3 of these patients had numerically higher CTC levels after completion of NAC and surgery compared to pre-NAC levels, 2 of whom had HR+/HER2- breast cancer and one of whom had TNBC. A total of 7 of 33 patients achieved a pathological complete response (PCR) to NAC, among whom 3 had matched pre- and post-treatment CTC results available; none of these 3 patients had detectable CTCs post-treatment. Conclusions Approximately 3 in 4 women with non-metastatic breast cancer who undergo NAC have detectable CTCs pre-treatment using the Epic Sciences Platform. Of 20 patients with matched pre-/post-treatment results, a high proportion (40%) have persistently detectable CTCs. Hence, CTCs may represent an additional measure of minimal residual disease for patients undergoing NAC for breast cancer.

Citation Format: Rania chehade, Arushi Jain, Veronika Moravan, Giuseppe Di Caro, Amanda Anderson, Megan M. Slade, Rick Wenstrup, Ana Elisa Lohmann, William Tran, Katarzyna Jerzak. A single-center prospective cohort study to evaluate circulating tumor cells as a monitoring tool in women with breast cancer treated with neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-01-17.

The Futility of Futility Analyses in Adjuvant Trials in Hormone Receptor Positive Breast Cancer

An interim analysis is commonly used in phase III superiority trials to compare treatment arms, with the goal of terminating exposure of patients to ineffective or unsafe drugs, or to identify highly effective therapies for earlier public disclosure. Traditionally, interim analyses have been designed to identify early evidence of extremely large benefit of the experimental approach, potentially leading to early dissemination of effective treatments. Increasingly, interim analysis has also involved analysis of futility which may lead to early termination of a trial that will not yield additional useful information This presents an important challenge in early-stage hormone receptor positive breast cancer, where recurrence often occurs late, with a steady annual event rate up to 20 years. Early analysis of events may miss late treatment effects that can be observed only with longer follow-up. We discuss approaches to futility analysis in adjuvant clinical trials in hormone receptor positive breast cancer, the role of the Data Safety Monitoring Committee in such analyses, considerations of the potential harms versus benefits of treatment, and the risks of continuing versus early stopping of a trial.

Radiotherapy and radiosensitization in breast cancer: Molecular targets and clinical applications

Relatively poor survival outcomes are observed in advanced or metastatic breast cancer, where local control of the primary or metastatic disease may be achieved by surgical resection, local ablative and radiation therapies. Radioresistance, poses a major challenge in achieving durable oncologic outcomes, mandating development of novel management strategies. Although multimodality approaches that combine radiotherapy with chemotherapy, or systemic agents, are utilized for radiosensitization and treatment of various malignancies, this approach has not yet found its clinical application in breast cancer. Some agents for breast cancer treatment can serve as radiosensitizers, creating an opportunity to enhance effects of radiation while providing systemic disease control. Hence, combination of radiotherapy with radiosensitizing agents have the potential to improve oncologic outcomes in advanced or metastatic breast cancer. This review discusses molecular targets for radiosensitization and novel systemic agents that have potential for clinical use as radiosensitizers in breast cancer.

Association of Obesity with Breast Cancer Outcome in Relation to Cancer Subtypes: A Meta-Analysis

Background

Obesity at breast cancer (BC) diagnosis has been associated with poor outcome, although the magnitude of effect in different BC subtypes is uncertain. We report on the association of obesity or overweight at diagnosis of nonmetastatic BC with disease-free (DFS) and overall survival (OS) in the following defined subtypes: hormone receptor positive/HER2 negative (HR+HER2−), HER2 positive (HER2+), and triple negative (TNBC).

Methods

We searched MEDLINE, EMBASE, and COCHRANE databases up to January 1, 2019. Study eligibility was performed independently by 2 authors. Studies reporting hazard ratios (HRs) of OS and/or DFS for obesity or overweight in BC subtypes were included. The pooled hazard ratio was computed and weighted using generic inverse variance and random effects models.

Results

Twenty-seven studies were included. Obese compared with nonobese women had worse DFS in all subtypes: the hazard ratios were 1.26 (95% confidence interval [CI] = 1.13 to 1.41, P < .001) for HR+HER2− BC, 1.16 (95% CI = 1.06 to 1.26, P < .001) for HER2+ BC, and 1.17 (95% CI = 1.06 to 1.29, P = .001) for TNBC. OS was also worse in obese vs nonobese women (HR+HER2− BC HR = 1.39, 95% CI = 1.20 to 1.62, P < .001; HER2+ BC HR = 1.18, 95% CI = 1.05 to 1.33, P = .006; and TNBC HR = 1.32, 95% CI = 1.13 to 1.53, P < .001). As opposed to obesity, overweight was not associated with either DFS or OS in HER2+ BC (HR = 1.02, 95% CI = 0.81 to 1.28, P = .85; and HR = 0.96, 95% CI = 0.76 to 1.21, P = .99, respectively) or TNBC (HR = 1.04, 95% CI = 0.93 to 1.18, P = .49; and HR = 1.08, 95% CI = 0.81 to 1.44, P = .17), respectively. In HR+HER2− BC, being overweight was associated with worse OS (HR = 1.14, 95% CI = 1.07 to 1.22, P < .001).

