Second-line chemotherapy in recurrent small cell lung cancer

Comparative characteristics of small cell lung cancer and Ewing's sarcoma: a narrative review

Background and Objective

Small cell lung cancer (SCLC) and Ewing's sarcoma (ES) at the disseminated stage are not amenable to therapy and have a dismal prognosis with low survival rates. Despite representing different tumor entities, treatment for both malignancies relies on cytotoxic chemotherapy that has not considerably changed for the past decades. The genomic background has been extensively studied and found to comprise inactivation of p53 and RB1 in case of SCLC and EWSR1/FLI1 rearrangement in case of ES resulting in aggressive tumors in adults with heavy tobacco consumption and as bone tumor in juveniles, respectively. New therapeutic modalities are urgently needed to improve the outcomes of both tumor entities, especially in patients with metastatic disease or recurrences. This review summarizes the common cell biologic and clinical characteristics of difficult-to-treat SCLC and ES and discusses their refractoriness and options to improve the therapeutic efficacy.

Methods

PubMed and Euro PMC were searched from January 1^st, 2012 to January 16^th, 2022 using the following key words: "SCLC", "Ewing´s sarcoma", "Genomics" and "Chemoresistance" as well as own work.

Key Content and Findings

Therapy of SCLC and ES involves the use of undirected cytotoxic drugs in multimodal chemotherapy and administration of topotecan for 2^nd line SCLC regimens. Despite highly aggressive chemotherapies, outcomes are dismal for patients with disseminated tumors. A host of unrelated drugs and targeted therapeutics have failed to result in progress for the patients and the underlying mechanisms of chemoresistance are still not clear. Identification of chemoresistance-reversing modulators in vitro and patient-derived xenografts of SCLC and ES has not translated into new therapies.

Conclusions

The global chemoresistance of SCLC and ES may be explained by physiological resistance at the tumor level and formation of larger spheroids that contain quiescent and hypoxic tumor cells in regions that occlude therapeutics. This type of chemoresistance is difficult to overcome and prevent the accumulation of effective drug concentration at the tumor cell level to a significant degree leaving therapeutic interventions of any kind ineffective.

Norcycloartocarpin targets Akt and suppresses Akt-dependent survival and epithelial-mesenchymal transition in lung cancer cells

In searching for novel targeted therapeutic agents for lung cancer treatment, norcycloartocarpin from Artocarpus gomezianus was reported in this study to promisingly interacted with Akt and exerted the apoptosis induction and epithelial-to-mesenchymal transition suppression. Selective cytotoxic profile of norcycloartocarpin was evidenced with approximately 2-fold higher IC50 in normal dermal papilla cells (DPCs) compared with human lung cancer A549, H460, H23, and H292 cells. We found that norcycloartocarpin suppressed anchorage-independent growth, cell migration, invasion, filopodia formation, and decreased EMT in a dose-dependent manner at 24 h, which were correlated with reduced protein levels of N-cadherin, Vimentin, Slug, p-FAK, p-Akt, as well as Cdc42. In addition, norcycloartocarpin activated apoptosis caspase cascade associating with restoration of p53, down-regulated Bcl-2 and augmented Bax in A549 and H460 cells. Interestingly, norcycloartocarpin showed potential inhibitory role on protein kinase B (Akt) the up-stream dominant molecule controlling EMT and apoptosis. Computational molecular docking analysis further confirmed that norcycloartocarpin has the best binding affinity of -12.52 kcal/mol with Akt protein at its critical active site. As Akt has recently recognized as an attractive molecular target for therapeutic approaches, these findings support its use as a plant-derived anticancer agent in cancer therapy.

Real World Analysis of Small Cell Lung Cancer Patients: Prognostic Factors and Treatment Outcomes

In this observational study, we assessed treatment patterns and prognostic factors in patients with small cell lung cancer (SCLC) in a large state-mandated healthcare organization in Israel. Methods: All incident cases with histologically confirmed SCLC who initiated systemic anti-cancer treatment between 2011 and 2017 were identified. Treatment patterns and overall survival (OS) were evaluated for each line of therapy. Results: A total of 235 patients were identified (61% male, median age 64 years, 95% ever smokers, 64% had extensive stage). The first-line treatment was platinum-etoposide regimen for 98.7% of the cohort. The second and third-line regimen were given to 43% and 12% of patients, respectively. Mean OS for extensive and limited stage patients was 9.1 and 23.5 months respectively. In a multivariable model, increased risk for mortality was observed among patients with an ECOG performance status (PS) of 2 compared to a PS of 0-1 for the extensive stage patients (Hazard ratio (HR) = 1.63, 95% confidence ratios (CI): 1.00-2.65); and for males compared to females for the limited stage patients (HR = 2.17; 95% CI: 1.12-4.20). Regarding all 2nd line patients in a multivariable model incorporating relevant confounding factors, demonstrated a significantly better outcome with platinum-based regimens compared to topotecan. Median survival after initiation of 2nd line in platinum-sensitive patients was longer (p = 0.056) for those re-challenged with platinum-based regimen (n = 7): 6.8mo (6.1-not reported (NR)), compared with those switched to a different treatment (n = 27): 4.5 mo (2.6-6.6) for extensive stage patients, and a non-significant difference was also observed for limited stage patients. Conclusion: To our knowledge, this is one of the largest real-world studies of SCLC patients. OS for SCLC patients was similar to that reported in clinical trials. PS for extensive stage patients and sex for limited stage patients were significant correlates of prognosis. Re-challenge of the platinum-based doublet was associated with longer OS compared to switching treatment in extensive stage patients.

