Pashtoon Kasi, M.D. M.S.

Pashtoon Kasi, M.D., is a gastrointestinal cancer specialist considered one of the nation’s leading experts in the genomics of cancer and the development of personalized therapies. He sees GI cancer patients at City of Hope's Orange County Lennar Foundation Cancer Center in Irvine, CA.

Inspired by his physician parents, Dr. Kasi gravitated toward oncology because he was intrigued by novel therapies that made a difference in patient outcomes and the promise he saw in future discoveries. 

Dr. Kasi is known for his work on the “NEST” clinical trial which determined that a combination of immunotherapy drugs called botensilimab and balstilimab were effective in markedly killing colorectal cancer when given before surgery (neoadjuvant), thereby allowing the body to fight the tumors “roots up.” This potentially offers new hope for cure for patients with this and other cancers. Additionally, he is highly regarded for his investigation of liquid biopsies, frequently collaborating with international researchers and industries.

Dr. Kasi’s patients on the East Coast ultimately led him to City of Hope^®. “Through them, I learned there was a tangible difference in the options City of Hope provided, and that patients were eager to experience this care,” he said.

Prior to City of Hope, Dr. Kasi was director of colon cancer and precision medicine research at Weill Cornell Medicine, where he led investigators studying liquid biopsies and their applications in diagnosing and treating colorectal and other cancers. He was also an associate professor at University of Iowa and an assistant professor at Mayo Clinic.

Dr. Kasi served a surgical internship at University of Texas Health Science Center and joined the International Scholars Program at the University of Pittsburgh for his residency. He also completed fellowships in oncology and hematology at Mayo Clinic and also a postdoctoral masters in clinical and translational research at Mayo.

In 2024, Dr. Kasi received OncoDaily’s Yvonne Award in Challenging the Status Quo, which recognizes individuals who have exhibited remarkable courage and innovation in oncology. At Mayo, he received the Tow Tan Humanism in Medicine Award, as well as the Hematology/Oncology Outstanding Achievement Award during his fellowship.

A parent of two young children, Dr. Kasi tries to find time for patient advocacy. He speaks Pashto and Urdu/Hindi.

• Ambrosini M, Rousseau B, Manca P, Artz O, Marabelle A, André T, Maddalena G, Mazzoli G, Intini R, Cohen R, Cercek A, Segal NH, Saltz L, Varghese AM, Yaeger R, Nusrat M, Goldberg Z, Ku GY, El Dika I, Margalit O, Grinshpun A, Kasi PM, Schilsky R, Lutfi A, Shacham-Shmueli E, Khan Afghan M, Weiss L, Westphalen CB, Conca V, Decker B, Randon G, Elez E, Fakih M, Schrock AB, Cremolini C, Jayachandran P, Overman MJ, Lonardi S, Pietrantonio F. Immune checkpoint inhibitors for POLE or POLD1 proofreading-deficient metastatic colorectal cancer. Ann Oncol. 2024 May 3:S0923-7534(24)00104-2.
  doi: 10.1016/j.annonc.2024.03.009. Epub ahead of print. PMID: 38777726.
• Pant S, Wainberg ZA, Weekes CD, Furqan M, Kasi PM, Devoe CE, Leal AD, Chung V, Basturk O, VanWyk H, Tavares AM, Seenappa LM, Perry JR, Kheoh T, McNeil LK, Welkowsky E, DeMuth PC, Haqq CM, O'Reilly EM. Lymph-node-targeted, mKRAS-specific amphiphile vaccine in pancreatic and colorectal cancer: the phase 1 AMPLIFY-201 trial. Nat Med. 2024 Feb;30(2):531-542.
  doi: 10.1038/s41591-023-02760-3. Epub 2024 Jan 9. PMID: 38195752; PMCID: PMC10878978.
• Lucas AP, Lewis AR, Kasi PM, Toskich BB, Paz-Fumagalli R. Abscopal downstaging of intermediate stage hepatocellular via combination cryoablation and immunotherapy with complete pathologic response. Radiol Case Rep. 2023 Dec 16;19(3):910-914. 
  doi: 10.1016/j.radcr.2023.11.062. PMID: 38188944; PMCID: PMC10770505.
• Kasi PM, Lee JK, Pasquina LW, Decker B, Vanden Borre P, Pavlick DC, Allen JM, Parachoniak C, Quintanilha JCF, Graf RP, Schrock AB, Oxnard GR, Lovly CM, Tukachinsky H, Subbiah V. Circulating Tumor DNA Enables Sensitive Detection of Actionable Gene Fusions and Rearrangements Across Cancer Types. Clin Cancer Res. 2024 Feb 16;30(4):836-848.
  doi: 10.1158/1078-0432.CCR-23-2693. PMID: 38060240; PMCID: PMC10870120.
• Lutfi A, Afghan MK, Swed B, Kasi PM. False-Positive Liquid Biopsy Assays Secondary to Overlapping Aberrant Methylation from Non-Cancer Disease States. Case Rep Oncol. 2023 Dec 5;16(1):1536-1541.
  doi: 10.1159/000535174. PMID:38058505; PMCID: PMC10697744.
• Kasi PM. Editorial: Case reports in gastrointestinal cancers : 2022. Front Oncol. 2023 Nov 16;13:1333174. doi: 10.3389/fonc.2023.1333174. PMID: 38044997; PMCID: PMC10690600.
• Malkawi W, Lutfi A, Afghan MK, Shah LM, Costandy L, Ramirez AB, George TC, Toor F, Salem AK, Kasi PM. Circulating tumour cell enumeration, biomarker analyses, and kinetics in patients with colorectal cancer and other GI malignancies. Front Oncol. 2023 Nov 17;13:1305181.
  doi: 10.3389/fonc.2023.1305181. PMID: 38044994; PMCID: PMC10693413.
• Kasi PM, Afable MG, Herting C, Lukanowski M, Jin Z. Anti-EGFR Antibodies in the Management of Advanced Colorectal Cancer. Oncologist. 2023 Dec 11;28(12):1034-1048
  . doi: 10.1093/oncolo/oyad262. PMID: 37774394; PMCID: PMC11025386.
• Kasi PM, Bucheit LA, Liao J, Starr J, Barata P, Klempner SJ, Gandara D, Shergill A, Madeira da Silva L, Weipert C, Zhang N, Pretz C, Hardin A, Kiedrowski LA, Odegaard JI. Pan-Cancer Prevalence of Microsatellite Instability-High (MSI-H) Identified by Circulating Tumor DNA and Associated Real-World Clinical Outcomes. JCO Precis Oncol. 2023 Sep;7:e2300118.
  doi: 10.1200/PO.23.00118. PMID: 37769226.
• Kasi PM, Hidalgo M, Jafari MD, Yeo H, Lowenfeld L, Khan U, Nguyen ATH, Siolas D, Swed B, Hyun J, Khan S, Wood M, Samstein B, Rocca JP, Ocean AJ, Popa EC, Hunt DH, Uppal NP, Garrett KA, Pigazzi A, Zhou XK, Shah MA, Hissong E. Neoadjuvant botensilimab plus balstilimab response pattern in locally advanced mismatch repair proficient colorectal cancer. Oncogene. 2023 Oct;42(44):3252-3259.
  doi: 10.1038/s41388-023-02835-y. Epub 2023 Sep 21. PMID: 37731056; PMCID: PMC10611560.