Chemotherapy strategies in the treatment of small cell lung cancer

What's New in SCLC? A Review

A few years ago the answer to the question in the title of this review would have been, "unfortunately not much" or even "nothing", likely eliciting knowing nods of agreement from oncologists. For the last 3 decades, SCLC has been notorious for its lack of progress, as drug after drug, over 60 of them, in fact, including inhibitors of VEGF, IGFR, mTOR, EGFR and HGF has failed and fallen by the wayside due to little or no impact on PFS or OS, while SCLC's cousin, NSCLC, has notched success after success with a spate of targeted treatment and immunotherapy regulatory approvals. However, a paradigm shift or, more appropriately, a 'paradigm nudge' is quietly underway in extensive stage SCLC with a series of agents that in early clinical trials have shown the potential to 'lift the curse' in SCLC, heretofore referred to as "a graveyard for drug development". These agents, constituting the "best of what's new" in SCLC, and discussed in this review following a brief overview of the classification, epidemiology, prognosis and current treatment of SCLC, include checkpoint inhibitors, antibody-drug conjugates, PARP inhibitors, epigenetic inhibitor/innate immune activator, and an inhibitor of RNA polymerase II. Compared to NSCLC, the therapeutic options are still limited but with one or more successes to build momentum and drive long-overdue R&D and clinical investment the hope is that the approval floodgates may finally open.

The role of second-line chemotherapy in small cell lung cancer: a retrospective analysis

Background

To evaluate the benefit of second-line chemotherapy with platinum-based treatment in patients with recurrent small cell lung cancer (SCLC).

Patients and methods

A total of 535 patients continued with follow-up or best supportive care if needed, and 229 patients who progressed after the completion of first-line chemotherapy were treated with second-line chemotherapy at the time of progression. In total, 103/229 patients received paclitaxel 190 mg/m² and carboplatin 5.5 area under the curve while 126/229 patients received etoposide 200 mg/m² and carboplatin 5.5 area under the curve every 28 days.

Results

Patients administered second-line chemotherapy lived significantly longer, with a median survival of 422 days compared to 228 days in patients with best supportive care alone (P<0.001). Patients who received paclitaxel as second-line chemotherapy lived for an average of 462 days (95% confidence interval: 409–514), versus 405 days in the etoposide group (95% confidence interval: 371–438), which was not statistically significant (P=0.086). The overall response rate was 8% for the paclitaxel group and 6% for the etoposide group. Patients with progression of the disease in more than 3 months had significantly better survival compared with those that progressed in less than 3 months (P<0.001).

Conclusion

Continuation with carboplatin/paclitaxel or carboplatin/etoposide as second-line chemotherapy has no significant survival impact, and it did not improve response rates.

Randomised phase II study of amrubicin as single agent or in combination with cisplatin versus cisplatin etoposide as first-line treatment in patients with extensive stage small cell lung cancer - EORTC 08062

PURPOSE

The EORTC 08062 phase II randomised trial investigated the activity and safety of single agent amrubicin, cisplatin combined with amrubicin, and cisplatin combined with etoposide as first line treatment in extensive disease (ED) small cell lung cancer (SCLC).

PATIENTS AND METHODS

Eligible patients with previously untreated ED-SCLC, WHO performance status (PS) 0-2 and measurable disease were randomised to 3 weekly cycles of either amrubicin alone 45mg/m(2) i.v. day(d) 1-3 (A), cisplatin 60mg/m(2) i.v. d1 and amrubicin 40mg/m(2) i.v. d1-3 (PA), or cisplatin 75mg/m(2) i.v. d1 and etoposide 100mg/m(2) d1, d2-3 i.v./po (PE). The primary end-point was overall response rate (ORR) as assessed by local investigators (RECIST1.0 criteria). Secondary end-points were treatment toxicity, progression-free survival and overall survival.

