Nk. Kim et al., ADJUVANT RADIATION-THERAPY IN RESECTABLE RECTAL-CANCER - SHOULD LOCALRECURRENCE RATES AFFECT THE DECISION, The American surgeon, 63(7), 1997, pp. 579-585
Adjuvant external beam pelvic radiotherapy (XRT) for resectable rectal
cancer has been mandated by the National Cancer Institute because of
reported 20 to 50 per cent reductions in local recurrence rates. Howev
er, these series' reported local recurrence rates are 18 to 39 per cen
t in the nonradiated patients, which seems extraordinarily high compar
ed to the 3 to 5 per cent rates reported by surgeons advocating procte
ctomy with complete mesorectal excision. This fact, coupled with the h
igh cost of XRT ($11,000-$14,000), the risk of radiation injury to sma
ll bowel and the neo-rectum, and the failure of XRT to provide any sur
vival advantage, raises questions as to the precise role of XRT for re
ctal cancer. The purpose of this study was to perform a review of 212
consecutive patients undergoing curative resection via low anterior re
section (LAR) or abdominoperineal resection (APR) for rectal cancer be
tween 1989 and 1993, focusing on local and distant recurrence rates an
d survival. The choice of surgery alone (SUR), preoperative radiation
(PRE) (45 Gy), or postoperative radiation (POST) (45-50 Gy) was at the
surgeon's discretion. There were no significant differences in male:f
emale ratio (SUR, 83:60; PRE, 14:8; POST, 34:13) or type of procedure
(SUR-LAR, 112:APR, 31; PRE-LAR, 5:APR 17; POST-LAR, 30:APR, 17) betwee
n the groups. There were no significant differences in age between the
preoperative and postoperative radiation groups (PRE, 64.0 +/- 2.4; P
OST, 59.2 +/- 1.7); however, age was significantly different (P < 0.05
) between the surgery-alone and the postoperative radiation groups (SU
R, 68.5 +/- 0.8; POST, 59.2 +/- 1.7). With a median follow-up of 49 mo
nths, there were no significant differences in local recurrence (SUR,
4.2%; PRE, 4.5%; POST, 2.1%); however, there was a significantly longe
r survival for the SUR group compared to the other groups (SUR, 45.9 m
onths; PRE, 36.4 months; POST, 39.3 months; P < 0.05 least significant
difference), The PRE group also had shorter survival compared to the
other groups when only Stage II and III lesions were studied (S, 40.0
months; PRE, 28.3 months; POST, 39.3 months). Local recurrences based
on TNM stage were: T1N0 (S, 0 of 27; PRE, 0 of 3); T2N0 (S, 4 of 49; P
RE, 0 of 7); T2N1 (S, 0 of 9; POST, 1 of 5); T3,4N0 (S, 2 of 37; PRE,
1 of 9; POST, 0 of 10); and T3,4N1,2 (S, 0 of 21; PRE, 0 of 3; POST, 0
of 30). The results of this series support the contention that procte
ctomy with complete mesorectal excision yields a 4.2 per cent local re
currence rate without the need for adjuvant XRT. In this series, if al
l the patients had received adjuvant radiation, an additional $2.2 mil
lion would have been added to the costs of medical care. Therefore, th
e potential risks, costs, and benefits of adjuvant pelvic XRT for rect
al cancer must be weighed against optimal benchmarks for local recurre
nce rate for surgery alone.