Nuclear-Biased DUSP6 Expression is Associated with Cancer Spreading Including Brain Metastasis in Triple-Negative Breast Cancer.

DUSP6 is a dual-specificity phosphatase (DUSP) involved in breast cancer progression, recurrence, and metastasis. DUSP6 is predominantly cytoplasmic in HER2+ primary breast cancer cells, but the expression and subcellular localization of DUSPs, especially DUSP6, in HER2-positive circulating tumor cells (CTCs) is unknown. Here we used the DEPArray system to identify and isolate CTCs from metastatic triple negative breast cancer (TNBC) patients and performed single-cell NanoString analysis to quantify cancer pathway gene expression in HER2-positive and HER2-negative CTC populations. All TNBC patients contained HER2-positive CTCs. HER2-positive CTCs were associated with increased ERK1/ERK2 expression, which are direct DUSP6 targets. DUSP6 protein expression was predominantly nuclear in breast CTCs and the brain metastases but not pleura or lung metastases of TNBC patients. Therefore, nuclear DUSP6 may play a role in the association with cancer spreading in TNBC patients, including brain metastasis.

Optimizing poly (ADP-ribose) polymerase inhibition through combined epigenetic and immunotherapy.

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with poor survival outcomes. Currently, there are no targeted therapies available for TNBCs despite remarkable progress in targeted and immune-directed therapies for other solid organ malignancies. Poly (ADP-ribose) polymerase inhibitors (PARPi) are effective anticancer drugs that produce good initial clinical responses, especially in homologous recombination DNA repair-deficient cancers. However, resistance is the rule rather than the exception, and recurrent tumors tend to have an aggressive phenotype associated with poor survival. Many efforts have been made to overcome PARPi resistance, mostly by targeting genes and effector proteins participating in homologous recombination that are overexpressed during PARPi therapy. Due to many known and unknown compensatory pathways, genes, and effector proteins, overlap and shared resistance are common. Overexpression of programmed cell death-ligand 1 (PD-L1) and cancer stem cell (CSC) sparing are novel PARPi resistance hypotheses. Although adding programmed cell death-1 (PD-1)/PD-L1 inhibitors to PARPi might improve immunogenic cell death and be crucial for durable responses, they are less likely to target the CSC population that drives recurrent tumor growth. Lysine-specific histone demethylase-1A and histone deacetylase inhibitors have shown promising activity against CSCs. Combining epigenetic drugs such as lysine-specific histone demethylase-1A inhibitors or histone deacetylase inhibitors with PARPi/anti-PD-1/PD-L1 is a novel, potentially synergistic strategy for priming tumors and overcoming resistance. Furthermore, such an approach could pave the way for the identification of new upstream epigenetic and genetic signatures.

The survival outcome of patients with metastatic colorectal cancer based on the site of metastases and the impact of molecular markers and site of primary cancer on metastatic pattern.

BACKGROUND: Pattern of spread in patients with metastatic colorectal cancer (mCRC) is variable and may reflect different biology in subsets of patients. This is a retrospective study to explore the outcome of patients with mCRC based on their site of metastasis at diagnosis and to explore the association between tumor characteristics [KRAS/RAS, BRAF, mismatch repair (MMR) status, site of primary] and the site of metastasis. METHODS: Patients from two Australian databases were divided into six groups based on site of metastasis at time of diagnosis of metastatic disease; lung-only, liver-only, lymph node-only or any patients with brain, bone or peritoneal metastases. Primary endpoint was overall survival (OS) of each cohort compared with the rest of the population. A Mantel-Haenszel chi-squared test used to explore the association between site of metastasis and selected tumor characteristics. RESULTS: Five thousand nine hundred and sixty-seven patients were included. In a univariate analysis, median OS was significantly higher when metastases were limited to lung or liver and shorter for those with brain, bone or peritoneal metastases (p < .001) in both datasets. BRAF mutation was strongly associated with peritoneal metastases (relative risk = 1.8, p < .001) with lower incidence of lung (RR = 0.3, p = .004) and liver (RR = 0.7, p = .005) limited metastases. Lung-only metastases were more frequent with KRAS/RAS mutation (RR = 1.4, p = .007). Left colon tumors were associated with bone (RR = 1.6, p < .001) and lung-only metastases (RR = 2.3, p = .001) while peritoneal spread was less frequent compared with right colon tumors (RR = 0.6, p < .001). Rectal cancer was associated with brain, bone and lung metastases (RR = 1.7; p = .002, 1.7; p < .001, 2.0; p < .001). Liver-only metastases were less frequent in deficient MMR tumors (RR = 0.7, p = .01). CONCLUSION: Survival duration with mCRC is related to the site of metastases with lung limited disease showing a more favorable survival outcome compared to other single metastatic site disease. The BRAF mutation and primary rectal cancer were associated with poor prognostic metastatic sites.