Conclusions

Obesity was associated with modestly worse DFS and OS in all BC subtypes.

The Effect of Metformin vs Placebo on Sex Hormones in Canadian Cancer Trials Group MA.32

BACKGROUND

Metformin has been associated with lower breast cancer (BC) risk and improved outcomes in observational studies. Multiple biologic mechanisms have been proposed, including a recent report of altered sex hormones. We evaluated the effect of metformin on sex hormones in MA.32, a phase III trial of nondiabetic BC subjects who were randomly assigned to metformin or placebo.

METHODS

We studied the subgroup of postmenopausal hormone receptor-negative BC subjects not receiving endocrine treatment who provided fasting blood at baseline and at 6 months after being randomly assigned. Sex hormone-binding globulin, bioavailable testosterone, and estradiol levels were assayed using electrochemiluminescence immunoassay. Change from baseline to 6 months between study arms was compared using Wilcoxon sum rank tests and regression models.

RESULTS

312 women were eligible (141 metformin vs 171 placebo); the majority of subjects in each arm had T1/2, N0, HER2-negative BC and had received (neo)adjuvant chemotherapy. Mean age was 58.1 (SD=6.9) vs 57.5 (SD=7.9) years, mean body mass index (BMI) was 27.3 (SD=5.5) vs 28.9 (SD=6.4) kg/m2 for metformin vs placebo, respectively. Median estradiol decreased between baseline and 6 months on metformin vs placebo (-5.7 vs 0 pmol/L; P < .001) in univariable analysis and after controlling for baseline BMI and BMI change (P < .001). There was no change in sex hormone-binding globulin or bioavailable testosterone.

CONCLUSION

Metformin lowered estradiol levels, independent of BMI. This observation suggests a new metformin effect that has potential relevance to estrogen sensitive cancers.

Changes in weight, physical and psychosocial patient-reported outcomes among obese women receiving treatment for early-stage breast cancer: A nationwide clinical study

BACKGROUND

Evidence on how weight loss correlates to health-related quality-of-life (HRQOL) among obese breast cancer (BC) patients is limited. We aimed to evaluate associations between weight changes and HRQOL.

METHODS

We included 993 obese women with stage I-II-III BC from CANTO, a multicenter, prospective cohort collecting longitudinal, objectively-assessed anthropometric measures and HRQOL data (NCT01993498). Associations between weight changes (±5% between diagnosis and post-treatment [shortly after completion of surgery, adjuvant chemo- or radiation-therapy]) and patient-reported HRQOL (EORTC QLQ-C30/B23) were comprehensively evaluated. Changes in HRQOL and odds of severely impaired HRQOL were assessed using multivariable generalized estimating equations and logistic regression, respectively.

RESULTS

14.1% women gained weight, 67.3% remained stable and 18.6% lost weight. Significant decreases in functional status and exacerbation of symptoms were observed overall post-treatment. Compared to gaining weight or remaining stable, obese women who lost weight experienced less of a decline in HRQOL, reporting better physical function (mean change [95%CI] for gain, stability and loss: -12.9 [-16.5,-9.3], -6.9 [-8.2,-5.5] and -6.2 [-8.7,-3.7]; pinteraction[weight-change-by-time] = 0.006), less dyspnea (+18.9 [+12.3,+25.6], +9.2 [+6.5,+11.9] and +3.2 [-1.0,+7.3]; pinteraction = 0.0003), and fewer breast symptoms (+22.1 [+16.8,+27.3], +18.0 [+15.7,+20.3] and +13.4 [+9.0,+17.2]; pinteraction = 0.044). Weight loss was also significantly associated with reduced odds of severe pain compared with weight gain (OR [95%CI] = 0.51 [0.31-0.86], p = 0.011) or stability (OR [95%CI] = 0.62 [0.41-0.95], p = 0.029). No associations between weight loss and worsening of other physical or psychosocial parameters were found.

CONCLUSIONS

This large contemporary study suggests that weight loss among obese BC patients during early survivorship was associated with better patient-reported outcomes, without evidence of worsened functionality or symptomatology in any domain of HRQOL.

Toronto Workshop on Late Recurrence in Estrogen Receptor-Positive Breast Cancer: Part 2: Approaches to Predict and Identify Late Recurrence, Research Directions

Late disease recurrence (more than 5 years after initial diagnosis) represents a clinical challenge in the treatment and management of estrogen receptor-positive breast cancer (BC). An international workshop was convened in Toronto, Canada, in February 2018 to review the current understanding of late recurrence and to identify critical issues that require future study. The underlying biological causes of late recurrence are complex, with the processes governing cancer cell dormancy, including immunosurveillance, cell proliferation, angiogenesis, and cellular stemness, being integral to disease progression. These critical processes are described herein as well as their role in influencing risk of recurrence. Moreover, observational and interventional clinical trials are proposed, with a focus on methods to identify patients at risk of recurrence and possible strategies to combat this in patients with estrogen receptor-positive BC. Because the problem of late BC recurrence of great importance, recent advances in disease detection and patient monitoring should be incorporated into novel clinical trials to evaluate approaches to enhance patient management. Indeed, future research on these issues is planned and will offer new options for effective late recurrence treatment and prevention strategies.

