CDK4/6-Inhibitors Versus Chemotherapy in Advanced HR+/HER2-Negative Breast Cancer: Results and Correlative Biomarker Analyses of the KENDO Randomized Phase II Trial.

BACKGROUND: The optimal treatment approach for hormone receptor-positive/HER2-negative metastatic breast cancer (HR+/HER2-negative MBC) with aggressive characteristics remains controversial, with lack of randomized trials comparing cyclin-dependent kinase (CDK)4/6-inhibitors (CDK4/6i) + endocrine therapy (ET) with chemotherapy + ET. MATERIALS AND METHODS: We conducted an open-label randomized phase II trial (NCT03227328) to investigate whether chemotherapy + ET is superior to CDK4/6i + ET for HR+/HER2-negative MBC with aggressive features. PAM50 intrinsic subtypes (IS), immunological features, and gene expression were assessed on baseline samples. RESULTS: Among 49 randomized patients (median follow-up: 35.2 months), median progression-free survival (mPFS) with chemotherapy + ET (11.2 months, 95% confidence interval [CI]: 7.7-15.4) was numerically shorter than mPFS (19.9 months, 95% CI: 9.0-30.6) with CDK4/6i + ET (hazard ratio: 1.41, 95% CI: 0.75-2.64). Basal-like tumors under CDK4/6i + ET exhibited worse PFS (mPFS: 11.4 months, 95% CI: 3.00-not reached [NR]) and overall survival (OS; mOS: 18.8 months, 95% CI: 18.8-NR) compared to other subtypes (mPFS: 20.7 months, 95% CI: 9.00-33.4; mOS: NR, 95% CI: 24.4-NR). In the chemotherapy arm, luminal A tumors showed poorer PFS (mPFS: 5.1 months, 95% CI: 2.7-NR) than other IS (mPFS: 13.2 months, 95% CI: 10.6-28.1). Genes/pathways involved in BC cell survival and proliferation were associated with worse outcomes, as opposite to most immune-related genes/signatures, especially in the CDK4/6i arm. CD24 was the only gene significantly associated with worse PFS in both arms. Tertiary lymphoid structures and higher tumor-infiltrating lymphocytes also showed favorable survival trends in the CDK4/6i arm. CONCLUSIONS: The KENDO trial, although closed prematurely, adds further evidence supporting CDK4/6i + ET use in aggressive HR+/HER2-negative MBC instead of chemotherapy. PAM50 IS, genomic, and immunological features are promising biomarkers to personalize therapeutic choices.

The efficacy and safety of enzalutamide with trastuzumab in patients with HER2+ and androgen receptor-positive metastatic or locally advanced breast cancer.

PURPOSE: Androgen receptor (AR) expression occurs in up to 86% of human epidermal growth factor receptor 2-positive (HER2+) breast cancers. In vitro, AR inhibitors enhance antitumor activity of trastuzumab, an anti-HER2 antibody, in trastuzumab-resistant HER2+ cell lines. This open-label, single-arm, phase II study evaluated the efficacy and safety of enzalutamide, an AR-signaling inhibitor, in patients with advanced HER2+ AR+ breast cancer previously treated with trastuzumab. METHODS: Eligible patients had measurable or non-measurable evaluable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1, Eastern Cooperative Oncology Group status ≤ 1, no history of brain metastases, and previously received ≥ 1 anti-HER2 regimen for advanced disease. Patients received 160 mg oral enzalutamide daily and 6 mg/kg intravenous trastuzumab every 21 days until disease progression or unacceptable toxicity. Primary end point was clinical benefit rate at 24 weeks (CBR24); secondary end points included progression-free survival (PFS) and safety. RESULTS: Overall, 103 women were enrolled [median age 60 years (range 34-83)]; 62% had received ≥ 3 lines of prior anti-HER2 therapy. CBR24, comprising patients with confirmed partial responses (5%) and durable stable disease at 24 weeks (19%), was 24% in the efficacy evaluable set (n = 89). CBR24 did not seem related to AR-expression levels or hormone receptor status. Median PFS was 3.4 months (95% confidence interval 2.0-3.8). Overall, 97 (94%) patients experienced treatment-emergent adverse events (TEAEs), with fatigue most common (34%). Dyspnea (4%) and malignant neoplasm progression (3%) were the only TEAEs grade ≥ 3 reported in ≥ 3 patients. 22 patients (21%) reported serious TEAEs. Four patients (4%) experienced fatal, non-drug-related TEAEs. CONCLUSIONS: Enzalutamide plus trastuzumab was well tolerated, and a subset of patients in this heavily pretreated population had durable disease control. Determination of biomarkers is needed to identify patients most likely to benefit from this combination. CLINICALTRIALS. GOV NUMBER: NCT02091960.

Insulin-like growth factor-1 receptor (IGF-1R) expression on circulating tumor cells (CTCs) and metastatic breast cancer outcome: results from the TransMYME trial.

PURPOSE: To evaluate the prognostic value of IGF-1R expression on circulating tumor cells (CTCs) in a prospective randomized clinical trial comparing chemotherapy plus metformin with chemotherapy alone in metastatic breast cancer (MBC) patients. METHODS: CTCs were collected at baseline and at the end of chemotherapy. An automated sample preparation and analysis system (CellSearch) were customized for detecting IGF-1R expression. The prognostic role of CTC count and IGF-1R was assessed for PFS and OS by univariate and multivariate analyses. RESULTS: Seventy-two out of 126 randomized patients were evaluated: 57% had ≥ 1 IGF-1R positive CTC and 37.5% ≥ 4 IGF-1R negative cells; 42% had CTC count ≥ 5/7.5 ml. At univariate analysis, the number of IGF-1R negative CTCs was strongly associated with risk of progression and death: HR 1.93 (P = 0.013) and 3.65 (P = 0.001), respectively; no association was detected between number of IGF-1R positive CTCs and PFS or OS (P = 0.322 and P = 0.840). The prognostic role of CTC count was confirmed: HR 1.69, P = 0.042 for PFS and HR 2.80 for OS, P = 0.002. By multivariate analysis, the prognostic role of the number of IGF-1R negative CTCs was maintained, while no residual prognostic role of CTC count or number of IGF-1R positive cells was found. CONCLUSION: Loss of IGF-1R in CTCs is associated with a significantly worse outcome in MBC patients. This finding supports further evaluation for the role of IGF-1R on CTCs to improve patient stratification and to implement new targeted strategies. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov (NCT01885013); European Clinical Trials Database (EudraCT No.2009-014,662-26).

Immunotherapy: The end of the "dark age" for metastatic triple-negative breast cancer?

The lack of effective therapies for metastatic triple-negative breast cancer (mTNBC) highlights the need for the development of novel treatment strategies. The cornerstone of treatment has long been represented by chemotherapy. Relevant evidence has recently emerged regarding the efficacy of immune checkpoint inhibitors, with the demonstration of a statistically significant improvement of progression-free survival with the addition of atezolizumab to nab-paclitaxel in the first-line treatment of mTNBC, accompanied by a substantial overall survival benefit in the PD-L1-positive subgroup. Despite this, it is necessary to identify the biomarkers that could allow a better selection of patients and combination regimens.

Phase II Study of Dehydroepiandrosterone in Androgen Receptor-Positive Metastatic Breast Cancer.