A Phase 1 Proof of Concept Study Evaluating the Addition of an LSD1 Inhibitor to Nab-Paclitaxel in Advanced or Metastatic Breast Cancer (EPI-PRIMED).

Objective: Lysine-Specific Demethylase-1 (LSD1) is overexpressed in breast cancer cells and facilitate mesenchymal properties which may contribute to therapeutic resistance and cancer progression. The purpose of this study was to investigate the safety of combination, nab-paclitaxel and phenelzine, an irreversible LSD1 inhibitor in patients with metastatic breast cancer (mBC). Methods: Eligible patients with mBC were treated with nab-paclitaxel (100mg/m2) weekly for 3 weeks with one week break in a 28-day cycle. Dose escalation of phenelzine followed the Cumulative Cohort Design and phenelzine treatment commenced from day 2 of first cycle. Eleven patients were screened, and eligible patients were enrolled in cohorts with the dose of phenelzine ranging from 45mg to 90mg. Results: The Optimum Biological Dose was established at 60mg of phenelzine daily in combination with nab-paclitaxel and considered as the recommended phase 2 dose. Most (95%) of adverse events were grade 1 or 2 with two grade 3 events being diarrhea and neutropenia at 45mg and 60mg phenelzine respectively, with no unexpected toxicity/deaths. Commonly reported toxicities were fatigue (n=4,50%), dizziness (n=6,75%), neutropenia (n=3,37.5%), peripheral neuropathy (n=3,37.5%), diarrhea (n=2,25%), and hallucination (n=2,25%). After a median follow up of 113 weeks, all patients showed disease progression on trial with 4 patients being alive at the time of data cut off, including one patient with triple negative breast cancer. Median progression-free survival was 34 weeks. Significant inhibition of LSD1 and suppression of mesenchymal markers in circulating tumor cells were noted. Conclusion: Phenelzine in combination with nab-paclitaxel was well tolerated, without any unexpected toxicities in patients with mBC and demonstrated evidence of antitumor activity. For the first time, this proof-of-concept study showed in-vivo inhibition of LSD1 suppressed mesenchymal markers, which are known to facilitate generation of cancer stem cells with metastatic potential. Clinical Trial Registration: ClinicalTrials.Gov NCT03505528, UTN of U1111-1197-5518.

Metastasectomy and BRAF mutation; an analysis of survival outcome in metastatic colorectal cancer.

BACKGROUND: Resection of oligometastases improves survival in metastatic colorectal cancer (mCRC). It is unclear whether the benefit is consistent for BRAF V600E mutant (MT) and wild type (WT) mCRC. This retrospective analysis explores the influence of BRAF MT on survival after metastasectomy. METHODS: Overall survival (OS) and recurrence-free survival (RFS) for BRAF MT and WT mCRC were evaluated. Survival was also analyzed in the cohort of BRAF MT with or without metastasectomy. RESULTS: Five hundred and thirteen patients who had undergone metastasectomy were identified, 6% were BRAF-MT. Median age 63. Median OS in BRAF MT vs WT: 25.7 vs 48.5 months (hazard ratio [HR] 1.95; 1.18-3.22). However, difference was not significant in a multivariate model. Right primary tumor, intact primary, >1 metastatic site, non-R0 resection, peritoneal metastasis, and synchronous metastasis were independent predictors of worse OS. Among 364 patients with RFS data there was no difference between BRAF MT and WT (16 vs 19 months, p=0.09). In another cohort of 158 BRAF-MT patients, OS was significantly better after metastasectomy compared to "no metastasectomy" (HR 0.34; 0.18-0.65, P= 0.001). Proficient mismatch repair status showed a trend toward worse survival after metastasectomy in BRAF MT (HR 1.71, P = 0.08). CONCLUSION: OS did not differ after metastasectomy between BRAF MT and WT in a multivariate model. Median OS was >2 years in this study after metastasectomy among BRAFV600E MT patients suggesting a survival benefit of metastasectomy in this group where systemic therapeutic options are limited. Metastasectomy may be considered in carefully selected BRAF-MT patients.

Targeting Nuclear LSD1 to Reprogram Cancer Cells and Reinvigorate Exhausted T Cells via a Novel LSD1-EOMES Switch.

