High-dose split-course radiation therapy for anal cancer: outcome analysis regarding the boost strategy (CORS-03 study).
OBJECTIVE
To retrospectively assess the clinical outcome in anal cancer patients treated with split-course radiation therapy and boosted through external-beam radiation therapy (EBRT) or brachytherapy (BCT).


METHODS
From January 2000 to December 2004, a selected group (162 patients) with invasive nonmetastatic anal squamous cell carcinoma was studied. Tumor staging reported was T1 = 31 patients (19%), T2 = 77 patients (48%), T3 = 42 patients (26%), and T4= 12 patients (7%). Lymph node status was N0-1 (86%) and N2-3 (14%). Patients underwent a first course of EBRT: mean dose 45.1 Gy (range, 39.5-50) followed by a boost: mean dose 17.9 Gy (range, 8-25) using EBRT (76 patients, 47%) or BCT (86 patients, 53%). All characteristics of patients and tumors were well balanced between the BCT and EBRT groups.


RESULTS
The mean overall treatment time (OTT) was 82 days (range, 45-143) and 67 days (range, 37-128) for the EBRT and BCT groups, respectively (p < 0.001). The median follow-up was 62 months (range, 2-108). The 5-year cumulative rate of local recurrence (CRLR) was 21%. In the univariate analysis, the prognostic factors for CRLR were as follows: T stage (T1-2 = 15% vs. T3-4 = 36%, p = 0.03), boost technique (BCT = 12% vs. EBRT = 33%, p = 0.002) and OTT (OTT <80 days = 14%, OTT ≥80 days = 34%, p = 0.005). In the multivariate analysis, BCT boost was the unique prognostic factor (hazard ratio = 0.62 (0.41-0.92). In the subgroup of patients with OTT <80 days, the 5-year CRLR was significantly increased with the BCT boost (BC = 9% vs. EBRT = 28%, p = 0.03). In the case of OTT ≥80 days, the 5-year CRLR was not affected by the boost technique (BCT = 29% vs. EBRT = 38%, p = 0.21).


CONCLUSIONS
In anal cancer, when OTT is <80 days, BCT boost is superior to EBRT boost for CRLR. These results suggest investigating the benefit of BCT boost in prospective trials.
Hannoun-Levi
Jean-Michel
JM
Antoine Lacassagne Cancer Center, Nice, France.
Ortholan
Cécile
C
Resbeut
Michel
M
Teissier
Eric
E
Ronchin
Philippe
P
Cowen
Didier
D
Zaccariotto
Audrey
A
Bénézery
Karen
K
François
Eric
E
Salem
Naji
N
Ellis
Steve
S
Azria
David
D
Gerard
Jean-Pierre
JP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001005:Anus Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy* / Q000556:secondary; D002295:Carcinoma, Transitional Cell / Q000473:pathology / Q000532:radiotherapy* / Q000556:secondary; D005260:Female; D005500:Follow-Up Studies; D005602:France; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging / Q000379:methods; D011878:Radiotherapy / Q000009:adverse effects / Q000379:methods; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome