Interventional radiological therapies in colorectal hepatic metastases

Several decades ago, colorectal cancer was infrequently diagnosed. Nowadays, it is the world's fourth most deadly cancer with almost 900 000 deaths annually. Besides an ageing population and dietary habits of high-income countries, unfavourable risk factors such as obesity, lack of physical exercise, and smoking increase the risk of colorectal cancer. Advancements in pathophysiological understanding have increased the array of treatment options for local and advanced disease leading to individual treatment plans. Treatments include endoscopic and surgical local excision, downstaging preoperative radiotherapy and systemic therapy, extensive surgery for locoregional and metastatic disease, local ablative therapies for metastases, and palliative chemotherapy, targeted therapy, and immunotherapy. Although these new treatment options have doubled overall survival for advanced disease to 3 years, survival is still best for those with non-metastasised disease. As the disease only becomes symptomatic at an advanced stage, worldwide organised screening programmes are being implemented, which aim to increase early detection and reduce morbidity and mortality from colorectal cancer.

Colorectal cancer (CRC) is one of the most common malignancies in the United States. Every 3 years, the American Cancer Society provides an update of CRC incidence, survival, and mortality rates and trends. Incidence data through 2013 were provided by the Surveillance, Epidemiology, and End Results program, the National Program of Cancer Registries, and the North American Association of Central Cancer Registries. Mortality data through 2014 were provided by the National Center for Health Statistics. CRC incidence rates are highest in Alaska Natives and blacks and lowest in Asian/Pacific Islanders, and they are 30% to 40% higher in men than in women. Recent temporal patterns are generally similar by race and sex, but differ by age. Between 2000 and 2013, incidence rates in adults aged ≥50 years declined by 32%, with the drop largest for distal tumors in people aged ≥65 years (incidence rate ratio [IRR], 0.50; 95% confidence interval [95% CI], 0.48-0.52) and smallest for rectal tumors in ages 50 to 64 years (male IRR, 0.91; 95% CI, 0.85-0.96; female IRR, 1.00; 95% CI, 0.93-1.08). Overall CRC incidence in individuals ages ≥50 years declined from 2009 to 2013 in every state except Arkansas, with the decrease exceeding 5% annually in 7 states; however, rectal tumor incidence in those ages 50 to 64 years was stable in most states. Among adults aged <50 years, CRC incidence rates increased by 22% from 2000 to 2013, driven solely by tumors in the distal colon (IRR, 1.24; 95% CI, 1.13-1.35) and rectum (IRR, 1.22; 95% CI, 1.13-1.31). Similar to incidence patterns, CRC death rates decreased by 34% among individuals aged ≥50 years during 2000 through 2014, but increased by 13% in those aged <50 years. Progress against CRC can be accelerated by increasing initiation of screening at age 50 years (average risk) or earlier (eg, family history of CRC/advanced adenomas) and eliminating disparities in high-quality treatment. In addition, research is needed to elucidate causes for increasing CRC in young adults. CA Cancer J Clin 2017. © 2017 American Cancer Society. CA Cancer J Clin 2017;67:177-193. © 2017 American Cancer Society.

To examine recurrence and survival rates for patients treated with hepatic resection only, radiofrequency ablation (RFA) plus resection or RFA only for colorectal liver metastases. Thermal destruction techniques, particularly RFA, have been rapidly accepted into surgical practice in the last 5 years. Long-term survival data following treatment of colorectal liver metastasis using RFA with or without hepatic resection are lacking. Data from 358 consecutive patients with colorectal liver metastases treated for cure with hepatic resection +/- RFA and 70 patients found at laparotomy to have liver-only disease but not to be candidates for potentially curative treatment were compared (1992-2002). Of 418 patients treated, 190 (45%) underwent resection only, 101 RFA + resection (24%), 57 RFA only (14%), and 70 laparotomy with biopsy only or arterial infusion pump placement ("chemotherapy only," 17%). RFA was used in operative candidates who could not undergo complete resection of disease. Overall recurrence was most common after RFA (84% vs. 64% RFA + resection vs. 52% resection only, P < 0.001). Liver-only recurrence after RFA was fourfold the rate after resection (44% vs. 11% of patients, P < 0.001), and true local recurrence was most common after RFA (9% of patients vs. 5% RFA + resection vs. 2% resection only, P = 0.02). Overall survival rate was highest after resection (58% at 5 years); 4-year survival after resection, RFA + resection and RFA only were 65%, 36%, and 22%, respectively (P < 0.0001). Survival for "unresectable" patients treated with RFA + resection or RFA only was greater than chemotherapy only (P = 0.0017). Hepatic resection is the treatment of choice for colorectal liver metastases. RFA alone or in combination with resection for unresectable patients does not provide survival comparable to resection, and provides survival only slightly superior to nonsurgical treatment.