Loay Kassem

Analysis of PI3K/mTOR Pathway Biomarkers and Their Prognostic Value in Women with Hormone Receptor–Positive, HER2-Negative Early Breast Cancer

BACKGROUND: The PI3K/AKT/mTOR pathway alterations have been shown to play significant roles in the development, progression, and metastatic spread of breast cancer. Furthermore, they have been implicated in the process of drug resistance, especially endocrinal therapies. In this study, we aimed to define the correlation between the PI3K mutations and the expression of the phosphorylated forms of different downstream molecules in women with estrogen receptor (ER)–positive, human epidermal growth factor receptor 2–negative (luminal) early breast cancer treated at Cairo university hospitals. METHODS: Next-generation sequencing was used to detect mutations in the PIK3CA hotspots (in exons 9 and 20). Immunohistochemistry was performed on tissue microarray blocks prepared from samples of 35 Egyptian luminal breast cancer patients in the pathology department of Centre Léon Bérard (CLB). The intensity and the percentage of stained tumor cells were integrated to define high versus low biomarker expression. The cytoplasmic and nuclear stainings were graded separately. Patients were followed for a median of 4.7 years (2.1 to 6.9 years). Correlation was done between PI3K mutations and the immunohistochemistry expression of pAKT, LKB1, p4EBP1, and pS6 ribosomal protein (pS6RP) with the clinicopathologic features and disease free survival (DFS) of the patients. RESULTS: Median age at diagnosis was 51.3 years (range, 25 to 82 years). Tumors were larger than 20 mm in 79.2% of the cases, whereas 57.9% had axillary lymph node deposits. Only 12.3% of the patients had SBR grade I tumors, 50.8% had grade II, and 36.8% had grade III. ERs were negative in 6 patients (17%) after pathology review. Thirty-two cases were assessable for LKB1 and pAKT, 33 for p4EBP1 and pS6RP, and 24 for PI3K mutations. Nuclear LKB1, cytoplasmic LKB1, nuclear pAKT, cytoplasmic pAKT, nuclear p4EBP1, and cytoplasmic pS6RP expression was high in 65.6%, 62.5%, 62.5%, 68.8%, 42.4%, and 57.6%, respectively. PIK3CA mutations were found in 7 patients (29.2%). PI3K mutations were correlated with nuclear localization of pAKT (i.e., decreased cytoplasmic pAKT, P = .04; and increased nuclear pAKT, P = .10). There was a tendency toward an inverse correlation between PI3K mutations and the expression of pS6RP (P = .10) and p4EBP1 (P = .19). Nuclear LKB1 expression was a marker of good prognosis. It was associated with smaller tumors (P = .05), more ER (P = .08) and progesteron receptor (PgR) positivity (P = .002). In the Kaplan Meier (KM) model, patients with high nuclear LKB1 had longer DFS (hazard ratio = 0.36; 95% confidence interval, 0.15-1.10; P = .08). Nuclear pAKT high expression also carried a tendency toward longer DFS (hazard ratio = 0.51; 95% confidence interval, 0.11-1.16; P = .13). The expression of p4EBP1, pS6RP, and the PI3K mutational status did not show any prognostic significance in our cohort. CONCLUSION: Among the studied biomarkers, only nuclear expression of LKB1 and pAKT tended to predict better survival in breast cancer patients. PI3K mutation was correlated with the expression of nuclear pAKT but not pS6RP or p4EBP1.

Targeting mTOR pathway in gynecological malignancies: Biological rationale and systematic review of published data

BACKGROUND mTOR inhibitors are widely used in different malignancies with several trials testing their efficacy and safety in gynecological malignancies. We aimed to review the current evidence that support the expansion of using such drugs in the treatment of advanced gynecological cancers. METHODS A comprehensive systematic review of literature has been conducted to include prospective trials that used everolimus, temsirolimus or ridaforolimus in the management of gynecological cancers and have available efficacy and toxicity results. RESULTS A total of 23 studies including 980 patients were considered eligible for our review. Our review included 16 phase II and 7 phase I studies with the majority of patients having uterine cancers. Regarding Endometrial cancer, the CBR ranged from 21% to 60% and median PFS from 2.8 months to 7.3 months. In Ovarian cancers, CBR ranged from 24% to 50% and median PFS from 3.2 months to 5.9 months. In the single phase II study in cervical cancer the CBR was 61% and median PFS was 3.5 months. The toxicity profile was consistent with what was observed previously in other malignancies with fatigue, mucositis, and hematological toxicities being the most common adverse events observed. CONCLUSION mTOR inhibitors seem to be a promising option in the second line management of advanced gynecological cancers with best safety and efficacy outcomes when given as a single agent or in combination with hormonal treatment. More research is needed for better patient selection.