Toronto Workshop on Late Recurrence in Estrogen Receptor-Positive Breast Cancer: Part 1: Late Recurrence: Current Understanding, Clinical Considerations

Disease recurrence (locoregional, distant) exerts a significant clinical impact on the survival of estrogen receptor-positive breast cancer patients. Many of these recurrences occur late, more than 5 years after original diagnosis, and represent a major obstacle to the effective treatment of this disease. Indeed, methods to identify patients at risk of late recurrence and therapeutic strategies designed to avert or treat these recurrences are lacking. Therefore, an international workshop was convened in Toronto, Canada, in February 2018 to review the current understanding of late recurrence and to identify critical issues that require future study. In this article, the major issues surrounding late recurrence are defined and current approaches that may be applicable to this challenge are discussed. Specifically, diagnostic tests with potential utility in late-recurrence prediction are described as well as a variety of patient-related factors that may influence recurrence risk. Clinical and therapeutic approaches are also reviewed, with a focus on patient surveillance and the implementation of extended endocrine therapy in the context of late-recurrence prevention. Understanding and treating late recurrence in estrogen receptor-positive breast cancer is a major unmet clinical need. A concerted effort of basic and clinical research is required to confront late recurrence and improve disease management and patient survival.

A phase II randomized clinical trial of the effect of metformin versus placebo on progression-free survival in women with metastatic breast cancer receiving standard chemotherapy

OBJECTIVES

Pre-clinical data suggest metformin might enhance the effect of chemotherapy in breast cancer (BC). We conducted a Phase II randomized trial of chemotherapy plus metformin versus placebo in metastatic breast cancer (MBC).

MATERIAL AND METHODS

In this double blind phase II trial we randomly assigned non-diabetic MBC patients on 1st to 4th line chemotherapy to receive metformin 850 mg po bid or placebo bid. Primary outcome was progression-free survival (PFS); secondary outcomes included overall survival (OS), response rate (RR), toxicity and quality of life (QOL). With 40 subjects and a type-one error of 0.2 (one-sided), a PFS hazard ratio (HR) of 0.58 could be detected with 80% power.

RESULTS

40 patients were randomized (22 metformin, 18 placebo) with a mean age of 55 vs 57 years and ER/PR positive BC in 86.4% vs 83.3% off metformin vs placebo, respectively. Mean BMI was 27kg/m2 in both arms. The majority of patients were on 1st line chemotherapy. Grade 3-4 toxicity occurred in 31.8% (metformin) vs 58.8% (placebo). Best response: Partial response 18.2% metformin vs 25% placebo, stable disease 36.4% metformin vs 18.8% placebo, progressive disease 45.4% metformin vs 56.2% placebo. Mean PFS was 5.4 vs 6.3 months (metformin vs placebo), HR 1.2 (95% CI 0.63-2.31). Mean OS was 20.2 (metformin) vs 24.2 months (placebo), HR 1.68 (95% CI 0.79-3.55).

CONCLUSION

In this population metformin showed no significant effect on RR, PFS or OS. These results do not support the use of metformin with chemotherapy in non-diabetic MBC patients.

Association of obesity with breast cancer outcome in relation to cancer subtypes

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Background: Obesity at breast cancer (BC) diagnosis is associated with poor outcome, although the magnitude of effect in different BC subtypes is uncertain. Here we report on the association of obesity at BC diagnosis with disease-free (DFS) and overall survival (OS) in the following subtypes: (i) hormone receptor (ER/PgR) +ve, HER2-ve, (ii) HER2+ve, any ER/PgR and (iii) triple negative (TN). Methods: We searched MEDLINE, EMBASE and COCHRANE databases to December 31, 2018 and meeting presentations (past 5 years) using predefined search terms. Study eligibility, data abstraction were performed independently by two authors; those reporting hazard ratios (HR) for obesity and DFS/OS in BC subtypes were included. Using Review Manager pooled HRs were computed and weighted using generic inverse variance in fixed and random effects models (results were similar, random effects are presented). Results: Of 10,702 titles, 26 studies (108,793 patients) were included. Pooled HR for DFS for obese vs non-obese were (i) ER/PgR+ve HER2-ve 1.21 (95% Confidence interval, CI; 1.12-1.31, p < 0.00001), (ii) HER2+ve, any ER/PgR 1.16 (95%CI, 1.06-1.26; p = 0.0006) and (iii) TN, 1.13 (95%CI; 1.05-1.22 p = 0.002). Pooled HRs for OS were (i) ER/PgR+ve, HER2-ve 1.45 (95%CI; 1.30-1.62 p < 0.00001), (ii) HER2+ve any ER/PgR 1.21 (95%CI; 1.10-1.34 p = 0.0001) and (iii) TN 1.13 (95%CI, 1.04-1.23, p = 0.003).PooledHR for OS (but not DFS) were somewhat higher in observational vs interventional studies in (i) ER/PgR+ve, HER2-ve 1.57 vs 1.36, HER2+ve any ER/PgR (ii) 1.37 vs 1.09 but not (iii) TN 1.12 vs 1.22 (p = 0.21, 0.03 and 0.48, respectively). Conclusions: Obesity was associated with a worse outcome in all BC subtypes. Higher HR for OS in observational studies in (i) ER/PgR+ve, HER2- and (ii) HER2+ve any ER/PgR BC may reflect selection of healthier patients for intervention trials.

