出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2014/10/30 02:58:58」(JST)
Anaplastic astrocytoma | |
---|---|
Classification and external resources | |
Micrograph of an anaplastic astrocytoma. H&E stain.
|
Anaplastic astrocytoma is a WHO grade III type of astrocytoma, which is a type of cancer of the brain. The overall age-standardized incidence is 3.5 per million person years with a peak incidence of 8 per million population in the 75 to 79 year age group.[1]
Anaplastic astrocytomas fall under the category of high grade gliomas (WHO grade III-IV), which are pathologically undifferentiated gliomas that carry a poor clinical prognosis. Unlike glioblastomas (WHO grade IV), anaplastic astrocytomas lack vascular proliferation and necrosis on pathologic evaluation.[2] Compared to grade II tumors, anaplastic astrocytomas are more cellular, demonstrate more atypia, and mitoses are seen.
Initial presenting symptoms most commonly are headache, depressed mental status, focal neurological deficits, and/or seizures.[3] The growth rate and mean interval between onset of symptoms and diagnosis is approximately 1.5–2 years but is highly variable,[3] being intermediate between that of low-grade astrocytomas and glioblastomas.[3] Seizures are less common among patients with anaplastic astrocytomas compared to low-grade lesions.[3]
Most high-grade gliomas occur sporadically or without identifiable cause.[4] However, a small proportion (less than 5%) of persons with malignant astrocytoma has a definite or suspected hereditary predisposition.[5] The main hereditary predispositions are mainly neurofibromatosis type I, Li-Fraumeni syndrome, hereditary nonpolyposis colorectal cancer and tuberous sclerosis.[4] Anaplastic astrocytomas have also been associated with previous exposure to vinyl chloride and to high doses of radiation therapy to the brain.[4]
The standard initial treatment is to remove as much of the tumor as possible without worsening neurologic deficits. Radiation therapy has been shown to prolong survival and is a standard component of treatment. There is no proven benefit to adjuvant chemotherapy or supplementing other treatments for this kind of tumor. Although temozolomide is effective for treating recurrent anaplastic astrocytoma, its role as an adjuvant to radiation therapy has not been fully tested.
Quality of life after treatment depends heavily on the area of the brain that housed the tumor. In many cases, patients with anaplastic astrocytoma may experience various types of paralysis, speech impediments, difficulties planning and skewed sensory perception. Most cases of paralysis and speech difficulties can be rehabilitated with speech, occupational, physical, and vision therapy.
The age-standardized 5-year relative survival rate is 23.6%.[1] Patients with this tumor are 46 times more likely to die than matched members of the general population.[1] It is important to note that prognosis across age groups is different especially during the first three years post-diagnosis. When the elderly population is compared with young adults, the excess hazard ratio (a hazard ratio that is corrected for differences in mortality across age groups) decreases from 10.15 to 1.85 at 1 to 3 years, meaning that the elderly population are much more likely to die in the first year post-diagnosis when compared to young adults (aged 15 to 40), but after three years, this difference is reduced markedly.[1] Typical median survival for anaplastic astrocytoma is 2-3 years. Secondary progression to glioblastoma multiforme is common. Radiation, younger age, female sex, treatment after 2000, and surgery were associated with improved survival in AA patients.[6]
|
全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.
リンク元 | 「脳腫瘍」「星状細胞腫」「神経膠腫」「subependymal giant cell astrocytoma」「astrocytic glioma」 |
関連記事 | 「anaplastic」 |
腫瘍別発生頻度 | 小児 | 成人 | |
神経膠腫 | 33% | 星状細胞腫 | 髄膜腫 |
髄膜腫 | 22% | 髄芽腫 | 膠芽腫 |
下垂体腺腫 | 15% | 頭蓋咽頭腫 | 下垂体腺腫 |
神経鞘腫 | 9% | 胚細胞腫 | 神経鞘腫 |
頭蓋咽頭腫 | 5% | 上衣腫 | 転移性脳腫瘍 |
部位 | 種類 | 小児 | 成人 |
頭蓋骨 | 頭蓋骨腫瘍 | ○ | ○ |
大脳半球 | 神経膠腫 | ○ | |
髄膜腫 | ○ | ||
松果体 | 胚細胞腫 | ○ | |
小脳半球 | 星細胞腫 | ○ | |
血管芽腫 | ○ | ||
小脳虫部 | 髄芽腫 | ○ | |
第四脳室 | 上衣腫 | ○ | |
鞍上部・ 視交叉部・ 下垂体部 |
頭蓋咽頭腫 | ○ | |
視神経膠腫 | ○ | ||
胚細胞腫 | ○ | ||
下垂体腺腫 | ○ | ||
髄膜腫 | ○ | ||
小脳橋角部 | 聴神経鞘腫 | ○ | |
脳幹部 | 神経膠腫 | ○ | ○ |
後発年齢 | 好発部位 | |
小脳星細胞腫 | 5~10歳 | 小脳半球 |
髄芽腫 | 5~10歳(男児に多い) | 小脳虫部から発生 |
頭蓋咽頭腫 | 10~15歳 | トルコ鞍上部 |
上衣腫 | 10~15,30~40歳 | 第四脳室、側脳室 |
髄芽腫 | 10~30歳 | 松果体部、トルコ鞍上部 |
脳幹部膠腫 | ~15歳 | 橋 |
視神経膠腫 | ~15歳 | 視神経視交叉 |
.