Beyond the Knife: The Evolving Nonsurgical Management of Oligometastatic Colorectal Cancer

Management of Oligometastatic Colorectal Cancer

The management of oligometastatic colorectal cancer differs from the treatment of metastatic colorectal cancer, and it is essential that those who treat oligometastatic disease be familiar with the treatment options for these patients. Although definitive treatment is often surgical, there are situations where local therapies such as SBRT or ablative techniques may better serve the patient. Adjuvant therapy should be provided to all patients, and neoadjuvant chemotherapy should be considered as well. The role of immunotherapy is currently limited due to the lack of clinical trials in this area.

Proton Beam Therapy in the Oligometastatic/Oligorecurrent Setting: Is There a Role? A Literature Review

BACKGROUND

Stereotactic ablative radiotherapy (SABR) and stereotactic radiosurgery (SRS) with conventional photon radiotherapy (XRT) are well-established treatment options for selected patients with oligometastatic/oligorecurrent disease. The use of PBT for SABR-SRS is attractive given the property of a lack of exit dose. The aim of this review is to evaluate the role and current utilisation of PBT in the oligometastatic/oligorecurrent setting.

METHODS

Using Medline and Embase, a comprehensive literature review was conducted following the PICO (Patients, Intervention, Comparison, and Outcomes) criteria, which returned 83 records. After screening, 16 records were deemed to be relevant and included in the review.

RESULTS

Six of the sixteen records analysed originated in Japan, six in the USA, and four in Europe. The focus was oligometastatic disease in 12, oligorecurrence in 3, and both in 1. Most of the studies analysed (12/16) were retrospective cohorts or case reports, two were phase II clinical trials, one was a literature review, and one study discussed the pros and cons of PBT in these settings. The studies presented in this review included a total of 925 patients. The metastatic sites analysed in these articles were the liver (4/16), lungs (3/16), thoracic lymph nodes (2/16), bone (2/16), brain (1/16), pelvis (1/16), and various sites in 2/16.

CONCLUSIONS

PBT could represent an option for the treatment of oligometastatic/oligorecurrent disease in patients with a low metastatic burden. Nevertheless, due to its limited availability, PBT has traditionally been funded for selected tumour indications that are defined as curable. The availability of new systemic therapies has widened this definition. This, together with the exponential growth of PBT capacity worldwide, will potentially redefine its commissioning to include selected patients with oligometastatic/oligorecurrent disease. To date, PBT has been used with encouraging results for the treatment of liver metastases. However, PBT could be an option in those cases in which the reduced radiation exposure to normal tissues leads to a clinically significant reduction in treatment-related toxicities.

Beyond the scalpel - mortality after liver surgery in patients with liver metastases - time to rethink the indications

Comment to Filman et al., Mortality after liver surgery in Germany. Br J Surg, 2019.

Initial systemic chemotherapeutic and targeted therapy strategies for the treatment of colorectal cancer patients with liver metastases

Introduction: The liver is the most common metastatic site in colorectal cancer with more than half the patients developing a liver metastasis either at the time of their diagnosis (synchronous) or later (metachronous). Surgical resection remains the principal curative approach that offers significant survival improvements. However, upfront surgery is only possible in about 10-20% of patients at the time of diagnosis, making the consideration of other treatment modalities essential. Areas covered: In this review, the authors provide an overview of the standard approaches for the initial management of patients with colorectal cancer with liver metastases. They then provide an up-to-date discussion of first-line systemic chemotherapy/targeted therapy options in the contexts of initially resectable and unresectable disease and review toxicities and complications following these options. Expert opinion: Advances in chemotherapeutic agents and biological targeted therapies have improved the prognosis of colorectal cancer with liver metastases. However, there is still no 'single best approach', making further trials necessary to provide more evidence.