The effect of metformin on sex hormones in non-diabetic breast cancer patients in CCTG MA.32: A Phase III randomized adjuvant trial of metformin versus placebo in addition to standard therapy

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Background: The effect of metformin on sex hormones (SHs) levels that may impact breast cancer (BC) outcome, is unclear. We evaluated the effect of metformin on SHs in a subgroup of women enrolled in the placebo-controlled MA.32 trial, a phase III randomized study of nondiabetic subjects with T1-3, N0-3 BC randomized to receive metformin 850 mg po bid or placebo for 5 years. Methods: Our substudy was conducted on the group of post-menopausal women with estrogen receptor (ER) and progesterone receptor (PR) negative BC and not receiving endocrine treatment enrolled in the trial. Post-menopausal was defined as prior bilateral oophorectomy or > 12 months since last menses without prior hysterectomy. Fasting blood and adherence to study drug at baseline and 6 months was required. Sex hormone binding globulin (SHBG), free testosterone and estradiol serum levels were evaluated using Roche Modular competitive ECLIA (electrochemiluminescense immunoassay). We compared change from baseline to 6 months in estradiol, SHBG and free testosterone between study arms using Wilcoxon sum rank tests and regression models to adjust for baseline BMI and weight change. Results: 304 women were eligible, 135 metformin vs 169 placebo; tumor stage and prior (neo)adjuvant chemotherapy (98% in both arms) and HER2 targeted treatment were well balanced between arms. At baseline mean age was 58.2±6.9 vs 57.6±7.9 years, mean BMI 26.9±4.9 vs 28.6±6.2 Kg/m2, median estradiol 29.82 vs 31.01 pmol/L, SHBG 80.6 vs 73.7 nmol/L and free testosterone 0.02 vs 0.03 nmol/L in metformin vs placebo patients, respectively. In univariable analysis, median estradiol decreased significantly between baseline and 6 months on the metformin vs placebo arm (-4.81 vs 0 pmol/L, p = < 0.0001); this difference remained significant after controlling for baseline BMI (p = 0.0001) and weight change (mean weight change -1.8±3.5 vs 0.4±3.5 Kg, p = < 0.0001 for metformin vs placebo respectively) between baseline and 6 months (p = 0.0007). In contrast, there was no significant change in SHBG or free testosterone (median change SHBG -5.5 vs -5.9 nmol/L, p = 0.33; median change free testosterone 0 vs 0 nmol/L, p = 0.33 for metformin vs placebo respectively). Conclusions: Metformin lowered estradiol levels, independent of weight change in non-diabetic post-menopausal women with ER and PR negative BC enrolled onto MA.32 trial. This observation suggests a new metformin action that has potential relevance to BC management.

Abstract P1-16-03: Phase II randomized clinical trial (RCT) of metformin (MET) vs placebo (PLAC) in combination with chemotherapy (CXT) in refractory locally advanced (LABC) or metastatic breast cancer (MBC)

Background: MET treatment of diabetes is associated with improved BC outcomes. Hirsch et al (Cancer Res 2009;69:7505-7511) suggested MET may act synergistically with CXT in BC rodent models. We conducted a double-blind Phase II RCT of CXT plus MET vs placebo in LABC/MBC.

Methods: Non-diabetic BC patients (pts) about to commence 1st-4th line CXT (prespecified anthracycline, taxane, vinorelbine, platinum or capecitabine; HER2 Rx permitted) for MBC or refractory LABC (any ER, PgR, HER2) were eligible if (i) age 18-75, (ii) ECOG 0-2, (iii) adequate hepatic, renal, bone marrow, cardiac function and (iv) measurable or evaluable disease. Those with CNS metastases, recent MET use or radiotherapy to target lesions, intake of ≥ 3 alcoholic drinks/day, history of lactic acidosis or current/planned pregnancy or lactation were ineligible. Randomization was to MET 850 mg po bid (or identical PLAC bid) with a 2 day ramp up of one tablet/day; dose was reduced/drug discontinued in a pre-specified manner for grade 2-4 toxicity. Disease status and toxicity/HRQOL were assessed at baseline and q9 weeks until progression. Primary outcome was progression-free survival (PFS); secondary outcomes included survival (OS), response and toxicity. With 40 subjects and type one error 0.2 (1-sided), a PFS HR of 0.58 could be detected with 80% power. PFS was analyzed using Cox proportional hazards regression.

