Table of Contents

Original ArticlesOptimal Management of Acute Lymphoblastic Leukemia (ALL) in Adult Patients During the Novel Coronavirus Disease 2019 (COVID-19) Pandemic ...........................................................................................................................07Ahmad Alhuraiji, Saleem Eldadah, Feras Alfraih, Ramesh Pandita, Ahmad Absi, Amr Hanbali, Mahmoud Aljurf, Riad El Fakih

Combined Intraoperative Radiotherapy (IORT) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) with Cytoreduction Surgery (CRS) as a Novel Approach in the Management of Resectable Pancreatic Cancer ....................................19Ayman Zaki Azzam, Tarek Mahmoud Amin

Peritoneal Carcinomatosis of Colorectal origin in Cyclosporine Immunosuppressed Rats .....................................................................27Elie Rassy, George Hilal, Viviane Track-Smayra, Joseph Kattan, Riad Sarkis, Aline Khazzaka

A Comparative Study of Uninterrupted Treatment by Radiotherapy versus Standard Gap Correction after Interruptions in Oropharyngeal Cancer .............................................................................................................................................31Satya Narayan, Neeti Sharma, Sweta Soni, Rajkumar Niwan

The Frequency and Specific Features of Rare Epidermal Growth Factor Receptor Mutations in Moroccan Patients with Lung Adenocarcinoma whose Tumors harbor positive EGFR mutations ..........................................................40Hind El Yacoubi, Mohamed Lemine Sow, Meryem El Ghouti, Fouad Kettani, Lamia Gamra, Amina Mestari, Lamia Jabri, Ibrahim Elghissassi, Hassan Errihani

Dosimetric Evaluation and Comparison Between Volumetric Modulated Arc Therapy (VMAT) and Intensity Modulated Radiation Therapy (IMRT) Plan in Head and Neck Cancers ..............................................................................45Murugaiyan Nagarajan, Ramesh Banu, Balraj Sathya, Thangavel Sundaram, Thirumalai Palanichamy Chellapandian

Mode of Presentation of Laryngeal Cancer: A Single Radiotherapy Institute Experience in Iraq ............................................................51Shkar Othman Arif, Yousif Ibrahem Al Chalabi, Hiwa Asaad Abdul Kareem, Karzan Marif Murad, Jalil Salih Ali, Sazgar Star Majeed, Shwan Ali Mohammed, Nyan Othman Saeed, Bamo Mohammed Muhsin, Ayah Said, Layth Mula-Hussain

Factors Affecting Survival in Glioblastoma: A 10-year Single-Center Experience from Saudi Arabia ...................................................58Abdullah Azab, Nasser Alsayegh, Omar Kashkari, Suliman Hanbazazah, Yazid Maghrabi, Fahad Alghamdi, Rolina Al-Wassia, Saleh S. Baeesa

Prognostic Impact of Alpha Fetoprotein at Diagnosis on Overall Survival of Single Small Hepatocellular Carcinomas ........................64N. Lahmidani, FZ. Hamdoun, M. Lahlali, H. Abid, M El Yousfi, DA .Benajah, M. El Abkari, SA. Ibrahimi

Clinical Outcomes of Head and Neck Cancer Patients Treated with Palliative Oral Metronomic Chemotherapy at a Tertiary Cancer Center in Kerala, India .......................................................................................................................68Vinin NV, Geetha Muttath, Joneetha Jones, Kalpita Shringarpure, Karthickeyan Duraisamy, Vanitha Priya Deenathayalan, Priya Rathi

Case ReportPrimary Squamous Cell Carcinoma of the Trachea: Two Cases Report ....................................................................................................75Amany Hussein, Khaled Al-Saleh, Mustafa El-Sherify, Hamdy Sakr, Jitendra Shete, Marwa Nazeeh

