Background: The purpose of the present study was to evaluate the changing r
ole of radiation therapy in rectal cancer and to determine the patterns of
referral of patients during a 15-year period.
Methods: From 1982 to 1997, 464 patients with carcinoma of the rectum were
referred to the Department of Radiation Oncology, Royal Prince Alfred Hospi
tal; 79% of patients had locoregional disease alone and 21% had distant met
astasis. Radiation therapy consisted of irradiation (definitive or palliati
ve) alone to the primary tumour in 9.7% of cases; preoperative radiation in
7.3% of cases; preoperative chemoradiation in 7.5% of patients; postoperat
ive radiation in 15.3% of patients: postoperative chemoradiation in 12.3% o
f patients; treatment of pelvic recurrence in 23.5% of patients and treatme
nt of metastases in 9.1% of patients. The remainder were treated elsewhere
(1.9%) or not treated(13.4%).
Results: There was an average annual 14% increase in referrals over the acc
rual period. Recurrent rectal cancer decreased from approximately 30% of re
ferrals during 1982-91 to approximately 10% in 1995-7. The use of postopera
tive adjuvant radiation reached a peak of 50% in 1993. The use of preoperat
ive radiation increased suddenly in 1994 from < 10% to a sustained rate of
approximately 30% of referrals. The use of chemoradiation commenced in 1990
for postoperative adjuvant treatment and in 1994 for preoperative treatmen
t. The median survival time from initial diagnosis was 35 months, with 2- a
nd 5-year survival rates of 62 and 28%, respectively. Survivals at 5 years
for patients treated with preoperative and postoperative radiation (with or
without chemotherapy) and with recurrent disease were 56, 44 and 21%, resp
ectively.
Conclusions: The present study illustrates the changing role of radiation t
herapy in the management of rectal cancer. The increase in referrals over t
he observation period was due to increased multidisciplinary input into the
initial management of these patients. based on reported clinical trials. T
he steady increase in the use of adjuvant therapy has paralleled a decrease
in referrals for treatment of recurrence and reflects current clinical res
ults. The sequencing of adjuvant therapy is changing currently, with greate
r emphasis on preoperative adjuvant treatment. Currently most adjuvant ther
apy includes chemotherapy.