PL2.1 Exploiting the DNAM-1 system for chimeric antigen receptor (CAR) T cell therapy of glioblastoma

BACKGROUND

Cancer immunotherapy with genetically engineered T cells that express a chimeric antigen receptor (CAR) has led to impressive responses in extracranial malignancies and is also explored against glioblastoma. However, CAR T cell strategies that are currently being explored against glioblastoma target single tumor antigens, which are non-homogeneously expressed and are prone to antigen escape. Furthermore, the immunosuppressive brain tumor microenvironment hampers anti-tumor efficacy.

METHODS

By immunohistochemistry and flow cytometry, we investigated the expression of CD155 and CD112, which are ligands to the activating immune cell receptor DNAX accessory molecule-1 (DNAM-1), in human and mouse glioma cell lines as well as in human glioblastoma samples. To understand their functional role, we generated CD155 or CD112 knock-out glioma cell lines using CRISPR/Cas9 and studied proliferation, sensitivity to irradiation or temozolomide as well as migration. To exploit the promiscuous binding features of DNAM-1, we generated different first or second-generation CAR T cells that use DNAM-1 as a tumor-binding domain. Subsequently, we investigated their anti-tumor activity in vitro in co-culture assays and in vivo in syngeneic orthotopic murine glioma models.

RESULTS

CD155 and CD112 are homogenously expressed in human and mouse glioma cell lines and human glioblastoma tissues. Knock-out of these ligands affected the migration of tumor cells, but did not affect proliferation or sensitivity to irradition or temozolomide. DNAM-1-based CAR T cells demonstrated high cytolytic activity and effector cytokine secretion in vitro. In vivo, DNAM-1 based CAR T cells reached to the tumor site in the brain upon intravenous administration, prolonged survival of orthotopic glioma-bearing mice and led to a durable anti-tumor response in a fraction of mice. The treatment was tolerated without toxicities.

CONCLUSION

We elucidated the tumor-intrinisic role of CD155 and CD112 and provide the first systematical preclincal assessment of DNAM-1 CAR T cells against glioma. These findings provide a rationale to test this immunotherapeutic strategy also in human glioma patients.

OS8.6 Sensitivity of human meningioma cells to the cyclin-dependent kinase inhibitor, TG02

BACKGROUND

Standards of care for meningioma include surgical resection, which may be curative, and radiotherapy as required. Pharmacotherapy plays only a minor role in this disease; however, novel systemic approaches are urgently needed for patients who are no longer candidates for local therapy.

MATERIAL AND METHODS

We generated primary cultures from surgically removed meningiomas to explore the activity of a novel cyclin-dependent kinase inhibitor, TG02, in meningioma cell cultures. Tumor and cell cultures were characterized by mutation profiling and DNA methylation profiling. DNA methylation data were used to allot each sample to one out of six previously established meningioma methylation classes: benign (ben)-1, 2, 3, intermediate (int)-A, B, and malignant (mal). The activity of TG02 was assessed by standard cell culture assays.

RESULTS

Cell cultures were derived from nine meningiomas. Four tumors assigned to the methylation class ben-2 showed the same class in the cell culture whereas cell cultures from five non-ben-2 tumors showed a different class, a more malignant class in four of five patients. Cell cultures were uniformly sensitive to the growth inhibitory effects of TG02 in the nanomolar range. Assignment of the cell cultures to a more malignant methylation classifier appeared to be more closely associated with TG02 sensitivity than assignment to a higher WHO grade of the primary tumors.

CONCLUSION

Primary cell cultures from meningioma facilitate the investigation of the anti-meningioma activity of novel agents. TG02, an orally available cyclin-dependent kinase inhibitor, warrants further exploration in this disease.

OS2.2 Chemotherapy for spinal gliomas in adults

BACKGROUND

Chemotherapy is a treatment option in patients diagnosed with anaplastic gliomas or glioblastomas of the spinal cord, or with recurrent lower graded WHO spinal gliomas that are no longer amenable to local treatment. The low incidence of spinal cord gliomas, particularly in adults, limits the ability to perform clinical trials. The role of chemotherapy in these tumors has remained unclear.

MATERIAL AND METHODS

We performed a retrospective study of 22 patients diagnosed with spinal gliomas who were treated with chemotherapy at any time during the disease course. Benefit from chemotherapy was estimated by applying Response assessment in neuro-oncology criteria. Data on radiotherapy, as well as the number of neurosurgical interventions were taken into consideration.

RESULTS

Most patients were diagnosed with astrocytoma WHO grade I-IV (N=14), the remaining patients were diagnosed with ependymoma (N=8). Median follow-up from start of chemotherapy was 92 months (95% CI, 72.6–111.4). The O6-methylguanyl-DNA-methyltransferase(MGMT)promoter methylation status was available in tumors of 12 patients: 9 tumors (75%) had an unmethylated MGMTpromoter. More than 50% of the patients had more than one neurosurgical intervention. After prior surgery 10 patients in the first-line setting had chemotherapy combined with radiotherapy, while 3 patients received chemotherapy only. The remaining 9 patients had initially received radiation therapy and chemotherapy was given at time of recurrence. In patients diagnosed with astrocytoma mainly temozolomide (TMZ) was applied (N=10), while one patient received CCNU and three patients had combination chemotherapy. Patients diagnosed with ependymoma had hydroxyurea (N=1), CCNU (N=1), TMZ (N=3) or combination chemotherapy (N=3). In the group of patients who had chemotherapy combined with radiation, response rates were as follows: anaplastic astrocytoma 3 stable diseases (SD), glioblastoma 1 complete response (CR) and 1 SD, and anaplastic ependymoma 1 SD. After chemotherapy in the group of patients previously irradiated, the following response rates were observed: 1 SD in pilocytic astrocytoma, 1 SD in diffuse astrocytoma, 3 SD in myxopapillary ependymoma, and 2 SD and 1 partial response (PR) in anaplastic ependymoma. All other patients experienced progressive disease. There was no indication for a favorable prognostic role ofMGMTpromoter methylation.

CONCLUSION

Spinal cord gliomas represent a heterogeneous group of tumors. Survival outcomes in response to chemotherapy in adult spinal glioma patients vary substantially, but individual patients appear to derive benefit from chemotherapy.

P14.25 Venous thromboembolic events in patients with brain metastases: the PICOS score

BACKGROUND

Venous thromboembolic events are significant complications in patients and possibly associated with an unfavorable outcome. Thrombosis risk is poorly defined for patients with brain metastasis, and available risk calculation scores are not validated for these patients.

MATERIAL AND METHODS

We identified 811 patients with brain metastasis followed at our institution and screened electronic charts retrospectively for the occurrence of venous thromboembolic events, along with candidate risk factors. Risk factors were tested in uni- and multivariate analyses and finally integrated in a score model for risk prediction.

RESULTS

Venous thromboembolic events were documented in 97 of 811 patients (12.0%). Primary tumors with high thrombogenicity (p=0.02, odds ratio 1.7, 95% CI 1.1–2.8), dexamethasone (p=0.011, odds ratio 2.27, 95% CI 1.5–4.5), chemotherapy (p=0.005, odds ratio 3.4, 95% CI 1.6–7.5), BMI > 35 kg/m2 (p=0.002, odds ratio 3.4, 95% CI 1.6–7.5) and immobilization (p=0.003, odds ratio 2.4, 95% CI 1.3–4.3) were confirmed as independent predictors of VTE. We derived a score model for venous thromboembolic event prediction, the PICOS (thrombogenic Primary, Immobilization, Chemotherapy, Obesity, Steroids) score (0–7 points). Receiver Operating Characteristic Curve Analysis demonstrated its prognostic accuracy (AUC=0.71, 95% CI 0.64–0.77), and its predictive capability was superior to that of other scores proposed for the evaluation of venous thromboembolic event risk such as the Khorana (AUC=0.51) or CONKO (AUC=0.52) scores.

CONCLUSION

We report a rate of venous thrombotic events of 12.0% in our cohort of 811 patients with brain metastasis. We define a risk model for prediction in of venous thrombotic events in patients with BM, the PICOS score. It may become a valuable tool for the identification of brain metastasis patients at high risk for venous thromboembolic events and be helpful for guidance of clinicians towards decision whether to start thrombosis prophylaxis. Further, the PICOS score might be used for stratification in controlled studies.

OS7.4 Calculating the net clinical benefit in brain tumor clinical trials by combining survival and health-related quality of life data using two methods: quality adjusted survival effect sizes (QASES) and joint modelling (JM)

BACKGROUND

The impact of treatment on both the quality and the quantity of life, i.e. the ‘net clinical benefit’, should be considered to inform glioma patients and facilitate shared decision making. We applied two methods (i.e. Quality Adjusted Effect Sizes (QASES) and Joint Modelling (JM)) that combine survival and health-related quality of life (HRQoL) data into one outcome, to gain insight in the net clinical benefit of a treatment strategy. In addition, we assessed if both methods result in similar interpretations.

MATERIAL AND METHODS

We calculated the net clinical benefit in one randomized controlled trial, EORTC 26951 comparing radiotherapy (RT) + PCV chemotherapy versus RT alone, as a proof of concept for other trials. With the QASES method, effect sizes for differences in survival and HRQoL between treatment arms were calculated. Next, the combined effect size can be determined by weighing the emphasis put on survival or HRQoL (e.g. survival more important). JM allows simultaneous modeling of a longitudinal outcome (HRQoL), and a time-to event outcome (survival). HRQoL scales/items that were selected for primary analysis in the main study were also selected for this analysis: fatigue, global health, social functioning, communication deficit, seizures, physical functioning, and nausea/vomiting.

RESULTS

288/386 patients completed baseline HRQoL forms and were included in the analysis. Overall survival (OS) was significantly longer with combined treatment (difference of 10.8 months). In contrast, the percentage of patients who experienced a clinically relevant deterioration (≥10 points) in nausea/vomiting, fatigue, social functioning and global health up to one year after treatment compared to baseline was larger in the RT+PCV arm. The QASES corresponded to a reduction in the median OS difference from 10.8 months to 6.8 months when adjusted for the HRQoL scales/items, when given equal weights to OS and HRQoL. JM analyses resulted in a theoretical loss of treatment effect in OS of 2–6% when adjusting for HRQoL.

CONCLUSION

Both methods showed that adjusting for the impact of treatment on a relevant HRQoL parameter reduced the survival benefit in the experimental treatment arm compared to standard treatment arm. Applying these methods may facilitate communicating the impact of treatment to patients in clinical practice.

OS7.6 Socioeconomic burden and associations with quality of life in meningioma patients

BACKGROUND

Socioeconomics affect the outcome of neurological patients, but the socioeconomic burden of brain tumors has not been studied in detail.

PATIENTS AND METHODS

This survey study in a clinically well-annotated cohort of meningioma patients was designed to explore socioeconomic status parameters at diagnosis and one year thereafter. The survey comprised level of education, profession, employment status, subjective work ability, monthly income and the EPICES social deprivation score. Quality of life (QoL) and symptom burden were queried utilizing the EORTC-QLQ-C30/BN20 and MDASI-BT. A multivariate binary regression model was applied to explore associations of socioeconomics with QoL.

RESULTS

Completed surveys were obtained from 249 of 410 patients (61%) who were invited to participate. The level of education was an apprenticeship or higher in 214 patients (86%). One year after diagnosis, there was a 20% decline in the fraction of employed patients and a more than twofold increase in unemployment and disability (p<0.001). There was a decrease in monthly income among patients with a baseline income below national average (p=0.008). On multivariate analyses, there was an association of inferior QoL with pre-operative unemployment or retirement (OR 2.43, 95% CI 1.02–5.88), whereas a subjective work ability of >70% was associated with better QoL (OR 0.37, 95% CI 0.15–0.92).

CONCLUSION

Socioeconomics assessments should be incorporated in prospective neuro-oncology clinical trials. A more detailed knowledge of the effects of socioeconomics on patient outcome will aid in identifying patients at risk for deterioration and allow to implement improved preventive and supportive strategies.

P14.41 Temporal muscle thickness is an independent prognostic marker in patients with progressive glioblastoma: translational imaging analysis of the EORTC-26101 trial

BACKGROUND

Temporal muscle thickness (TMT) was described as surrogate marker of skeletal muscle mass and prognostic parameter in brain metastasis patients. This study aimed to evaluate the prognostic relevance of TMT in patients with progressive glioblastoma.

MATERIAL AND METHODS

TMT was analyzed on the baseline cranial magnetic resonance (MR) images of 596 patients with progression of glioblastoma after radio-chemotherapy enrolled in the EORTC 26101 trial. An optimal TMT cutoff for overall survival (OS) and progression free survival (PFS) was defined in the training cohort (n=260 patients enrolled in phase 2 part of EORTC 26101). Patients were grouped as “below” or “above” the TMT cutoff and associations with OS and PFS were tested using the Cox model. The findings were validated in a test cohort (n=308 patients enrolled in phase 3 part of EORTC 26101).

