Artificial Intelligence in Digital Pathology: What Is the Future? Part 2: An Investigation on the Insiders.

Motivation: This study deals with the introduction of artificial intelligence (AI) in digital pathology (DP). The study starts from the highlights of a companion paper. Objective: The aim was to investigate the consensus and acceptance of the insiders on this issue. Procedure: An electronic survey based on the standardized package Microsoft Forms (Microsoft, Redmond, WA, USA) was proposed to a sample of biomedical laboratory technicians (149 admitted in the study, 76 males, 73 females, mean age 44.2 years). Results: The survey showed no criticality. It highlighted (a) the good perception of the basic training on both groups, and (b) a uniformly low perceived knowledge of AI (as arisen from the graded questions). Expectations, perceived general impact, perceived changes in the work-flow, and worries clearly emerged in the study. Conclusions: The of AI in DP is an unstoppable process, as well as the increase of the digitalization in the health domain. Stakeholders must not look with suspicion towards AI, which can represent an important resource, but should invest in monitoring and consensus training initiatives based also on electronic surveys.

Artificial Intelligence in Digital Pathology: What Is the Future? Part 1: From the Digital Slide Onwards.

This commentary aims to address the field of Artificial intelligence (AI) in Digital Pathology (DP) both in terms of the global situation and research perspectives. It has four polarities. First, it revisits the evolutions of digital pathology with particular care to the two fields of the digital cytology and the digital histology. Second, it illustrates the main fields in the employment of AI in DP. Third, it looks at the future directions of the research challenges from both a clinical and technological point of view. Fourth, it discusses the transversal problems among these challenges and implications and introduces the immediate work to implement.

Combined Analysis of Intragastric Malignant Exfoliation and Ca 72.4 Concentration in Stomach Adenocarcinoma: The "GL1 Ca 72.4" Parameter.

INTRODUCTION/OBJECTIVE: Differently from other digestive malignancies, gastric cancer (GC) pathobiology is still little known and understood. Recently, cytopathology and molecular biology on gastric juice/gastric lavage (GJ/GL) of GC patients have provided novel and interesting results in terms of screening, diagnosis, prognosis, and therapy. However, entertaining cytologic examination and molecular test as a unified solo-run test is previously unreported. Our aim was to assess the new parameter "GL Ca 72.4" for GC patients. METHODS: Between April 2012 and July 2013, GJ/GL obtained from 37 surgical GC patients were tested for the presence/absence (GL1/GL0) of exfoliated malignant cells along with the intragastric concentration of Ca 72.4 (normal value <6.49 ng/mL: Ca 72.4n; elevated level ≥6.49 ng/mL: Ca 72.4+). RESULTS: At a median follow-up of 79.3 months, all the GC alive patients were "GL0 Ca 72.4n." The "GL1 Ca 72.4+" parameter, in comparison with GL0 Ca 72.4n, strongly correlated with deeper tumor invasion (p = 0.027), severe nodal metastasis (p = 0.012), worst metastatic node ratio (p = 0.041), higher number of metastatic lymph nodes (30 vs. 20 nodes, p = 0.014), angiolymphatic invasion (p = 0.044), advanced stage (p = 0.034), and adjuvant therapy (p = 0.044). The Kaplan-Meier model showed that GL1 Ca 72.4+ subjects had shorter overall survival (OS) than GL0 Ca 72.4n cases (9.7 vs. 43.2 months, respectively, p = 0.042). At univariate analysis, the GL1 Ca 72.4+ parameter resulted a significant prognostic factor for OS (p = 0.023). CONCLUSIONS: The combined cyto-molecular parameter "GL1 Ca 72.4+" appears to be a strong indicator of aggressive tumor behavior and a significant prognostic factor of poor survival for GC patients.

Elevated Gastric Juice Carbohydrate Antigen 72.4 (Ca 72.4) Is an Independent Prognostic Factor of Poor Survival for Gastric Cancer Patients.