Bilateral Vocal Cord Immobility After Chemoradiotherapy For Nasopharyngeal Carcinoma ...................................................................80Selvamalar Vengathajalam, Thevagi Maruthamuthu, Nik Fariza Husna Nik Hassan, Irfan Mohamad

Toxic Leukoencephalopathy: An unusual Presentation by 5-Fluorouracil Infusion .................................................................................84Virendra Kumar Meena, Punnet Pareek, Satya Narayan, Sweta Soni

Transformation of Grade I Follicular Lymphoma to Anaplastic Large Cell Lymphoma CD30+ ALK1 - with Complete Response to Brentuximab Vedotin and High-Dose Methotrexate ................................................................................87Mubarak Al-Mansour, Hatim Al-Maghraby, Bader Shirah

Conference Highlights/Scientific Contributions• News Notes .............................................................................................................................................................................................91

• Scientific events in the GCC and the Arab World for 2020 ...................................................................................................................95

27

Abstract

Objective: We evaluate the seeding step of peritoneal carcinomatosis cancer as a surrogate for the role of the omentum in colorectal tumors.

Methods: The study included 5 groups of adult male Sprague Dawley rats: immunocompetent rats (group 1), immunosuppressed rats without omentectomy (group 2), immunosuppressed rats with omentectomy (group 3), immunosuppressed rats with omentectomy receiving NSAID (group 4), and immunosuppressed rats without omentectomy receiving NSAID (group 5). Except for group 1, the rats were immunosuppressed using cyclosporine orally at a dose of 25 mg/kg/day that was started 48 hours before tumor cell infiltration in the peritoneum. All the rats received an intraperitoneal suspension of 10 million Caco-2 cancer cells. Rats in groups 1, 2, and 3 were followed up without further interventions and rats in groups 4 and 5 received naproxen 180mg/kg until rat sacrifice. Cyclosporine and naproxen were continued in

the corresponding groups until the killing after 21 days of tumor cell infiltration.

Results: Fourteen rats survived the experiment during the observation period and remained in good clinical condition except for one rat (from group 4) that deceased at week 2. At day 21 before sacrifice, mean weight variations showed a +4% in group 0, -9% in group 1, -18% in group 2, -31% in group 3 and -36% in group 4. Light microscopy did not identify any tumor cells in the abdominal cavity or thorax solid organs but showed a granulomatous reaction that involved the majority of the organs.

Conclusion: The conclusions of this study are limited by the small number of rats as it is a pilot study to design an animal model with peritoneal carcinomatosis. Further steps in this study will include more aggressive cancer cell lines such as HT29 and more aggressive immunosuppression in a larger number of rats.

Keywords: peritoneal carcinomatosis; seed and soil; pathophysiology; colon; hematogenous metastasis

Original Article

Peritoneal Carcinomatosis of Colorectal origin in Cyclosporine Immunosuppressed Rats

Elie Rassy1, George Hilal2, Viviane Track-Smayra3, Joseph Kattan1, Riad Sarkis4, Aline Khazzaka4

1 Department of Hematology-Oncology, Saint Joseph University – Faculty of Medicine, Lebanon 2 Cancer and Metabolism Laboratory, Saint-Joseph University – Faculty of Medicine, Lebanon

3 Department of Pathology, Saint Joseph University – Faculty of Medicine, Lebanon 4 Surgical Research Laboratory, Saint Joseph University, Beirut, Lebanon

Corresponding author: Elie Rassy MD, MSc. Department of Hematology-Oncology, Saint Joseph University, Faculty of Medicine, Lebanon. Email: elie.

rassy@hotmail.com

IntroductionColorectal cancer ranks among the most common

malignancies and major causes of cancer-related mortality 1. It ultimately causes death by distant organ invasion, notably to the liver and the peritoneum which are the most frequent of colorectal metastases 2. Peritoneal dissemination is encountered in 8.2-25% of patients with colorectal cancer and is associated with high morbidity and mortality 3-4. Patients with peritoneal carcinomatosis (PC) commonly undergo aggressive treatment strategies, in the absence of other metastatic sites, but the chances of recurrences remain considerable 5. Preclinical animal-based research remains an essential tool in the unraveling of the pathophysiology of the PC and the subsequent therapeutic insights gained therefrom 6.

