Do you treat rectosigmoid/upper rectal cancers with neoadjuvant chemoradiation?

The 12-year update to the phase III pre-op RT Dutch rectal trial found a local control benefit with RT regardless of location (VanGijn et al., Lancet Oncol. 2011; 12(6):575-82.). In the Dutch update, tumor location was analyzed as a continuous variable. This is different from the every 5 cm cut-offs analyzed in the initial Dutch report by Kapiteijn et al. published in 2001, which found a lack of RT benefit for tumors 10.1-15 cm from the verge (similar findings to the updated Swedish results published in 2005). Of note, in the Dutch update the benefit from RT actually significantly increased with distance from the verge, but the significance of this difference disappeared when the analysis was restricted to patients with a negative circumfer...

If the tumor is high (> 12 cm) based on straight procto (not a flexible scope) I base the decision on the pelvic imaging. If it is in (part or whole) in the pelvis I add pelvic RT. For cT3N0, especially for a woman of childbearing age, I do give them the option of not receiving RT after a discussion of the benefits/risks. However for T3N+ I always add RT.

This is an interesting question that comes up quite frequently in the clinic, and it's surprising to me that there hasn't been more dedicated literature on the topic. I agree with the above commenters that bulky/node-positive tumors and those with an intrapelvic location on imaging generally warrant RT. We routinely stage patients with MRI and our radiologists routinely report the relationship of the tumor to the peritoneal reflection (above vs. below vs. straddling), and that is probably the most "objective" criterion we have. Since ultimately the goal is preventing local recurrence, multidisciplinary input and the opinion of the surgeon regarding the likelihood of threatened margins is also crucial.

First of all, I wouldn't NOT treat a cancer because it was rectosigmoid (double negative intended). If a tumor originates in the mid to upper pelvis, but is encroaching on vessels neighboring organs, it has as much need for aggressive preoperative treatments an advanced rectal cancer.

With rectosigmoid cancers that appear to be readily resectable but are bulky or clinical T3 or N+ we often will give a short five fraction course of RT followed one or two working days by surgery. Unless the margin comes back positive, (which has only happened once to me) I would not give any postoperative RT. Functionally it is better for these patients to have had preoperative RT than postoperative RT to both sides of the anastomosis.

Bob Myerson

This is a question that often comes up and in our experience, these cases are thoroughly discussed in MCC. Radiology review is absolutely necessary to define the tumor's relation, i.e. i) is it wholly or partly within the true pelvis ii) its relationship to APR iii) nodes iv) threatened margins.

It is not uncommon that after MCC discussion, we would recommend neoadjuvant chemoRT, even if the tumor is deemed above the recto-sigmoid junction.