Международный неврологический журнал Том 18, №8, 2022
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Моноцентрове ретроспективне дослідження результатів хірургічного лікування пілоцитарної астроцитоми в дорослих. Невелика серія випадків і огляд літератури
Авторы: Dipak Chaulagain, Volodymyr Smolanka, Andriy Smolanka, Taras Havryliv, Abdalrahman Nassar, Mujahed Ayasi
Uzhhorod Regional Clinical Center of Neurosurgery and Neurology, Uzhhorod National University, Uzhhorod, Ukraine
Рубрики: Неврология
Разделы: Клинические исследования
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Резюме
Актуальність. Піковий вік розвитку пілоцитарної астроцитоми (ПА), різновиду доброякісної пухлини мозочка, припадає на вік від 10 до 20 років. Пухлина, відома як пілоцитарна астроцитома в дорослих, зустрічається надзвичайно рідко. Отже, дуже мало відомо про характеристики цих пухлин. Матеріали та методи. Ми ретроспективно проаналізували дані пацієнтів віком від 18 років із патологічно підтвердженою пілоцитарною астроцитомою, які перенесли операцію з видалення пухлини між січнем 2010 року й січнем 2020 року та перебували під наглядом до січня 2022 року. Результати. Хоча спочатку 32 випадки були позначені як ПА, у дослідження включили лише 4 пацієнтів (2 чоловіки і 2 жінки) з пілоцитарною астроцитомою, яким у середньому було 26,75 року. Середній вік чоловіків на момент встановлення діагнозу дорівнював 28 рокам, смертності чи рецидивів у цій групі не зафіксовано. Середній вік пацієнток на момент встановлення діагнозу був 25 років. Після закінчення періоду спостереження одна жінка була живою. Причина смерті другої пацієнтки не пов’язана з пухлиною. Середній термін спостереження за жінками становив 36 місяців, а середня загальна виживаність — 42 місяці. Висновки. Пілоцитарна астроцитома в дорослих розвивається інакше, ніж у дітей. Показано, що обсяг хірургічної резекції та розташування пухлини впливають на прогноз. Якщо можливо, тотальна резекція має бути основним типом лікування. Спостерігаються хороші показники виживаності та нечасті рецидиви.
Background. The peak age for the development of pilocytic astrocytomas (PA), a type of benign cerebellar tumor, is between the ages of 10 and 20. The tumor known as adult pilocytic astrocytoma is extremely rare. Consequently, very little is understood about the characteristics of these tumors. Materials and methods. We retrospectively reviewed the records of patients older than 18 years with pathologically proven pilocytic astrocytoma who had surgery to remove the tumor between January 2010 and January 2020 and were followed until January 2022. Results. Although 32 cases were initially recognized as PA, we only ended up including 4 patients (2 male and 2 female) with adult pilocytic astrocytoma, their mean age was 26.75 years. The mean age of male patients at diagnosis was 28 years, and there were no mortality or recurrences. The mean age of female patients at diagnosis was 25.5 years. One female was still living after the follow-up period ended. The cause of death of another female patient was unrelated to tumor. Women had a median follow-up of 36 months, and their mean overall survival was 42 months. Conclusions. Pilocytic astrocytoma in adults acts differently than in children. The extent of surgical resection and the location of the tumor were shown to influence the prognosis. When possible, total resection should be the primary treatment. Good survival rates and little recurrence are seen.
Ключевые слова
астроцитома; пілоцитарна астроцитома; гліома; обсяг резекції
astrocytoma; pilocytic astrocytoma; glioma; extent of resection
Introduction
According to the World Health Organization, pilocytic astrocytoma (PA) is a grade I tumor with a peak in the first two decades of life and no gender differences. The cerebellum is the typical site of PA development [1]. Adults, however, are extremely elusive [2]. Compact regions of bipolar astrocytes linked with Rosenthal fibers are found in PA, as well as protoplasmic astrocytes, microcysts, and eosinophilic granular masses [1].
The benign and slow-growing nature of PA means that patients have a relatively good prognosis. Surgery is the treatment of choice since it is curative in cases of a large complete resection. There is a wide range of reported survival rates after surgery, from 86 to 100 % after five years; gross complete resection leads to better survival. The result may not be as optimistic as the prediction suggests due to a number of factors. Worse outcomes have been linked to incomplete resection and tumors in surgically inaccessible areas [3–5].
Even worse outcomes were seen in a recent study of PA in adulthood [2]. Few studies have focused on adult PA patients; therefore, it is unclear how age affects prognosis [2, 6, 7]. There have been examples in adults, although their clinical features remain unknown. Accor-ding to the available data, this adult version is uncommon. During the last decade, we have recorded 4 cases of PA in adults.
The goal of this study was to examine the surgical outcomes of PA in adults and to identify potential influencing factors.
Materials and methods
Center of Neurosurgery and Neurology cared for 32 patients with PA between 2010 and 2020. We did not include 28 patients in our study because they were either under 18 years of age or had missing records. Four patients’ medical histories were examined retrospectively. Two males and two females with mean age of 28 and 25.5 years, respectively, were included in our study. Data of these patients were taken for the final analysis because they met our inclusion criteria. We performed surgery in adults diagnosed with pilocytic astrocytoma (astrocytoma grade I as determined histopathologically). Until January 2022, their progress could be followed. Patient demographics, clinical history, radiographic findings, surgical peculiarities, tumor features, and pathology information were registered. There was a general consensus that all cases were related to neurological complaints. Preoperative magnetic resonance imaging (MRI) with and without gadolinium was performed in all patients meeting inclusion criteria. MRI scan was also performed within 72 hours after surgery in all cases. Based on preoperative (X) and postoperative volume (Y), the extent of resection (EOR) was calculated: EOR = X – Y/X × × 100 %. After obtaining EOR again, we classified our data into: 1) more than 99 % as gross total resection; 2) 91–99 % as near total resection; 3) 70–90 % as subtotal resection; 4) less than 70 % as partial resection; 5) biopsy. Patients were followed for a median of 36 months after discharge, with a range of 2 to 144 months. As part of the follow-up for each patient, a series of MRI scans were taken.
