<em>Do patients achieving pathological complete response (pCR) following neoadjuvant treatment for locally advanced rectal cancer (LARC) need adjuvant chemotherapy?</em> — ASN Events
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  3. Do patients achieving pathological complete response (pCR) following neoadjuvant treatment for locally advanced rectal cancer (LARC) need adjuvant chemotherapy?

Do patients achieving pathological complete response (pCR) following neoadjuvant treatment for locally advanced rectal cancer (LARC) need adjuvant chemotherapy? (#3)

Anis Hamid 1 , Jeremy Shapiro 1 2 , Paul McMurrick 2 , Ian Porter 1 2 , Peter Carne 1 2 , Andrew Haydon 1 2
  1. Alfred Health, Richmond, VIC, Australia
  2. Cabrini Health, Malvern, VIC, Australia

Background: Optimal treatment for LARC includes neoadjuvant “short-course” radiotherapy or long-course chemo-radiotherapy. While a recent Australian phase III trial has reported similar outcomes for both approaches1, one advantage of long course chemo-radiotherapy is the potential for tumour downstaging to complete pathological response in 10-15% of patients, a sub-group with an excellent long term prognosis2,3. Uncertainty exists regarding the need for post-operative chemotherapy in such patients with ypT0N0 rectal cancer2,3.

Aim: To review the treatment given and outcomes (RFS, OS) of all consecutive patients achieving a pathological complete response following neoadjuvant treatment for locally advanced rectal cancer.

Method: All patients undergoing neoadjuvant radiotherapy or chemoradiotherapy for locally advanced rectal cancer at 2 centres including public and private patients between 1999 and 2012 were identified using hospital databases, and their histopathology reports of their resection specimens were reviewed to identify patients achieving pathological complete response. The medical records of these cases were then reviewed and data collected on initial stage, pre-operative treatment, administration of adjuvant chemotherapy, local and distant recurrences as well as overall survival.

Results: Approximately 15% of 375 consecutive patients undergoing curative intent rectal cancer surgery were identified as having a pathological complete response (ypT0N0). The use of post-operative chemotherapy, local recurrence rates and Disease-free and Overall Survival rates will be presented at the meeting.

  1. Ngan et al. Randomized trial of short-course radiotherapy versus long-course chemoradiation comparing rates of local recurrence in patients with T3 rectal cancer: Trans-Tasman Radiation Oncology Group trial 01.04. J Clin Oncol. 2012 Nov 1;30(31):3827-33
  2. Nelson and Benson. Pathological complete response after neoadjuvant therapy for rectal cancer and the role of adjuvant therapy. Curr Oncol Rep. 2013 Apr;15(2):152-61
  3. Zorcolo et al. Complete pathologic response after combined modality treatment for rectal cancer and long-term survival: a meta-analysis. Ann Surg Oncol. 2012 Sep;19(9):2822-32