LESSONS LEARNED: The androgen receptor (AR) is present in most breast cancers (BC), but its exploitation as a therapeutic target has been limited.This study explored the activity of dehydroepiandrosterone (DHEA), a precursor being transformed into androgens within BC cells, in combination with an aromatase inhibitor (to block DHEA conversion into estrogens), in a two-stage phase II study in patients with AR-positive/estrogen receptor-positive/human epidermal growth receptor 2-negative metastatic BC.Although well tolerated, only 1 of 12 patients obtained a prolonged clinical benefit, and the study was closed after its first stage for poor activity. BACKGROUND: Androgen receptors (AR) are expressed in most breast cancers, and AR-agonists have some activity in these neoplasms. We investigated the safety and activity of the androgen precursor dehydroepiandrosterone (DHEA) in combination with an aromatase inhibitor (AI) in patients with AR-positive metastatic breast cancer (MBC). METHODS: A two-stage phase II study was conducted in two patient cohorts, one with estrogen receptor (ER)-positive (resistant to AIs) and the other with triple-negative MBC. DHEA 100 mg/day was administered orally. The combination with an AI aimed to prevent the conversion of DHEA into estrogens. The main endpoint was the clinical benefit rate. The triple-negative cohort was closed early. RESULTS: Twelve patients with ER-positive MBC were enrolled. DHEA-related adverse events, reported in four patients, included grade 2 fatigue, erythema, and transaminitis, and grade 1 drowsiness and musculoskeletal pain. Clinical benefit was observed in one patient with ER-positive disease whose tumor had AR gene amplification. There was wide inter- and intra-patient variation in serum levels of DHEA and its metabolites. CONCLUSION: DHEA showed excellent safety but poor activity in MBC. Although dose and patient selection could be improved, high serum level variability may hamper further DHEA development in this setting.

Androgen receptor in advanced breast cancer: is it useful to predict the efficacy of anti-estrogen therapy?

BACKGROUND: Androgen receptor (AR) is widely expressed in breast cancer (BC) but its role in estrogen receptor (ER)-positive tumors is still controversial. The AR/ER ratio has been reported to impact prognosis and response to antiestrogen endocrine therapy (ET). METHODS: We assessed whether AR in primary tumors and/or matched metastases is a predictor of efficacy of first-line ET in advanced BC. Patients who had received first-line ET (2002-2011) were recruited, while those given concomitant chemotherapy or trastuzumab or pretreated with > 2 lines of chemotherapy were excluded. ER, progesterone receptor (PgR), Ki67 and AR expression were assessed by immunohistochemistry, and HER2 mainly by fluorescent in-situ hybridization. Cut-offs of 1 and 10% immunostained cells were used to categorize AR expression. RESULTS: Among 102 evaluable patients, biomarkers were assessed in primary tumors in 70 cases and in metastases in 49, with 17 patients having both determinations. The overall concordance rate between primary tumors and metastases was 64.7% (95% CI 42%-87.4%) for AR status. AR status did not affect TTP significantly, whereas PgR and Ki67 status did. AR/PgR ≥0.96 was associated with a significantly shorter TTP (HR = 1.65, 95% CI 1.05-2.61, p = 0.028). AR status in primary tumors or metastases was not associated with progressive disease (PD) as best response. In contrast, Ki67 ≥ 20% and PgR < 10% showed a statistically significant association with PD as best response. CONCLUSIONS: AR expression does not appear to be useful to predict the efficacy of ET in advanced BC, whereas Ki67 and PgR exert a greater impact on its efficacy.

Androgen and oestrogen receptors as potential prognostic markers for patients with ductal carcinoma in situ treated with surgery and radiotherapy.

Ductal carcinoma in situ (DCIS) is a heterogeneous disease that has been investigated less extensively than invasive breast cancer. Women with DCIS are mainly treated with conservative surgery almost exclusively followed by radiotherapy. However, as radiation treatment is not always effective, the search for biomarkers capable of identifying DCIS lesions that could progress to invasive cancer is ongoing. Although conventional biomarkers have been thoroughly studied in invasive tumours, little is known about the role played by androgen receptor (AR), widely expressed in DCIS. A series of 42 DCIS patients treated with quadrantectomy and radiotherapy were followed for a period of up to 95 months. Of these, 11 had recurrent DCIS or progressed to invasive cancer. All tumours were analysed for clinical pathological features. Conventional biomarkers and androgen receptor expression were determined by immunohistochemistry. Our results showed that AR was higher in tumours of relapsed patients than non-relapsed patients (P value: 0.0005). Conversely, oestrogen receptor (ER) was higher, albeit not significantly, in non-relapsed patients than in relapsed patients. AR/ER ratio was considerably different in the two subgroups (P value: 0.0033). Area under the curve (AUC) values were 0.85 for AR and 0.80 for the AR/ER ratio. These preliminary results highlight the potentially important role of both AR and the AR/ER ratio as prognostic markers in DCIS.

