Treatment options for advanced non-small-cell lung cancer (NSCLC) after osimertinib failure are limited, and osimertinib continuation is recommended for selected patients. Metronomic oral vinorelbine is an effective treatment with less toxicity for advanced NSCLC.
The objective of the study was to investigate the effects of osimertinib plus metronomic oral vinorelbine on epidermal growth factor receptor (EGFR)-mutant advanced NSCLC beyond limited progression on osimertinib.
We have reviewed the medical records of 28 patients with EGFR-mutant advanced NSCLC who had received osimertinib continuation plus metronomic oral vinorelbine beyond limited progression on osimertinib. We also evaluated the clinicopathological characteristics of enrolled patients, as well as the efficacy and toxicity of the treatment.
After a median follow-up period of 14.1 months, 57.1% (16/28) of cases showed NSCLC progression. The median progression-free survival (PFS) period under osimertinib plus metronomic oral vinorelbine was 9.4 months (95% confidence interval, 1.562-17.238 months), with a disease control rate of 89.3% and objective response rate of 17.9%. PFS did not differ between patients who had previously received osimertinib as first- (n = 16) and second-line (n = 12) therapy (median, 11.4 and 4.7 months, P = 0.391). In addition, the median PFS duration did not differ according to the efficacy (PFS2 ≥ 6 months vs. <6 months) of previous osimertinib monotherapy (median, 5.8 and 9.4 months, P = 0.677).
Osimertinib continuation in conjunction with metronomic oral vinorelbine may enable overcoming TKI resistance and prolong the survival of patients with EGFR-mutant advanced NSCLC beyond limited progression on osimertinib treatment.

BACKGROUND: 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.
METHODS: 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.
CONCLUSIONS: 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.