Results: 40 pts were randomized (22 MET, 18 PLAC). Mean age 55.4 vs 56.9 years; ER/PgR+ in 86.4 vs 83.3%; time from 1st metastases to randomization 297 vs 405 days, in MET vs PLAC respectively. MET pts were more likely to have visceral metastases (95.5% vs 72.2% PLAC) and less likely to be HER2+ (9.1% vs 23.5% PLAC). CXT was 1st line in 68.2% MET and 66.7% PLAC pts. Toxicity - # events: Gr 4: 0 MET vs 1 PLAC, Gr 3: 14 MET vs 14 PLAC; Gr 1 or 2: 193 MET (mainly GI) vs 53 PLAC. Best response: PR 18.2% MET vs 22.2% PLAC, SD 31.8% MET vs 11.1% PLAC, PD 45.4% MET vs 50.0% PLAC, P = 0.41. Mean PFS 164 days MET vs 192 days PLAC; HR (MET vs PLAC) 1.14 (95% CI 0.59-2.2), 1-sided p=0.65. Mean OS 645 MET vs 831 PLAC days; HR (MET vs PLAC) 1.6, 95% CI 0.72-3.54, 1-sided p=0.88.

Conclusion: In these BC pts receiving 1st-4th line CXT, MET (vs PLAC) did not improve response rates, PFS or OS. Gr 1 and 2 toxicity was higher with MET than PLAC. These results do not support use of MET with CXT in refractory LABC/MET BC. MA32, an adjuvant trial of MET vs PLAC in early BC will provide information on MET in the adjuvant setting.

Funded by the Breast Cancer Research Foundation (New York) and Hold'em for Life Charity (Toronto)

Citation Format: Goodwin PJ, Ennis M, Cescon DW, Elser C, Haq R, Hamm CM, Lohmann AE, Pimentel I, Chang MC, Dowling RJ, Stambolic V. Phase II randomized clinical trial (RCT) of metformin (MET) vs placebo (PLAC) in combination with chemotherapy (CXT) in refractory locally advanced (LABC) or metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-16-03.

Association of Metabolic, Inflammatory, and Tumor Markers With Circulating Tumor Cells in Metastatic Breast Cancer

Background

Circulating tumor cells (CTCs) are associated with worse prognosis in metastatic breast cancer (BC). We evaluated the association of metabolic, inflammatory, and tumor markers with CTCs in women with metastatic BC before commencing a new systemic therapy.

Methods

Ninety-six patients with newly diagnosed or progressing metastatic BC without current diabetes or use of anti-inflammatory agents were recruited from four Ontario hospitals. Women provided fasting blood for measurement of metabolic, inflammatory, and tumor markers and CTCs. CTCs were assayed within 72 hours of collection using CellSearch. Other blood was frozen at –80°C, and assays were performed in a single batch. Associations between CTC counts with study factors were evaluated using Spearman correlation, and the chi-square or Fisher exact test. All statistical tests were two-sided and P value ≤ .05 was considered statistically significant.

Results

The median age was 60.5 years; 90.6% were postmenopausal. The cohort included hormone receptor–positive (87.5%), HER2–positive (15.6%), and triple-negative (10.4%) BCs. Patients were starting firstline (35.5%), second-line (26.0%), or third-or-later-line therapy (38.5%). CTC counts (per 7.5 mL of blood) ranged from 0 to 1238 (median 2); an elevated CTC count, defined as five or more CTCs, was detected in 42 (43.8%) patients. Those with liver metastases (vs not) more frequently had an elevated CTC count (59.0% vs 33.3%, P = .02). CTCs were significantly associated with C-reactive protein (R = .22, P = .02), interleukin (IL)-6 (R = .25, P = .01), IL-8 (R = .38, P = .0001), plasminogen activator inhibitor 1 (R = .31, P = .001), carcinoembryonic antigen (R = .31, P = .002), and cancer antigen 15-3 (R = .40, P = .0001) and inversely associated with body mass index (R = –.23, P = .02) and leptin (R = –.26, P = .01).

Conclusions

CTC counts were positively associated with tumor and inflammatory markers and inversely associated with some metabolic markers, potentially reflecting tumor burden and cachexia.

Abstract P3-08-08: Prognostic associations of plasma hepcidin in early breast cancer (BC)

Background: Intra-tumor RNA expression of hepcidin has been linked to adverse metastasis-free survival in women with early BC, but the prognostic implications of this inflammatory marker and iron-regulating peptide are unknown.

Methods: Using an ELISA assay, we measured plasma hepcidin in the banked blood of 518 women who were recruited from 1989-1996 for a prospective cohort study regarding diet and lifestyle factors in BC. Blood had been obtained 4-12 weeks post-operatively and prior to treatment with radiation, chemotherapy or hormonal therapy. Women ages 18 to 75 with T1-3, N0-1, M0 BC who underwent surgery and axillary dissection were included; those with metabolic disorders were excluded. Tumor size, grade and ER/PR expression were abstracted from pathology reports; HER2 status was unknown. Median follow-up was 12.1 years (range, 0.2 to 17 years).