Impact of body mass index (BMI) on the prognosis of high-risk early breast cancer (EBC) patients treated with adjuvant chemotherapy.

The association between obesity and prognosis in early breast cancer (EBC) is unclear, especially when aggressive phenotypes are considered. We evaluated the influence of BMI on the prognosis of women with high-risk EBC enrolled in a phase III trial of adjuvant chemotherapy (CT). The association was assessed in 1066 patients with rapidly proliferating tumors, randomized to receive adjuvant CT with or without anthracyclines. Disease-free survival (DFS) and overall survival (OS) were calculated by Kaplan-Meier; multivariate analysis was performed according to age, tumor size, nodal, estrogen receptor (ER), and HER2 status and type of CT. Information on BMI was available for 959 women. Of these, 529 (55.2 %) were overweight or obese. Median age was 52 years. A total of 457 (47.7 %) patients had nodal involvement. Centralized pathology was performed in 850 cases: 522 (61.4 %) were ER positive, and 194 (22.8 %) were HER-2 positive. At a median follow-up of 103 months (range 1-188), 5-year DFS was 81 % (95 % CI 77-85), 82 % (95 % CI 77-86), and 76 % (95 % CI 70-83), in normal, overweight, and obese women, respectively (p = 0.44). Five-year OS was 92 % (95 % CI 89-95), 94 % (95 % CI 91-96), and 89 % (95 % CI 84-93), respectively (p = 0.60). BMI was not associated by multivariate analysis with differences in DFS or OS. Higher BMI had no influence on prognosis in high-risk EBC patients treated with CT. These data are consistent with prior observations and suggest that in aggressive biological subtypes, the impact of host factors on patient prognosis is minor.

A phase II study of a dose-density regimen with fluorouracil, epirubicin, and cyclophosphamide on days 1 and 4 every 14 days with filgrastim support followed by weekly paclitaxel in women with primary breast cancer.

BACKGROUND: Recent evidence shows that use of anthracycline and taxane adjuvant chemotherapy and dose-dense regimens, consisting of more frequent administration of the drugs, have improved outcomes for breast cancer patients. In this study, we evaluated administration of an epirubicin-based regimen with paclitaxel in a sequential, dose-dense schedule as adjuvant treatment for patients with high-risk primary breast cancer. METHODS: In a phase II Simon two-stage design study, we evaluated the feasibility of a modified fluorouracil, epirubicin, and cyclophosphamide (FEC) regimen at high dose intensity (fluorouracil 500 mg/m(2) i.v. on days 1 and 4, epirubicin 60 mg/m(2) i.v. on days 1 and 4, and cyclophosphamide 500 mg/m(2) i.v. on days 1 and 4; all drugs were administered every 14 days for 3 cycles) with granulocyte colony-stimulating factor support followed by dose-intense weekly paclitaxel 100 mg/m(2) for 8 cycles. In 11 patients with breast cancer following quadrantectomy (n = 8) or modified radical mastectomy (n = 3), any grade 3 (G3) or higher nonhematologic toxicity (excluding alopecia, nausea or vomiting, and bone pain, which might be a consequence of the administration of filgrastim) and adherence to the scheduled dose-dense treatment (deliverability) were monitored with the purpose of enrolling an additional 27 patients in the case of a satisfying toxicity profile and deliverability of the planned treatment (at least 7 patients completing the treatment). RESULTS: Five of 11 patients experienced G3 or higher nonhematologic toxicity during the FEC regimen. We did not observe G3 or higher nonhematologic toxicity related to paclitaxel treatment. In particular, three patients experienced G3 fatigue, one patient had G3 oral mucositis, three patients had G3 hypokalemia, one patient had G3 syncope, one patient had G3 transaminitis (alanine aminotransferase), one patient experienced G4 pulmonary thromboembolism, and 1 patient had a G3 breast infection. Four of 11 patients received the regimen with a 25% dose reduction of day 1 and 4 administrations of FEC. Seven of 11 patients required FEC delay ≥7 days in at least 1 cycle, regardless of dose intensity. Two patients failed to complete the FEC regimen. Two of the remaining 9 patients were treated with paclitaxel delay ≥7 days in at least one cycle. After a median follow-up of 28 months, 9 patients were continuously disease free. CONCLUSION: The tolerability rate of a dose-density regimen with FEC followed by weekly paclitaxel was considered not promising for completing the accrual of this study.

