Article Abstract

Outcomes of rectal cancer with liver oligometastases

Authors: Lucas Resende Salgado, Howard Hsu, Kevin Du


Purpose: In patients with oligometastatic colorectal cancer to the liver, long term survival is possible and a multi-modality treatment approach may be considered. This is a report of a single institution experience of oligometastatic rectal cancer patients after treatment of the primary tumor and pelvic lymph nodes with extended course chemoradiation therapy.
Methods: Between 2004 and 2013, 26 oligometastatic rectal cancer patients with liver metastases were treated with extended course chemoradiation at our institution followed by total mesorectal excision (TME). Amongst these there were 17 men and 9 women. The mean age at the time of diagnosis was 59.8 years, with a range from 36 to 87 years of age. Eleven patients had metastases in other sites in addition to liver, and one patient in our cohort had lung metastasis with no liver metastasis. Kaplan-Meier method was used to generate overall survival (OS), progression free survival (PFS), distant metastases (DM) and local control (LC).
Results: OS rates were 95%, and 70% at 12 and 24 months respectively, with a mean survival time of 40.5 months. PFS rates were 91% and 36% at 12 and 24 months respectively, with a mean PFS time of 23.1 months. LC rates were 91% and 66% at 12 and 24 months respectively. DM rates were 0% and 61% at 12 and 24 months respectively. Finally, when censoring deaths, progression of liver metastases and distant progression, Kaplan-Meier analysis demonstrated five events of local failure.
Conclusions: This series demonstrated an OS of 70% at 24 months, with a mean survival of 40.5 months. Significantly, LC was only 66% despite the use of extended course chemoradiation and TME. This data suggests that many patients with oligometastatic rectal cancer will survive past 2 years, and that a substantial number will fail locally as well as distantly. Therefore, a multimodality approach is reasonable. Recent data suggests that a hypofractionated radiation regiment of 25 Gy in 5 Gy fractions allows an equivalent LC compared to extended course chemoradiation with 50.4 Gy in 1.8 Gy fractions. A short course of radiation may be more consistent with the goals of care of the oligometastatic rectal cancer patient who is at high risk of recurrence.