BACKGROUND/AIM: As of 2020, carbohydrate antigen 72.4 (Ca 72.4) has been rarely investigated in the gastric juice (GJ) of patients with gastric cancer (GC). Our aim was to analyze the significance and role of this tumor antigen in the GJ of our GC population. PATIENTS AND METHODS: Between April 2012 and July 2013, 37 patients with operable GC were prospectively investigated to determine the GJ Ca 72.4 levels before surgical manipulation. RESULTS: GJ Ca 72.4 ≥6.49 ng/ml strongly correlated with the traditional categories of aggressive cancer (advanced tumor depth and stage, lymph node invasion and metastatic lymphatic ratio, indication to adjuvant treatment). It also associated with shorter survival (p=0.049) and is, thus, suggested as an independent factor of poor prognosis in GC patients (p=0.047). CONCLUSION: The GJ Ca 72.4 parameter should be considered an indicator of an aggressive tumor phenotype and should be used in the prognostic assessment of GC patients.

Advances in Intraluminal Exfoliative Cytology of Gastric Cancer: Oncologic Implication of the Sixth Metastatic Route (Metastasis VI).

Historically, analysis of intragastric exfoliative cytology (IEC) of gastric cancer (GC) was used with a diagnostic intent only. With the successful advent of endoscopic biopsy, the rate of detection of GC has improved worldwide and, as a consequence, IEC has been progressively abandoned. Today, however, there is a renewed interest in this field of research, as witnessed by several pertinent publications. As discussed in this review, in fact, currently the importance of analyzing IEC in patients with early and advanced GC seems to reside in its clinicopathological and prognostic significance. In fact, compared to non-sloughing tumors, GC exhibiting intragastric exfoliation was recently associated with an aggressive tumor phenotype (characterized by deeper infiltration of the gastric wall, lymph nodal or distant metastases, angiolymphatic and perineural invasion) and poorer prognosis. Adoption of IEC examination in routine practice might help identify patients at higher risk of developing local recurrence and peritoneal metastasis from early and advanced GC, optimizing their treatment and improving quality of life and life expectancy.

Gastric Lavage Malignant Cells (yGL) and Hypohemoglobinemia (yAnemia) as New Systems of Tumor Regression Grading and Prognostic Prediction for Gastric Cancer After Neoadjuvant Treatment.

BACKGROUND/AIM: Although reckoned necessary for survival benefit, neoadjuvant chemotherapy (NAC) of gastric cancer (GC) patients has so far provided questionable results. Consequently, searching for new and clearer systems of response to NAC, post-NAC re-evaluation and prognostic prediction appears essential. The purpose of this study was to examine endogastric cytopathology and hemoglobin level count as new features, potentially useful for GC patients after NAC. PATIENTS AND METHODS: Between April 2012 and October 2018, 21 of 116 patients with resectable GC received NAC and were investigated for the presence of free-floating malignant cells in their gastric lavage (yGL1) and the development of hypohemoglobinia (yAnemia). RESULTS: yGL1 and yAnemia were found in 11 and 12 patients, respectively. yGL1 correlated with the traditional parameters of tumor regression (p=0.0424). Both yGL1 and yAnemia were found to be independent predictive factors of overall and progression-free survival (p≤0.0364). CONCLUSION: In the light of our results, the yGL1 and yAnemia appear two promising, simple and interesting clinicopathological features which should always be examined for better clarifying GC patients' response to NAC.

Long non-coding RNAs in the gastric juice of gastric cancer patients.

