SHON expression predicts response and relapse risk of breast cancer patients after anthracycline-based combination chemotherapy or tamoxifen treatment

Background

SHON nuclear expression (SHON-Nuc⁺) was previously reported to predict clinical outcomes to tamoxifen therapy in ERα⁺ breast cancer (BC). Herein we determined if SHON expression detected by specific monoclonal antibodies could provide a more accurate prediction and serve as a biomarker for anthracycline-based combination chemotherapy (ACT).

Methods

SHON expression was determined by immunohistochemistry in the Nottingham early-stage-BC cohort (n = 1,650) who, if eligible, received adjuvant tamoxifen; the Nottingham ERα⁻ early-stage-BC (n = 697) patients who received adjuvant ACT; and the Nottingham locally advanced-BC cohort who received pre-operative ACT with/without taxanes (Neo-ACT, n = 120) and if eligible, 5-year adjuvant tamoxifen treatment. Prognostic significance of SHON and its relationship with the clinical outcome of treatments were analysed.

Results

As previously reported, SHON-Nuc⁺ in high risk/ERα⁺ patients was significantly associated with a 48% death risk reduction after exclusive adjuvant tamoxifen treatment compared with SHON-Nuc⁻ [HR (95% CI) = 0.52 (0.34–0.78), p = 0.002]. Meanwhile, in ERα⁻ patients treated with adjuvant ACT, SHON cytoplasmic expression (SHON-Cyto⁺) was significantly associated with a 50% death risk reduction compared with SHON-Cyto⁻ [HR (95% CI) = 0.50 (0.34–0.73), p = 0.0003]. Moreover, in patients received Neo-ACT, SHON-Nuc⁻ or SHON-Cyto⁺ was associated with an increased pathological complete response (pCR) compared with SHON-Nuc⁺ [21 vs 4%; OR (95% CI) = 5.88 (1.28–27.03), p = 0.012], or SHON-Cyto⁻ [20.5 vs. 4.5%; OR (95% CI) = 5.43 (1.18–25.03), p = 0.017], respectively. After receiving Neo-ACT, patients with SHON-Nuc⁺ had a significantly lower distant relapse risk compared to those with SHON-Nuc⁻ [HR (95% CI) = 0.41 (0.19–0.87), p = 0.038], whereas SHON-Cyto⁺ patients had a significantly higher distant relapse risk compared to SHON-Cyto⁻ patients [HR (95% CI) = 4.63 (1.05–20.39), p = 0.043]. Furthermore, multivariate Cox regression analyses revealed that SHON-Cyto⁺ was independently associated with a higher risk of distant relapse after Neo-ACT and 5-year tamoxifen treatment [HR (95% CI) = 5.08 (1.13–44.52), p = 0.037]. The interaction term between ERα status and SHON-Nuc⁺ (p = 0.005), and between SHON-Nuc⁺ and tamoxifen therapy (p = 0.007), were both statistically significant.

Conclusion

SHON-Nuce⁺ in tumours predicts response to tamoxifen in ERα⁺ BC while SHON-Cyto⁺ predicts response to ACT.

Derivation of Breast Cancer Cell Lines Under Physiological (5%) Oxygen Concentrations

Background: Most human breast cancer cell lines currently in use were developed and are cultured under ambient (21%) oxygen conditions. While this is convenient in practical terms, higher ambient oxygen could increase oxygen radical production, potentially modulating signaling pathways. We have derived and grown a series of four human breast cancer cell lines under 5% oxygen, and have compared their properties to those of established breast cancer lines growing under ambient oxygen.

Methods: Cell lines were characterized in terms of appearance, cellular DNA content, mutation spectrum, hormone receptor status, pathway utilization and drug sensitivity.

Results: Three of the four lines (NZBR1, NZBR2, and NZBR4) were triple negative (ER-, PR-, HER2-), with NZBR1 also over-expressing EGFR. NZBR3 was HER2+ and ER+ and also over-expressed EGFR. Cell lines grown in 5% oxygen showed increased expression of the hypoxia-inducible factor 1 (HIF-1) target gene carbonic anhydrase 9 (CA9) and decreased levels of ROS. As determined by protein phosphorylation, NZBR1 showed low AKT pathway utilization while NZBR2 and NZBR4 showed low p70S6K and rpS6 pathway utilization. The lines were characterized for sensitivity to 7-hydroxytamoxifen, doxorubicin, paclitaxel, the PI3K inhibitor BEZ235 and the HER inhibitors lapatinib, afatinib, dacomitinib, and ARRY-380. In some cases they were compared to established breast cancer lines. Of particular note was the high sensitivity of NZBR3 to HER inhibitors. The spectrum of mutations in the NZBR lines was generally similar to that found in commonly used breast cancer cell lines but TP53 mutations were absent and mutations in EVI2B, LRP1B, and PMS2, which have not been reported in other breast cancer lines, were detected. The results suggest that the properties of cell lines developed under low oxygen conditions (5% O₂) are similar to those of commonly used breast cancer cell lines. Although reduced ROS production and increased HIF-1 activity under 5% oxygen can potentially influence experimental outcomes, no difference in sensitivity to estrogen or doxorubicin was observed between cell lines cultured in 5 vs. 21% oxygen.

