There was no difference between the continuously treated patients (arm A) and the intermittently treated patients (arm C). Median survival in the intent-to-treat population (n = 815 in both groups) was 15.8 months (IQR, 9.4-26.1) in arm A and 14.4 months (IQR, 8.0-24.7) in arm C (HR, 1.084; 80% CI, 1.008-1.165). In the per-protocol population, which included only those patients who were free from progression at 12 weeks and randomly assigned to continue treatment or go on a chemotherapy holiday (arm A, n = 467; arm C, n = 511), median survival was 19.6 months (IQR, 13.0-28.1) in arm A and 18.0 months (IQR, 12.1-29.3) in arm C (HR, 1.087, 95% CI, 0.986-1.198). The upper limits of CIs for HRs in both analyses were greater than the predeﬁned noninferiority boundary. While intermittent chemotherapy was not deemed noninferior, there appeared to be clinically insignificant differences in patient outcomes.
Approximately 15% to 25% of colorectal cancer patients will present with liver metastases at diagnosis, and another 25% to 50% will develop metachronous hepatic metastasis following resection of the primary tumor.[66,67,68] Although only a small proportion of patients with liver metastasis are candidates for surgical resection, advances in tumor ablation techniques and in both regional and systemic chemotherapy provide a number of treatment options.
Hepatic metastasis may be considered to be resectable based on the following:[17,21,24,25,26,27]
- Limited number of lesions.
- Intrahepatic locations of lesions.
- Lack of major vascular involvement.
- Absent or limited extrahepatic disease.
- Sufficient functional hepatic reserve.
For patients with hepatic metastasis considered to be resectable, a negative-margin resection has resulted in 5-year survival rates of 25% to 40% in mostly nonrandomized studies, such as the NCCTG-934653 trial.[17,21,24,25,26,27] Improved surgical techniques and advances in preoperative imaging have allowed for better patient selection for resection.
Patients with hepatic metastases that are deemed unresectable will occasionally become candidates for resection if they have a good response to chemotherapy. These patients have 5-year survival rates similar to patients who initially had resectable disease. Radiofrequency ablation has emerged as a safe technique (2% major morbidity and <1% mortality rate) that may provide long-term tumor control.[69,70,71,72,73,74,75] Radiofrequency ablation and cryosurgical ablation remain options for patients with tumors that cannot be resected and for patients who are not candidates for liver resection.[76,77,78]