The development of PC starts with colorectal cancer that successfully detach from the primary tumors and complete successive steps of peritoneal cavity migration, colonization, and invasion of subperitoneal space followed proliferation and angiogenesis 7 . The detachment of the cancer cells from the primary tumor in the context of colorectal cancer might occur according to two scenarios: 1) spread of cancer results following full-thickness invasion or rupture of the bowel wall; and 2) dissemination of cancer cells from a primary tumor during surgery 8. The mechanism of tumor cell seeding

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Peritoneal Carcinomatosis in Cyclosporine Immunosuppressed Rats, Elie Rassy, et. al.

in the peritoneum is not fully elucidated. One hypothesis is that cancer cells usually attach to the endothelial fenestration at the level of the omental milky spots 9. This process is facilitated by the higher intracapillary pressure and the active inflammatory process at this level 10. Another hypothesis considers that PC has a different pathogenesis as peritoneal dissemination may occur in patients that underwent omentectomy as part of their primary colectomy 8.

This study aimed to establish a new xenograft model of peritoneal dissemination in colorectal tumors and to evaluate the seeding step of PC as a surrogate for the omental role in colorectal tumors.

Methods

Animals

Adult male Sprague Dawley rats weighing 400 ± 50 g were used throughout the experiment. The rats were kept under specific-pathogen-free conditions with autoclaved water and laboratory food ad libitum. All food cups and water bottles were replaced a minimum of twice weekly.

Tumor cell suspension

Caco-2 cancer cells were purchased from ATCC (American Type Cell Culture, Manassas, VA, USA) and were cultured in Dulbecco’s Modified Eagle Medium (Sigma-Aldrich, Germany) supplemented with 10% fetal bovine serum and 1% Penicillin/Streptomycin and were incubated in a 5% CO2 humid incubator at 37˚C.

Study design

Fifteen rats were assigned to five groups: immunocompetent rats (group 1), immunosuppressed rats without omentectomy (group 2), immunosuppressed rats with omentectomy (group 3), immunosuppressed rats with omentectomy receiving NSAID (group 4), and immunosuppressed rats without omentectomy receiving NSAID (group 5). Except for group 1, the rats were immunosuppressed using cyclosporine (Sandimum 50 mg/mL/Novartis, North Ryde, NSW, Australia) orally at a dose of 25 mg/kg/day that was started 48 hours before tumor cell infiltration in the peritoneum. Each rat received a suspension of 10 million Caco-2 cancer cells that was slowly injected intraperitoneally.

Thereafter, rats in groups 1, 2, and 3 were followed up without further interventions and rats in groups 4 and 5 received naproxen 180 mg/kg until rat sacrifice. Cyclosporine and naproxen were continued in the corresponding groups until the killing after 21 days of tumor cell infiltration. Stretch slides were made of the mesentery of the small bowel and the greater omentum,

liver, diaphragm, omentectomy incision site, and diaphragm. The obtained samples were cut into 8 µm sections with the cryostat and processed with hematoxylin and eosin for light microscopy. Immunohistochemistry was performed on all the obtained samples.

Ethics approval

All institutional and national guidelines for the care and use of laboratory animals were followed. All animal experiments were approved by the local ethical committee of Saint Joseph University – Faculty of Medicine.

ResultsOf the 15 rats included in this study, 14 rats survived

the experiment during the observation period and remained in good clinical condition and one rat (from group 4) deceased at week 2. At day 21 before sacrifice, mean weight variations showed a +4% in group 0, -9% in group 1, -18% in group 2, -31% in group 3 and -36% in group 4.