Abstract P2-05-16: Gene expression in synchronous primary, axillary nodal and disseminated breast cancer cells

Disseminated Tumour Cells (DTC) have been found in the bone marrow (BM) of up to 70% of patients with breast cancer metastatic to axillary lymph nodes. They are a biologically and therapeutically interesting tumour cell population. Although there is uncertainty about their relationship to cancer prognosis, DTC provide a valuable window into the processes by which primary tumour (PT) cells disseminate. DTC can be enriched from BM by immunoaffinity using antibodies directed against epithelial cell markers such as EpCAM. To better understand the changing gene expression patterns that may accompany breast cancer metastasis, we have compared the whole genome RNA expression profiles of matched PT, axillary lymph node metastases (LNM), and EpCAM-enriched cells from the BM of seven patients. Compared to PT, axillary LNM had consistently altered expression of RNAs encoding matrix metalloproteinases (MMP), growth factors, transcription factors, as well as downstream targets of Catenin-a, Tumour Necrosis Factor (TNF)-a and miR-22. Once the gene expression patterns of potentially contaminating BM cells were subtracted, compared to PT and LNM EpCAM-enriched MB cells had consistently elevated expression of RNAs encoding metabolic enzymes, ribosomal proteins, and DNA-binding factors such as YB-1. The gene expression changes we identify are candidate mediators of breast cancer metastases and represent attractive targets for further study on a cell by cell basis.

Citation Format: Reuben J Broom, Cherie Blenkiron, Richard Harman, Erica Whineray Kelly, Stephen Allpress, Katherine Gale, Sam Rice, Peter Shin, Anna Brown, Annette Lasham, Cristin Print. Gene expression in synchronous primary, axillary nodal and disseminated breast cancer cells [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 P2-05-16.

Clinical experience with sunitinib dose escalation in metastatic renal cell carcinoma

The oral multi-targeted tyrosine kinase inhibitor sunitinib malate is a standard first-line therapy in clear-cell metastatic renal cell carcinoma (mRCC). Sunitinib is usually administered daily for 4 weeks, followed by 2 weeks without treatment. Some patients experience worsening of disease symptoms during the treatment break. We report three cases of mRCC in whom continuous daily dosing and dose escalation were evaluated. In two cases, sunitinib was well tolerated at doses of 75 mg continuously and in all cases escalation of dose enabled regain of disease control. This suggests that continuous higher daily dosing of sunitinib is feasible and may provide additional clinical benefit for selected patients who experience minimal toxicity on the standard schedule.

Everolimus and zoledronic acid in patients with renal cell carcinoma with bone metastases: a randomized first-line phase II trial

BACKGROUND

Bone metastases from renal cell carcinoma (RCC) are a major cause of morbidity. Post hoc analysis has suggested that bone turnover markers can identify patients at risk of skeletal-related events (SREs) among those receiving zoledronic acid. This study sought to evaluate the effect on bone metastases of everolimus alone compared with everolimus plus zoledronic acid.

PATIENTS AND METHODS

Thirty treatment-naive patients with RCC and ≥ 1 bone metastases were randomized 1:1 to everolimus (10 mg daily) versus everolimus plus zoledronic acid (4 mg intravenously 4-weekly). Bone-specific assessments were performed at baseline and at weeks 1, 4, 8, and 12. Treatment was continued on allocated arm until progression per RECIST 1.1 (Response Evaluation Criteria in Solid Tumors, version 1.1). The primary outcome measure was urine N-telopeptide (uNTX) level, with secondary measures of plasma C-telopeptide (CTX), quality of life (Functional Assessment of Cancer Therapy-Bone Pain [FACT-BP], Brief Pain Inventory [BPI]), progression-free survival (PFS), SREs, and safety.

RESULTS

After 12 weeks, reduction in mean uNTX and CTX on everolimus plus zoledronic acid relative to everolimus was 68.4% (95% CI, 60.1%-74.9%; P < .0001) and 76.2% (95% CI, 67.3%-82.7%; P < .0001), respectively. There was no evidence of a difference for FACT-BP (P = .5), but evidence was favorable for BPI Severity (P = .05) and BPI Interference (P = .06). Median PFS was 7.5 months (95% CI, 3.4-11.2) on everolimus plus zoledronic acid and 5.4 months (95% CI, 3.2-6.3) on everolimus (P = .009). Median time to first SRE was 9.6 months (95% CI, 4.3-15.5) on everolimus plus zoledronic acid and 5.2 months (95% CI, 1.6-8.2) on everolimus (P = .03).

CONCLUSION

In this RCC population, the addition of zoledronic acid to everolimus significantly reduced bone resorption markers and may prolong tumor control.