Results
Four patients’ records (2 male and 2 female) were finally included into our paper. The mean age of men at diagnosis was 28 years. By the end of follow-up, there was no male mortality or recurrence. The mean age of women at diagnosis was 25.5 years. By the end of follow-up period, one woman was alive. Mean overall survival in females was 42 months, one woman had no recurrence. According to Burkhard et al., while there is a minor preference for the supratentorial space in adults (55 %), the cerebellum is the most common site for tumors in children (67 %) [3]. The distribution of PA was as follows: cerebellum — 1 case, brainstem — 3 cases. Only data from resectable PA in adult patients were analyzed, based on preoperative imaging. Due to tumor location, a gross total resection was possible in one patient, and near total resection was achieved in one case. Partial resection was performed in 2 patients.
Outcomes and survival analysis
The duration of the follow-up was 2–144 months, with a median of 36 months. From a total of 4 adults diagnosed with PA, three were doing well after 42 months on average and one died. One patient experienced a recurrence. We anticipate that the survival rate will reflect the positive prognosis of this tumor type, as demonstrated by previous follow-up studies.
Discussion
Pilocytic astrocytomas are slow-growing, benign tumors with well-defined borders, and they are most frequent in children and young adults. This is the primary cause of glioma in young people [1, 8]. The low-grade glioma known as pediatric astrocytoma affects children and young adults and is characterized by slow growth and well-defined borders. To date, it has been determined to be the most frequent glioma in children, ma-king up as much as 25 % of all brain tumors removed in neurosurgical practice. However, pediatric astrocytoma is incredibly uncommon in adults, accounting for only 2.3 % of all brain tumors [2]. Unfortunately, very little is known about the features of PA in adults because of the paucity of research in this population. This ten-year retrospective study discusses the demographics and treatment outcomes of a cohort of adult patients with PA treated at the Clinical Center of Neurosurgery and Neurology.
For the first time, cases older than 30 years are being recognized. A tumor was detected by Rossi et al. [9] in the hypophysis of a man aged 40, and Kehler reported four cases in people aged 40 and up, albeit the details of these cases were not specified [10]. Of the 37 patients discussed by Lee et al. [11], only one was older than 20 years. Burkhard et al. recent series included 55 participants; 11 of them were 30 or older [3]. In our case, only 4 of our 32 patients with PA were 18 or older.
While PA can manifest anywhere along the neuraxis, it is most often found in midline structures such as ce-rebellum, optic chiasm, and brainstem. The cerebellum is the most prevalent origin of PA, as shown by one case discovered in our retrospective study of adult pilocytic astrocytoma, while 3 tumors were located in the brainstem. Patients presenting with PA have varying clinical manifestations depending on the size and site of the lesion. Our study found that most people with posterior fossa PA also had difficulties walking due to symptoms of increased intracranial pressure (such as headaches, vo-miting, and impaired vision).
Multiple studies have shown that the location and extent to which a tumor was excised after surgery signi-ficantly impact one’s prognosis. Univariate Cox proportional hazards regression analysis of 865 adult patients with PA from the USA National Cancer Institute (NCI) Surveillance, Epidemiology, and End Results Program database showed that gross total resection reduced the risk of death by a factor of 0.2 compared to subtotal resection or biopsy [12]. In a similar vein, Stüer et al. [2] found that individuals whose tumors were only partially removed had a fourfold higher recurrence rate than those whose tumors were removed completely. Total tumor removal is not only related with improved outcomes, but also curative, as shown by our findings. For the patients in our study who underwent a total tumor removal, there were no recorded cases of recurrence or death. Optic chiasm and brainstem PA are associated with worse outcomes due to the increased difficulty of access and complete excision. Therefore, tumors in these areas tend to have poorer outcomes. One patient with brainstem PA had a recurrence of tumor, while another patient with brainstem PA passed away during follow-up.
Adult PA are so rare that very little is known about their behavior. Depending on whatever study you read, the prognosis for PA in adults can range from excellent to poor [2, 3, 8, 12]. This is due to conflicting data showing either greater survival rates or worse prognoses and a higher likelihood of tumor recurrence following surgical excision. The mortality rates of PA patients in the NCI database were significantly higher as they got older. Survival rates decreased dramatically with age, from 96.5 % at 5–19 years to 52.9 % at over 60 years of age [12].
Among 44 adult patients in a retrospective study, 5-year survival was 87 % and progression-free survival was 72 % [2]. On the other hand, Brown et al. found progression-free survival and overall survival rates of 95 % after 5 years in a prospective study comprising 20 patients [7].
Based on the data gathered, we can conclude that PA in adults is not completely benign; in fact, we found that 1/4 of our study population experienced a tumor recurrence and 1/4 died throughout the study period, with an overall survival rate of 42 months. The discrepancy between this study’s findings and those of other investigations may be attributable, in part, to the small sample size of adult patients examined.
Conclusions
Adult pilocytic astrocytoma is an uncommon tumor with a clinical presentation similar to that of childhood/adolescence. The standard of care appears to be surgical resection. The outlook is good if total resection can be performed. To confirm these preliminary findings, more research is needed. Extent of resection and tumor site were shown to be significant determinants of prognosis. Currently, we urge careful monitoring and follow-up for adult PA patients.
Received 15.12.2022
Revised 22.12.2022
Accepted 26.12.2022
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