Tumeurs du sein luminales (récepteurs hormonaux positifs, HER2 négatives) au stade avancé : les nouvelles options thérapeutiques en 2015

Despite improvements in early detection, surgery and systemic therapy, metastatic breast cancer remains a major cause of death. Luminal type breast cancers expressing hormone estrogen receptor (ER) or progesterone (PR) and without HER2 overexpression are generally sensitive to endocrine therapy, but raise the issue of the occurrence of resistance to treatment, particularly at metastatic stage. A better understanding of hormone resistance may guide the development of new therapeutics. New strategies aim at enhancing and prolonging of endocrine sensitivity, by optimizing existing schemes, or by combining an endocrine therapy with a targeted therapies specific to hormone resistance pathways: ER signaling, PI3K/AKT/mTOR and Cyclin Dependent Kinase (CDK). Key corners of 2014 include confirmation of benefit of high dose fulvestrant, and commercialization of everolimus as the first mTOR inhibitor in this indication. Other strategies are being tested dealing with new endocrine therapies or new molecular targets such as PI3K inhibitors, insulin-like growth factor receptor (IGF-R) and histone deacetylase (HDAC) inhibitors. Coming years may be fruitful and might radically change our way to treat these patients.

Fatigue, alopecia and stomatitis among patients with breast cancer receiving cyclin-dependent kinase 4 and 6 inhibitors: a systematic review and meta-analysis.

ABSTRACT Background: Cyclin-dependent kinase (CDK) inhibitors emerge as efficacious agents in hormone positive metastatic breast cancer with more acceptable toxicity profiles than cytotoxic chemotherapy. However, some adverse effects such as fatigue, alopecia and stomatitis, vastly concern patients. Methods: The search was conducted in PubMed, American Society of Clinical Oncology meeting library, European Society for Medical Oncology meeting abstract, and the San Antonio meeting abstract databases. We identified phase 2 or 3 trials recruiting patients with breast cancer, randomized to receive hormonal treatment plus either CDK4/6 inhibitors or placebo. We considered studies providing incidence of fatigue, alopecia and stomatitis relevant. Results: One thousand records were screened. 34 studies were considered relevant. Four studies were found to be eligible for meta-analysis with a total of 2007 patients. The relative risk for all grade fatigue was 1.34 [95% CI: 1.17–1.54, p < 0.0001], for all grade alopecia was 2.14 [95% CI: 1.23–3.73, p = 0.007], and for all grade stomatitis 4.87 [95% CI: 2.11–11.24, p = 0.0002]. In addition, the relative risk for high grade fatigue was 2.40 [95% CI: 1.10–5.26, p = 0.03]. Conclusion: CDK4/6 inhibitors were associated with an increased risk of fatigue, alopecia and stomatitis. Further studies with self-reported questionnaires may elucidate the impact of the increased risk of these selected adverse effects on the patients’ quality of life.

Breast Cancer Targeting through Inhibition of the Endoplasmic Reticulum-Based Apoptosis Regulator Nrh/BCL2L10

Drug resistance and metastatic relapse remain a top challenge in breast cancer treatment. In this study, we present preclinical evidence for a strategy to eradicate advanced breast cancers by targeting the BCL-2 homolog Nrh/BCL2L10, which we discovered to be overexpressed in >45% of a large cohort of breast invasive carcinomas. Nrh expression in these tumors correlated with reduced metastasis-free survival, and we determined it to be an independent marker of poor prognosis. Nrh protein localized to the endoplasmic reticulum. Mechanistic investigations showed that Nrh made BH4 domain-dependent interactions with the ligand-binding domain of the inositol-1,4,5-triphosphate receptor (IP3R), a type 1/3 Ca2+ channel, allowing Nrh to negatively regulate ER-Ca2+ release and to mediate antiapoptosis. Notably, disrupting Nrh/IP3R complexes by BH4 mimetic peptides was sufficient to inhibit the growth of breast cancer cells in vitro and in vivo Taken together, our results highlighted Nrh as a novel prognostic marker and a candidate therapeutic target for late stage breast cancers that may be addicted to Nrh.Significance: These findings offer a comprehensive molecular model for the activity of Nrh/BCL2L10, a little studied antiapoptotic molecule, prognostic marker, and candidate drug target in breast cancer. Cancer Res; 78(6); 1404-17. ©2018 AACR.

