What adjuvant therapy would you offer for rectosigmoid junction adenocarcinoma after initial LAR?

The ideal treatment of rectosigmoid cancers is often nebulous, as depending on their presentation, they can be approached like rectal cancer or colon cancer.

Given that this patient had initial surgery, I would approach this patient as a higher risk stage 2 colon cancer, based on the perforation as well as perineural invasion. If a candidate for combination adjuvant therapy, I would favor 3 months of capecitabine/oxaliplatin based on the updated analysis of this patient population from the IDEA c...

I agree with all of the above. The early postoperative trials did not stratify for risk factors such as T and N stage, number of negative nodes, or importantly distance from the anal verge. When the NSABP R-02 trial did not show a survival benefit chemo radiation versus chemo therapy alone, the interpretation was that it was because subgroups of patients did not benefit. Subsequently, a pool analysis by Gunderson et al., PMID 15067027, of most of the trials up to that point showed differences in...

I agree with Dr. @Dr. First Last that 3 months of Capecitabine (+/- oxaliplatin depending on patient specific factors) is appropriate here.

The only situation I would consider adding radiation as part of adjuvant treatment, in this case, is if it was truly a rectal cancer (completely below the peritoneal reflection) AND radial margins were positive.