Baker K S, Anderson J R, Link M P, Grier H E, Qualman S J, Maurer H M, Breneman J C, Wiener E S, Crist W M
Intergroup Rhabdomyosarcoma Study Group, Arcadia, CA 91066-6012, USA.
J Clin Oncol. 2000 Jun;18(12):2427-34. doi: 10.1200/JCO.2000.18.12.2427.
To compare failure-free survival (FFS) and survival for patients with local or regional embryonal rhabdomyosarcoma treated on the Intergroup Rhabdomyosarcoma Study (IRS)-IV with that of comparable patients treated on IRS-III.
Patients were retrospectively classified as low- or intermediate-risk. Low-risk patients were defined as those with primary tumors at favorable sites, completely resected or microscopic residual, or orbit/eyelid primaries with gross residual disease and tumors less than 5 cm at unfavorable sites but completely resected. Intermediate-risk patients were all other patients with local or regional tumors.
Three-year FFS improved from 72% on IRS-III to 78% on IRS-IV for patients with intermediate-risk embryonal rhabdomyosarcoma (P =.02). Subset analysis revealed two groups that benefited most from IRS-IV therapy. FFS at 3 years for patients with resectable node-positive or unresectable (group III) embryonal rhabdomyosarcoma arising at certain favorable sites (head and neck [not orbit/eyelid or parameningeal] and genitourinary [not bladder or prostate]) improved from 72% on IRS-III to 92% on IRS-IV (P =.01). Similarly, 3-year FFS for patients with completely resected tumor or with only microscopic disease remaining (group I or II) at unfavorable sites improved from 71% on IRS-III to 86% on IRS-IV (P =.04). Only patients with unresectable embryonal rhabdomyosarcoma (group III) at unfavorable sites had no improvement in outcome on IRS-IV (3-year FFS for IRS-III and IRS-IV, 72% and 75%, respectively; P =.31).
IRS-IV therapy benefited certain subgroups of patients with intermediate-risk embryonal rhabdomyosarcoma. A doubling of the intensity of cyclophosphamide (or ifosfamide equivalent) dosing per cycle between IRS-III and IRS-IV is thought to be a key contributing factor for this improvement.
比较接受横纹肌肉瘤协作组（IRS）-IV研究治疗的局部或区域胚胎性横纹肌肉瘤患者与接受IRS-III研究治疗的可比患者的无失败生存率（FFS）和总生存率。
患者被回顾性分类为低风险或中风险。低风险患者定义为原发肿瘤位于有利部位、完全切除或有微小残留的患者，或眼眶/眼睑原发肿瘤有大体残留但在不利部位肿瘤小于5 cm且完全切除的患者。中风险患者为所有其他局部或区域肿瘤患者。
中风险胚胎性横纹肌肉瘤患者的三年FFS从IRS-III研究中的72%提高到IRS-IV研究中的78%（P = 0.02）。亚组分析显示有两个亚组从IRS-IV治疗中获益最大。在某些有利部位（头颈部[不包括眼眶/眼睑或脑膜旁]和泌尿生殖系统[不包括膀胱或前列腺]）发生的可切除淋巴结阳性或不可切除（III组）胚胎性横纹肌肉瘤患者的三年FFS从IRS-III研究中的72%提高到IRS-IV研究中的92%（P = 0.01）。同样，在不利部位肿瘤完全切除或仅残留微小病灶（I组或II组）的患者的三年FFS从IRS-III研究中的71%提高到IRS-IV研究中的86%（P = 0.04）。仅在不利部位有不可切除胚胎性横纹肌肉瘤（III组）的患者在IRS-IV研究中的结局无改善（IRS-III和IRS-IV研究的三年FFS分别为72%和75%；P = 0.31）。
IRS-IV治疗使中风险胚胎性横纹肌肉瘤患者的某些亚组获益。IRS-III和IRS-IV研究之间每个周期环磷酰胺（或异环磷酰胺等效物）给药强度加倍被认为是这一改善的关键因素。
