Slow accrual

This research trial studies the gut microbiome in fecal samples from patients with cancer that has spread to other parts of the body who are undergoing chemotherapy or immunotherapy. Studying samples of feces from patients with metastatic cancer in the laboratory may help doctors learn if the make-up of the gut microbiome has a positive or negative influence to a patient's response to chemotherapy or immunotherapy.

PRIMARY OBJECTIVES:

I. To quantitatively determine the composition of the microflora and their gene and protein expression levels in patients with metastatic colorectal cancer being treated with fluorouracil (5-FU) based chemotherapy, or anti-PD1 immunotherapy.

SECONDARY OBJECTIVES:

I. Compare the changes in species composition and in the metabolic activities (as determined in the primary objective) with response to chemotherapy or immunotherapy.

II. Compare the changes in species composition and in the metabolic activities (as determined in the primary objective) with toxicities and side effects resulting with chemotherapy or immunotherapy.

OUTLINE:

Patients undergo collection of fecal specimens at baseline, prior to start of each course of chemotherapy or immunotherapy, at the end of weeks 2, 4, 6, and 8, at the end of course 3 and courses thereafter of chemotherapy or immunotherapy, and at the time of disease progression or going off-treatment. Fecal specimens are analyzed via 16S ribosomal ribonucleic acid (RNA) gene sequencing, meta-transcriptomics analysis, and meta-proteomics analysis.

Inclusion Criteria:

• Must be willing and able to provide fecal samples according to protocol schedule
• COHORT A
• Diagnosis of metastatic colorectal cancer, where the metastatic disease has not been previously treated
• Scheduled to begin fluorouracil/leucovorin calcium/oxaliplatin (FOLFOX) or folinic acid-fluorouracil-irinotecan (FOLFIRI) based chemotherapy for the advanced disease
• Must have radiologic evidence of disease
• COHORT B
• Diagnosis of metastatic cancer
• Scheduled to begin pembrolizumab or another anti-PD-1 or anti-PD-L1 antibody as single agent therapy for the treatment of the advanced disease
• Must have physical or radiologic evidence of disease

Exclusion Criteria:

• Patients with a colostomy or any other issues that may prevent the standard methods for collection of stool are not eligible for this study
• Patients are not enrolled or a research protocol for treatment

Cohort A: Patients with metastatic colorectal cancer who will begin a FOLFOX or FOLFIRI based treatment regimen as the 1st treatment for the metastatic disease.

Cohort B: Patients with metastatic cancer who will begin Pembrolizumab (or another anti-PD-1 or anti-PD-L1 antibody) as single agent treatment for the metastatic disease.