Lysine specific demethylase 1 (LSD1) is a key epigenetic eraser enzyme implicated in cancer metastases and recurrence. Nuclear LSD1 phosphorylated at serine 111 (nLSD1p) has been shown to be critical for the development of breast cancer stem cells. Here we show that circulating tumor cells isolated from immunotherapy-resistant metastatic melanoma patients express higher levels of nLSD1p compared to responders, which is associated with co-expression of stem-like, mesenchymal genes. Targeting nLSD1p with selective nLSD1 inhibitors better inhibits the stem-like mesenchymal signature than traditional FAD-specific LSD1 catalytic inhibitors such as GSK2879552. We also demonstrate that nLSD1p is enriched in PD-1+CD8+ T cells from resistant melanoma patients and 4T1 immunotherapy-resistant mice. Targeting the LSD1p nuclear axis induces IFN-γ/TNF-α-expressing CD8+ T cell infiltration into the tumors of 4T1 immunotherapy-resistant mice, which is further augmented by combined immunotherapy. Underpinning these observations, nLSD1p is regulated by the key T cell exhaustion transcription factor EOMES in dysfunctional CD8+ T cells. EOMES co-exists with nLSD1p in PD-1+CD8+ T cells in resistant patients, and nLSD1p regulates EOMES nuclear dynamics via demethylation/acetylation switching of critical EOMES residues. Using novel antibodies to target these post-translational modifications, we show that EOMES demethylation/acetylation is reciprocally expressed in resistant and responder patients. Overall, we show for the first time that dual inhibition of metastatic cancer cells and re-invigoration of the immune system requires LSD1 inhibitors that target the nLSD1p axis.

Rate of cancer progression as a predictive marker of efficacy of immunotherapy; an analysis in metastatic non-small-cell lung cancer.

Aim: To explore the value of rate of cancer progression (ROP) prior to starting PD-1 inhibitors as a predictive and prognostic biomarker. Materials & methods: Retrospective data of patients with metastatic non-small-cell lung cancer treated with second-line PD-1 inhibitors were collected. Patients were divided into two groups: slow and rapid based on their ROP. Results: A total of 73 patients were eligible. Progression-free survival (PFS) was significantly shorter in rapid ROP, compared with slow (1.7 vs 4.8 months; HR: 2.42; 95% CI: 1.36-4.30; p = 0.008), as was the overall survival (OS; 5.6 vs 18.7 months; HR: 2.30; 95% CI: 1.13-4.69; p = 0.02). Overall response rate (40 vs 17%) was numerically higher in slow ROP than rapid (p = 0.19). PFS/OS did not correlate with the best response to their last chemotherapy or time to progression from previous line of therapy. Presence of a targetable mutation negatively correlated with PFS/OS. Conclusion: ROP prior to starting PD-1 inhibitors correlates with survival. PFS/OS were shorter in rapid ROP.

Optimise not compromise: The importance of a multidisciplinary breast cancer patient pathway in the era of oncoplastic and reconstructive surgery.

Modern breast cancer care is a complex multidisciplinary undertaking in which the integrated function of multiple constituent parts is critical, and where changes to one therapeutic component may profoundly influence the delivery and outcomes of another. Oncoplastic and reconstructive breast surgery has evolved in the era of longer survival rates for women with breast cancer and aims to enhance oncological and cosmetic outcomes. However, concurrently there has been an expansion in the indications for post-mastectomy radiation therapy (Abdulkarim et al., 2011; Early Breast Cancer Trialists' Collaborative Group (EBCTCG), 2014; Poortmans et al., 2015; Wang et al., 2011), the recognition of several biologically distinct breast cancer subtypes (Perou et al., 2000; Sørlie et al., 2001, 2003; Cheang et al., 2008, 2009; Sotiriou et al., 2003; Millar et al., 2011; Blows et al., 2010; Schnitt, 2010; Haque et al., 2012; Dai et al., 2015) and the development of recommendations for prophylactic surgery for high-risk women, including BRCA-mutation carriers (James et al., 2006; Domchek et al., 2010). Primary systemic therapy is increasingly utilised yet has varying efficacy depending on tumour biology (Cortazar et al., 2014). In this paper we review the evidence which informs the multidisciplinary team opinion in the era of oncoplastic and reconstructive breast surgery. We aim to describe an optimal multidisciplinary approach which balances competing risks of multimodal therapies to optimise oncological and cosmetic outcomes.

Isolated immune-related pancreatic exocrine insufficiency associated with pembrolizumab therapy.