Gastrointestinal adverse effects of cyclin-dependent kinase 4 and 6 inhibitors in breast cancer patients: a systematic review and meta-analysis

Background: Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors show promising results in metastatic breast cancer. However, an increased incidence of adverse events is remarkable. Among others, gastrointestinal (GI) involvement is of momentous impact on patients and their quality of life. Methods: Our search included PubMed, ASCO, ESMO and SABCS databases. Randomized phase II/III trials in metastatic breast cancer receiving CDK4/6 inhibitors were identified and considered relevant based on providing a sufficient safety profile on the incidence of adverse GI effects. Results: Of the 999 records initially screened for relevance, 33 articles were found relevant and 4 studies were finally eligible for meta-analysis with a total of 2007 patients. The relative risk (RR) for all-grade nausea was 1.48 [95% confidence interval (CI): 1.12–1.93, p = 0.005], vomiting was 1.74 (95% CI: 1.09–2.76, p = 0.02), decreased appetite was 1.42 (95% CI: 1.07–1.88, p = 0.02), and for diarrhea it was 1.44 (95% CI: 1.19–1.74, p = 0.0002). Meanwhile, the RR for high-grade nausea was 1.10 (95% CI: 0.29–4.13, p = 0.89), vomiting was 1.38 (95% CI: 0.25–7.75, p = 0.72), decreased appetite was 4.00 (95% CI: 0.87–18.37, p = 0.07), and high-grade diarrhea was 1.19 (95% CI: 0.44–3.21, p = 0.73). Conclusion: Selective CDK4/6 inhibitors were not associated with higher-grade GI toxicities reflecting a well-tolerated safety profile. Regarding the increase in all-grade GI toxicities, it needs further caution with addition of cytotoxic chemotherapy.

Predicting Brain Metastasis in Breast Cancer Patients: Stage Versus Biology

Background: Brain metastasis (BM) is a life‐threatening event in breast cancer patients. Identifying patients at a high risk for BM can help to adopt screening programs and test preventive interventions. We tried to identify the incidence of BM in different stages and subtypes of breast cancer. Patients and Methods: We reviewed the clinical records of 2193 consecutive breast cancer patients who presented between January 1999 and December 2010. We explored the incidence of BM in relation to standard clinicopathological factors, and determined the cumulative risk of BM according to the disease stage and phenotype. Results: Of the 2193 included women, 160 (7.3%) developed BM at a median follow‐up of 5.8 years. Age younger than 60 years (P = .015), larger tumors (P = .004), lymph node (LN) positivity (P < .001), high tumor grade (P = .012), and HER2 positivity (P < .001) were associated with higher incidence of BM in the whole population. In patients who presented with locoregional disease, 3 factors independently predicted BM: large tumors (hazard ratio [HR], 3.60; 95% confidence interval [CI], 1.54‐8.38; P = .003), axillary LN metastasis (HR, 4.03; 95% CI, 1.91‐8.52; P < .001), and HER2 positivity (HR, 1.89; 95% CI, 1.0‐3.41; P = .049). A Brain Relapse Index was formulated using those 3 factors, with 5‐year cumulative incidence of BM of 19.2% in those having the 2 or 3 risk factors versus 2.5% in those with no or 1 risk factor (P < .001). In metastatic patients, 3 factors were associated with higher risk of BM: HER2 positivity (P = .007), shorter relapse‐free interval (P < .001), and lung metastasis (P < .001). Conclusion: Disease stage and biological subtypes predict the risk for BM and subsequent treatment outcome.

