Current Colorectal Cancer Reports

In patients with unresectable colorectal liver metastases (CRLM), radiofrequency ablation (RFA) might be a good alternative, whenever possible. In contrast to systemic therapy, the aim of RFA is to achieve complete local tumor control in an attempt to provide long-term survival. In this article we discuss the available evidence regarding the treatment of patients with unresectable CRLM, focusing on RFA in conjunction with modern systemic therapies. We observed that the available evidence in the existing literature is limited, and often consists of level 2 and 3 evidence, thereby hampering any firm conclusions. Nonetheless, RFA seems superior to chemotherapy alone in patients with liver-only disease amenable for RFA. However, the combination of RFA and chemotherapy has been demonstrated to be feasible and safe, lending support to the concept of RFA followed by chemotherapy, in order to reduce local recurrence rates and prolong survival.

Colorectal cancer is a major cause of morbidity and mortality across the world. Although surgery alone is very effective for patients with early stage disease, patients with more advanced disease required a combined modality approach. Standard doses of radiation therapy are usually ineffective in controlling localized disease that cannot be widely resected. Radiation dose escalation with intraoperative radiation therapy (IORT) has been investigated for many years as a component of a trimodality strategy in patients at high risk for local recurrence. This paper reviews the evidence supporting inclusion of IORT in addition to external beam radiation, surgery, and chemotherapy in patients with very locally advanced primary rectal cancer and patients with locally advanced recurrent rectal cancer.

Screening for colorectal cancer by full colon imaging has major advantages for detection of precancerous polyps. Colonoscopy is not feasible in all settings and is undesirable in some because of its cost, risk, need for sedation, and limited capacity. The Aer-O-Scope (GI View Ltd.; Ramat Gan, Israel) is a self-propelled, diagnosis-only colonoscope. Its propulsion system utilizes two balloons, one inflated and fixed in position in the rectum and a second, mobile balloon with a capsule endoscope fixed to the advancing end and a supply cable trailing from the opposite end. Gas insufflated between the balloons advances the mobile balloon. Propulsion has proven effective in pig and human colons in small studies. The imaging capsule has a forward viewing lens with a 90° angle of view and an “Omni” lens with 360° circumferential vision, including 25° of both forward vision and retrovision. The imaging system has proven effective in both in vivo and in vitro porcine models.

Personalized medicine appears to be the inevitable consequence of improvements in our understanding of the mechanisms of action of chemotherapeutic agents, as well as the description of the human genome and its impact on our understanding of the genes involved in DNA repair and drug metabolism. These rapid developments have been associated with the first efforts to establish genetic predictors of chemotherapy efficacy and toxicity for the chemotherapy drugs active in colorectal cancer—fluorouracil, irinotecan, and oxaliplatin.

Liver metastases are the most common manifestation of metastatic disease in colorectal cancer, and synchronous metastases occur in around 50% of patients. In rectal cancer, this presentation is uniquely challenging because of issues related to competing treatments and sequencing of therapy. Though there is published data on the management of rectal tumor and liver metastasis from colorectal cancer (CRC) individually, data on the management of synchronous disease is sparse. This is a heterogeneous group of patients and should be managed on a case by case basis and with multidisciplinary evaluation. To this end, we present four cases that highlight several of the issues associated with the management presenting with resectable synchronous liver metastasis from rectal cancer.

In Japan, adjuvant chemotherapy for colon cancer was mainly developed using oral fluoropyrimidines. However, all Japanese studies to date have failed to demonstrate a statistically significant survival benefit of adjuvant chemotherapy with a combination of uracil and tegafur (UFT) monotherapy over surgery alone in patients with stage II or III colon cancer. The non-inferiority trials comparing different oral fluoropyrimidine monotherapies showed any fluoropyrimidine except S-1 was comparable in patients with stage III colon cancer. Japanese guideline plays an important role in the distribution of the optimal adjuvant treatment. In addition, the tolerability of oxaliplatin-based adjuvant chemotherapy was confirmed, and a multigene assay was validated in Japanese patients. A global collaboration is ongoing to test whether disease-free survival with 3 months of oxaliplatin-based adjuvant chemotherapy was non-inferior to that with 6 months of identical chemotherapy in patients with stage III or high-risk stage II colon cancer and is one of the best model task forces for the coordination of future adjuvant chemotherapy regimens in patients with colon cancer. These findings and further research will help define treatment duration and patient selection criteria for the personalization of adjuvant chemotherapy for colon cancer.

Approximately 20 % of patients diagnosed with colorectal cancer present with metastatic disease at the time of diagnosis, predominantly to the liver. Surgical resection is the only real chance at a cure for a majority of these patients. A subset of patients present with unresectable disease with systemic and local therapy as the only available options. The advent of irinotecan- and oxaliplatin-based systemic therapy has increased median survival from about 5 months to greater than 20 months in metastatic disease. Addition of local therapy has the potential to further improve outcomes. With many avenues of regional therapy available, radioembolization with Yttrium-90 tagged microspheres offers a selective, targeted, and well-tolerated option. In this paper, we discuss the current evidence for radioembolization use as first-line adjunctive therapy and as salvage therapy. Based on current evidence, there appears to be an increase in liver-specific progression-free survival and an increase in overall survival when used as salvage therapy. Considerations for use in downstaging to resectable disease still need further investigation.