Differently from other digestive malignancies, gastric cancer (GC) carcinogenesis seems more heterogeneous and unclear. This entails failing in identification of reliable serum tumor markers for screening early GC (EGC) as well as persisting ominous prognosis of this disease. Recently, investigation of human noncoding genome, especially long noncoding molecules (lncRNAs), has provided promising data. As for GC, however, since the current information on GC-specific lncRNAs is still scarce and comes largely from analyses performed on tissue or serum of affected patients, we decided to review the current literature dealing with expression of such molecules in the gastric juice (GJ) of GC patients. In the case of GC, in fact, several cytological and molecular works have already demonstrated GJ to be an interesting biological material for improving clinicopathologic and prognostic knowledge of this cancer. For this review, we burrowed into the literature on lncRNAs expressed in GJ of GC patients. PubMed, Science Direct, Scopus, Web of Science, Google Scholar and ResearchGate were the search engines entertained. As of 2018, only seven studies have been reported. LINC00152, AA174084, UCA1, RMRP, ABHD11-AS1, LINC00982 and H19 were the GJ lncRNAs examined. Following our review, we can conclude that, due to their high specificity and reliability, GJ lncRNAs should deserve a prominent role in the field of GC research: importantly, they could be used for screening EGC, ameliorating the existing methods of staging (which are still far from being completely accurate), improving the prognostic capacity of the current diagnostic armamentarium and, finally, providing new and valuable therapeutic targets.

Preoperative gastric lavage in gastric cancer patients undergoing surgical, endoscopic or minimally invasive treatment: An oncological measure preventing peritoneal spillage of intragastric cancer cells and development of related metastases.

In addition to classical metastatic pathways, recently gastric cancer was described having an alternative route called "endoluminal exfoliation". Provisional analyses demonstrated, in fact, this kind of shedding is associated with several clinico-pathological features indicative of aggressive behavior and resulted to be an independent prognostic factor entailing poor prognosis. Compared with non-sowing counterparts, in fact, patients affected with exfoliating early and advanced gastric carcinomas met with shorter overall survival, disease free survival, progression free survival and time to tumor progression. In spite of these interesting results, however, the clinico-pathological and oncological significance of this unconventional metastatic route is still to be clarified. Such an investigation is further urged by the increasing widespread employment of minimally invasive treatments for gastric cancer which include a wide spectrum of intragastric interventions and maneuvers. Indeed, endoscopic mucosal resection, endoscopic submucosal dissection, endoscopic full-thickness resection, intragastric laparoscopic surgery and hybrid procedures all take place inside of the stomach. However, iatrogenic perforations can occur during execution of these treatments leading to spillage of malignant cells from gastric to the peritoneal cavity or trocar insertion sites. Furthermore, many other gastric conditions and interventions can collide with endogastric presence of floating cancer cells: spontaneous ulceration or perforation, laparotomy surgery, gastrointestinal occlusion, diverticula. Viability, migration and intraluminal transportability of the intragastric floating cancer cells represents another original and intriguing topic. All these considerations led us to entertain the hypothesis that removing the exfoliated cancer cells from the gastric lumen could save patients from the dreaded potential risk of spillage. Performing gastric lavage before starting any kind of tumor intervention could be the most appropriate procedure to adopt with prophylactic intent. Should our speculation prove to be clinically significant, preoperative gastric lavage should be pointed out as a simple but cogent method useful for preventing oncological mishaps such as spillage of gastric cancer cells and development of related recurrences or metastases.

Gastric Cancer Cells in Peritoneal Lavage Fluid: A Systematic Review Comparing Cytological with Molecular Detection for Diagnosis of Peritoneal Metastases and Prediction of Peritoneal Recurrences.

BACKGROUND/AIM: Detecting free tumor cells in the peritoneal lavage fluid of gastric cancer patients permits to assess a more accurate prognosis, predict peritoneal recurrence and select cases for a more aggressive treatment. Currently, cytology and molecular biology comprise the two most popular methods of detection that are under constant study by researchers. MATERIALS AND METHODS: We burrowed into the available literature comparing cytological with molecular detection of free intraperitoneal gastric cancer cells. PubMed, Science Direct, Scopus and Google Scholar were the search engines investigated. RESULTS: As of 2017, 51 dedicated studies have been published. Messenger RNA of carcinoembryonic antigen was the genetic target most frequently described. The genetic technique is usually superior to cytology in sensitivity (38-100% vs. 12.3-67% respectively), whereas cytological examination tends to show a slight pre-eminence in specificity (approximately 100%). CONCLUSION: So far, given the imperfection of each method, employment of both cytology and molecular examination seem to be mandatory.

