Evans M P, Podratz K C
Mayo Clinic, Rochester, Minnesota 55905, USA.
Clin Obstet Gynecol. 1996 Sep;39(3):696-706. doi: 10.1097/00003081-199609000-00017.
For several decades, clinical and histologic assessment of various phenotypic properties has provided a basis for treatment planning. However, it is recognized that, preoperatively, clinical assessment identifies only 20% of patients with advanced disease. Furthermore, the variability in intraoperative sampling, the subjectivity and limitations of histologic interpretation, and the variability in response to standardized treatment modalities represent concerns associated with the current treatment of endometrial carcinoma. Presumably, early dissemination, early recurrence, treatment refractoriness and, ultimately, compromised survival are reflections of the inherent biologic characteristics of the tumor. A reasonable assumption is that proscribed molecular events determine various behavioral characteristics of tumors that become manifested at the time of transformation rather than evolving as the tumor volume increases. Therefore, the identification of one or more of these quantifiable molecular variables that directly or indirectly assess tumor biology would assist clinicians in determining patient risk status and in selecting treatment options. As noted, DNA ploidy is an independent, broadly applicable, quantifiable predictor of progression-free survival in patients with endometrial cancer and, therefore, warrants designation as a major prognostic factor or therapeutic determinant. Aneuploidy implies the presence of an abnormal quantity of genomic material and imparts a progressively less favorable prognosis as the DNA index increases. These assayable aberrancies of cellular DNA content presumably reflect the more extreme alterations at the molecular level. Because neoplastic transformation is generally a multistep process, aberrations in several proto-oncogenes or tumor suppressor genes (or both) presumably must be realized before a clinical malignancy develops. A number of genes that encode for various regulatory proteins are overexpressed in endometrial cancer. Whether these aberrancies are fundamental to the pathogenesis of this disease process is unclear. Nevertheless, there appears to be an association between DNA ploidy and the overexpression of several regulatory genes, such as c-fms, K-ras, HER-2/neu, and p53. Although overexpression of these oncogenes and tumor suppressor genes harbor prognostic significance in endometrial cancer, the ploidy status of the tumor appears to represent the most cogent objective variable. As the etiopathogenesis of endometrial carcinoma becomes more discernible, one can envision a limited number of tissue-specific molecular-genetic indices characterizing the risk status of patients. Because the estimated number of deaths from endometrial cancer has doubled since 1987, reassessing of the therapeutic determinants for this disease process is important. The management objective for endometrial cancer by the turn of the century should be the identification of patients at high risk for advanced disease or post-treatment recurrences (or both) at the time of clinical declaration of symptoms and diagnosis. Such pretreatment identification would afford patients at high risk for advanced or recurrent disease access to physicians with special expertise and would facilitate the evaluation and application of new or modified therapeutic modalities. Equally important would be the identification of patients at low risk for untoward outcome, thereby avoiding the cost and morbidity of excessive therapeutic measures.
几十年来,对各种表型特征进行临床和组织学评估为治疗方案的制定提供了依据。然而,人们认识到,术前临床评估仅能识别出20%的晚期疾病患者。此外,术中采样的变异性、组织学解释的主观性和局限性以及对标准化治疗方式反应的变异性,都是与目前子宫内膜癌治疗相关的问题。据推测,早期播散、早期复发、治疗难治性以及最终生存受损,都是肿瘤内在生物学特性的反映。一个合理的假设是,特定的分子事件决定了肿瘤在转变时表现出的各种行为特征,而不是随着肿瘤体积的增加而演变。因此,识别一个或多个直接或间接评估肿瘤生物学的可量化分子变量,将有助于临床医生确定患者的风险状态并选择治疗方案。如前所述,DNA倍性是子宫内膜癌患者无进展生存期的一个独立、广泛适用且可量化的预测指标,因此有理由被指定为主要的预后因素或治疗决定因素。非整倍体意味着基因组物质数量异常,并且随着DNA指数的增加,预后逐渐变差。细胞DNA含量的这些可检测异常可能反映了分子水平上更极端的改变。由于肿瘤转化通常是一个多步骤过程,在临床恶性肿瘤发生之前,可能必须在几个原癌基因或肿瘤抑制基因(或两者)中出现异常。许多编码各种调节蛋白的基因在子宫内膜癌中过度表达。这些异常是否是该疾病发病机制的根本尚不清楚。然而,DNA倍性与几种调节基因(如c-fms、K-ras、HER-2/neu和p53)的过度表达之间似乎存在关联。尽管这些癌基因和肿瘤抑制基因的过度表达在子宫内膜癌中具有预后意义,但肿瘤的倍性状态似乎是最有说服力的客观变量。随着子宫内膜癌病因发病机制变得更加清晰,人们可以设想有少数组织特异性分子遗传指标来表征患者的风险状态。自1987年以来,子宫内膜癌估计死亡人数增加了一倍,因此重新评估该疾病的治疗决定因素很重要。到本世纪末,子宫内膜癌的管理目标应该是在临床症状声明和诊断时,识别出有晚期疾病或治疗后复发(或两者)高风险的患者。这种预处理识别将使有晚期或复发性疾病高风险的患者能够接触到具有专业知识的医生,并将促进新的或改良治疗方式的评估和应用。同样重要的是识别出不良后果低风险的患者,从而避免过度治疗措施的成本和发病率。