Univariable Cox regression models were used to determine the association between hepcidin and i) time to distant BC recurrence (primary outcome), and ii) time to death due to any cause. Multivariable Cox proportional hazards models were adjusted for age (continuous), T stage (T2, T3, Tx vs T1), tumor grade (3 vs 2 or 1), N stage (node positive vs negative), ER/PR expression (both ER and PR negative vs either positive) a-priori. Associations between hepcidin and CRP, IL6, insulin, cholesterol, glucose, vitamin D, total iron, transferrin, and soluble transferrin receptor; sTfR were explored (Pearson's coefficients).

Results: Hepcidin ranged from 4.70-190.70 ng/L (median 16.25; IQR 16.40 ng/L). To ensure normal distribution, a transformed [-1/sqrt (x)] hepcidin variable was used for prognostic analyses. Average age was 50.3±9.7 years. 16% were obese [body mass index (BMI) &gt;30kg/m2], 30% (n=156) were node positive, 35% (n=181) had grade 3 tumors and 71% (n=370) had ER and/or PR positive tumors. 77% underwent a lumpectomy, 73% (n=380) received adjuvant radiotherapy and 39% (n=203) received adjuvant chemotherapy.

Plasma hepcidin was not univariably associated with either time to distant BC recurrence (HR for 75th percentile versus 25th 1.20; 95%CI 0.79-1.32) or time to death due to any cause (HR 1.23; 95%CI 0.95-1.59) in the overall cohort; multivariable results were similar. In pre-planned analyses, the prognostic association of hepcidin differed by BMI (≤30 vs &gt;30 kg/m2; interaction p-values &lt;0.05): among obese women, higher hepcidin was significantly associated with a shorter time to distant BC recurrence in both univariable (HR 1.81; 95%CI 1.06–3.10) and multivariable (HR 1.84; 95%CI 1.04–3.25) models. Higher hepcidin was associated with shorter time to death due to any cause in a univariable model (HR 1.91; 95%CI 1.13–3.22) but not in a multivariable analysis. There was a moderate association between hepcidin and total iron (r=0.35), transferrin (r=0.43) and sTfR (r=-0.39); associations with IL6, CRP and metabolic factors were very weak (r&lt;0.2).

Conclusion: Higher plasma hepcidin was independently associated with a shorter time to distant BC recurrence in obese women but not in the overall cohort. Further investigation of hepcidin and mechanisms linking it to adverse BC outcomes is warranted.

Citation Format: Jerzak KJ, Lohmann AE, Ennis M, Nemeth E, Ganz T, Goodwin PJ. Prognostic associations of plasma hepcidin in early breast cancer (BC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-08-08.

Abstract P6-12-22: Sexual health in long-term breast cancer survivors

Background Significant sexual dysfunction is reported in women with breast cancer (BC) in the years following diagnosis. It is unclear whether symptoms persist over time in BC survivors (BCS) as long-term data compared to healthy controls is lacking. We compared sexual functioning in long-term BCS to controls and explored the impact of adjuvant therapy on sexual health. Methods A cohort of women with localized BC recruited from 1989 to 1996 was prospectively followed as previously described. BCS without recurrence and controls without BC were contacted between 2005 and 2007 and answered self-reported quality of life questionnaires. Sexual health was measured with the Sexual Activity Questionnaire (SAQ). Vasomotor, gynecological and bladder symptoms were scored using the Menopausal Symptom Scale (scale ranges 0-4) based on the Breast Cancer Prevention Trial Symptom Checklist. Regression analysis was used to compare groups, with and without adjustment for age (quadratic) and menopausal status. P values &lt;0.05 were considered significant. Results 248 of 285 BCS and 159 of 167 controls completed the SAQ. The median time from diagnosis of BCS was 12.5 years. BCS were slightly older (61.9 vs 59.1 years, p=0.0004) and somewhat more likely to be post-menopausal (94.4 vs 85.5%, p=0.0025) than controls. Overall, fewer BCS were sexually active than controls (45.2 vs 59.7%, p=0.0041). This difference was no longer significant when adjusted for age and menopausal status (odds ratio 0.68, p=0.075). In those sexually active, no significant differences were noted on the SAQ Pleasure and Discomfort scales.Differences in adjuvant treatment were not significantly associated with being sexually active or the SAQ subscales. BCS scored higher (worse) on the gynecological and bladder symptom scale than controls (0.66 vs 0.43, p=0.0036, adjusted difference 0.24, p=0.0029; 0.60 vs 0.41, p=0.02, adjusted difference 0.18, p=0.029 respectively), but no difference was seen in vasomotor scores. Gynecological symptom scores were greatest in BCS who received adjuvant chemotherapy. Conclusion Despite more frequent long-term gynecological and bladder symptoms, sexual health is similar in BCS and controls. Adjuvant chemotherapy is associated with persistent gynecological symptoms and interventions aimed at improving these could improve quality of life.

Citation Format: Soldera SV, Ennis M, Lohmann AE, Goodwin PJ. Sexual health in long-term breast cancer survivors [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-12-22.