Laparoscopic Intragastric Surgery for Treating Early Gastric Cancer.

BACKGROUND/AIM: Although there is an increasing number of studies on laparoscopic resection of early gastric cancer (EGC), as of 2018 no standardized strategy exists. We reviewed available literature dealing with laparoscopic intragastric (intraluminal) surgery (LIGS) conducted for patients with EGC to better define indications, benefits and limitations of this particular minimally invasive technique. MATERIALS AND METHODS: PubMed, MEDLINE, Science Direct, Scopus, Web of Science, Google Scholar and ResearchGate were the search engines investigated. Only LIGS for EGC was entertained; studies conducted for other gastric diseases were excluded. Suitable articles written in all languages were included in the review. RESULTS: As of 2018, we found 19 studies dealing with LIGS for EGC: studies on 72 humans and four pigs were identified. Among 72 human participants, there were 59 mucosal, five submucosal and one subserosal cancer. CONCLUSION: Based on our review, LIGS appears as a cogent option to endoscopic resection for treating superficial EGC.

Gastric Juice MicroRNAs as Potential Biomarkers for Screening Gastric Cancer: A Systematic Review.

BACKGROUND/AIM: To date, the combination of gastroscopy with biopsy remains the only test validated for screening gastric cancer (GC). Currently, analysis of circulating microRNAs (miRNAs or miRs) is providing interesting information on GC prognosis, but since these molecules are shared by several types of cancer, its clinical use could be questionable and difficult. MicroRNAs in gastric juice (GJ) could represent a cogent alternative to screening GC by biopsy. MATERIALS AND METHODS: We investigated the pertinent literature dealing with GC GJ microRNAs through four popular search engines (PubMed, Science Direct, Scopus and Google Scholar). RESULTS: As of 2017, only four studies had been published and were all from Chinese experience. MiR-421, miR-129, miR-21, miR-106a and miR-133a were the five molecules studied in the GJ of the enrolled patients. CONCLUSION: The GJ miRNA test is reliable and reproducible. The discussed GJ miRNAs appear to be new potential biomarkers for the screening of GC.

Utility of Nasogastric Tube for Medical and Surgical Oncology of Gastric Cancer: A Prospective Institutional Study on a New and Precious Application of an Old and Economic Device.

BACKGROUND/AIM: Concerning gastric cancer (GC), nasogastric tube (NGT) is routinely employed for peri-operative decompression and palliative enteral nutrition. Additionally, we believe to have found a further application. PATIENTS AND METHODS: Between April 2012 and April 2017, 96 GC patients received preoperative nasogastric lavage (GL). All samples were cytologically examined to detect the presence (GL1) or absence (GL0) of malignant cells. Data were analyzed with classificatory, staging and prognostic purpose. RESULTS: GL1 was detected in 46 GC patients: association with tumor depth, lymph node and distant metastasis, lymphovascular and peri-neural invasion, diffuse type and signet-ring cells was significant (respectively p=0.0274, 0.0324, 0.0446, 0.0287, <0.0001, 0.0413, <0.0001). GL1 entailed significantly poorer overall (OS), progression-free, disease-free survival and tumor progression (18 vs. 32 months). At multivariate analysis, GL1 was an independent prognostic factor for worse OS (p=0.0287). CONCLUSION: NGT seems an economic oncologic measure useful for obtaining information on GC staging and prognosis.

Blockade of Stearoyl-CoA-desaturase 1 activity reverts resistance to cisplatin in lung cancer stem cells.

