1037 Efficacy and treatment outcome of preoperative chemoradiation therapy (CRT) for primary non-resectable rectal cancer

262

1. J. Radiation

Oncology

0 Biology

0 Physics

Volume

36, Number

1, Supplement,

1996

1036 EXPERIENCE CANCER

WITH

Depsrtmeats

ENDORECTAL

of Radiotherapy

the Departmeat

of Radiation

ULTRASOUND

‘, sad Surgical Oncology3,

Purpose: To evaluate the value chemoradiatioa for rectal caacer.

Oacology2,

University

AND

The University

of Virginia

of pretreatment

CHEMORADIATION

of Texas, M.D. Anderson

ultrasound

in staging

FOR

Cancer Center, Houston

Health Scieace Center, Charlottesville,

eadorectal

Eadorectal ultrasound Materials sad Methods: chemomdiatioa for rectal cancer. Treatment consisted

PREOPERATIVE

RECTAL

Texas sad

Virginia.

and predicting

response

to preoperative

was performed in 116 patients prior to administration of preoperative of 45 Gy in 25 fractions over 5 weeks with continuous infusion 5-fluorouracil

(300 a@m2/day). Determined by eadorectal ultrasound, tbe pretreatment stage distribution, was uT2 NO in 2%, uT3 NX in 5%, uT3 NO iu 42%, uT3 Nl ia 42%, uT4 NO ia 2% aad uT4 NX ia 4%. Badorectal ultrasound was not performed ia 4% of cases. Surgery was performed approximately 6 weeks following completion of chemoradiation ia all patients. Results: The posttreatment pathological tumor stages were Tis-2 NO in 26%, T2 Nl in 5%, T3 NO in 20%, T3 Nl in 15%, T4 NO in 5% aad T4 Nl ia 1%. Overall 28% of patients achieved a complete response to preoperative chcmoradiation. Dowastagiag occurred ia 61% of patients after chemoradiatioa sad stabilization of disease stage in 35%. Oaly 4% of our study population had disease that was more advanced, either due to underestimation of tumor extent by eadorectal ultrasound or tumor progression under therapy, at the tirne of surgical resection. Preoperative eadorectal ultrasound staging was predictive of overall response to therapy [pzZO.O5], complete response [p
Eadorectal

ultrasound

reliably

evaluated

pretreahneat

extent of hanor sad the findings

were predictive

of response

to

1037 EFFICACY AND TREATMENT OUTCOME OF PREOPERATIVE FOR PRIMARY NON-RESECTABLE RECTAL CANCER C. Roedel ‘, R. Fietkau Department

of Radiation

‘, G.G. Grabeabauer Therapy

‘, Surgery

‘, L. Keilholz

’ , H. Kessler

*, Surgical Pathology

Purpose: To assess efficacy, toxicity and treatment corn&e these results with postoperative CRT.

CHEMORADIATION

outcome

*, 0. Dworak

‘, University

of preoperative

THERAPY

(CRT)

‘, R. Sauer ’

of Erlangen,

Gerrnaay

CRT for rectal cancer not amenable

for primary

surgery,

and to

Material & Methods: Between 1987 and 1995,73 patients (pts) with primary rectal cancer were treated at our institution. 24 pts with tethered or fixed tumor (Mason CS III, IV; uT4: 17/24, uT3: 7/24, cM1: 5/24) received preoperative CRT, 49 pts @T4: 18 %, pT3: 76 %, pT2: 6 %; pN3: 40 %, pNl/2: 39 %, pN0: 21 %, cM1: 6%, UICC IV: 6 %, UICC III: 74 %, UICC II: 20 %) were treated postoperatively. Radiotherapy (RT) was given by a 3-4 field box technique with 6-10 MV-photons. Daily fraction size was 180 cGy, total dose 5040 cGy including 540 cGy local boost, specified to the ICRU reference point. During the first sad fifth week of RT 5-FU (1000 mg/m*/24 h) was administered by continuous infusion for 120 hours. Toxicity was recorded following (modified) WHO-criteria. The median follow-up for pre- and postoperative group was 42 months (range: 16-74 months) and 37 months (range: 13-65 months), respectively. RcsuItsz Four to six weeks after completion of preoperative CRT 19 of 24 pts underwent surgery (1209 abdominoperineal resection, 709 anterior resection). 5 pts had progressive disease/metastasis and were excluded from surgery. Fifteen resections were curative (RO, MO), one patient had microscopic (RI), three patients gross residual tumor (R2). Turnor stage after surgery was: ypT4: 2/19, ypT3: 12119, ypT2: 7/19; ypN3: 3/19, ypNl/2: 509, ypN0: 1 l/19). The actuarial survival rate for pts with preoperative CRT and curative resection was 77 % at five years. Patients receiving postoperative CRT after curative resection (RO: 44/49) showed an actuarial survival rate of 68 % at five years (n.s.). Prognosis was poor for patients with residual tumor (14 % five-year-survival). Acute toxicity was significantly reduced with tbe preoperative approach (grade 3-diarrhea 11 % vs. 29 %, p = 0.03; grade 3-erythema 16 % vs. 41 %, p = 0.04). Conclusion: Complete resection (RO) is the most important prognostic factor in the treatment of rectal cancer. If the tumor is not amenable to primary surgery, preoperative CRT shows excellent downstaging. Reduced toxicity should encourage further trials including preoperative CRT.