Update on the treatment of small cell lung cancer (SCLC)

Exploration of spatial distribution of brain metastasis from small cell lung cancer and identification of metastatic risk level of brain regions: a multicenter, retrospective study

Objectives

This study aimed to explore the spatial distribution of brain metastases (BMs) from small cell lung cancer (SCLC) a homogenous sample, and to identify the metastatic risk levels in brain regions.

Methods

T1-enhanced magnetic resonance imaging (MRI) from SCLC patients were retrospectively reviewed from three medical institutions in China. All images were registered to the standard brain template provided by the Montreal Neurological Institute (MNI) 152 database, followed by transformation of the location of all BMs to the space of standard brain. The MNI structural atlas and Anatomical Automatic Labeling (AAL) atlas were then used to identify the anatomical brain regions, and the observed and expected rates of BMs were compared using 2-tailed proportional hypothesis testing. The locations and sizes of brain lesions were analyzed after image standardization.

Results

A total of 215 eligible patients with 1033 lesions were screened by MRI, including 157 (73%) males and 58 (27%) females. The incidence of crucial structures were as follows: hippocampus 0.68%, parahippocampal 0.97%, brainstem 2.05%, cauate 0.68%, putamen 0.68%, pallidum 0.2%, thalamus 1.36%. No BMs were found in the amygdala, pituitary gland, or pineal gland. The cumulative frequency of the important structures was 6.62%. Based on the results of MNI structural atlas, the cerebellum, deep white matter and brainstem was identified as a higher risk region than expected for BMs (P = 9.80 ×10⁻¹⁵, 9.04 ×10⁻⁶), whereas temporal lobe were low-risk regions (P = 1.65 ×10⁻⁴). More detailed AAL atlas revealed that the low-risk regions for BMs was inferior frontal gyrus (P = 6.971 ×10⁻⁴), while the high-risk regions for BMs was cerebellar hemispheres (P = 1.177 ×10⁻⁹).

Conclusion

Many crucial structures including the hippocampus, parahippocampus, pituitary gland and thalamus etc. have low frequency of brain metastases in a population of SCLC patients. This study provides the help to investigate the clinical feasibility of HA-WBRT and non-uniform dose of PCI in a population of SCLC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-021-00410-w.

Small cell lung carcinoma cell line screen of etoposide/carboplatin plus a third agent

The SCLC combination screen examined a 9-point concentration response of 180 third agents, alone and in combination with etoposide/carboplatin. The predominant effect of adding a third agent to etoposide/carboplatin was additivity. Less than additive effects occurred frequently in SCLC lines sensitive to etoposide/carboplatin. In SCLC lines with little or no response to etoposide/carboplatin, greater than additive SCLC killing occurred over the entire spectrum of SCLC lines but never occurred in all SCLC lines. Exposing SCLC lines to tubulin-targeted agents (paclitaxel or vinorelbine) simultaneously with etoposide/carboplatin resulted primarily in less than additive cell killing. As single agents, nuclear kinase inhibitors including Aurora kinase inhibitors, Kinesin Spindle Protein/EG5 inhibitors, and Polo-like kinase-1 inhibitors were potent cytotoxic agents in SCLC lines; however, simultaneous exposure of the SCLC lines to these agents along with etoposide/carboplatin, generally, resulted in less than additive cell killing. Several classes of agents enhanced the cytotoxicity of etoposide/carboplatin toward the SCLC lines. Exposure of the SCLC lines to the MDM2 inhibitor JNJ-27291199 produced enhanced killing in 80% of the SCLC lines. Chk-1 inhibitors such as rabusertib increased the cytotoxicity of etoposide/carboplatin to the SCLC lines in an additive to greater than additive manner. The combination of GSK-3β inhibitor LY-2090314 with etoposide/carboplatin increased killing in approximately 40% of the SCLC lines. Exposure to the BET bromodomain inhibitor MK-8628 increased the SCLC cell killing by etoposide/carboplatin in 20-25% of the SCLC lines. Only 10-15% of the SCLC lines had an increased response to etoposide/carboplatin when simultaneously exposed to the PARP inhibitor talazoparib.

Platinum-Etoposide Chemotherapy in Elderly Patients With Small-Cell Lung Cancer: Results of a Randomized Multicenter Phase II Study Assessing Attenuated-Dose or Full-Dose With Lenograstim Prophylaxis—A Forza Operativa Nazionale Italiana Carcinoma Polmonare and Gruppo Studio Tumori Polmonari Veneto (FONICAP-GSTPV) Study

Purpose

Small-cell lung cancer (SCLC) is increasingly diagnosed in elderly patients, who are at higher risk of treatment-related morbidity and mortality. We conducted a randomized two-stage phase II study to assess the therapeutic index of two different platinum/etoposide regimens, attenuated-dose (AD) and full-dose (FD) plus prophylactic lenograstim.

Patients and Methods

SCLC patients older than 70 years were randomized to receive four courses of cisplatin 25 mg/m2 on days 1 and 2, and etoposide 60 mg/m2 on days 1, 2, and 3 every 3 weeks (AD); or cisplatin 40 mg/m2 on days 1 and 2, and etoposide 100 mg/m2 on days 1, 2, and 3 every 3 weeks, plus lenograstim 5 mg/kg days 5 through 12, every 3 weeks (FD). A combined primary end point named therapeutic success (TS), which took into account activity, toxicity, and compliance, was used.

Results

Ninety-five patients were enrolled. Seventy-five percent and 72% of the patients in the AD and FD arms, respectively, completed the treatment as per protocol. Response rate was 39% and 69% in the AD and FD arms, respectively, and 1-year survival probability was 18% and 39%, respectively. Treatment was well tolerated in both groups, with no grade 3 to 4 myelotoxicity in the AD arm, and 12% myelotoxicity in the FD arm. Overall, the observed TSs were 10 (36%) of 28 patients and 42 (63%) of 67 patients for AD and FD treatments, respectively.

Conclusion

In elderly patients with SCLC a full-dose cisplatin/etoposide regimen combined with prophylactic lenograstim is active and feasible, while attenuated doses of the same regimen are associated with a poor therapeutic outcome.

A randomized pilot study of SRL172 (Mycobacterium vaccae) in patients with small cell lung cancer (SCLC) treated with chemotherapy

BACKGROUND

SRL172 is a suspension of heat killed Mycobacterium vaccae, that has been found to be a potent immunological adjuvant when used with autologous cells in animal models. This is a phase II study to test the clinical activity, feasibility and safety of combining SRL172 with chemotherapy to treat patients with small cell lung cancer (SCLC).

METHODS

Patients were randomized to receive chemotherapy with (n=14) or without (n=14) SRL172. The chemotherapy was either platinum-based (MVP, n=10) or anthracycline-based (ACE, n=18). SRL172 was given intradermally on day 0, weeks 4, 8 and then 3-6 monthly.

RESULTS

The treatment arms were well balanced for disease extent (43% with limited stage in each arm). The toxicity of chemotherapy and overall response at 12-15 weeks (57%) was the same for both treatment regimens. Median survival was 8.6 months and 12.9 for patients treated with chemotherapy alone and with the combination respectively (P=0.10). The survival trend was similar for both disease extent and chemotherapy regimen employed in favour of combination chemotherapy with SRL172.

CONCLUSIONS

There is a trend to improved median survival in SCLC with the combination of chemotherapy and SRL172 with no increased toxicity and irrespective of drug regimen. A phase III study examining chemotherapy in combination with SRL172 in SCLC is now underway.