RESULTS

An optimal baseline TMT cutoff of 7.2 mm was obtained in the training cohort for both OS and PFS (AUC=0.64). Univariate analyses estimated a hazard ratio (HR) of 0.54 (95% CI:0.42, 0.70, p<0.0001) for OS and a HR of 0.49 (95% CI: 0.38, 0.64, p<0.0001) for PFS for the comparison of training cohort patients above versus below the TMT cutoff. This was confirmed in multivariate testing for OS (HR of 0.54, 95% CI: 0.41, 0.70, p<0.0001) and PFS (HR of 0.47, 95% CI: 0.36, 0.61, p<0.0001) adjusted for the important risk factors with relevance in the trial for OS (Steroid use at baseline, HR of 1.58, 95% CI: 1.19, 2.11, p = 0.002; MGMT Status, HR of 0.51, 95% CI: 0.36, 0.72, p<0.001; maximum diameter ≥ 40mm, HR of 2.49, 95% CI: 1.41, 4.41, p = 0.002; central hemisphere involvement, HR of 1.97, 95% CI: 1.37, 2.84, p<0.001) and PFS (Neurological deficit, HR of 1.44, 95% CI:1.09, 1,92, p = 0.011; Steroid use at baseline, HR of 1.42, 95% CI: 1.08, 1.86, p = 0.011; MGMT status, HR of 0.61, 95% CI: 0.43, 0.87, p = 0.007; Number of target lesion >1, HR of 2.47, 95% CI: 1.38, 4,41, p = 0.002). Similar results were obtained in the validation cohort.

CONCLUSION

TMT is an independent prognostic parameter in patients with progressive glioblastoma. This parameter is easily assessable on routine MR images and may help to better define frail patient populations and thus facilitate patient management by supporting patient stratification for therapeutic interventions or clinical trials.

OS1.6 Peripheral blood immune profiles at first recurrence of IDH wild type glioblastoma after standard chemoradiotherapy predict overall survival: secondary analyses of the phase II DIRECTOR trial

BACKGROUND

Isocitrate dehydrogenase (IDH) wildtype glioblastoma is associated with distinctive peripheral blood immune cell profiles that evolve under first line chemoirradiation with temozolomide. Whether peripheral blood immune cell profiles at recurrence are associated with survival of IDH wildtype glioblastoma has not been studied in detail.

PATIENTS AND METHODS

Peripheral blood mononuclear cells (PBMC) of 21 healthy donors and of 52 clinically well-annotated patients with IDH wildtype glioblastoma were analyzed by 11-color flow cytometry at 1st recurrence after standard chemoirradiation with temozolomide and at 2nd recurrence after dose-intensified temozolomide re-challenge. Patients were treated within the randomized phase II trial DIRECTOR, which explored the efficacy of dose-intensified temozolomide at first recurrence of glioblastoma. Patients were classified based on unsupervised analyses of PBMC profiles at 1stand 2ndrecurrence. Associations with survival were explored in multivariate Cox models controlling for established prognostic and predictive factors.

RESULTS

At 1strecurrence, two patient clusters were identified which differed in CD4+ T-cell fractions, but not with respect to CD8+ T-cells, CD4+;CD25+;FoxP3+ regulatory T-cells, B-cells or monocytes. The composition of CD4+, CD8+ or regulatory T-cell fractions was similar in both clusters. All control samples clustered with the CD4high cluster. Patients in both clusters did not differ by established prognostic factors, including age, O6-methylguanine-DNA-methyl-transferase (MGMT) gene promoter methylation, tumor volume, Karfnosky performance score or steroid use. Progression-free survival was similar (CD4high vsCD4low 2.1 vs 2.4 months, p=0.19), whereas post-recurrence overall survival was longer among the CD4highcluster (12.7 vs 8.7 months, p= 0.004). At 2nd recurrence, monocyte fractions increased, whereas memory CD4+ T-cell fractions decreased. Unsupervised segregation of patients by CD4+ subpopulations yielded two clusters characterized by the abundance of memory T-cell fractions and higher memory CD4+ fractions were associated with longer overall survival at 2nd recurrence (p=0.004). The reported prognostic associations were retained in multivariate Cox models controlling for established prognostic factors.

CONCLUSION

We conclude that temozolomide-associated memory CD4+ T-cell depletion may have deteriorating effects on the survival of glioblastoma patients.

