Assessing Response to Imatinib in GIST

Video

In a seminal study that assessed the efficacy of imatinib in patients with gastrointestinal stromal tumor (GIST), those with tumors 3 centimeters or larger were randomized to receive placebo or imatinib. The study showed a significant improvement in recurrence-free survival with imatinib, says Syma Iqbal, MD. However, a large limitation of this study was that it did not take into account the mitotic rate of the tumor.

Another study evaluating imatinib enrolled patients with high-risk features at baseline, explains Anthony P. Conley, MD. These individuals had tumors greater than 10 centimeters, high mitotic rates, or tumor rupture. Results showed a greater survival benefit in the cohort that received 3 years of imatinib compared with those who received 1 year of imatinib. While these findings altered treatment approaches with respect to duration of therapy in patients with high-risk GIST, the optimal length of treatment remains unclear, says Iqbal. Some clinical trials have assessed the use of up to 5 years of imatinib in the adjuvant setting, adds Conley.

Patients who have undergone surgical resection of their GIST should be followed on a regular basis with physical examination and cross-sectional imaging with a CT scan of the abdomen and pelvis, if the tumor is located in the abdomen, and a CT scan of the chest for esophageal GIST, recommends Robert H. I. Andtbacka, MD. These scans should be performed every 3 to 6 months, as per National Comprehensive Cancer Network recommendations.

The scans may reveal solid tumors that have metastasized to the liver or those that have decreased in density and vascularity following surgical resection and adjuvant treatment, says Andtbacka. Individuals who have tumor recurrence typically undergo tumor biopsy to determine the mutational status of the malignancy.

Andtbacka and his colleagues often utilize immunohistochemical analysis and staining to test for c-KIT, DOG1, protein kinase C-theta, and platelet derived growth factor receptor, as well as mutations in exon 9, 11, 13, and 17. How patients respond to treatment depends on these mutations, comments Andtbacka.

Related Videos
In this fifth episode of OncChats: Leveraging Immunotherapy in GI Malignancies, Toufic Kachaamy, MD, of City of Hope, Sunil Sharma, MD, of City of Hope, and Madappa Kundranda, MD, PhD, of Banner MD Anderson Cancer Center, discuss next steps for research, including vaccination strategies, personalized cellular therapies, and more.
In this fourth episode of OncChats: Leveraging Immunotherapy in GI Malignancies, experts discuss research efforts being made with organoids to address existing questions with immunotherapy and the exploration of multimodality approaches to improve outcomes.
In this third episode of OncChats: Leveraging Immunotherapy in GI Malignancies, Toufic Kachaamy, MD, of City of Hope, Sunil Sharma, MD, of City of Hope, and Madappa Kundranda, MD, PhD, of Banner MD Anderson Cancer Center, discuss the potential benefits of utilizing immunotherapy approaches earlier on in the disease course.
In this second episode of OncChats: Leveraging Immunotherapy in GI Malignancies, Toufic Kachaamy, MD, of City of Hope, Sunil Sharma, MD, of City of Hope, and Madappa Kundranda, MD, PhD, of Banner MD Anderson Cancer Center, explain the challenges faced with preventing or detecting these cancers early and the understanding that is needed to develop effective early detection methods and move the needle forward.
In this first episode of OncChats: Leveraging Immunotherapy in GI Malignancies, Toufic Kachaamy, MD, of City of Hope, Sunil Sharma, MD, of City of Hope, and Madappa Kundranda, MD, PhD, of Banner MD Anderson Cancer Center, discuss the potential for early detection multiomic assays and the work that still needs to be done to encourage their widespread use.
Joachim G. J. V. Aerts, MD, PhD
Nathaniel Myall, MD
Martin Cannon, PhD, professor, Department of Microbiology, University of Arkansas for Medical Sciences College of Medicine
Pedro Barata, MD, MSc
In this fourth episode of OncChats: Examining LIFU–Aided Liquid Biopsy in Glioblastoma, Manmeet Singh Ahluwalia, MD, and Michael W. McDermott, MD, discuss the key objectives of the phase 3 LIMITLESS study (NCT05317858) examining low-intensity focused ultrasound with immunotherapy and chemotherapy in patients with lung cancer and brain metastases.
Related Content
Hesham Abdullah, MD

Dostarlimab/Chemo Receives FDA Priority Review for Expanded Indication in Endometrial Cancer

April 24th 2024
Article
Marvels in Medicine: Allison Talks Everything from Advances in Immunotherapy to Jamming With Willie Nelson

Marvels in Medicine: Allison Talks Everything from Advances in Immunotherapy to Jamming With Willie Nelson

November 22nd 2021
Podcast
Elizabeth Plimack, MD, MS, FASCO

Immunotherapy-Based Approaches Make Waves in Bladder Cancer

April 17th 2024
Article
Dietrich Details Data and Future Research With Immunotherapy in Stage III NSCLC

Dietrich Details Data and Future Research With Immunotherapy in Stage III NSCLC

September 20th 2021
Podcast
Matthew Galsky, MD

Adjuvant Nivolumab Provides Sustained DFS Benefit, Favors OS in Muscle-Invasive Urothelial Cancer

April 16th 2024
Article
Do-Youn Oh, MD, PhD, professor, Division of Medical Oncology, Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine

Durvalumab Plus Chemo Sustains 3-Year OS Benefit in Advanced Biliary Tract Cancer

April 16th 2024
Article