Published online Mar 24, 2023. doi: 10.5306/wjco.v14.i3.131
Peer-review started: September 21, 2022
First decision: November 14, 2022
Revised: November 27, 2022
Accepted: February 21, 2023
Article in press: February 21, 2023
Published online: March 24, 2023
Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal tumors of gastrointestinal tract. The most common sites of metastases are the liver and the peritoneum, whereas breast metastases from GIST are extremely rare. We present a second case of GIST breast metastasis.
We found a case of breast metastasis from rectum GIST. A 55-year-old female patient presented with rectum tumor with multiply liver lesions and metastasis in the right breast. Abdominal-perineal extirpation of rectum was performed, histology and immunohistochemistry study showed GIST, mixed type with CD117 and DOG-1 positive staining. The patient was taking imatinib 400 mg for 22 mo with stable disease. Because of growth of the breast metastasis the treatment was changed twice: The dose of imatinib was doubled with further progression in the breast lesion and then the patient was receiving sunitinib for 26 mo with partial response in the right breast and stable disease in the liver lesions. The breast lesion increased and right breast resection was done – surgery on local progression, the liver metastases were stable. Histology and immunohistochemistry studies revealed GIST metastasis, CD 117 and DOG 1 positive with KIT exon 11 mutation. After surgery the patient resumed imatinib. Until now the patient has been taking imatinib 400 mg for 19 mo without progression, last follow up was in November 2022.
GISTs breast metastases are extremely rare, we described the second case. At the same time second primary tumors have been reported frequently in patients diagnosed with GISTs and breast cancer is one of the most common second primary tumors in patients with GISTs. That is why it is very important to distinguish primary from metastatic breast lesions. Surgery on local progression made it possible to resume less toxic treatment.
Core Tip: We presented the second case of gastrointestinal stromal tumor (GIST) metastasis to the breast, which is a very extraordinary condition. The most common metastatic sites of GIST are the liver and the peritoneum and at the same time metastasis to the breast from extramammary carcinomas is extremely rare and in this clinical situation it is obligatory to exclude breast cancer. Our patient received two lines of treatment due to metastatic disease and had a local progression on imatinib and sunitinib therapy, growth only lesion in the breast, we removed increased metastasis (surgery on local progression), that allowed to return to less toxic treatment, the patient resumed imatinib until now.