Neoadjuvant imatinib treatment reduces tumor size and decreases metastasis risk as well as tumor-related deaths, compared to adjuvant imatinib treatment following surgery, in patients with localized rectal gastrointestinal stromal tumors (GIST). These are the findings of a new study published in the Journal of Surgical Oncology.
These findings are important because they provide new ideas about the treatment of GIST that might lead to better survival outcomes without the need to unnecessarily expand imatinib treatment.
Surgery is the main treatment for localized GIST, with adjuvant imatinib improving survival in high‐risk patients. However, there have not been many studies that compared the effect of imatinib treatment perioperatively or post-surgery.
Read more about GIST treatment
Here, a team of researchers from China aimed to compare the effectiveness of neoadjuvant imatinib treatment followed by surgery and adjuvant imatinib treatment to that of upfront surgery followed by adjuvant imatinib treatment in patients with localized rectal GIST.
To do so, they analyzed outcomes in 85 people with localized rectal GIST. Of those, 33 had upfront surgery plus or minus adjuvant imatinib and 52 had neoadjuvant imatinib plus surgery plus adjuvant imatinib.
The results showed that patients’ response rate to neoadjuvant imatinib was 65.9%.
Patients who received neoadjuvant therapy had better distant recurrence-free survival and disease-specific survival compared to those who underwent upfront surgery. More specifically, the 5-year recurrence-free survival was 97.8% in patients who received neoadjuvant imatinib therapy while it was 71.9% for those who had upfront surgery. Similarly, the 5-year disease-specific survival was 100% compared to 77.1% in patients receiving neoadjuvant imatinib and upfront surgery, respectively.
Finally, there was no significant difference in terms of overall survival between the 2 treatment groups but the 5-year overall survival was higher (97.8%) in patients who received neoadjuvant imatinib compared to those who had upfront surgery (71.9%).
“In patients with localized rectal GIST, neoadjuvant imatinib not only shrunk the tumor size but also decreased the risk of metastasis and tumor-related deaths when compared to upfront surgery and adjuvant imatinib alone,” the researchers concluded.
Ling JY, Ding MM, Yang ZF, et al. Comparison of outcomes between neoadjuvant imatinib and upfront surgery in patients with localized rectal GIST: An inverse probability of treatment weighting analysis. J Surg Oncol. Published online September 8, 2021. doi:10.1002/jso.26664