RESULTS

The number of randomised/eligible patients who started treatment was 33/28 in A, 33/30 in PA and 33/30 in PE, respectively. Grade (G) ⩾3 haematological toxicity in A, PA and PE was neutropenia (73%, 73%, 69%); thrombocytopenia (17%, 15%, 9.4%), anaemia (10%, 15%, 3.1%) and febrile neutropenia (13%, 18%, 6%). Early deaths, including treatment related, occurred in 1, 3 and 3 patients in A, PA and PE arms, respectively. Cardiac toxicity did not differ among the 3 arms. Out of 88 eligible patients who started treatment, ORR was 61%, (90% 1-sided confidence intervals [CI] 47-100%), 77% (CI 64-100%) and 63%, (CI 50-100%) for A, PA and PE respectively.

CONCLUSION

All regimens were active and PA met the criteria for further investigation, despite slightly higher haematological toxicity.

Treatment options for small cell lung cancer - do we have more choice?

Small cell lung cancer (SCLC) is a significant health problem worldwide because of its high propensity for relapse. This review discusses existing and future therapies for the treatment of SCLC.

Eukaryotic nucleotide excision repair: from understanding mechanisms to influencing biology

Repair of bulky DNA adducts by the nucleotide excision repair (NER) pathway is one of the more versatile DNA repair pathways for the removal of DNA lesions. There are two subsets of the NER pathway, global genomic-NER (GG-NER) and transcription-coupled NER (TC-NER), which differ only in the step involving recognition of the DNA lesion. Following recognition of the damage, the sub-pathways then converge for the incision/excision steps and subsequent gap filling and ligation steps. This review will focus on the GGR sub-pathway of NER, while the TCR sub-pathway will be covered in another article in this issue. The ability of the NER pathway to repair a wide array of adducts stems, in part, from the mechanisms involved in the initial recognition step of the damaged DNA and results in NER impacting an equally wide array of human physiological responses and events. In this review, the impact of NER on carcinogenesis, neurological function, sensitivity to environmental factors and sensitivity to cancer therapeutics will be discussed. The knowledge generated in our understanding of the NER pathway over the past 40 years has resulted from advances in the fields of animal model systems, mammalian genetics and in vitro biochemistry, as well as from reconstitution studies and structural analyses of the proteins and enzymes that participate in this pathway. Each of these avenues of research has contributed significantly to our understanding of how the NER pathway works and how alterations in NER activity, both positive and negative, influence human biology.

Management of metastatic carcinoma of the uveal tract: an evidence-based analysis

Uveal metastasis from carcinoma is the most common cause of ocular malignancy in adults and represents an increasing problem in the context of an ageing population and enhanced survival of stage IV cancer patients. The reported prevalence of clinically evident uveal metastases in carcinoma patients ranges from 2% to 9%, with breast and lung cancer together accounting for between 71% and 92% of cases. Most patients (66-97%) have a known history of cancer and, although the majority have metastatic lesions elsewhere, up to 33% may present with an isolated ocular metastasis. These lesions may progress rapidly and are potentially sight-threatening. Early diagnosis and appropriate timely treatment are therefore of paramount importance to maintain patients' quality of life. The diagnosis is usually clinical and detailed descriptions of symptomatology and physical characteristics are provided. In 21-50% of patients, involvement is bilateral. External beam radiotherapy (EBRT), chemotherapy, hormone and biological therapies, brachytherapy, transpupillary thermotherapy, laser photocoagulation/photodynamic therapy and enucleation are therapeutic modalities described in the literature for the management of uveal metastases. The strongest evidence favours timely EBRT for the management of sight-threatening uveal metastases. The published evidence supporting EBRT for sight-threatening uveal metastases was given a grade B (strong support for recommendation). Newer alternative therapies are emerging and may have a role in selected patients; however, there are unfortunately few large studies examining such treatments for carcinoma metastatic to the eye. The role of these modalities will be further clarified with the results of larger comparative trials.