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

Patient Info: Cindy Mette, Female | Stage IV

Biomarkers: MSI-high

Cindy’s tumor responded to the experimental Werner helicase inhibitor, with falling CEA levels and radiologic response. The response was continuing in 2025 while she remained on the clinical trial.

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Stage III MSI-High Colorectal Adenocarcinoma: Briana's Survivor Story

Patient Info: Briana Ghbein, Under 40 | Stage III

Biomarkers: MSH2 mutation, dMMR/MSI-H

Postoperative pathology after her 2024 treatment showed no evidence of disease.

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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.

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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.

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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.

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Stage III dMMR transverse colon cancer: colectomy and adjuvant FOLFOX with no recurrence on CT

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

Biomarkers: Loss of MLH1 and PMS2; BRAF mutation; MMR-deficient colorectal cancer

After colectomy and initiation of planned adjuvant FOLFOX, surveillance abdominal CT showed no recurrence or metastasis.

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MSI-H locally advanced right colon cancer: pathologic complete response after oxaliplatin, capecitabine, and immunotherapy

Patient Info: Anonymized, Female, 60s

Biomarkers: MSI-H on tumor gene testing

After oxaliplatin, capecitabine, and sindilizumab conversion therapy followed by laparoscopic radical right hemicolectomy, postoperative pathology showed no viable tumor cells and tumor regression grade 0 complete response.

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Lynch syndrome bifocal colon cancer: complete pathological remission after sintilimab

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

Biomarkers: Lynch-associated colon cancer with MSI-H and KRAS/NRAS/BRAF wild type; tumor markers were low or near normal.

As of April 2025, pathology after proximal colectomy showed tumor regression grade 0 with complete pathological remission, and follow-up found no recurrence or metastasis.

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Metastatic MSI-H colon cancer reaches pathologic complete response after immunotherapy and bevacizumab

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

Biomarkers: KRAS, MSI-H

Metastatic Site: liver

The resected liver lesions showed pathologic complete response, and the last CT/MRI in November 2023 showed no recurrence or metastasis, more than 5 years after diagnosis.

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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.

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Sophie: Stage IV Colorectal Cancer

Patient Info: Sophie, Female | Stage IV

Biomarkers: BRAF mutation; MSI

Metastatic Site: Liver; lymph nodes; other torso lesions

As of August 2024, Sophie had been declared cancer-free after Stage IV BRAF-mutated/MSI bowel cancer responded to nivolumab/ipilimumab-based immunotherapy, with PET imaging and liver surgery biopsy showing no cancerous cells.

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Stage IV BRAF Colorectal Cancer: Sophie's Survivor Story

Patient Info: Sophie, Female | Stage IV

Biomarkers: BRAF-mutated; MSI / microsatellite instability

Metastatic Site: liver; lymph nodes including neck

As of June 2024, Sophie had been off treatment for nearly 3 years and described herself as currently cancer-free after surgery, chemotherapy, immunotherapy, and liver surgery showing no cancer cells.

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MSI-High Colorectal Cancer: Stephanie's Patient Story

Patient Info: Stephanie Dobson, Female, Under 40

Biomarkers: MSI-high; Lynch syndrome

The rectal tumor was shrinking on immunotherapy and early treatment-related fatigue was improving.

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Pembrolizumab produced a complete response in unresectable dMMR colon cancer

Patient Info: Anonymized, female, 70+

Biomarkers: dMMR/MSI-H; MLH1 loss; MSH2 loss; RAS/BRAF wild type; MLH1 promoter hypermethylation

Surgery found a pathological complete response with no residual cancer in the colon or 58 lymph nodes, and follow-up showed no relapse.

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Pembrolizumab enabled complete response and surgery for unresectable dMMR colon cancer

Patient Info: Anonymized, male, 60s

Biomarkers: dMMR/MSI-H; MLH1 loss; PMS2 loss; BRAF mutation; MLH1 promoter hypermethylation

The surgical specimen showed a pathological complete response with no residual cancer and 0 of 43 lymph nodes involved, and follow-up showed no relapse.

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Pembrolizumab and surgery for metastatic dMMR colorectal cancer with major response

Patient Info: Anonymized, female, 50s | Stage IV

Biomarkers: dMMR/MSI-H; MLH1 loss; PMS2 loss; BRAF/RAS wild type; RET::NCOA4 fusion; MLH1 promoter hypermethylation

Metastatic Site: non-regional lymph nodes

Surgery showed a major pathological response with less than 10% viable tumor. Pembrolizumab was restarted after surgery, and no relapse had been documented.

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Pembrolizumab led to complete response before surgery for metastatic dMMR colon cancer

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

Biomarkers: dMMR/MSI-H; MLH1 loss; PMS2 loss; BRAF mutation; heterozygous MUTYH p. pathogenic variant

Metastatic Site: liver

The 2023 liver resection showed a pathological complete response with no residual tumor, and he entered follow-up without additional therapy.

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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.

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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.

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Stage II MSI-High Colorectal Cancer: Shannon's Survivor Story

Patient Info: Shannon, Female, Under 40 | Stage II

Biomarkers: MSI-H; Lynch syndrome; MLH1 mutation

As of October 2023, Shannon had no recurrence described while approaching year 5 after Stage IIA colon cancer surgery and continued intensive Lynch syndrome surveillance.

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

Patient Info: Kelly, Female, Under 40 | Stage III

Biomarkers: dMMR; MSI-H

As of September 2023, Kelly remained in remission after 9 dostarlimab immunotherapy infusions for Stage III dMMR/MSI-H rectal cancer, avoiding the expected chemo/radiation/surgery pathway.

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A young man with metastatic rectal cancer and inherited BRCA1 and MLH1 mutations

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

Biomarkers: Germline BRCA1 c.4065_4068delTCAA and MLH1 c.232G>T mutations; tumor microsatellite instability-high; loss of MLH1 and PMS2 expression; elevated tumor mutational burden; loss of heterozygosity of wild-type MLH1.

Metastatic Site: liver

The rectal and liver tumors showed a partial response, no viable carcinoma was found in the resected liver lesions, and maintenance nivolumab continued without evidence of growth or recurrence.

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Cancer Survivor Story: Colon Cancer (Lynch Syndrome)

Patient Info: Shannon, Female, Under 40 | Stage II

Biomarkers: Lynch syndrome; MSI-high / dMMR

As of May 2020, Shannon was considered cancer-free after surgery-only treatment for Stage IIA MSI-high/Lynch-associated colon cancer and remained on strict Lynch syndrome surveillance.

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Cecal cancer revealing Muir-Torre syndrome with an MSH2 mutation

Patient Info: Anonymized, female

Biomarkers: MSI-high; loss of MSH2 expression; truncating MSH2 mutation

A woman with multiple sebaceous tumors and a strong family history of colorectal cancer was found to have MSI-high cecal cancer and an MSH2 mutation consistent with Muir-Torre syndrome.

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