Poor prognosis in lung cancer has been attributed to the presence of lung cancer stem cells (CSCs) which resist chemotherapy and cause disease recurrence. Hence, the strong need to identify mechanisms of chemoresistance and to develop new combination therapies. We have previously shown that Stearoyl-CoA-desaturase 1 (SCD1), the enzyme responsible for the conversion of saturated to monounsaturated fatty acids is upregulated in 3D lung cancer spheroids and is an upstream activator of key proliferation pathways ß-catenin and YAP/TAZ. Here we first show that SCD1 expression, either alone or in combination with a variety of CSCs markers, correlates with poor prognosis in adenocarcinoma (ADC) of the lung. Treatment of lung ADC cell cultures with cisplatin enhances the formation of larger 3D tumor spheroids and upregulates CSCs markers. In contrast, co-treatment with cisplatin and the SCD1 inhibitor MF-438 reverts upregulation of CSCs markers, strongly synergizes in the inhibition of 3D spheroids formation and induces CSCs apoptosis. Mechanistically, SCD1 inhibition activates endoplasmic reticulum stress response and enhances autophagy. These data all together support the use of combination therapy with SCD1 inhibitors to achieve better control of lung cancer.

Early Gastric Cancer Exfoliating into Gastric Lavage (GL1 EGC) Shows a More Aggressive Behavior and Poorer Survival Compared to the Non-Exfoliative Counterpart (GL0 EGC).

BACKGROUND/AIM: Early gastric cancer (EGC) is usually associated with excellent prognosis. Some cases, however, entail a poorer survival. Our aim was to assess if EGC exfoliating into gastric lavage (GL) has a more aggressive behavior than the non-exfoliative counterpart. PATIENTS AND METHODS: Between April 2012 and April 2017, 96 gastric cancer patients were prospectively submitted to preoperative GL to detect the presence (GL1) or absence (GL0) of exfoliated malignant cells. RESULTS: A total of 16 patients had EGC. T1b cases had significantly poorer overall (OS), progression-free (PFS) and disease-free survival (DFS) than their GL0 counterpart (16.3 vs. 61 months, p=0.0032). Similarly, the entire T1 class (T1a plus T1b EGCs) showed worse OS, PFS, DFS (15.5 vs. 61 months, p=0.0008) and time-to-tumor progression (17 vs. 61 months, p=0.0103). CONCLUSION: In the case of EGC, the GL0-GL1 classification should become a routine clinical practice to identify the aggressive tumor phenotypes requiring for closer follow-up or additional treatment.

Cytological diagnostic features of late breast implant seromas: From reactive to anaplastic large cell lymphoma.

Late breast implant seroma may be the presentation of a breast implant-associated anaplastic large cell lymphoma (BI-ALCL), which claims for a prompt recognition. However, BI-ALCL diagnosis on fine-needle aspiration (FNA) might be challenging for pathologists lacking experience with peri-implant breast effusions. Sixty-seven late breast implant seromas collected by FNA from 50 patients were evaluated by Papanicolaou smear stain and immunocytochemistry on cell blocks. A diagnostic algorithm based on the cellular composition, cell morphology and percentage of CD30+ cells was developed. Histological evaluation of the corresponding peri-prosthetic capsules was also performed. Most of the effusions (91% of the samples) were classified as reactive and 9% as BI-ALCL. In the BI-ALCL cases, medium-to-large atypical cells expressing CD30 represented more than 70% of the cellularity, whereas in in the reactive effusions CD30+ elements were extremely rare (<5%) and consisted of non-atypical elements. The reactive effusions were categorized into three patterns: i) acute infiltrate with prominent neutrophilic component (33% of the samples); ii) mixed infiltrate characterized by a variable number of neutrophils, lymphocytes and macrophages (30% of the samples); iii) chronic infiltrate composed predominantly of T lymphocytes or macrophages with only sporadic granulocytes (37% of the samples). The inflammatory cytological patterns were consistent with the histology of the corresponding capsules. Our results indicate that cytological analysis of late breast implant effusions, supported by the knowledge of the heterogeneous cytomorphological spectrum of late seromas, is a valuable approach for the early recognition of BI-ALCL.

Measuring Intragastric Tumor Markers in Gastric Cancer Patients: a Systematic Literature Review on Significance and Reliability.