Efficacy of endocrine therapy in relation to progesterone receptor and Ki67 expression in advanced breast cancer.

We assessed whether progesterone receptor (PgR) and Ki67 in primary tumors and/or matched metastases are predictors of clinical benefit from first-line endocrine therapy (ET) in advanced breast cancer. We evaluated patients treated at our institute with first-line ET (2002-2011), excluding those receiving concomitant chemotherapy or trastuzumab or pretreated with >2 lines of chemotherapy. A cut-off of 20 % immunostained cells was used for PgR and Ki67. The main endpoint was time-to-progression (TTP). Groups were compared by the log-rank test and Cox multivariate analysis. In the 135 assessable patients (93 % were receiving an aromatase inhibitor; biomarker assessment had been performed on primary tumors in 77 cases, on metastases in 23 and on both in 35), median TTP was 16 months (median follow-up 43 months). The overall discordance rate between primary tumors and metastases was 23 % for Ki67 and 31 % for PgR. A longer median TTP (24 vs. 12 months, P = 0.012) was seen for PgR >20 % in metastases. Ki67 showed a trend for TTP prediction in the entire case series (P = 0.062). Patients with high Ki67 and low PgR in metastases had a median TTP of only 5 months. High Ki67 in primary tumors (P = 0.026) or metastases (P = 0.01) predicted disease progression at the first evaluation. PgR in metastases remained a significant independent predictor of TTP at multivariate analysis (HR 2.45). In an ER-high population, PgR >20 % in metastases identified patients with a long TTP on endocrine treatment, while Ki67 >20 % was associated with an increased risk of non-response.

Benefit from anthracyclines in relation to biological profiles in early breast cancer.

There are no validated predictors of benefit from anthracyclines. We compared cyclophosphamide, methotrexate, 5-fluorouracil (CMF), and epirubicin in different sequences with CMF alone in a phase III trial on operable breast cancers. Outcomes were analyzed in relation to tumor biological profiles to identify potential predictors of the efficacy of different treatments/drug combinations. Patients with N- or 1-3N+ tumors, were randomized to receive (a) epirubicin (4 cycles) followed by CMF (4 cycles); (b) CMF (4 cycles) followed by epirubicin (4 cycles), or (c) CMF (6 cycles) alone. Immunohistochemical assessments of estrogen (ER) and progesterone (PgR) receptors, HER2 and Ki67 were available for 705 patients (arm A/B/C: 276/269/160). Prognostic and predictive relevance was analyzed by log-rank tests and Cox models. Ki67 > 20 % and absent/low expression of ER and PgR were associated with worsen disease-free (DFS) and overall survival (OS). In patients with triple negative tumors (ER-, PgR-, HER2-), epirubicin-containing regimens yielded better DFS (HR 0.33, 95 % CI 0.17-0.62, P = 0.0007) and OS (HR 0.24, 95 % CI 0.10-0.57, P = 0.001) compared with CMF alone, whereas no differences were found in patients with HER2-positive (HER2+, ER-, PgR-) subtype. Treatment by subtype interaction (HER2-positive vs. others) was significant for DFS (χ (2) = 6.72, P = 0.009). In triple unfavorable (ER-, PgR-, Ki67 > 20 %) tumors, the use of epirubicin yielded better DFS (HR 0.45,95 % CI 0.26-0.78, P = 0.005) and OS (HR 0.30, 95 % CI 0.15-0.63, P = 0.001). Epirubicin-containing regimens seem to be superior to CMF alone in patients with highly proliferating, triple negative or triple unfavorable tumors.

CD99 Expression and Prognostic Impact in Glioblastoma: A Single-Center Cohort Study.