We report a case of isolated immune-related pancreatic exocrine insufficiency in a patient treated with pembrolizumab for metastatic melanoma. This patient presented with explosive diarrhea and was treated with high dose corticosteroids for possible immune-related colitis. However, biopsies from colon and duodenum did not show any histological evidence of colitis/enteritis. Serum amylase and lipase were not elevated. There was no evidence of pancreatitis or pancreatic metastases on imaging. Significantly lower fecal elastase test on two occasions confirmed the diagnosis of pancreatic exocrine insufficiency. He was treated with pancreatic enzyme supplementation with complete resolution of diarrhea. This case reinforces the importance of awareness and anticipation of unusual immune-related adverse events related to checkpoint inhibitors.

Massive fatal pulmonary haemorrhage during bevacizumab treatment following microwave ablation therapy for oligometastatic lung metastasis from rectal cancer.

Although thoracic ablative therapies are generally safe procedures, fatal complications can occur. Bevacizumab is a standard-of-care treatment along with chemotherapy for metastatic colorectal cancer. Although uncommon, unpredictable serious adverse events can occur secondary to bevacizumab. We report a case of fatal intrapulmonary haemorrhage as a result of arteriopulmonary fistula in a patient after microwave ablation of pulmonary colorectal cancer metastasis while on bevacizumab. Antiangiogenetic properties of bevacizumab are associated with delayed wound healing, which might have been a crucial factor in the development of arteriopulmonary fistula and haemorrhage.

Dose modifications in adjuvant chemotherapy for solid organ malignancies: A systematic review of clinical trials.

Toxicities of systemic cancer therapies are often less frequently observed in clinical trials than in clinical practice, due to the careful selection of patients with fewer comorbidities. Although guidelines exist for the estimation of chemotherapy dose, clinical factors like age, comorbid illness and extremes of body habitus are not considered in the method of dose calculation, which can result in significant toxicity. We reviewed the referenced clinical trials from which the evidence-based curative-intent cancer treatment protocols were developed for EVIQ, which is an Australian government, online resource. This review shows that a significant proportion of patients in curative-intent clinical trials experience toxicities that result in dose modifications-dose reduction, dose delays or missed doses-despite strict selection criteria and intense monitoring. Thus, even in ideal, clinical-trial settings chemotherapy dose calculation remains imprecise and subject to adjustment as clinically appropriate. In real-world clinical practice, dose alterations or modifications in response to toxicities need to be thoroughly discussed and implemented with clear understanding of the patient with appropriate documentation. This review may be used as a reference in these situations to elaborate the extent of toxicities seen in clinical trials with optimal settings.

Intravesical Gemcitabine versus Intravesical Bacillus Calmette-Guérin for the Treatment of Non-Muscle Invasive Bladder Cancer: An Evaluation of Efficacy and Toxicity.

BACKGROUND: Intravesical Bacillus Calmette-Guérin (BCG) remains the standard adjuvant treatment for non-muscle invasive bladder cancer (NMIBC) following transurethral resection; however, BCG failure and related toxicities are common. OBJECTIVES: To compare the efficacy and toxicity of intravesical BCG and gemcitabine in the treatment of NMIBC. METHODS: Retrospective data were collected in the region of Canberra, Australia from January 2010 to December 2015. The survival cutoff was December 2016. Primary end point was disease-free survival (DFS) and secondary end point was toxicity. After optimal transurethral resection all patients received weekly intravesical BCG or gemcitabine for 6 weeks and maintenance treatment according to their risk. The recurrence was defined as histology proven tumor recurrence (any grade), or appearance of carcinoma in situ. RESULTS: One hundred and three patients were evaluable, 52 treated with BCG and 51 with gemcitabine with a median age of 77 and 78, and were mostly male. Approximately half of each received maintenance therapy. The groups were well balanced, apart from some difference in cancer risk groups. Twenty-one percent in the BCG group and 29% in the gemcitabine group had received prior BCG. Median follow up was 15.0 months. Median DFS was 19.6 months for BCG, whereas median DFS was not reached with gemcitabine. There was a trend toward improved DFS with gemcitabine in multivariate analysis, HR: 0.49 (95% CI: 0.22-1.06, p = 0.07). Adverse events were significantly less frequent with gemcitabine (7 versus 44%, p ≤ 0.05). There were four cases of systemic BCG infection. CONCLUSION: Intravesical gemcitabine was associated with a trend toward better DFS with significantly lower toxicity when compared with BCG. Intravesical BCG remains the standard first-line adjuvant therapy; however, intravesical gemcitabine could be a reasonable alternative in cases where BCG is contraindicated and for patients who are intolerant or refractory to BCG. A prospective phase 3 trial is needed to confirm the benefits of gemcitabine over BCG.