As of 2017, no serum tumor marker has shown high levels of sensitivity or specificity for early detection, classification, staging, prediction and prognosis of patients affected by gastric cancer. In this regard, since 1975 several authors have investigated the gastric juice or gastric lavage of patients with gastric adenocarcinoma in order to determine the concentrations of intragastric tumor markers and discover the perfect antigen for this cancer. To date, however, a systematic review of the literature on intragastric tumor markers is still unreported. After a thorough search, we found important as well as unimportant findings and have come to clearly defined conclusions. We believe that describing the current state of knowledge achieved by the scientific community in this particular field of research could augment information on the complex pathobiology of gastric cancer and entail a deeper understanding of its unpredictable malignant behavior.

Interobserver reproducibility of cytologic p16INK4a /Ki-67 dual immunostaining in human papillomavirus-positive women.

BACKGROUND: The accumulation of cyclin-dependent kinase inhibitor 2A (p16ink4a ) protein in a cell is associated with neoplastic progression in precancerous cervical lesions. Dual staining for p16ink4a and Ki-67 has been proposed as a triage test in cervical cancer screening for women who test positive for human papillomavirus DNA. In this study, interobserver reproducibility of the interpretation of this test was assessed. METHODS: Forty-two immunostained, liquid-based cytology slides were divided into 2 sets and were interpreted by 17 to 21 readers from 9 different laboratories, yielding a total of 816 reports. Immunostaining results were classified as positive, negative, inconclusive, or inadequate. After evaluation of the first set of slides and before circulation of the second set, the results were discussed in a plenary meeting. The 10 slides with the most discordant results were evaluated again by selected expert cytopathologists. RESULTS: The overall κ value was 0.612 (95% confidence interval [CI], 0.523-0.701), it was higher for the positive and negative categories (κ = 0.692 and κ = 0.641, respectively), and it was almost null for the inconclusive category (κ = 0.058). Considering only readers from laboratories with documented experience, the κ value was higher (κ = 0.747; 95% CI, 0.643-0.839) compared with nonexperienced centers (κ = 0.498; 95% CI, 0.388-0.616). The results were similar in both sets of slides (κ = 0.505 [95% CI, 0.358-0.642] and κ = 0.521 [95% CI, 0.240-0.698] for the first and second sets, respectively). Reinterpretation of the slides with the most discordant results did not provide any improvement (first evaluation, κ = 0.616 [95% CI, 0.384-0.866]; second evaluation, κ = 0.403 [95% CI, 0.182-0.643]). CONCLUSIONS: Dual staining for p16 ink4a and Ki-67 demonstrated good reproducibility, confirming its robustness, which is a necessary prerequisite for its adoption as a triage test in cervical cancer screening programs that use human papillomavirus DNA as a primary test. Cancer Cytopathol 2017;125:212-220. © 2016 American Cancer Society.

Detection of cancer cells and tumor markers in gastric lavage of patients with gastric cancer: Do these findings have a clinicopathological significance and oncological implication?

Although decreasing in the incidence over the last years, currently gastric adenocarcinoma represents the second cause of cancer related-death worldwide. Further knowledge and novel therapies are desperately needed in order to make the prognosis of these patients more acceptable. Infact, even though in recent years numerous staging parameters have been largely studied and unanimously recognized for their clinical and prognostic value, today too many shadows still exist around the capacity to predict exactly the natural history or post-treatment behavior of this cancer even among patients of the same stage. This study has identified the presence of isolated cancer cells as well as tumor markers (CEA, Ca 19.9, Ca 72.4 and Ca 50) from the gastric lavage of patients affected by gastric adenocarcinoma. Such findings led to the hypothesis that endoluminal exfoliation of neoplastic cells and the release of their products (tumor markers) into the gastric juice might be an expression of neoplastic behavior as well as aggressive malignancy. Should this hypothesis become a reality, some important progress could be made in the knowledge, staging, prediction as well as management and follow-up of this inauspicious type of cancer.

