Escalated radiation dose alone vs. concurrent chemoradiation for locally advanced and unresectable rectal cancers: results from phase II randomized study.
OBJECTIVE
This trial was undertaken to compare the rates of resectability between patients treated with neoadjuvant concurrent chemoradiation vs. boosted radiotherapy alone.


METHODS
Patients with clinically unresectable rectal cancer were randomized to receive external beam radiation therapy (EBRT) to pelvis (45 Gy) with concurrent oral Capecitabine (CRT group; Arm 1) or EBRT to pelvis (45 Gy) alone followed by 20 Gy dose of localized radiotherapy boost to the primary tumor site (RT with boost group, Arm 2). All patients were assessed for resectability after 6 weeks by clinical examination and by CT scan and those deemed resectable underwent surgery.


RESULTS
A total of 90 patients were randomized, 46 to Arm 1 and 44 to Arm 2. Eighty seven patients (44 in Arm 1 and 41 in Arm 2) completed the prescribed treatment protocol. Overall resectability rate was low in both the groups; R0 resection was achieved in 20 (43 %) patients in Arm 1 vs. 15 (34 %) in Arm 2. Adverse factors that significantly affected the resectability rate in both the groups were extension of tumor to pelvic bones and signet ring cell pathology. Complete pathological response was seen in 7 and 11 %, respectively. There was greater morbidity such as wound infection and delayed wound healing in Arm 2 (16 vs. 40 %; p = 0.03).


CONCLUSIONS
Escalated radiation dose without chemotherapy does not achieve higher complete (R0) tumor resectability in locally advanced inoperable rectal cancers, compared to concurrent chemoradiation.
Department of Radiation Oncology, Tata Memorial Centre, Mumbai, India. reena.engineer@gmail.com
Reena
R
Engineer
K M
KM
Mohandas
P J
PJ
Shukla
S V
SV
Shrikhande
U
U
Mahantshetty
S
S
Chopra
M
M
Goel
S
S
Mehta
P
P
Patil
M
M
Ramadwar
K
K
Deodhar
S
S
Arya
Shyam Kishore
SK
Shrivastava
D000328:Adult; D000368:Aged; D059248:Chemoradiotherapy; D018572:Disease-Free Survival; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery / Q000628:therapy*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult