The role of anthracyclines in small cell lung cancer

Real-life second-line epirubicin-paclitaxel regimen as treatment of relapsed small-cell lung cancer: EpiTax study

BACKGROUND

Few therapeutic options are approved as second-line treatment after failure of platinum-based chemotherapy for patients with extensive-stage small-cell lung cancer (ES-SCLC). Topotecan widespread use remains challenged by the risk of severe toxicities in a pretreated population. Little is known about the efficacy and safety of epirubicin-paclitaxel doublet in second-line and beyond and especially cerebral outcomes.

METHODS

EpiTax is a retrospective multicenter observational real-life study. We evaluated the efficacy of epirubicin 90 mg/m² combined with paclitaxel 175 mg/m² every 3 weeks in SCLC patients after failure of at least one line of platinum-based chemotherapy. The primary endpoint was progression-free survival (PFS). Secondary endpoints were overall survival (OS), objective response rate (ORR), disease control rate (DCR), intracranial control rate (ICR), and safety.

RESULTS

A total of 29 patients were included. The median of previous systemic therapy lines was 2 (1-4). Eleven patients received the treatment in the second line. Characteristics of patients were a median age of 60 years (45-77), 65.5% of males with 72.4% of PS 0-1. Fifteen patients had a history of brain metastases. Median PFS and OS achieved 11.0 (95% CI, 8.1-16.3) and 23 (95% CI, 14.1-29.6) weeks, respectively. ORR was 34.5% and DCR was 55.2%. ICR was 3/15 (20%). Grade 3-4 adverse events were mainly hematological and concerned 7 patients. No case of febrile neutropenia or toxic death was reported.

CONCLUSION

Epirubicin-paclitaxel association highlighted promising efficacy with PFS and OS of 11 and 23 weeks, respectively, ORR of 34.5%, and a tolerable safety profile. This doublet could represent another valuable therapeutic option for ES-SCLC patients treated in the second line and beyond.

Second-line therapy for small cell lung cancer: exploring the potential role of circulating tumor cells

BACKGROUND

Small cell lung cancer (SCLC) is an aggressive and invasive variant of lung tumors. SCLC, especially in advanced stages, is distinguished by extremely high numbers of circulating tumor cells (CTCs) in comparison to other malignancies. CTCs are operative in tumor spread and are currently enumerated to assess prognosis and response to cytotoxic therapy. Chemosensitivity of SCLC CTCs compared to primary tumors and metastases is not known.

METHODS

Establishment of two SCLC CTC cell lines, namely BHGc7 and BHGc10, allowed the in vitro characterization of their chemosensitivity to the second-line chemotherapeutics topotecan and epirubicin in comparison to a range of SCLC cell lines.

RESULTS

The SCLC CTC cell lines exhibited an approximately 7- and 12-fold increased chemosensitivity to epirubicin compared to topotecan, respectively, in in vitro cytotoxicity assays. In comparison to a panel of six SCLC cell lines, the two CTC lines showed a significantly higher chemosensitivity to epirubicin (range, 3- to 16-fold) and topotecan (range, 2.2- to 14.4-fold), respectively.

CONCLUSIONS

CTC cell lines derived from SCLC patients with recurrent disease exhibit high chemosensitivity to epirubicin vs. topotecan and show considerable more cytotoxicity in response to both compounds in comparison to a panel of SCLC cell lines. Thus, a decrease in the number of CTCs in response to second-line chemotherapy in SCLC patients may overestimate the effect on resident SCLC lesions and metastases.

Smoking, inflammation and small cell lung cancer: recent developments

Small cell lung cancer (SCLC) accounts for 15 % of all lung tumors and represents an invasive neuroendocrine malignancy with poor survival rates. This cancer is highly prevalent in smokers and characterized by inactivation of p53 and retinoblastoma. First in vitro expansion of circulating tumor cells (CTCs) of SCLC patients allowed for investigation of the cell biology of tumor dissemination. In the suggested CTC SCLC model, the primary tumor attracts and educates tumor-promoting and immunosuppressive macrophages which in turn arm CTCs to spread and generate distal lesions. Preexisting inflammatory processes associated with chronic obstructive pulmonary disease (COPD) seem to potentiate the subsequent activity of tumor-associated macrophages (TAM). Activation of signal transducer and activator of transcription 3 (STAT3) and expression of chitinase-3-like 1/YKL-40 in SCLC CTCs seems to be associated with drug resistance. In conclusion, inflammation-associated generation of invasive and chemoresistant CTCs most likely explains the characteristic features of SCLC, namely early dissemination and rapid failure of chemotherapy.

Identification of CREB3L1 as a Biomarker Predicting Doxorubicin Treatment Outcome

BACKGROUND

Doxorubicin has been shown to inhibit proliferation of cancer cells through proteolytic activation of CREB3L1 (cAMP response element binding protein 3-like 1), a transcription factor synthesized as a membrane-bound precursor. Upon doxorubicin treatment, CREB3L1 is cleaved so that the N-terminal domain of the protein can reach the nucleus where it activates transcription of genes that inhibit cell proliferation. These results suggest that the level of CREB3L1 in cancer cells may determine their sensitivity to doxorubicin.

METHODS

Mice transplanted with 6 lines of renal cell carcinoma (RCC) were injected with doxorubicin to observe the effect of the chemotherapy on tumor growth. Immunohistochemistry and bioinformatics analyses were performed to compare CREB3L1 levels in types of cancer known to respond to doxorubicin versus those resistant to doxorubicin.

RESULTS

Higher levels of CREB3L1 protein are correlated with increased doxorubicin sensitivity of xenograft RCC tumors (p = 0.017 by Pearson analysis). From patient tumor biopsies we analyzed, CREB3L1 was expressed in 19% of RCC, which is generally resistant to doxorubicin, but in 70% of diffuse large B-cell lymphoma that is sensitive to doxorubicin. Doxorubicin is used as the standard treatment for cancers that express the highest levels of CREB3L1 such as osteosarcoma and malignant fibrous histiocytoma but is not generally used to treat those that express the lowest levels of CREB3L1 such as RCC.

CONCLUSION

Identification of CREB3L1 as the biomarker for doxorubicin sensitivity may markedly improve the doxorubicin response rate by applying doxorubicin only to patients with cancers expressing CREB3L1.