Analyzing Gastric Lavage of Gastric Cancer Patients: A Prospective Observational Study on Cytopathology and Determination of Intragastric CEA, CA 19.9, CA 72.4, and CA 50.

OBJECTIVES: To investigate gastric lavage (GL) cytopathology and immunometric analysis as novel clinicopathologic and prognostic parameters for gastric cancer (GC). STUDY DESIGN: In 38 patients with gastric adenocarcinoma, we performed a cytopathologic analysis and an immunometric assay of GL using four tumor markers (CEA, CA 19.9, CA 72.4, and CA 50). The intragastric tumor marker levels were compared with a control group consisting of 41 non-GC patients to determine a statistically significant cutoff value. RESULTS: GL cytopathology demonstrated the presence of cancer cells in 13 (34.2%) of the 38 GC patients: such a finding correlated to the parameters pT and pN with a statistically significant validity (p < 0.0267 and p < 0.0306, respectively). Measurement of intragastric CA 19.9 and CA 50 attained a statistically significant cutoff value (p < 0.002 and p < 0.0096, respectively), which was invalidated by the low sensitivity of the ROC curve analysis. CONCLUSIONS: In contrast to determination of its tumor markers, GL cytopathology correlated well with pT and pN staging parameters. Should this and other features be corroborated by future studies, the GL cytology test could be routinely used to detect aggressive types of GC even at early stages and result in important progress in the knowledge, staging, prediction, as well as management and follow-up of this inauspicious type of cancer.

Human lung adenocarcinoma cell cultures derived from malignant pleural effusions as model system to predict patients chemosensitivity.

BACKGROUND: Lung cancer is the leading cause of cancer related deaths and Malignant Pleural Effusion (MPE) is a frequent complication. Current therapies suffer from lack of efficacy in a great percentage of cases, especially when cancer is diagnosed at a late stage. Moreover patients' responses vary and the outcome is unpredictable. Therefore, the identification of patients who will benefit most of chemotherapy treatment is important for accurate prognostication and better outcome. In this study, using malignant pleural effusions (MPE) from non-small cell lung cancer (NSCLC) patients, we established a collection of patient-derived Adenocarcinoma cultures which were characterized for their sensitivity to chemotherapeutic drugs used in the clinical practice. METHODS: Tumor cells present in MPEs of patients with NSCLC were isolated by density gradient centrifugation, placed in culture and genotyped by next generation sequencing. In a subset of cases patient derived xenografts (PDX) were obtained upon tumor cell inoculation in rag2/IL2 knock-out mice. Isolated primary cultures were characterized and tested for drug sensitivity by in vitro proliferation assays. Additivity, antagonism or synergy for combinatorial treatments were determined by analysis with the Calcusyn software. RESULTS: We have optimized isolation procedures and culture conditions to expand in vitro primary cultures from Malignant Pleural Effusions (MPEs) of patients affected by lung adenocarcinomas, the most frequent form of non small cell lung cancer. Using this approach we have been able to establish 16 primary cultures from MPEs. Cells were banked at low passages and were characterized for their mutational pattern by next generation sequencing for most common driver mutations in lung cancer. Moreover, amplified cultures were shown to engraft with high efficiency when injected in immunocompromised mice. Cancer cell sensitivity to drugs used in standard chemotherapy regimens was assessed either individually or in combination. Differential chemosensitivity and different mutation profiles were observed which suggests that this isolation method could provide a platform for predicting the efficacy of chemotherapy in the clinical setting. Most importantly for six patients it was possible to establish a correlation between drug response in vitro and response to therapy in the clinic. CONCLUSIONS: Results obtained using primary cultured cells from MPEs underscore the heterogeneity of NSCLC in advanced stage as indicated by drug response and mutation profile. Comparison of data obtained from in vitro assays with patients' responses to therapy leads to the conclusion that this strategy may provide a potentially useful approach for evaluating individual chemosensitivity profile and tailor the therapy accordingly. Furthermore, combining MPE-derived primary cultures with their genomic testing allows to identify patients eligible to trials with novel targeted agents.