Response to preoperative chemoradiation
increases the use of sphincter-preserving surgery in patients with locally advanced low
rectal carcinoma Christopher H. Crane, M.D.Department of Radiation Oncology,
The University of Texas M. D. Anderson Cancer Center, Houston, Texas The authors
reviewed the records of 238 patients with T3 or T4 low rectal carcinoma ( 6 cm from the
anal verge) who underwent preoperative pelvic chemoradiation (45 Gy/25 fractions/5 weeks,
n = 182 or 52.5 Gy/30 fractions/5 weeks, n = 56 with continuous infusion 5-fluorouracil at
300 mg/m2, Monday to Friday) followed by mesorectal (n = 223) or local excision (n = 15).
Overall, 49% of patients (117 of 238) had sphincter-preserving
surgery. The clinical complete response rate was 47%. Independent predictors of
sphincter preservation included the year of surgery, tumor distance from the anal verge,
circumferential tumor involvement, and response to chemoradiation. The sphincter
preservation rate increased over the period of the study (from 28% [December 1989 to
December 1992] to 44% [January 1993 to December 1996] to 67% [January 1997 to December
2000]). The difference in the rates of sphincter preservation according to response was
most striking among patients with tumors 3 cm or less from the anal verge (44% vs. 22%, P
= 0.01). The pelvic disease recurrence rate among patients undergoing sphincter-preserving
surgery has been less than 10% since January 1993 and was not statistically different
between the groups treated from January 1993 to December 1996 and from January 1997 to
December 2000. |