Epidemiologic Evaluation of Central Nervous System Sarcomas in Iran: A 2009-2014 Survey

Research Article

Austin J Clin Case Rep. 2021; 8(4): 1207.

Epidemiologic Evaluation of Central Nervous System Sarcomas in Iran: A 2009-2014 Survey

Seddighi AS1, Nikouei A2, Seddighi A1*, Akbari ME3, Arjmand Y2, Ommi D4, Zali A5 and Hosseini M2

1Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Functional Neurosurgery Research Center of Shohad Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

2GP Member of Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Functional Neurosurgery Research Center of Shohad Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

3Cancer Research Center, Shohada Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

4Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Functional Neurosurgery Research Center of Shohad Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

5Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Functional Neurosurgery Research Center of Shohad Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

*Corresponding author: Afsoun Seddighi, Associate Prof of Neurosurgery. Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Functional Neurosurgery Research Center of Shohad Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Received: April 22, 2021; Accepted: May 13, 2021; Published: May 20, 2021

Abstract

Sarcomas rise from mesenchymal layers and may transform to variable malignant lesions in multiple organs systems. Although they are mostly localized, many of them have predilection of distant sites away from their primary origins and subsequent metastasis to different anatomical locations of body. Soft Tissue Sarcomas (STSs) represent one percent of adult and about 7% of pediatric malignancies. Although insignificant in number, these tumors may complicate patient’s overall health status compared with other malignancies, because of their numerous subtypes and variable features which may pose an everlasting challenge to both clinical and surgical treatment strategies. Existence of these complications and a relatively small available data regarding Central Nervous System’s (CNS) sarcomas, encouraged authors to conduct a retrospective study in a 6-year period to evaluate the specific epidemiological features of CNS sarcomas, including brain, spinal cord and meningeal layer sarcomas extracted from Iranian National Cancer Registry (INCR). Our study revealed CNS sarcoma’s trend to affect males more than females, affecting them most in their midlife and a higher prevalence of brain involvement compared to spinal cord and meningeal layers. Also, we have provided detailed morphological features of the tumors, as well as patient’s geographical distribution, with Northern parts of Iran have the lowest incidence rate (10.06%). Moreover, our analysis of crude rate revealed lower Age Specific Incidence Rate (ASIR) of CNS Sarcomas than expected number of cases compared to standard world population by World Health Organization (WHO)’s ASIR as 0.035 person per 100000-years. Authors believe this report of epidemiological assessment of CNS sarcomas in Iran could act as a foundation for better understanding the underlying pathophysiological mechanism as it is the first survey in developing countries and selection of optimal treatment strategies based on improved understanding of these neoplasms.

Keywords: Sarcoma; Soft tissue sarcoma; Central nervous system; Epidemiologic study

Introduction

Being derived from Greek word sarx meaning flesh, sarcomas originates from transformed mesenchymal cells with numerous subtypes and various distribution pattern and prognosis [1]. Mentioned versatility coupled with its rarity, are two main factors responsible for restricted reports of sarcomas description throughout history, which account for current limited knowledge on appropriate management of different types of sarcomas [2,3]. The American Cancer Society’s estimation of new bone and soft tissue sarcomas are 3500 and 12750 cases in the United States by the end of 2019 [4]. Considering the total estimate of new diagnosed cancer is 1762450 cases, bone and soft tissue sarcomas constitute about 0.2 and 0.7% of newly diagnosed malignancies respectively, making total cases of estimated new sarcomas roughly 1% of all new diagnosed cancers [5- 7]. Following previous statements regarding description of sarcomas rarity, multiple studies suggest lifetime risk of development of this cancer as about 0.001% [8]. Among these tumors, Central Nervous System (CNS) sarcomas represent an extremely rare subgroup with less than 1% of all sarcomas, originating mostly as a result of distant metastasis, direct invasion to the brain parenchyma and radiation associated sarcomas in young individuals [9,10]. Undifferentiated sarcoma, fibrosarcoma and malignant fibrous histiocytoma were among the most commonly found subtypes of CNS sarcomas in the past decade [11]. In addition to previous reports of incidence rate of CNS sarcoma of 3 per 10 million person-years, primary Intracranial Sarcomas (IS) which were first described in 1929, have incidence rate from 0.1 to 4.3% based on multiple types of studies with variable definition of primary IS [12,13]. Inclusion of reticulum cell sarcoma, circumscribed sarcoma of cerebellum and hemangiopericytoma and report’s inconsistency in unified definition of primary IS have contributed to this high value of incidence despite its rarity [14]. Since epidemiologic and descriptive studies are the cornerstones of enhanced understanding of these group of malignancies, authors decided to describe the epidemiologic aspect of CNS sarcomas and the prevalence of these challenging tumors in brain and spinal column and their subtypes in a 6-year period in Iran from 2009 to 2014.

Methods

In this retrospective study, authors have analyzed patients with confirmed histopathological study of CNS sarcomas in Iranian population. Patients with CNS sarcomas were identified from Iranian National Cancer Registry (INCR) from April 2009 to December 2014. Also, authors extracted population data of from Iranian National Cancer Registry. Patient’s demographic data including age, sex, living environment and city, primary tumor location and histopathological subtype based on World Health Organization (WHO) classification system of sarcoma with confirmed diagnosis, were gathered and recorded. Patient’s specific tumor data documented in INCR have been filed based on histopathological and radiological confirmation, with roughly 16700 documented sarcoma patients were analyzed in the same mentioned 6-year period. Due to recent changes of STSs classification system and ongoing updates, authors have reported both macroscopic and microscopic tumor description as tumor’s morphology and its classification, respectively. Since some tumors have higher incident rate in specific geographical areas, we have analyzed the geographical distribution pattern of our patients to find a possible relevant “hot-zone” for CNS sarcomas in Iran, given that it may lead to extended research on potential environmental hazards and carcinogens. Also, authors performed statistical analysis using SPSS program version 22 to perform Age Specific Incidence Rate (ASIR) and its annual trend.

Results

In this study, authors have thoroughly examined the INCR’s information in a period between 2009 to 2014, and analyzed 298 patients with confirmed diagnosis of CNS sarcomas, either of brain (primary IS) or spinal cord, out of the 16700 sarcoma patients. Our analysis revealed 180 males and 118 females with male to female ratio of 1.52 and a periodic prevalence of 1.78%. Specific details of CNS sarcoma prevalence among both sexes is described in Table 1.