Chloe E. Atreya, MD, PhD, assistant clinical professor, Department of Medicine, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, discusses maintenance therapy for patients with colorectal cancer (CRC).

Although there is no standard of care maintenance therapy for patients with CRC, guidelines have suggested some strategies that may work in select patients. The NCCN guidelines highlight certain studies that have shown a progression-free survival benefit with maintenance strategies that include either fluorouracil (5-FU) or capecitabine with or without bevacizumab (Avastin).

Overall survival benefit was not significant with either the 5-FU or capecitabine maintenance regimens, Atreya says, so the jury is still out. Additionally, Atreya says that a new study has shown that bevacizumab alone is no better than observation. Maintenance therapy for patients with CRC remains a personalized decision, Atreya concludes.

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Chloe E. Atreya, MD, PhD, assistant clinical professor, Department of Medicine, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, discusses maintenance therapy for patients with colorectal cancer.

Dr. Atreya Discusses Maintenance Therapy for CRC

Chloe E. Atreya, MD, PhD, assistant clinical professor, Department of Medicine, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, discusses questions regarding sidedness in colorectal cancer (CRC).

Tumor sidedness is established as an independent prognostic factor that Atreya says will impact how patients with CRC are treated. Although there are known differences in the microbiome of the right and left side of the colon, the reason behind that is not yet understood. Atreya says that the microbiome is playing an increasingly important role in CRC research. According to the NCCN guidelines, EGFR-targeted antibodies are an option for patients who have left-sided 

 wild-type tumors, but are not recommended for use in those with 

-mutated or right-sided tumors in the first-line setting.

There is also research investigating the potential with cancer stem cells on the right and left side of the colon. Each side has different embryologic origins, and that may impact potential treatment, Atreya explains.

Chloe E. Atreya, MD, PhD, assistant clinical professor, Department of Medicine, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, discusses questions regarding sidedness in colorectal cancer.

Dr. Atreya on Questions Remaining With Tumor Sidedness in CRC

Chloe E. Atreya, MD, PhD, assistant clinical professor, Department of Medicine, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, discusses the molecular subgroups in metastatic colorectal cancer (mCRC) and viable treatment options for patients with microsatellite instability (MSI)-high and 

Subgroups include patients who have MSI-high and 

-mutated tumors. The CheckMate-142 study combined nivolumab (Opdivo) with or without ipilimumab (Yervoy). The combination in that study yielded a 55% overall response rate and 80% disease control rate.

-mutated tumors, the 2018 National Comprehensive Cancer Network (NCCN) guidelines now include the S1406 strategy. The study looked at the use of irinotecan plus cetuximab (Erbitux) and vemurafenib (Zelboraf) as a potential option for these patients in the second-line setting. Although it is not FDA approved, its inclusion in the NCCN guidelines will make it more available for patients with 

-mutated colon cancers to receive vemurafenib.

Chloe E. Atreya, MD, PhD, assistant clinical professor, Department of Medicine, University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, discusses the molecular subgroups in metastatic colorectal cancer (mCRC) and viable treatment options for patients with microsatellite instability (MSI)-high and BRAF-mutated cancers.

Chloe E. Atreya, MD, PhD

Articles

Dr. Atreya Discusses Maintenance Therapy for CRC

Dr. Atreya on Questions Remaining With Tumor Sidedness in CRC

Dr. Atreya on How the NCCN Guidelines Have Impacted Treatment Options in mCRC