Pembrolizumab for Colorectal Cancer: 11 Real Stories

11 stories match colorectal cancer and pembrolizumab. 10 of them mention surgery.

Cancer Stories

JJ, who was diagnosed with Stage IV Colorectal CancerColorectal Cancer

Stage IV MSI-High Colorectal Cancer: JJ's Patient Story

Patient Info: JJ, Male, Under 40 | Stage IV

Biomarkers: Lynch syndrome; microsatellite instability

Metastatic Site: Abdominal wall; lymph nodes throughout the body

At the latest scan, the main abdominal tumor remained stable. JJ had completed 126 rounds of chemo-immunotherapy and continued treatment every 3 weeks; small lung nodules were being watched but were not confirmed as metastases.

The Patient Story
OutcomeStable Disease / Ongoing Therapy
A patient, who was diagnosed with Stage IV Colorectal AdenocarcinomaColorectal Cancer

Stage IV MSI-H KRAS-mutant colorectal adenocarcinoma: severe pembrolizumab-associated hypercalcemia resolved with steroids and zoledronic acid

Patient Info: Anonymized, Female, 70+ | Stage IV

Biomarkers: KRAS G12xa mutation; MSI-H; BRAF wild type; NRAS wild type; PTH low-normal

Metastatic Site: liver

After the second pembrolizumab dose, severe hypercalcemia and electrolyte abnormalities resolved with high-dose glucocorticoids, zoledronic acid, and supportive care; cancer response was not yet described.

PubMed Central
OutcomeCare Ongoing
Tommy, who was diagnosed with Stage III Colorectal CancerColorectal Cancer

Stage III MSI-High Colorectal Cancer: Tommy's Survivor Story

Patient Info: Tommy Allen, Male, 50s | Stage III

Biomarkers: MSI-high; Lynch syndrome

As of November 2025, Tommy was cancer-free 5 years after pembrolizumab, ileostomy, Whipple procedure, partial colectomy, and ileostomy closure for Stage III MSI-high colon cancer with Lynch syndrome.

MD Anderson
OutcomeCancer-Free / NED
A patient, who was diagnosed with Stage III Colorectal AdenocarcinomaColorectal Cancer

Stage III MSI-H/dMMR ascending colon cancer: complete response to pembrolizumab without surgery

Patient Info: Anonymized, Female, 70+ | Stage III

Biomarkers: dMMR/MSI-H with high TMB, BRAF, BRCA2 mutation, KRAS/NRAS wild-type, HER2-negative, PD-L1-negative; Lynch testing negative.

After 10 months of pembrolizumab, PET/CT showed complete metabolic response and colonoscopy biopsies were negative for malignancy; she continued nonoperative management after declining surgery.

PubMed Central
OutcomeCancer-Free / NED
Nick, who was diagnosed with Stage IV Colorectal AdenocarcinomaColorectal Cancer

Stage IV Colorectal Adenocarcinoma: Nick's Patient Story

Patient Info: Nick Sprague, Male, 40s | Stage IV

Metastatic Site: distant lymph nodes in abdomen/near aorta and left…

As of July 2024, Nick was living with Stage IVA colon cancer and receiving Keytruda/pembrolizumab with fewer side effects than chemotherapy; no NED status had been reached.

The Patient Story
OutcomeLiving With Cancer
A patient, who was diagnosed with Colorectal AdenocarcinomaColorectal Cancer

Colorectal cancer: using a blood test (ctDNA) to guide immunotherapy after surgery — Case 1

Patient Info: Anonymized, Male, 50s

Biomarkers: KRAS ; TMB 11 mutations/Mb; loss of MLH1 and PMS2; dMMR/MSI-H; germline multigene panel negative; ctDNA positive after surgery and chemotherapy

Pembrolizumab cleared ctDNA within about 3 months. After completing 1 year of immunotherapy, surveillance CT showed no evidence of disease and ctDNA remained negative.

PubMed Central
OutcomeCancer-Free / NED
A patient, who was diagnosed with Colorectal AdenocarcinomaColorectal Cancer

Colorectal cancer: using a blood test (ctDNA) to guide immunotherapy after surgery

Patient Info: Anonymized, Male, 40s

Biomarkers: dMMR/MSI-H; pathogenic germline MLH1 c.1459C>T consistent with Lynch syndrome; postoperative ctDNA rose during chemotherapy and became near-undetectable on pembrolizumab

He continued pembrolizumab with no evidence of disease on interval CT and near-undetectable ctDNA. Grade 1 thyroiditis was monitored without treatment interruption.

PubMed Central
OutcomeIn Treatment
Dania, who was diagnosed with Stage IV Colorectal CancerColorectal Cancer

Stage IV Colorectal Cancer: Dania's Patient Story

Patient Info: Dania, Female, Under 40 | Stage IV

Biomarkers: Not reported; pathology supported Keytruda eligibility

Metastatic Site: Liver; peritoneum

As of December 2023, Dania had Stage IV colon cancer but described an excellent response to Keytruda, successful colon/hernia surgery, and successful liver surgery while still healing and continuing follow-up.

The Patient Story
OutcomeResponding Well
JJ, who was diagnosed with Stage IV Colorectal CancerColorectal Cancer

Stage IV Colorectal Cancer: JJ's Patient Story

Patient Info: JJ, Male, Under 40 | Stage IV

Biomarkers: Microsatellite-mutated disease mentioned in clinical-trial context; exact MSI/MMR result not otherwise specified

Metastatic Site: Abdominal wall; lymph nodes; stomach/intestinal outlet…

As of January 2023, JJ was living with incurable Stage IV colon cancer on pembrolizumab/Keytruda clinical-trial infusions every 3 weeks; the trial had kept the abdominal tumor mass from spreading and had helped him live beyond the prognosis he feared, but it was not described as curative.

The Patient Story
OutcomeResponding Well
A patient, who was diagnosed with Stage III Colorectal CancerColorectal Cancer

Colon Cancer With an MLH1 Deletion and Lynch Syndrome

Patient Info: Anonymized, Male, Under 40 | Stage III

Biomarkers: dMMR with loss of MLH1 and PMS2. Familial MLH1 c.1057_1060delGCTG frameshift deletion identified; its clinical significance had not previously been reported.

The colon cancer progressed rapidly despite postoperative and second-line therapy, and he died from multiple organ failure one week after pembrolizumab was started.

PubMed Central
OutcomeIn Memory