Can we cure oligometastatic rectal adenocarcinoma with synchronous liver metastasis: a pre-operative short-course radiotherapy and induction chemotherapy regimen.


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Shagufta Mirza1,Kim Last2,Mark Teo3,Nathalie Casanova3,Rachel Cooper3,David Sebag-Montefiore3,Fei Sun3
1Leeds Teaching Hospital,Leeds, UK,2York Teaching Hospital,York,3Leeds Teaching Hospital, Leeds

Abstract

Background

The treatment dilemma of rectal cancers with synchronous liver oligometastases (SLOM) is whether to prioritize the primary tumour or systemic disease. There is potential risk for local or systemic progression during prolonged induction chemotherapy (ICT) or long course concurrent chemo-radiotherapy respectively. Since 2012, the Leeds Cancer Centre and surrounding cancer units have offered short course radiotherapy (SCRT) 25Gy in 5 fractions, followed by 12 weeks (6 cycles) of oxaliplatin-fluoropyrimidine ICT prior to surgery.

Method

Between January 2012 and March 2017, 41 rectal cancer patients with synchronous liver oligometastases (SLOM) were planned for SCRT and ICT. Intention-to-treat analysis was performed. Pelvic failure was defined as distant or pelvic progression during neoadjuvant treatment precluding surgery, or pelvic recurrence following curative surgery. Distant failure was defined as distant or pelvic progression during neoadjuvant treatment precluding metastatectomy, or distant recurrence following curative surgery.

Results

At diagnosis, 41/41 patients had threatened mesorectal fascia. 14/41 patients had borderline resectable or unresectable SLOM. All patients completed SCRT and 39/41 had ICT (median 6 cycles). Post treatment pelvic restaging: 33/41 patients had partial or complete responses of the primary tumour and 3/41 stable disease. 5/41 had no pelvic restaging due to systemic progression. Post-treatment liver restaging: 18/41 patients had partial or complete responses. 10/41 stable disease, and 10/41 progressive disease.3/41 had no liver restaging due to pelvic or systemic progression. 29/41 patients had primary tumour resections of which 16/41 then had liver metastatectomies.

Median follow-up was 37.2 months.  8/41 patients had no progression or recurrence. 3/41 pelvic failure only, 19/41 distant failure only and 11/41 both distant and pelvic failure. Seven patients with relapsed disease had salvage surgery. Median and 3-year overall survival were 27.4 months and 43.4 % respectively.

Conclusion

SCRT followed by ICT is a feasible strategy achieving reasonable cure rates for oligometastatic rectal adenocarcinoma.