LKB1 regulates PRMT5 activity in breast cancer: LKB1 regulates PRMT5 activity in breast cancer

Protein arginine methyltransferase 5 (PRMT5) is the main enzyme responsible for the symmetrical dimethylation of arginine residues on target proteins in both the cytoplasm and the nucleus. Though its activity has been associated with tumor progression in various cancers, the expression pattern of this oncoprotein has been scarcely studied in breast cancer. In the current work, we analyzed its expression in a large cohort of breast cancer patients, revealing higher nuclear PRMT5 levels in ERα‐positive tumors and an association with prolonged disease free and overall survival. Interestingly, high PRMT5 nuclear expression was also associated with higher nuclear liver kinase B1 (LKB1), suggesting that a functional relationship may occur. Consistently, several approaches provided evidence that PRMT5 and LKB1 interact directly in the cytoplasm of mammary epithelial cells. Moreover, although PRMT5 is not able to methylate LKB1, we found that PRMT5 is a bona fade substrate for LKB1. We identified T132, 139 and 144 residues, located in the TIM‐Barrel domain of PRMT5, as target sites for LKB1 phosphorylation. The point mutation of PRMT5 T139/144 to A139/144 drastically decreased its methyltransferase activity, due probably to the loss of its interaction with regulatory proteins such as MEP50, pICln and RiOK1. In addition, modulation of LKB1 expression modified PRMT5 activity, highlighting a new regulatory mechanism that could have clinical implications.

Abiraterone acetate/androgen deprivation therapy combination versus docetaxel/androgen deprivation therapy combination in advanced hormone-sensitive prostate cancer: a network meta-analysis on safety and efficacy

Abstract Background: A major, yet precisely studied, shift has occurred in the treatment of advanced hormone-sensitive prostate cancer (HSPC) by the addition of docetaxel to androgen deprivation therapy (ADT) in the first line. Recently, two landmark trials showed that abiraterone acetate (AA) can be an effective alternative along with ADT in the same setting. We implemented a network meta-analysis to compare the safety and efficacy of the two combinations. Methods: PubMed database, ASCO and ESMO meeting library databases of all results published until June 2017 were searched using the keywords: “prostate cancer” AND “docetaxel” OR “abiraterone acetate”. Efficacy endpoints including progression-free survival (PFS) and overall survival (OS), and safety endpoints (including treatment related deaths and selected adverse events) were assessed. Results: Twenty relevant studies were retrieved and assessed for eligibility. Of those trials, eight were found potentially eligible. Inconsistent reporting of efficacy outcomes limited our analysis to M1 HSPC. The pooled hazard ratios (HRs) of OS and PFS of the direct comparison of abiraterone acetate plus ADT versus ADT were 0.63 (95% CI: 0.545–0.717) and 0.38 (95% CI: 0.34–0.43), respectively. Meanwhile, in the trials of docetaxel plus ADT the pooled HRs of OS and PFS were 0.75 (95% CI: 0.65–0.86) and 0.634 (95% CI: 0.57–0.70), respectively. The indirect comparison showed that the HRs of OS and PFS in DOC + ADT in comparison to AA + ADT were 1.2 (95% CI: 0.98–1.46) and 1.65 (1.40–1.94), respectively. The pooled RR of treatment-related mortality in docetaxel + ADT versus AA + ADT was 1.438 (95% CI: 0.508–4.075). Conclusion: Patients with metastatic HSPC (mHSPC) who received abiraterone acetate with ADT had better PFS and less toxicity compared to those receiving docetaxel with ADT. A trend towards superior OS and fewer treatment-related deaths was also observed, but was statistically non-significant. In view of lacking clear OS advantage, the choice between docetaxel and AA should include a discussion with the patient about the potential toxicities and impact on quality of life of each regimen.

Treatment of HER2-positive early breast cancer: How to best balance efficacy and toxicity?

