Irinotecan as a second-line chemotherapy for small cell lung cancer: a systemic analysis

Real World Patient Eligibility for Second Line Lurbinectedin Based Treatment in Small Cell Lung Cancer: Understanding Epidemiology and Estimating Health Care Utilization

BACKGROUND

In the ATLANTIS study, second-line lurbinectedin/doxorubicin did not improve overall survival (OS), however patients with a chemotherapy-free interval (CTFI) of ≥180 days had an improved progression free survival (PFS). The objective of this retrospective study was to identify the proportion of real-world small cell lung cancer (SCLC) patients who are suitable for lurbinectedin-based therapy based on these criteria.

METHODS

A retrospective study of all SCLC referred to BC Cancer between 2012 and 2017 was conducted. Patient demographics, staging, treatment, and survival data were collected retrospectively. Baseline characteristics were compared using descriptive statistics. OS was calculated using Kaplan-Meier curves. Statistically significant p-value was <0.05.

RESULTS

A total of 1048 patients were identified. Baseline characteristics: median age 68 years, 47% male, 61% current smoking status, 68% extensive disease. Best supportive care was received by 22%. First-line systemic therapy was platinum doublet for 71% of the population. Second-line systemic therapy was delivered to 22%. Of the 219 patients who received second-line systemic therapy after platinum doublet, 183 patients had a CTFI of ≥90 days and 107 patients had a CTFI of ≥180 days. Patients originally treated as limited stage disease, received platinum doublet as second line, received thoracic radiation (RT) or prophylactic cranial irradiation (PCI) were more likely to have a CTFI of ≥90 and ≥180 days.

CONCLUSION

In our real-world SCLC population, only 21% of the SCLC population received second-line therapy after platinum doublet with 17% achieving CTFI of ≥90 days and 10% CTFI of ≥180 days. Based on this retrospective review, only a small fraction of platinum-treated patients would be preferentially offered lurbinectedin in the second-line setting.

Microbiota-Host-Irinotecan Axis: A New Insight Toward Irinotecan Chemotherapy

Irinotecan (CPT11) and its active metabolite ethyl-10-hydroxy-camptothecin (SN38) are broad-spectrum cytotoxic anticancer agents. Both cause cell death in rapidly dividing cells (e.g., cancer cells, epithelial cells, hematopoietic cells) and commensal bacteria. Therefore, CPT11 can induce a series of toxic side-effects, of which the most conspicuous is gastrointestinal toxicity (nausea, vomiting, diarrhea). Studies have shown that the gut microbiota modulates the host response to chemotherapeutic drugs. Targeting the gut microbiota influences the efficacy and toxicity of CPT11 chemotherapy through three key mechanisms: microbial ecocline, catalysis of microbial enzymes, and immunoregulation. This review summarizes and explores how the gut microbiota participates in CPT11 metabolism and mediates host immune dynamics to affect the toxicity and efficacy of CPT11 chemotherapy, thus introducing a new concept that is called "microbiota-host-irinotecan axis". Also, we emphasize the utilization of bacterial β-glucuronidase-specific inhibitor, dietary interventions, probiotics and strain-engineered interventions as emergent microbiota-targeting strategies for the purpose of improving CPT11 chemotherapy efficiency and alleviating toxicity.

Perspectives and controversies regarding the use of natural products for the treatment of lung cancer

Lung cancer is the leading cause of cancer‐related mortality both in men and women and accounts for 18.4% of all cancer‐related deaths. Although advanced therapy methods have been developed, the prognosis of lung cancer patients remains extremely poor. Over the past few decades, clinicians and researchers have found that chemical compounds extracted from natural products may be useful for treating lung cancer. Drug formulations derived from natural compounds, such as paclitaxel, doxorubicin, and camptothecin, have been successfully used as chemotherapeutics for lung cancer. In recent years, hundreds of new natural compounds that can be used to treat lung cancer have been found through basic and sub‐clinical research. However, there has not been a corresponding increase in the number of drugs that have been used in a clinical setting. The probable reasons may include low solubility, limited absorption, unfavorable metabolism, and severe side effects. In this review, we present a summary of the natural compounds that have been proven to be effective for the treatment of lung cancer, as well as an understanding of the mechanisms underlying their pharmacological effects. We have also highlighted current controversies and have attempted to provide solutions for the clinical translation of these compounds.

Puerarin increases the chemosensitivity of hepatocellular carcinoma cells

The present study investigated the effect of puerarin (Pu) on the sensitivity of HepG2 human hepatocellular carcinoma (HCC) cells to chemotherapeutic drugs to determine the possible mechanism. HepG2 cells were treated with different concentrations of Pu and cisplatin (CDDP), alone or in combination. MTT assay was used to determine the inhibitory effects of the different drugs on HepG2 cells. Cell morphology was observed by inverted microscopy. The expression of B-cell lymphoma 2 (Bcl-2) and Bax protein was measured by western blot analysis. Pu and CDDP, alone or in combination, inhibited the proliferation of HepG2 cells. The inhibitory effect of CDDP combined with Pu on HepG2 cells was significantly higher than that of the single drug treatments (p<0.01). In addition, compared with the single drug groups, cellular morphology was significantly altered and the apoptotic rate of cells and the expression of Bax protein were significantly increased (p<0.01). However, the expression of Bcl-2 protein was significantly decreased (p<0.01) in the combined drug group. In conclusion, Pu can increase the sensitivity of HCC to chemotherapeutic drugs, enhance the inhibitory effect of chemotherapeutic drugs on cell proliferation and synergistically induce apoptosis of HepG2 cells. The mechanism is likely related to the upregulation of Bax protein and the downregulation of Bcl-2 protein.

Treatment mechanism of matrine in combination with irinotecan for colon cancer

The inhibitory effect of matrine (MA) was studied in combination with irinotecan (CPT-11) on proliferation of human colon carcinoma cell line HT29. We also explored the mechanism of cell apoptosis induction in HT29. HT29 cells were treated with different concentrations of MA and CPT-11 alone and in combination. The growth inhibition in HT29 cells was evaluated using MTT assay. Apoptosis was detected using AV-PI double staining flow cytometry. Transmission electron microscopy was used to detect structural changes in cells. Topoisomerase (TOPO) I, Bax and Caspase-3 expression levels were evaluated using western blot analysis. MA and CPT-11 alone and in combination, inhibited the proliferation of HT29 cells, whereas the combination treatment exhibited higher inhibitory effect (P<0.01). This suggests the existence of synergistic cytotoxicity. Compared with each treatment alone, the combination treatment caused more significant damage to cell structure, and caused a significantly higher apoptosis rate (P<0.01). Additionally, the combination treatment increased TOPO I, Bax and Caspase-3 expression levels (P<0.01). In conclusion, MA in combination with CPT-11 synergistically inhibited HT29 cell proliferation and induced apoptosis in these cells. The mechanism may be related to upregulation of the TOPO I, Bax and Caspase-3 protein expression.