Association of Obesity-Related Metabolic Disruptions With Cancer Risk and Outcome

Over the past 40 years, the prevalence of obesity has increased epidemically worldwide, which raises significant concerns regarding public health and the associated economic burden. Obesity is a major risk factor for several conditions including cardiovascular disease and type 2 diabetes, and recent evidence suggests that obesity negatively affects cancer risk and outcome. The relationship between obesity and cancer is complex and involves multiple factors both at the systemic and cellular level. Indeed, disruptions in insulin metabolism, adipokines, inflammation, and sex hormones all contribute to the adverse effects of obesity in cancer development and progression. The focus of this review will be the impact of these systemic obesity-related factors on cancer biology, incidence, and outcome. Potential therapeutic interventions and current clinical trials targeting obesity and its associated factors will also be discussed.

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 &lt;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=&lt;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 P1-09-02: BMI and metabolic factors in long-term breast cancer survivors: Changes from diagnosis and comparison to non-breast cancer controls

Background: The metabolic syndrome is associated with poor breast cancer (BC) outcome. We evaluated changes from diagnosis in metabolic factors and BMI in long-term survivors and compared their status at long-term follow-up (LTFU) to that of age-matched women with no history of BC.

Methods: A total of 535 women with early breast cancer were enrolled between 1989 and 1996 and followed prospectively. From 2005 to 2007, those alive without distant recurrence were re-contacted to participate in a long-term followed-up study and 285 agreed. A control group of 167 age-matched women without cancer history was recruited from women presenting for screening mammograms. Mean changes in metabolic factors from diagnosis to long-term follow-up were assessed with paired t-tests. In spite of matching, controls were younger and had higher income than survivors and the comparison to controls was made using age-adjusted regression models. Variables were transformed to normality before statistical testing.

Results: With a median follow-up of 12.5 years, BC survivors gained on average 2.35 kg and BMI, waist and hip circumference, waist-hip ratio, glucose, insulin, HOMA, total cholesterol and its components (but not triglycerides) increased significantly. After age adjustment, waist circumference, glucose, HOMA and total triglycerides were significantly higher in BC survivors compared to controls

Comparison of LTFU BC survivors to non-cancer controls Unadjusted mean ± standard deviationUnadjusted mean ± standard deviation  BC patientscontrolsP-value for age-adjusted differencewaist circumference (cm)85 ± 1281 ± 10.01Glucose (mmol/L)5.5 ± 1.05.2 ± 0.9.01Insulin (pmol/L)60.9 ± 50.547.1 ± 28.3.06HOMA2.25 ± 2.241.64 ± 1.24.03Triglycerides (mmol/L)1.28 ± 0.641.10 ± 0.57.01BMI (kg/m2)26.3 ± 4.925.4 ± 4.5.26

Despite exclusion of BC patients with diabetes at study entry, 24.9% of BC survivors self reported diabetes or pre-diabetes (1.99%/year) versus 12.6% in controls (OR 2.3, p= .0017).

Conclusion: The metabolic status of long-term BC survivors deteriorated over time and age-adjusted at LTFU were worse with respect to a number of factors compared to the control group.

Citation Format: Ana Elisa Lohmann, Marguerite Ennis, Pamela J Goodwin. BMI and metabolic factors in long-term breast cancer survivors: Changes from diagnosis and comparison to non-breast cancer controls [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-09-02.

Hype versus hope: metformin and vitamin D as anticancer agents

There has been increasing interest in the use of metformin and vitamin D to reduce cancer risk and improve outcomes. Metformin, an oral antidiabetic drug, improves insulin resistance and has been associated with reduced cancer incidence and cancer mortality. Low levels of vitamin D have also been associated with increased cancer risk, mainly in retrospective studies, and it has been suggested that vitamin D supplementation might play a role in cancer prevention. Preclinical data provide a biologic rationale for these associations; however, the human data arise predominantly from observational studies and caution is needed in their translation into clinical practice. This is because of the recognized limitations of observational studies, such as time-related survival biases, selection and referral biases, short follow-up, and the presence of confounding factors that can lead to spurious or inaccurate findings. Combined examination of associations with cancer risk and outcome (occurring when exposure in a population that does not yet have cancer is analyzed in relation to cancer death) may yield results that are difficult to interpret. Finally, associations across all cancers may differ from those in specific cancer types. These shortcomings can be overcome in properly designed and adequately powered prospective randomized trials; however, such trials are both expensive and time consuming. We review the literature examining the associations of metformin and vitamin D with cancer, discussing weakness and strengths and making recommendations for further research and clinical practice.

Evaluation of the clinical benefits of nanoparticle albumin-bound paclitaxel in women with metastatic breast cancer in British Columbia

BACKGROUND

Altered formulations of taxanes may lack cross-resistance with standardly used solvent-based taxanes. The primary objective of the present study was to assess the clinical benefit of nanoparticle albumin-bound (nab)-paclitaxel in women with metastatic breast cancer previously treated with and without adjuvant taxane in British Columbia.

METHODS

The BC Cancer Agency Pharmacy data repository and Breast Cancer Outcomes Unit database were linked to identify all patients who received nab-paclitaxel in British Columbia since its introduction in 2007. Hormone receptor status, demographic characteristics, number of cycles prescribed, and time to treatment failure were extracted and analyzed.