Glioblastoma is the most frequent and aggressive brain tumor in adults. This study aims to evaluate the expression and prognostic impact of CD99, a membrane glycoprotein involved in cellular migration and invasion. In a cohort of patients with glioblastoma treated with surgery, radiotherapy and temozolomide, we retrospectively analyzed tumor expression of CD99 by immunohistochemistry (IHC) and by quantitative real-time polymerase chain reaction (qRT-PCR) for both the wild type (CD99wt) and the truncated (CD99sh) isoforms. The impact on overall survival (OS) was assessed with the Kaplan-Meier method and log-rank test and by multivariable Cox regression. Forty-six patients with glioblastoma entered this study. Immunohistochemical expression of CD99 was present in 83%. Only the CD99wt isoform was detected by qRT-PCR and was significantly correlated with CD99 expression evaluated by IHC (rho = 0.309, p = 0.037). CD99 expression was not associated with OS, regardless of the assessment methodology used (p = 0.61 for qRT-PCR and p = 0.73 for IHC). In an exploratory analysis of The Cancer Genome Atlas, casuistry of glioblastomas CD99 expression was not associated with OS nor with progression-free survival. This study confirms a high expression of CD99 in glioblastoma but does not show any significant impact on survival. Further preclinical studies are needed to define its role as a therapeutic target in glioblastoma.

A Pictorial Essay Describing the CT Imaging Features of COVID-19 Cases throughout the Pandemic with a Special Focus on Lung Manifestations and Extrapulmonary Vascular Abdominal Complications.

With the Omicron wave, SARS-CoV-2 infections improved, with less lung involvement and few cases of severe manifestations. In this pictorial review, there is a summary of the pathogenesis with particular focus on the interaction of the immune system and gut and lung axis in both pulmonary and extrapulmonary manifestations of COVID-19 and the computed tomography (CT) imaging features of COVID-19 pneumonia from the beginning of the pandemic, describing the typical features of COVID-19 pneumonia following the Delta variant and the atypical features appearing during the Omicron wave. There is also an outline of the typical features of COVID-19 pneumonia in cases of breakthrough infection, including secondary lung complications such as acute respiratory distress disease (ARDS), pneumomediastinum, pneumothorax, and lung pulmonary thromboembolism, which were more frequent during the first waves of the pandemic. Finally, there is a description of vascular extrapulmonary complications, including both ischemic and hemorrhagic abdominal complications.

An interesting presentation of a rare association of the Wilkie and Nutcracker syndromes.

Superior mesenteric artery syndrome also known as Wilkie's syndrome (WS) and Nutcracker syndrome (NCS) are 2 rare vascular syndromes characterized by the reduction of the aortomesenteric space. In the WS the reduction of the aortomesenteric angle leads to compression of the third portion of the duodenum. In the NCS the reduced aortomesenteric space usually causes a left renal vein (LVR) entrapment and the clinical presentation is a left flank pain, micro/macrohematuria and proteinuria. Arterial hypertension can be an unusual manifestation of the NCS. Herein, we describe the case of a 37-year-old woman with a history of breast cancer and abdominal subocclusion, with a recent onset of arterial hypertension whose enhanced computed tomography (CT) showed a reduced angle between the abdominal aorta and superior mesenteric artery with the CT findings of both the WS and NCS.

Analysis of PD-L1 and CD3 Expression in Glioblastoma Patients and Correlation with Outcome: A Single Center Report.

With the advent of immunotherapies, the field of cancer therapy has been revived with new hope, especially for cancers with dismal prognoses, such as the glioblastoma multiforme (GBM). Currently, immunotherapies should potentiate the host's own antitumor immune response against cancer cells, but it has been documented that they are effective only in small subsets of patients. Therefore, accurate predictors of response are urgently needed to identify who will benefit from immune-modulatory therapies. Brain tumors are challenging in terms of treatments. The immune response in the brain is highly regulated, and the immune microenvironment in brain metastases is active with a high density of tumor-infiltrating lymphocytes (TILs, CD3+ T cells) in certain patients and, therefore, may serve as a potential treatment target. In our study, we performed immunohistochemistry for CD3 and PD-L1 along the routine assessment of the O6-methylguanine-methyltransferase (MGMT) promoter methylation status and the IDH1 and 2 status in a single center cohort of 69 patients with GBM (58 primary tumors and 11 recurrences) who underwent standard multimodal therapies (surgery/radiotherapy/adjuvant temozolamide). We analyzed the association of PD-L1 tumor expression and TILs with overall survival (OS). The PD-L1 expression was observed in 25 of 58 (43%) newly diagnosed primary glioblastoma specimens. The sparse-to-moderate density of TILs, identified with CD3+ expression, was found in 48 of 58 (83%) specimens. Neither PD-L1 expression nor TILs were associated with overall survival. In conclusion, TILs and/or PD-L1 expression are detectable in the majority of glioblastoma samples, and even if they slightly relate to the outcome, they do not show a statistically significant correlation.

