Mutations of EGFR or KRAS and expression of chemotherapy-related genes based on small biopsy samples in stage IIIB and IV inoperable non-small cell lung cancer

Characterization of distinct types of KRAS mutation and its impact on first-line platinum-based chemotherapy in Chinese patients with advanced non-small cell lung cancer

We performed this retrospective study to investigate whether the KRAS mutation status and its subtypes could predict the effect of first-line platinum-based chemotherapy in Chinese patients with non-small cell lung cancer (NSCLC). Patients received who had KRAS mutations were enrolled. Correlations between KRAS mutations, specific mutant subtypes and responses to chemotherapy were analyzed using Kaplan-Meier and Cox proportional hazard methods. A total of 2,183 cases who received KRAS mutation detection were included. A total of 218 of these cases were indicated to have KRAS mutations. KRAS mutations were identified more commonly in males compared with females (P=0.035). The most common subtypes were G12C, G12D and G12V. Among 73 KRAS mutant patients and 100 EGFR/ALK/KRAS wild-type patients with advanced NSCLC, KRAS-mutant NSCLC patients had a significantly shorter progression-free survival (P=0.007) compared with NSCLC patients with KRAS wild-type. In addition, there was a shorter but marginally statistically significant progression-free survival (PFS) in KRAS mutant patients with adenocarcinoma compared with those with non-adenocarcinoma (P=0.051). In the KRAS mutant group, patients with the KRAS G12V mutation had the poorest PFS compared with non-G12V mutant cases (P=0.045). In conclusion, KRAS mutation was a negative predictive factor of PFS in Chinese patients with advanced NSCLC who received first platinum-based chemotherapy. Patients with KRAS G12V mutations exhibited the poorest PFS compared with those with other KRAS mutant types.

Establishment of patient-derived tumor xenograft (PDTX) models using samples from CT-guided percutaneous biopsy

This study aimed to investigate the feasibility of the establishment of a human cancer xenograft model using samples from computed tomography (CT)-guided percutaneous biopsy. Fresh tumor tissues obtained from 10 cancer patients by CT-guided percutaneous biopsy were subcutaneously inoculated into NOD-Prkdcem26Il2rgem26Nju (NCG) mice to establish human patient-derived tumor xenograft (PDTX) models. The formation of first and second generation xenografts was observed, and tumor volume was recorded over time. Tumor tissue consistency between the PDTX model and primary tumors in patients was compared using H&E staining and immunohistochemistry. Pharmacodynamic tests of clinically used chemotherapeutic drugs were conducted on second generation xenografts, and their effects on tumor growth and body weight were observed. CT-guided percutaneous biopsy samples were successfully collected from 10 patients with advanced cancers. The PDTX model was established in mice using tumor samples obtained from 4 cancer patients, including one small cell carcinoma sample, two adenocarcinoma samples, and one squamous cell carcinoma sample. The success rate was 40%. The obtained PDTX model maintained a degree of differentiation, and morphological and structural characteristics were similar to primary tumors. The pharmacodynamic test of chemotherapeutic drugs in the PDTX model revealed a therapeutic effect on tumor growth, as expected. CT-guided percutaneous biopsy samples can be effectively used to establish a PDTX model, and test these chemotherapy regimens.

Relationship between EGFR gene mutation and local metastasis of resectable lung adenocarcinoma

Background

Resectable lung adenocarcinoma is dominated by peripheral distribution, and surgical resection is the main treatment protocol. However, high recurrence rate remains after surgery. Lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutation has strong invasion ability, but the effects of this mutation on local invasion in early lung adenocarcinoma have been rarely studied. This study aimed to assess the effects of EGFR mutation on local invasion in resectable lung adenocarcinoma.

Methods

A retrospective analysis of 103 patients clinically diagnosed with peripheral lung adenocarcinoma was included. They underwent preoperative bronchoscopy, which indicated grades 2 or 3 bronchial involvement (lumen of the lobe or segment). The associations of EGFR mutation with pleural invasion, endobronchial metastasis, and lymph node metastasis were analyzed according to pathologies of pleural invasion and lymph node metastasis, as well as EGFR gene mutation detected by postoperative pathological specimens. Statistical analyses were performed by unpaired Chi-square test using the SPSS16.0 software.

Results

In patients with EGFR mutation, pleural invasion, endobronchial metastasis, and lymph node metastasis rates were 62.5, 39.1, and 34.4%, respectively, indicating statistically significant differences (p = 0.003). Meanwhile, the pleural invasion rate in patients with wild-type EGFR was 43.6%, significantly reduced compared with patients with mutated EGFR (62.5%; p = 0.018). In addition, the endobronchial metastasis rate in patients with wild-type EGFR was 17.9%, significantly lower than in patients with EGFR mutation (39.1%; p = 0.005). However, lymph node metastasis rates were similar between EGFR mutated and wild-type patients (34.4 vs 25.6%, respectively, p > 0.05).

Conclusions

Early resectable lung adenocarcinoma patients with EGFR mutation showed a higher rate of local invasion compared with those harboring wild-type EGFR. This finding provides a basis for improved therapy.

Trial registration

This study was supported by Project of Medical and Health Science Technology in Shandong Province (2015WS0376)

Heterogeneous prognosis and adjuvant chemotherapy in pathological stage I non-small cell lung cancer patients

Background

Even after curative resection, the prognosis of pathological stage I non-small cell lung cancer (NSCLC) can be heterogeneous, and the use of adjuvant chemotherapy in these patients is controversial. We aimed to identify the prognostic factors and role of adjuvant chemotherapy in pathological stage I NSCLC.

Methods

We retrospectively analyzed the correlations between clinicopathological factors and survival in 179 patients with resected pathological stage I NSCLC.

Results

After a median follow-up of 93 months, overall and disease-free survival were not significantly different between pathological stage IA (n = 138) and IB (n = 41) patients. The prognosis of pathological stage I patients with poorly differentiated tumors was significantly worse than that of those with non-poorly differentiated tumors (P = 0.003). Multivariate analysis revealed that poor tumor differentiation was an independent factor for poor survival (hazard ratio = 6.889). A marginally significant survival benefit was observed in poorly differentiated pathological stage I patients who received adjuvant chemotherapy (P = 0.053).

Pathological stage IA patients who received adjuvant chemotherapy had a worse prognosis than those who did not receive adjuvant chemotherapy (P < 0.001), whereas pathological stage IA patients with poorly differentiated tumors who received adjuvant chemotherapy had better survival than who did not receive adjuvant chemotherapy (P < 0.001).

Conclusions

Poor differentiation is an independent prognostic factor in pathological stage I NSCLC after surgical resection. Adjuvant chemotherapy may be beneficial in poorly differentiated pathological stage IA NSCLC patients.