RESULTS

From 2007 to 2011, 138 patients in British Columbia received nab-paclitaxel, with 122 patients available for analysis. Most (70.5%) received adjuvant chemotherapy; about a quarter (24.6%) received an adjuvant taxane. Patients who received adjuvant taxane were more likely to have node-positive (86.7% vs. 48.9%, p = 0.007), estrogen receptor-negative (46.7% vs. 13.0% p < 0.001) disease and to receive initial adjuvant radiotherapy (76.7% vs. 51.1%, p < 0.001). For the entire cohort, the median number of nab-paclitaxel cycles prescribed was 4.4 (range: 0.3-13). The median number of nab-paclitaxel cycles was greater when that agent was given as first- or second-line therapy than as third-line or greater therapy (5.0 cycles vs. 3.7 cycles respectively). The median time to treatment failure was 96 days in the prior adjuvant taxane group (range: 0-361) and 73.5 days in the no prior adjuvant taxane group (range: 0-1176).

CONCLUSIONS

This retrospective study demonstrates potential clinical activity of nab-paclitaxel in metastatic breast cancer regardless of whether patients had prior exposure to adjuvant taxanes.

Abstract P4-16-04: Outcome of stage II/III breast cancer treated with neoadjuvant versus adjuvant radiotherapy in British Columbia

Backgroud: Neoadjuvant radiotherapy (NRT) is generally recommended after systemic therapy for inoperable stage III breast cancer. At the BCCA, neoadjuvant radiation is also frequently offered for patients with operable node positive disease after neoadjuvant chemotherapy. There is a lack of randomised trial data comparing outcomes in stage II/III breast cancer when radiation therapy is delivered neoadjuvantly versus adjuvantly.

Aim: The primary objective of this study is to assess the clinical outcomes, as measured by relapse-free survival (RFS), overall survival (OS), and breast cancer-specific survival (BCSS), of women with stage II/III breast cancer treated with neoadjuvant chemotherapy and either neoadjuvant or adjuvant radiotherapy.

Methods: Patients were identified by linking the Breast Cancer Outcomes Unit (BCOU) with the British Columbia Cancer Agency Pharmacy data repository. Inclusion criteria included: Female, referred to BCCA with newly diagnosed disease, clinical stage II or III breast cancer, neoadjuvant chemotherapy, breast surgery performed as part of the initial treatment plan, RT (given adjuvantly or neo-adjuvantly to the breast/chest wall +/− regional nodes). Patients were excluded if they had a previous or synchronous in situ or invasive breast cancer. Demographic data, treatment characteristics, ER, PR and HER-2 status (when available) were extracted. Data was analyzed using descriptive statistics and Kaplan Méier curves survival analyses were produced using SPSS, V. 14.

Results: Between Jan 1, 1995 and Dec 31, 2008, 687 patients with stage II/III disease were identified. 394 patients received neo-adjuvant and 293 patients received adjuvant radiation. Patients treated with neoadjuvant vs. adjuvant RT differed in age (median: 51yrs vs. 49yrs, p &lt; 0.001), margin status (86.5% negative/5.1% positive/ 8.4% unknown vs. 94.2% negative/1.7% positive/4.1% unknown, p = 0.02), surgery (94.2% vs. 87.7% mastectomy, p = 0.003), and type of chemotherapy (50.3% vs. 24.6% anthracycline only, p &lt; 0.001) respectively. No differences in 5-year RFS (60.0 vs. 64.8 %, respectively, p = 0.07), 5 year BCSS (67.9 vs. 73.1 %, respectively p = 0.17) and 5-year OS (66.2 vs. 72.5 %, respectively, p = 0.06) were seen in the neoadjuvant vs. adjuvant population.

Patients with metastatic breast cancer using bevacizumab as a treatment: is there still a role for it?

OPINION STATEMENT

Over the last few decades, the angiogenesis mechanism has increasingly been studied and implicated in cancer pathophysiology. At present, it is known that angiogenesis plays a relevant role in tumor growth, and more importantly many new molecules exists can potentially interfere with this process. Bevacizumab, a humanized monoclonal antibody targeting the vascular endothelial growth factor A (VEGF-A) now commonly used in the treatment of colorectal, renal cell, and brain cancer, is the first anti-angiogenesis drug delivered in combination with chemotherapy that has consistently shown clinical efficacy in the treatment of breast cancer. Since the ECOG 2100 trial has shown that bevacizumab added to paclitaxel as a first-line treatment for advanced breast cancer nearly doubled the time to progression and tumor response rate, its approval was granted almost worldwide. However, other phase III trials revealed a smaller absolute improvement in progression-free survival (PFS) and response rates, and no trials yet have demonstrated survival enhancement which led to a great controversy and debate over the use of bevacizumab. The discrepancy between PFS and overall survival also raises the question of whether or not bevacizumab has been applied sub-optimally in some of the studies, if a predictive biomarker(s) exists to select the group of patients whom would receive the greatest benefit and what is the appropriate clinical end-point for approval and funding of new targeted agents. In this article we will review the bevacizumab mechanism of action and the clinical trials that assessed its benefit in the treatment of metastatic breast cancer (MBC).