Keys H, Gibbons S K
Department of Radiation Oncology, Cancer Center, Albany Medical College, NY 12208, USA.
J Natl Cancer Inst Monogr. 1996(21):89-92.
Locally advanced or recurrent cervical cancer is highly responsive to treatment and at least moderately curable with effective aggressive treatment. Radiation therapy is the mainstay of treatment for patients with this cancer. The roles for surgery and chemotherapy are as yet unproved, and both modalities are currently under investigation for their potential roles in the management of these conditions. Exenterative surgery clearly has an established utility for central pelvic failures after prior radiation therapy. Postsurgical pelvic recurrences are rarely successfully treated for cure, but considerable palliative effect is possible. The roles of intraoperative irradiation, sensitizing chemotherapy, and radical resection with interstitial irradiation are all under investigation at this time. Much has been learned over the past several decades about what parameters are important for successful radiation therapy for cervical cancers of stages IIB-IVA. While the traditional staging work-up for these patients included excretory urography, barium enema, examination under anesthesia, cystoscopy, and proctoscopy, there is now good evidence that computed tomography scan with intravenous contrast and office examination and biopsy are sufficient, with cystoscopy reserved for those few patients in whom clinical or imaging data suggest a higher risk of involvement. Surgical lymph node staging, especially of para-aortic lymph nodes, may be worthwhile in certain settings (e.g., for entry into research protocols), but it has no demonstrated role in routine clinical practice. Evidence is clear and convincing that effective treatment for these disease stages requires the inclusion of intracavitary brachytherapy. The role of interstitial brachytherapy is less clear, although there are some fervent advocates of this procedure. The debate continues about the use of low-dose-rate versus high-dose-rate brachytherapy. Treatment dose, volume, and length of treatment course are all important variables with outcome implications. The central disease requires a total dose of 8000-9000 cGy for maximal control probability, with larger tumors requiring the higher doses. The three-dimensional treatment volume must adequately surround the cancer and its likely routes of spread. Overall treatment time should be kept as short as possible, within the limits of conventional, tolerable fractionation. The potential theoretical advantage of hyperfractionated external-beam irradiation has yet to be verified in this disease but is of interest. It will be tested in an upcoming Gynecologic Oncology Group clinical trial. The negative prognostic significance of hypoxia in cervical cancers in general has been reported recently. While tumor cell hypoxia is almost certainly a problem in this disease, hypoxic cell sensitizers have not yet been found to improve treatment results. In clinical practice, reoxygenation probably occurs in these tumors. The role of paraaortic lymph node elective irradiation has been of interest for more than 20 years and was the subject of two randomized trials with quite different results. The Radiation Therapy Oncology Group trial found significantly improved survival in the treatment group assigned to receive paraaortic irradiation, when compared with the pelvic treatment group. However, a similar study by the European Organization for Research and Treatment of Cancer found no difference. The results of treatment today are substantially improved from those seen two decades ago. About 75% of patients with stage IIB disease and fully 50% of patients with stage IIIB disease are now cured with conventional irradiation alone. Clearly, there is still a need for further improvement. Of patients with urinary bladder involvement, 10%-20% are long-term survivors, as are 25%-30% of patients with para-aortic lymph node metastases. While these improvements are significant, there is clearly room for further progress. (ABSTRACT TRUNCATED)
局部晚期或复发性宫颈癌对治疗高度敏感,通过有效的积极治疗至少有中度治愈的可能。放射治疗是这类癌症患者的主要治疗手段。手术和化疗的作用尚未得到证实,目前这两种治疗方式在这些疾病管理中的潜在作用都在研究中。广泛性手术对于先前放疗后中央盆腔复发显然具有既定的效用。术后盆腔复发很少能成功治愈,但有相当大的姑息作用。术中放疗、增敏化疗以及间质内放疗的根治性切除术目前都在研究中。在过去几十年里,人们对IIB-IVA期宫颈癌成功放疗的重要参数有了很多了解。虽然这些患者传统的分期检查包括排泄性尿路造影、钡剂灌肠、麻醉下检查、膀胱镜检查和直肠镜检查,但现在有充分证据表明,静脉注射造影剂的计算机断层扫描、门诊检查和活检就足够了,膀胱镜检查仅适用于少数临床或影像学数据提示受累风险较高的患者。手术淋巴结分期,尤其是腹主动脉旁淋巴结分期,在某些情况下(如参与研究方案)可能是有价值的,但在常规临床实践中尚未显示出作用。有明确且令人信服的证据表明,这些疾病阶段的有效治疗需要包括腔内近距离放疗。间质内近距离放疗的作用尚不清楚,尽管有一些该方法的热烈支持者。关于低剂量率与高剂量率近距离放疗的使用争论仍在继续。治疗剂量、体积和疗程长度都是对治疗结果有影响的重要变量。中央型疾病为达到最大控制概率需要8000-9000 cGy的总剂量,较大肿瘤需要更高剂量。三维治疗体积必须充分包围癌症及其可能的扩散途径。总体治疗时间应在常规、可耐受分割的限度内尽可能缩短。超分割外照射的潜在理论优势在这种疾病中尚未得到证实,但值得关注。它将在即将开展的妇科肿瘤学组临床试验中进行测试。最近有报道称,一般情况下缺氧在宫颈癌中具有负面预后意义。虽然肿瘤细胞缺氧几乎肯定是这种疾病中的一个问题,但尚未发现缺氧细胞增敏剂能改善治疗效果。在临床实践中,这些肿瘤可能会发生再氧合。腹主动脉旁淋巴结选择性放疗的作用20多年来一直备受关注,并且是两项结果差异很大的随机试验的主题。放射治疗肿瘤学组的试验发现,与盆腔治疗组相比,接受腹主动脉旁放疗的治疗组患者生存率显著提高。然而,欧洲癌症研究与治疗组织的一项类似研究未发现差异。如今的治疗结果比二十年前有了显著改善。现在约75%的IIB期疾病患者和整整50%的IIIB期疾病患者仅通过传统放疗就能治愈。显然,仍有进一步改善的需求。膀胱受累的患者中,10%-20%是长期存活者,腹主动脉旁淋巴结转移患者中25%-30%是长期存活者。虽然这些改善很显著,但显然仍有进一步进展的空间。(摘要截选)