Proton therapy for small cell lung cancer

A Promising Treatment Strategy for Lung Cancer: A Combination of Radiotherapy and Immunotherapy

Lung cancer is a leading cause of cancer-related deaths worldwide despite advances in treatment. In the past few decades, radiotherapy has achieved outstanding technical advances and is being widely used as a definitive, prophylactic, or palliative treatment of patients with lung cancer. The anti-tumor effects of radiotherapy are considered to result in DNA damage in cancer cells. Moreover, recent evidence has demonstrated another advantage of radiotherapy: the induction of anti-tumor immune responses, which play an essential role in cancer control. In contrast, radiotherapy induces an immunosuppressive response. These conflicting reactions after radiotherapy suggest that maximizing immune response to radiotherapy by combining immunotherapy has potential to achieve more effective anti-tumor response than using each alone. Immune checkpoint molecules, such as cytotoxic T-lymphocyte-associated protein 4, programmed cell death-1/programmed death-ligand 1, and their inhibitors, have attracted significant attention for overcoming the immunosuppressive conditions in patients with cancer. Therefore, the combination of immune checkpoint inhibitors and radiotherapy is promising. Emerging preclinical and clinical studies have demonstrated the rationale for these combination strategies. In this review, we outlined evidence suggesting that combination of radiotherapy, including particle therapy using protons and carbon ions, with immunotherapy in lung cancer treatment could be a promising treatment strategy.

Treatments for combined small cell lung cancer patients

Background

Combined small cell lung cancer (CSCLC) is a subtype of small cell lung cancer (SCLC) which contains both components of SCLC and non-small cell lung cancer (NSCLC). The prognostic outcomes and treatment strategy of it are still unclear. A large-scale retrospective study was performed to investigate proper treatments for CSCLC.

Methods

All cases of CSCLC were identified from the SEER database during the period of 2004–2016. Clinical characteristics, first-line treatments, surgical procedures and survival data including overall survival (OS) and cancer-specific survival (CSS) were analyzed.

Results

A total of 37,639 SCLC patients were identified. CSCLC accounted for 2.1% (784/37,639). The mean age of CSCLC cohort is 67.3±9.9 years old. Male and white ethnicity patients were accounted for larger proportions (55.7% and 80.4%). The oncological characteristics of CSCLC were consistent with SCLC that most of patients were diagnosed as higher grade and advanced stages. The prognosis of CSCLC was better than SCLC but worse than NSCLC in IA-IIIA stages. No difference was observed in IIIB-IV. Surgery was beneficial in IA-IB stage CSCLC. Adjuvant chemotherapy seemed to have few effects on early stage patients. Trimodality treatment could significantly improve OS in IIA-IIIA CSCLC patients. Chemotherapy-based treatment is predominant choice in advanced stage patients.

Conclusions

CSCLC is a rare and special subtype of SCLC. It has better survival outcome than non-CSCLC in early stage. Surgical treatment is crucial in early stage of CSCLC. Prognostic improvement might be achieved from trimodality treatment in stage IIA-IIIA. Chemotherapy-based treatments should be considered in advanced stage. The effect of surgical treatments in advanced stage patients should be further investigated.

The impact of symptoms and comorbidity on health utility scores and health-related quality of life in small cell lung cancer using real world data

PURPOSE

Small cell lung cancer (SCLC) is a highly fatal disease associated with significant morbidity, with a need for real-world symptom and health utility score (HUS) data. HUS can be measured using an EQ-5D-5L questionnaire, however most captured data is available in non-SCLC (NSCLC) only. As new treatment regimens become available in SCLC it becomes important to understand factors which influence health-related quality of life and health utility.

METHODS

A prospective observational cohort study (2012-2017) of ambulatory histologically confirmed SCLC evaluated patient-reported EQ-5D-5L-derived HUS, toxicity and symptoms. A set of NSCLC patients was used to compare differential factors affecting HUS. Clinical and demographic factors were evaluated for differential interactions between lung cancer types. Comorbidity scores were documented for each patient.

RESULTS

In 75 SCLC and 150 NSCLC patients, those with SCLC had lower mean HUS ((SCLC vs NSCLC: mean 0.69 vs 0.79); (p < 0.001)) when clinically stable and with progressive disease: ((SCLC mean HUS = 0.60 vs NSCLC mean HUS = 0.77), (p = 0.04)). SCLC patients also had higher comorbidity scores ((1.11 vs 0.73); (p < 0.015)). In multivariable analyses, increased symptom severity and comorbidity scores decreased HUS in both SCLC and NSCLC (p < 0.001); however, only comorbidity scores differentially affected HUS (p < 0.0001), with a greater reduction of HUS adjusted per unit of comorbidity in SCLC.

CONCLUSION

Patients with advanced SCLC had significantly lower HUS than NSCLC. Both patient cohorts are impacted by symptoms and comorbidity, however, comorbidity had a greater negative effect in SCLC patients.

miR-216a-5p inhibits malignant progression in small cell lung cancer: involvement of the Bcl-2 family proteins

Objective

microRNAs are regulatory molecules regarded as important in the pathogenesis of different types of tumors. microRNA-216a (miR-216a-5p) has been identified as a tumor suppressor in multiple malignancies. However, the role of miR-216a-5p in the pathogenesis of small cell lung cancer (SCLC) remains obscure. The objective of this study was to investigate the role of the miR-216a-5p/Bcl-2 axis in SCLC pathogenesis.

Materials and methods

All the experimental methods used were as follows: microarray analysis, cell culture, transient, and stable gene transfection; real-time fluorescence PCR; Western blot; flow cytometry for cell cycle analysis; in vitro proliferation assay; in vitro wound healing experiment; in vivo xenograft model in nude mice; and dual luciferase reporter assay. All statistical analyses were carried out using GraphPad Prism 7 software. Statistical significance was analyzed by Student’s t-test or one-way ANOVA. P <0.05 (typically compared with the negative control group) was considered as significant and is marked with an asterisk in the figures.

Results

In this study, we observed that miR-216a-5p is downregulated in SCLC cell lines compared to that in the normal human bronchial epithelial cell line 16-HBE. In vitro and in vivo experiments demonstrate that upregulation of miR-216a-5p significantly decreased cell growth and migration and its downregulation increased SCLC cell proliferation and migration and influenced the cell cycle. Using bioinformatics analyses, we predicted that the important antiapoptotic gene Bcl-2 is targeted by miR-216a-5p, and we identified a functional miR-216a-5p binding site in the 3′-UTR of Bcl-2 using luciferase reporter assay. Furthermore, we determined that suppression of miR-216a-5p modulated the expression of Bcl-2, Bax, and Bad proteins (Bcl-2 family proteins), while Bcl-2 knockdown abrogated the effect of miR-216a-5p downregulation on cell proliferation, cell migration, and the cell cycle.

Conclusion

Taken together, these findings suggest that miR-216a-5p regulates SCLC biology via Bcl-2 family proteins. Therefore, our study highlights the role of the miR-216a-5p/Bcl-2 axis in SCLC pathogenesis.