OS3.4 Karnofsky and WHO performance scores of brain tumour patients may limit inclusion in protocols though they depend on clinician status

BACKGROUND

Inclusion criteria for oncological protocols often use the Karnofsky performance score (KPS) >=70 or the WHO performance score (PS) 0–2 as a cut-off value. Inclusion of neuro-oncology patients may be hampered, when general condition is preserved, while performance is decreased due to physical handicap. The goal of this study is to compare the KPS and PS assessments according to the status of the clinician.

MATERIAL AND METHODS

A cross-sectional survey was conducted through ANOCEF and EANO networks. Clinicians evaluated KPS and PS in 6 clinical situations concerning neuro oncology patients (from youngest and fittest to oldest, crippled with comorbidities).

RESULTS

The rate of PS <70 or PS> 2 increased significantly from case 1 to 6.

Sex or nationality of the clinicians had no impact when adjusting on clinician characteristics. Conversely, speciality (residents/general practitioner vs neurosurgeons vs neurologists vs oncologists), impacted KPS or PS evaluations (p<.0001 and p=0.0046, respectively). Residents or general practitioner estimate KPS much lower than the others specialities. Neurosurgeons estimate PS more severely. Clinicians who were not used to including patients in clinical trials proposed lower KPS scores (p = 0.0008). This tendancy was not shown on PS. Eldest physicians significantly rated more severely than the youngest (p = 0.0459 and p <.0001 for KPS and PS, respectively).

In a multivariate analysis, age and speciality were correlated with KPS and PS rating even if adjusted on cases.

Discordant decision for protocol inclusion (i:e: (KPS) >=70 vs PS 0–2) showed little discrepancy in case 1 (2.3%), while discrepancy increased to respectively 16, 46, 39, 33 and 43% for cases 2 to 6: in nearly all cases, the KPS would have denied access to a trial, while WHO Ps would have allowed

CONCLUSION

Rating of KP and PS is subjective in neuro oncology patients: influenced by speciality, age and inclusion habit (for KPS) of clinicians, PS 0–2 allows usually more inclusion than KPS>=70 in more severely disabled patients. A Neuro oncology specific KPS and/or PS definition is warranted to allow more widely inclusion of patients with exclusive neurologic handicap.

Enantioselective fragmentation of an achiral molecule in a strong laser field

Chirality is omnipresent in living nature. On the single molecule level, the response of a chiral species to a chiral probe depends on their respective handedness. A prominent example is the difference in the interaction of a chiral molecule with left or right circularly polarized light. In the present study, we show by Coulomb explosion imaging that circularly polarized light can also induce a chiral fragmentation of a planar and thus achiral molecule. The observed enantiomer strongly depends on the orientation of the molecule with respect to the light propagation direction and the helicity of the ionizing light. This finding might trigger new approaches to improve laser-driven enantioselective chemical synthesis.

MiR-16-5p is frequently down-regulated in astrocytic gliomas and modulates glioma cell proliferation, apoptosis and response to cytotoxic therapy

AIMS

Aberrant expression of microRNAs (miRNAs) is frequent in various cancers including gliomas. We aimed to characterize the role of miR-16-5p as a candidate tumour suppressor miRNA in gliomas.

METHODS

Real-time PCR-based approaches were used for miRNA and mRNA expression profiling of glioma and non-neoplastic brain tissues as well as glioma cell lines. Protein levels were determined by Western blotting. In vitro analyses were performed following overexpression of miR-16-5p, trichostatin A (TSA) treatment, and siRNA-mediated knock-down of HDAC3 in glioma cells. Effects of miR-16-5p on glioma cell viability, apoptosis and response to irradiation and temozolomide (TMZ) were assessed.

RESULTS

Expression of miR-16-5p was reduced relative to control brain tissue in isocitrate dehydrogenase (IDH)-mutant astrocytomas of World Health Organization (WHO) grades II, III and IV, and a subset of IDH-wildtype glioblastomas WHO grade IV. MiR-16-5p expression was lower in IDH-mutant than in IDH-wildtype gliomas, and down-regulated in IDH-wildtype glioma lines. MiR-16-5p overexpression reduced expression of important cell cycle and apoptosis regulators in glioma cells, including CDK6, CDC25A, CCND3, CCNE1, WEE1, CHEK1, BCL2 and MCL1. In line, CDK6, WEE1, CHEK1, BCL2 and MCL1 transcript levels were increased in WHO grade III or IV gliomas. TSA treatment and HDAC3 knockdown in glioma cells induced miR-16-5p up-regulation and reduced expression of its targets. Moreover, miR-16-5p overexpression inhibited proliferation and induced apoptosis in various glioma cell lines and increased sensitivity of A172 glioma cells to irradiation and TMZ.

