Importance: Surgical resection is standard treatment for patients with colorectal cancer (CRC) liver metastases (LM). Limited data describe practice and outcomes among elderly patients.
Objective: To describe management and outcomes of surgical resection of CRC LM in elderly patients in routine practice.
Design, setting, and participants: Population-based retrospective cohort study of routine clinical practices in the Canadian province of Ontario. All cases of CRC in Ontario who underwent resection of LM between January 1, 2002, and December 31, 2009, were identified using the population-based Ontario Cancer Registry and included in this study. Complete information about vital status in the Ontario Cancer Registry was available up to December 31, 2012; cause of death was available up to December 31, 2010. Final study analyses were performed March 13, 2015. Surgical resections of CRC LM were identified from hospital admission records. Pathology reports provided details regarding extent of disease and surgical procedure. Patients were classified into 3 age groups: younger than 65 years, 65 to 74 years, and 75 years or older. We describe volume of resected CRC LM as a ratio of incident cases per CRC LM resection. Use of perioperative chemotherapy was identified through linked electronic treatment and physician billing records. Preoperative and postoperative chemotherapy was defined as chemotherapy given within 16 weeks of surgery.
Main outcomes and measures: Overall survival and cancer-specific survival measured from time of LM resection.
Results: We identified 1310 patients: 710 (54%) younger than 65 years; 414 (32%) 65 to 74 years; and 186 (14%) 75 years or older. Case volumes of CRC LM resection varied substantially across age groups. For patients younger than 65 years, there was 1 resection per 26 incident cases; 65 to 74 years, 1 per 38; and 75 years or older, 1 per 101 (P<.001). Patients less than 65 years of age had a mean of 2.3 lesions; 65 to 74 years, 2.0; and 75 years or older, 1.6 (P<.001). For patients younger than 65 years, mean size of the largest lesion was 4.0 cm; patients 65 to 74 years, 4.4 cm; and 75 years or older, 4.5 cm (P=.04). The likelihood patients younger than 65 years were to undergo a major liver resection of more than 3 segments was 65%; 65 to 74 years, 65%; and 75 years or older, 42% (P=.04). The percentage of patients younger than 65 years who underwent perioperative chemotherapy was 71% (501 of 710); 65 to 74 years, 57% (237 of 414); and 75 years or older, 41% (77 of 186) (P<.001). The incidence of 90-day mortality for patients younger than 65 years was 2% (11 of 710); 65 to 74 years, 5% (20 of 414); and 75 years or older, 8% (14 of 186) (P<.001). Cancer-specific survival at 5 years for patients younger than 65 years of age was 49%; 65 to 74 years, 47%; and 75 years or older, 35% (P<.001). Overall survival for patients younger than 65 years was 49%; 65 to 74 years, 44%; and 75 years or older, 28% (P<.001).
Conclusions and relevance: Resection of CRC LM is associated with greater risk of postoperative mortality among elderly patients despite less aggressive treatment. Although the long-term outcomes are inferior to younger patients, a substantial proportion of elderly patients will have long-term survival.