Rectal Cancer: Second Most Important Decision

Continue from the previous post…

Of course, prior to surgery, other considerations such as pre-operative radiotherapy, pre-op chemo-radiotherapy, post-op radiotherapy, post-op chemo-radiotherapy, short course radiotherapy, long course radiotherapy and adjuvant chemotherapy all need to be discussed with your oncologist in order to get the best outcome.

The second most important decision after finding yourself a good colorectal surgeon is deciding on appropriate pre-operative or post-operative treatment options to improve treatment outcome further.

I will make it simple.

I assumed you have MRI pelvis ready for assessment and also have found a good colorectal surgeon who is ever ready to operate.

Assuming Already Operated – Post-Operative Treatment

Post-operative chemo-radiation improve both overall survival and reduce local recurrence when compared with just post-operative radiation only.

Improvement in 5-year survival rate from 40% with radiation alone to 55% with concurrent chemoradiation. Krook JE (1991)
Reduction of local recurrence from 63% with radiation alone to 41% in with concurrent chemoradiation. Krooke JE (1991)

Side effects from addition of chemotherapy such as nausea, vomiting, oral ulcers, diarrhoea and low blood counts are mostly tolerable and manageable.

Post op chemo-radiation is normally given to patients whose histopathology report showed T3, T4, N+ or positive circumferential margin (CRM+).

Screen Shot 2018-08-21 at 10.35.37 PM.png
Above table showing significant improvement in local recurrence with post-op chemo-RT. Also, the 5-year OS was higher in the post-op chemo-RT group, although not statistically significant. Gastrointestinal Tumor Study Group – ‎1985

Other than that, no further treatment for T1, T2 and N0.

TNM staging system for colorectal cancer

Assuming Not Operated Yet – Pre-Operative Treatment


Pre-op short course RT, followed by surgery (within 1 week) when compared with surgery alone surgery alone even reported long term improvement in overall survival and local recurrence for SCRT. (Swedish Rectal Cancer Trial)

  • The overall survival rate (13 years!) in the irradiated group was 38% v 30% in the non-irradiated. The cancer-specific survival rate in the irradiated group was 72% v 62% in the non-irradiated group and the local recurrence rate was 9% v 26%, respectively. (J Folkesson, ‎2005)
Screen Shot 2018-08-21 at 11.46.17 PM.png
Overall survival analysis for all stages; survival rate at 13 years in the irradiated group was 38% v 30% in the non-irradiated (only surgery). Swedish Rectal Cancer Trial: Long Lasting Benefits From Radiotherapy on Survival and Local Recurrence Rate. (J Folkesson, ‎2005)

Pre-op short course radiotherapy (SCRT = 5 fractions, followed by surgery) is equivalent when compared with pre-op long course chemo-radiotherapy (LCCRT, followed by surgery). (T Latkauskas, ‎2012)

  • Equal local recurrence and overall survival
  • Lower acute toxicity

Important: In operable rectal cancer, pre-op short course RT alone improve overall survival and local recurrence.

Inoperable/ locally advanced

For inoperable or locally advanced cases, pre-operative long course chemo-radiation (CRT) is the standard treatment.

Both radiotherapy (25-28 fractions) and chemotherapy is given concurrently over 5-6 weeks, followed by surgery 6-8 weeks later.

It’s is recommended for all T3 tumor with mesorectal invasion, T4 tumor or positive lymph nodes (LN+) in order to get the best chance of R0 (no cancer cells seen microscopically at the resection margin) surgery.

In a trial comparing pre-op long course CRT vs post-op long course CRT

  • Lower local recurrence and both acute and late side effects in pre-op long course C-RT. (R Sauer, ‎2004)
Screen Shot 2018-08-21 at 11.44.55 PM
Lower local recurrence in pre-op long course chemo-radiotherapy (C-RT). (R Sauer, ‎2004)

These are just very brief summary of pre-op and post-op treatment that are recommended for rectal cancer.

I hope this will help you to prepare for your consultation with your oncologist.

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