CONCLUSION

Reduced expression of miR-16-5p contributes to glioma cell proliferation, survival and resistance to cytotoxic therapy.

Cerebrospinal fluid cell-free tumour DNA as a liquid biopsy for primary brain tumours and central nervous system metastases

Challenges in obtaining tissue specimens from patients with brain tumours limit the diagnosis and molecular characterisation and impair the development of better therapeutic approaches. The analysis of cell-free tumour DNA in plasma (considered a liquid biopsy) has facilitated the characterisation of extra-cranial tumours. However, cell-free tumour DNA in plasma is limited in quantity and may not reliably capture the landscape of genomic alterations of brain tumours. Here, we review recent work assessing the relevance of cell-free tumour DNA from cerebrospinal fluid in the characterisation of brain cancer. We focus on the advances in the use of the cerebrospinal fluid as a source of cell-free tumour DNA to facilitate diagnosis, reveal actionable genomic alterations, monitor responses to therapy, and capture tumour heterogeneity in patients with primary brain tumours and brain and leptomeningeal metastases. Profiling cerebrospinal fluid cell-free tumour DNA provides the opportunity to precisely acquire and monitor genomic information in real time and guide precision therapies.

Breakdown of the Spectator Concept in Low-Electron-Energy Resonant Decay Processes

We suggest that low-energy electrons, released by resonant decay processes, experience substantial scattering on the electron density of excited electrons, which remain a spectator during the decay. As a result, the angular emission distribution is altered significantly. This effect is expected to be a common feature of low-energy secondary electron emission. In this Letter, we exemplify our idea by examining the spectator resonant interatomic Coulombic decay of Ne dimers. Our theoretical predictions are confirmed by a corresponding coincidence experiment.

Reduction of Breast Cancer Treatment Delay as a Result of Efforts Carried Out by Two Brazilian NGOs

Background: Brazilian breast cancer patients present disease often at advanced stages (III, IV). Previous studies indicated that system delay is a causal factor of bad prognosis and increased mortality rate. In the state of Paraíba, northeast of Brazil, two non-governmental organizations (NGOs) Américas Amigas and Mulheres de Peito de Campina Grande (MLDP), promote faster access to treatment by donating diagnostic mammography and biopsies as well as anatomo-histopathological and immunohistochemical analysis. Aim: The current study aimed at evaluating the effectiveness of the assistance provided by both NGOs and comparing patient flow between HNL and FAP, two reference cancer centers in João Pessoa and Campina Grande, respectively. Methods: Time-to-treatment was analyzed for different time intervals between first medical consultation and initiation of treatment. Comparison was performed between three groups of patients: 40 patients from Hospital Napoleão Laureano (HNL) in João Pessoa; 80 patients from Fundação Assistencial da Paraíba (FAP) in Campina Grande and 15 patients from FAP, who received support from the NGOs. Kaplan-Meier analysis was performed to compare time-intervals among the groups. To estimate the impact of socioeconomic variables Cox regression analysis was performed. Results: Mean time-interval between first medical consultation and hospital admission was 135 (SD=21.0), 370 (SD=73.7) and 515 (SD=36.6) days, for patients of HNL, MLDP and FAP, respectively ( P = 0.0021). Time intervals analyzed for patients within the FAP hospital, between first medical consultation and hospital admission, tended to be shorter for patients who were assisted by the NGOs, compared with those who did not receive any assistance from the NGOs. Patients who had consulted specialized oncological health services beforehand had an increased chance (HZ=2.32; 95% CI: 1.17-4.60; P = 0.016) of being admitted at the reference hospital within 90 days after the first medical consultation, compared with those who had not consulted such specialized services. There were no significant differences between HNL and FAP, regarding the time interval between hospital admission and treatment initiation ( P = 0.21). Conclusion: The assistance to patients provided by the two NGOs, aimed at speeding up the diagnosis process, accelerated patient flow between first medical consultation and admission at the hospitals. Regarding HNL, patients from the inland had been sent by primary health units in their municipalities, directly to the cancer reference hospital in João Pessoa, without being referred to an in-between health service. Such procedure explains the variation of time intervals when admissions at FAP and HNL are compared. The results of the current study indicate that by providing faster breast cancer diagnosis, the NGOs’ mediation can significantly improve patient flow.