Gross examination of the abdominal cavity in rats of groups 2, 3, 4, and 5 showed diffuse dissemination of white infracentimetric nodules involving the intraabdominal cavity and lung parenchyma whereas those of group 1 did not present macroscopic anomalies (Figure 1). Examination of the thoracic cavity identified gross abnormalities in the two surviving rats from group 4 and one rat from group 1 and group 2. None of the rats had pleural effusion or ascites (Figure 1 and Table 1). Histologic analyses using light microscopy and immunohistochemistry did not identify any malignant process in the abdominal or thoracic cavity of the rats and corroborated the existence of multiple granulomatous reactions on the slides of the white nodules involving the majority of the organs.

DiscussionColorectal PC remains little studied in preclinical

models when compared to ovarian cancer or liver metastasis research. The literature describes few nude animal models with PC of colorectal origin but these models are expensive and do not accurately behave like immunocompetent animals 11. The immune suppression of immunocompetent animals followed by cancer cell injection in the peritoneal cavity better mimics the clinical situation present in human patients and allows a better understanding of the exact pathophysiology of PC 12.

Our study design relying on directly injecting the cancer cells inside the peritoneal cavity focuses on the seeding process of PC which requires that the cancer cells evade apoptosis, attach to secondary sites and

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Figure 1: Gross examination showing white nodules in the abdominal (liver, kidneys, mesentery, omentum) and thoracic (lungs) cavities.

Table 1: Metastatic sites involved in peritoneal carcinomatosis of colorectal origin in cyclosporine immunosuppressed rats

Group Rats Liver Bowels Kidneys Stomach Pancreas Peritoneum Diaphragm LungNumber

of organs involved

Group 1Immunocompetent rats

Rat 1 No No No No No No No No 0

Rat 2 No No No No No No No No 0

Rat 3 No No No No No No No Yes 1

Group 2Immunosuppressed rats without omentectomy

Rat 1 No No No No No Yes No No 1

Rat 2 Yes No No No No Yes No Yes 3

Rat 3 Yes No No No No Yes No No 2

Group 3 Immunosuppressed rats with omentectomy

Rat 1 No No Yes No No Yes No No 2

Rat 2 No No Yes No No Yes No No 2

Rat 3 Yes No Yes Yes No Yes No No 4

Group 4Immunosuppressed rats with omentectomy receiving NSAID

Rat 1 Yes Yes Yes Yes No Yes No Yes 6

Rat 2 Yes Yes Yes No Yes Yes No Yes 6

Rat 3 Deceased at week 2

Group 5 Immunosuppressed rats without omentectomy receiving NSAID

Rat 1 No No Yes No No Yes No No 2

Rat 2 No No Yes No No Yes No No 2

Rat 3 No No No No No Yes No No 1

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Peritoneal Carcinomatosis in Cyclosporine Immunosuppressed Rats, Elie Rassy, et. al.

proliferate8. Failure to complete any step of this metastatic cascade results in metastatic inefficiency 13-14. We did not observe any tumor growth in the abdominal or thoracic cavity. Nevertheless, we detected diffuse granulomatous reactions in both cavities which is a distinctive form of chronic inflammation that may be a surrogate of immune activity to block the neoplastic proliferation15-16.

In contrast to immunocompetent rats (group 1), immunosuppressed rats developed peritoneal granulomatous reactions; however, lung nodules were observed. Notably, immunosuppressed rats with omentectomy and receiving NSAID had a higher rate of granulomatous reactions in the lungs. We speculate that PC was initiated only in immunosuppressed rats however the metastasization process was hampered by the mounting immune system that led to a granulomatous reaction.

ConclusionThe small number of rats inherent to the concept

of a pilot study limits any conclusion. Further steps in this study will use a higher number of cancer cells for injections, a more intensive immunosuppression strategy with close follow up of cyclosporinemia, and assessment of tumors biomarkers and immune system reactions.

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