Several trastuzumab-based chemotherapeutic regimens have been approved worldwide for the treatment of HER2-positive early breast cancer (EBC) patients, with apparently no clue for a truly preferable one. Most of these regimens have emerged from the classic anthracycline-taxane sequential combinations, typically used during the (neo)adjuvant phases of all BC subtypes. In the pivotal trials, the addition of trastuzumab for 1 year to any anthracycline-containing regimen could significantly reduce the risk of relapse by 27%-40% and the risk of death by 25%-37%. Nonetheless, and from a safety perspective, there was a 3to 10-fold increase in the incidence of congestive heart failure (CHF) among patients received trastuzumab with anthracycline-containing regimens, compared to those treated with chemotherapy alone. Trastuzumab-associated cardiac toxicity, has been explained by several pre-clinical studies, that confirmed a cardioprotective role of HER2 signaling pathway when the heart is exposed to anthracycline treatment. Trastuzumab, as it blocks the HER2 survival signals in tumor cells as well as in cardiomyocytes, is thus expected to aggravate anthracycline induced cardiac damage. Among all trastuzumab-based regimens, the combination of docetaxel, carboplatin, and trastuzumab (for 1 year), generically known as TCH regimen, is considered unique as its chemotherapy backbone is not approved in early-stage BC patients, except for those with HER2-positive disease. The TCH regimen was proposed based on a robust synergy detected when trastuzumab was added to platinum and docetaxel, which was not the case, with paclitaxel or anthracyclines. It was anticipated that an anthracycline-free regimen like TCH, would significantly reduce the incidence of cardiotoxicity, and thereby offer a safer approach in treating HER2-positive EBC patients. Accordingly, the BCIRG-006 trial was designed to compare the efficacy and safety of AC-T (4 cycles of doxorubicin and cyclophosphamide followed by 4 cycles of docetaxel) as a standard treatment, vs 2 trastuzumab-based regimens: AC-TH and TCH. The 5and 10-year results, have shown a significant disease free survival (DFS) and overall survival (OS) benefit in both trastuzumab-containing arms compared to chemotherapy alone arm, with no statistical advantage of AC-TH over TCH. An important and clinically relevant result of BCIRG-006 was the rate of CHF, which was 5-fold higher in the AC-TH arm compared to TCH arm (2.0%, vs 0.4%, respectively, P = .0005). Hence, the cardiac safety of TCH is considered as the most favorable among all trastuzumab-containing regimens used in the clinic. An added advantage of TCH, vs AC-TH, was related to the quality of life (QOL) data, which supported the use of TCH as a significantly more tolerable treatment option. However, it remains that the use of docetaxel is typically associated with several acute toxicities, among which febrile neutropenia (FN) is especially relevant, being a life threatening event, necessitating hospitalization, and subsequent dose delays/reductions, which may compromise treatment efficacy and QOL. It is well understood that prophylactic use of granulocyte colony-stimulating factor (G-CSF) can significantly reduce the incidence of FN, in patients receiving myelotoxic chemotherapeutic regimens. In this context, G-CSF is given either as primary prophylaxis (PPG), starting with first cycle and continued in subsequent chemotherapy cycles, or secondary prophylaxis, where it is given only after the occurrence of a FN event. According to EORTC and ASCO Guidelines, PPG is recommended only for patients at ≥20% risk of FN, as reported by large controlled clinical trials. Unfortunately, the incidence of FN without G-CSF treatment is widely variable across clinical studies, and is often reported at much higher rates among patients treated in the real world practice, as many high-risk populations are encompassed in such cohort studies, while they are usually disqualified from randomized clinical trials. For instance, the US Oncology group reported a 5% FN incidence in patients receiving TC (docetaxel/cyclophosphamide) regimen, while numerous studies using the same regimen have reported a much higher incidence of FN ranging between 25% and 50%, being 29% in a pooled meta-analysis. Likewise, the incidence of FN among patients treated with TCH has been reported to range from 7.1% to 41.0%, being 9.8% in the BCIRG-006 trial. Importantly, in this trial, another 11% of TCH-treated patients developed neutropenic infection, which collectively brings neutropenia-associated complications to the 20% threshold, proposed for PPG. Nevertheless, the guidelines do not clearly include TCH among the regimens requiring PPG. In the current issue of TBJ, Bayo et al. have published their results on the impact of PPG on the toxicity profile of 95 EBC patients treated with TCH. In this series, around two-thirds of the patients did not receive PPG, while the remaining patients received PPG. The authors reported a significant difference in the incidence of FN between the 2 cohorts (31.67% vs 8.57%, respectively, P = .01). Interestingly, patients in the PPG cohort had significant reductions of some grades 3 and 4 nonhematological toxicities, including stomatitis, fatigue, nausea, and vomiting. It would have been exciting to see the impact of such toxicity reductions on the QOL of the 2 cohorts included in this study, which was not conceivable, in view of its retrospective design. In a much larger prospective study (GEICAM 9805), the use of PPG, in patients treated by TAC regimen, was also associated with a significant reduction in Received: 3 August 2017 | Accepted: 3 August 2017 DOI: 10.1111/tbj.12932