Complement protein C1q stimulates hyaluronic acid degradation via gC1qR/HABP1/p32 in malignant pleural mesothelioma.

Complement component C1q can act as a pro-tumorigenic factor in the tumor microenvironment (TME). The TME in malignant pleural mesothelioma (MPM) is rich in C1q and hyaluronic acid (HA), whose interaction enhances adhesion, migration and proliferation of malignant cells. HA-bound C1q is also capable of modulating HA synthesis. Thus, we investigated whether HA-C1q interaction would affect HA degradation, analyzing the main degradation enzymes, hyaluronidase (HYAL)1 and HYAL2, and a C1q receptor candidate. We first proceeded with the characterization of HYALs in MPM cells, especially HYAL2, since bioinformatics survival analysis revealed that higher HYAL2 mRNA levels have an unfavorable prognostic index in MPM patients. Interestingly, Real-Time quantitative PCR, flow cytometry and Western blot highlighted an upregulation of HYAL2 after seeding of primary MPM cells onto HA-bound C1q. In an attempt to unveil the receptors potentially involved in HA-C1q signaling, a striking co-localization between HYAL2 and globular C1q receptor/HABP1/p32 (gC1qR) was found by immunofluorescence, surface biotinylation and proximity ligation assays. RNA interference experiments revealed a potentially regulatory function exerted by gC1qR on HYAL2 expression, since C1QBP (gene for gC1qR) silencing unexpectedly caused HYAL2 downregulation. In addition, the functional blockage of gC1qR by a specific antibody hindered HA-C1q signaling and prevented HYAL2 upregulation. Thus, C1q-HA interplay is responsible for enhanced HYAL2 expression, suggesting an increased rate of HA catabolism and the release of pro-inflammatory and pro-tumorigenic HA fragments in the MPM TME. Our data support the notion of an overall tumor-promoting property of C1q. Moreover, the overlapping localization and physical interaction between HYAL2 and gC1qR suggests a potential regulatory effect of gC1qR within a putative HA-C1q macromolecular complex.

The Predictive and Prognostic Role of RAS-RAF-MEK-ERK Pathway Alterations in Breast Cancer: Revision of the Literature and Comparison with the Analysis of Cancer Genomic Datasets.

Although gene alterations of the RAS/RAF/MEK/ERK pathway are uncommon in breast cancer, this pathway is frequently activated in breast tumors, implying its role in tumor progression. We describe, after a revision of the literature, the frequency and types of gene alterations affecting this pathway in breast cancer by analyzing some public datasets from cBioPortal. Moreover, we consider their prognostic and predictive impact on treatment response, along with the role of transcriptomic predictors of RAS pathway activation. Our analysis shows that the driver alterations in RAS/RAF/MEK/ERK pathway-related genes are detected in 11% of primary breast cancers. The most frequently mutated genes are NF1 and KRAS, while copy number alterations mainly affect KRAS and BRAF, especially in basal-like tumors. The subgroup of patients carrying these alterations shows a worse prognosis; alterations in NF1 and RAF1 are associated with significantly reduced breast-cancer-specific survival in multivariate analysis. The literature review shows that the pathway is implicated, either by genetic or epigenetic alterations or by signaling network adaptations, in the mechanisms of sensitivity and resistance to a wide range of drugs used in the treatment of breast cancer. A thorough understanding of these alterations is critical for developing combination therapies that can delay or overcome drug resistance.