Analysis of molecular cytogenetic changes in metastatic renal cell carcinoma in the setting of everolimus treatment: a pilot project

BACKGROUND

The mTOR inhibitors have improved outcomes for patients with metastatic renal cell carcinoma (mRCC) but the duration of benefit is variable. Currently there are no predictive biomarkers for preselecting patients who are more likely to benefit from these agents. We undertook an exploratory translational study evaluating molecular cytogenetic changes in the context of outcomes from treatment with everolimus.

PATIENTS AND METHODS

Ten patients with clear cell mRCC treated with everolimus were enrolled. Pretreatment tissue specimens were analyzed for molecular cytogenetic changes using fluorescence in situ hybridization and progression-free survival (PFS) data were obtained. Gene probes chosen for this analysis were: Von Hippel Lindau, fragile histidine triad, fibroblast growth factor receptor (FGFR) 1, FGFR3, PDGFβ, PDGFRβ, epidermal growth factor receptor, and myelocytomatosis viral oncogene.

RESULTS

Median PFS was 8.75 months. Two patients with the longest PFS (28 months and 23 months) had gain of PDGFβ and PDGFRβ. This was also observed in 3 other patients who had a PFS of 11.5 months, 8 months, and 5.5 months, respectively. Cytogenetic evolution was observed between primary and metastatic specimens.

CONCLUSION

PDGFβ and PDGFRβ gene status might be of relevance to everolimus therapy. Further research evaluating the utility of these potential biomarkers is required.

Small molecule targeted therapies for the second-line treatment for metastatic renal cell carcinoma: a systematic review and indirect comparison of safety and efficacy

BACKGROUND

Patients with metastatic renal cell carcinoma (mRCC) and a good performance status typically receive an anti-vascular endothelial growth factor receptor (VEGFR) TKI (sunitinib or pazopanib) as initial therapy. Upon disease progression or intolerance, there are four orally administered agents approved in the second-line setting (including cytokine-refractory). However, head-to-head comparative trial data are limited. In this study, an indirect statistical comparison of safety and efficacy was undertaken between axitinib, sorafenib, pazopanib and everolimus in second-line therapy mRCC.

METHODS

A systematic review of major databases was conducted from January 2005 to June 2013 for randomized controlled trials (RCTs) evaluating at least one of the four agents in second-line mRCC. Bayesian mixed treatment comparison models were fitted to assess relative effectiveness on multiple endpoints such as objective response rates, dose-limiting grade III/IV toxicities, treatment discontinuations and progression-free survival (PFS).

RESULTS

Four RCTs met the inclusion criteria. All four agents seem able to induce tumor shrinkage and to provide patients with a clinically meaningful PFS benefit. Axitinib was superior to pazopanib [hazard ratio (HR) 0.64; 95 % credible interval (95 % Crl) 0.42-0.96] and sorafenib (HR 0.70; 95 % Crl 0.57-0.87) in terms of PFS. However, axitinib was associated with an elevated risk of fatigue and to a lesser extent stomatitis.

CONCLUSIONS

Keeping in mind the caveats associated with cross-trial statistical comparisons, axitinib provides superior PFS relative to pazopanib and sorafenib. Everolimus, an mammalian target of rapamycin inhibitor, is mechanistically distinct from the other agents and remains a useful option for patient's post-anti-VEGFR TKI failure.

Changes in estrogen receptor, progesterone receptor and Her-2/neu status with time: discordance rates between primary and metastatic breast cancer

BACKGROUND

Changes in the receptor profile between primary and metastatic breast cancer tissue have been suggested. The degree of hormone receptor discordance in archival paired pathological samples was evaluated.

MATERIALS AND METHODS

Archival data were collected on 100 patients for whom tissue from primary and metastatic sites was available. Estrogen receptor (ER), progesterone receptor (PR) and Her-2/neu status in the primary and metastasis were compared.

RESULTS

The discordance rate for ER was 17.7% (2-sided p=0.0039) with 9.7% of tumours changing from ER-positive to ER-negative and 8.0% changing from ER-negative to ER-positive. The discordance rate for PR was 37.3% (2-sided p<0.0001), with all of these tumours changing from PR-positive to PR-negative. No significant discordance for Her-2/neu was found.

CONCLUSIONS

This series suggests that significant discordance exists for hormone receptor status between primary and metastatic breast cancer samples. Loss of PR was particularly frequent.

A durable complete remission between two isolated presentations of metastatic breast cancer, the second with intracardiac disease

We report a case of a postmenopausal patient with hormone receptor-positive breast cancer who, while receiving tamoxifen, experienced relapse with isolated ovarian metastases 4.5 years after her primary treatment. After resection of her pelvic disease, she commenced anastrozole, and while receiving this, remained disease free for an additional 7.5 years before experiencing relapse again with isolated metastatic disease in an unusual location: intracardiac disease causing superior vena cava obstruction.