Prognostic value of baseline hemoglobin-to-red blood cell distribution width ratio in small cell lung cancer: A retrospective analysis

Background

This study aimed to investigate the prognostic value of baseline hemoglobin‐to‐red blood cell distribution width ratio (HRR) in patients with small cell lung cancer (SCLC).

Methods

We retrospectively analyzed the medical records of patients with newly diagnosed SCLC who had received first‐line chemotherapy at the Department of Pulmonary Oncology of the PLA 307 Hospital between January 2008 and October 2018. The optimal cutoff value of the continuous variables was determined using the X‐tile software. Univariate and multivariate analyses were conducted using Cox proportional hazard models. The Kaplan‐Meier method was used for survival analysis, with differences tested using the log‐rank test.

Results

A total of 146 patients were included. The cutoff value for HRR was determined as 0.985. Statistically significant differences were observed in sex, smoking history, stage, radiotherapy combination, neutrophil‐to‐lymphocyte ratio, platelet‐to‐lymphocyte ratio, hemoglobin, and red blood cell distribution width between the high and low HRR groups. The median overall survival (OS) was nine and 17.5 months in the low and high HRR groups, respectively (P < 0.001). The median progression‐free survival (PFS) was five and 8.5 months, respectively (P < 0.001). Univariate and multivariate analyses showed low HRR to be an independent predictor of a poor prognosis for OS (hazard ratio = 3.782; 95% confidence interval, 2.151–6.652; P < 0.001) and PFS (hazard ratio = 2.112; 95% confidence interval, 1.195–3.733; P = 0.01) in SCLC.

Conclusion

Low HRR was associated with poorer OS and PFS in patients with SCLC and can be a potentially valuable prognostic factor for these patients.

Key points

The prognostic value of the baseline hemoglobin‐to‐red blood cell distribution width ratio was evaluated in patients with small cell lung cancer.

In this population, this ratio was an independent predictor of overall survival and progression‐free survival. This ratio, an inexpensive and routine parameter, can be used as a prognostic factor in small cell lung cancer.

Should Stereotactic Radiosurgery Be Considered for Salvage of Intracranial Recurrence after Prophylactic Cranial Irradiation or Whole Brain Radiotherapy in Small Cell Lung Cancer? A Population-Based Analysis and Literature Review

BACKGROUND

Prophylactic cranial irradiation (PCI) improves survival and prevents intracranial recurrence (IR) in limited stage (LS) and extensive stage (ES) small cell lung cancer (SCLC). However, despite PCI, IR affects 12%-45%, and limited data exist regarding salvage brain reirradiation (ReRT). We performed a population-based review of IR in SCLC.

METHODS

Demographic, treatment, and outcome data of consecutive patients (N = 371) with SCLC assessed at a tertiary cancer centre (01/2013-12/2015) were abstracted, and summary statistics calculated. Kaplan-Meier estimates and univariate and multivariate analysis (MVA) via the Cox proportional hazard model were performed.

RESULTS

Median age was 66.1 years, and 59.8% were Eastern Cooperative Oncology Group (ECOG) performance status 0-2. Median survival was 24 months (95% CI 18.3-29.7 months) for LS (N = 103) and 7 months (95% CI 6.1-7.9 months) for ES (N = 268). 72 of 103 patients with LS and 97 of 214 of those with ES received PCI. 54 of 268 ES presented with brain metastases (BM) of whom 46 of 54 received whole brain RT (WBRT). 18.9% (32/169) recurred post-PCI (13 LS; 19 ES) and 30.4% (14/46) recurred after WBRT. Of those who recurred/progressed after cranial RT, 56.5% (26/46) had <5 BM, 39.1% had no extracranial disease, and 50% were ECOG 0-2. In retrospect, 17 of 46 would have been candidates for salvage stereotactic radiosurgery: 13 post-PCI and 4 post-WBRT.

CONCLUSIONS

This cohort challenges commonly held beliefs that IR is always diffuse, associated with clinical deterioration, and synchronous with systemic failure. Approximately 1 in 3 SCLC patients with IR after PCI or WBRT appear clinically appropriate for salvage stereotactic radiosurgery.

[Comparison of Efficacy and Safety of Different Therapeutic Regimens as Second-line Treatment for Small Cell Lung Cancer]

背景与目的

小细胞肺癌是一种侵袭性非常强的肿瘤，其主要治疗方案是细胞毒化疗，尽管有较高的初始治疗缓解率，但大部分患者在一线治疗后会出现复发或进展。目前只有较少的证据证明二线治疗能给复发或晚期小细胞肺癌患者带来生存获益，指南推荐药物较多，但临床多依据经验制定方案。本研究回顾性分析小细胞肺癌患者不同二线治疗方案的疗效和安全性，以指导临床医生更客观地选择小细胞肺癌二线治疗方案。

方法

回顾性分析了309例接受二线治疗的小细胞肺癌患者，其中157例患者进展后仅予最佳支持治疗，其余152例患者进行了二线化疗。采用Kaplan-Meier法生存曲线及Log-rank检验等统计学方法，观察终点为客观缓解率（objective response rate, ORR）、疾病控制率（disease control rate, DCR）、无进展生存时间（progression-free survival, PFS）、总生存时间（overall survival, OS）和安全性分析。

结果

接受二线化疗的患者较二线仅接受最佳支持治疗的患者生存获益明显，两组患者自一线治疗开始的OS分别为11.5个月和6.0个月（P < 0.001），并且前者无论何种复发类型，在二线治疗ORR、DCR、PFS和OS上均明显优于后者。接受二线化疗患者，其ORR为39.5%，DCR为59.2%，中位PFS和中位OS分别为3.3个月和5.3个月。据方案将二线化疗患者分组，敏感型复发患者由采用含VP-16方案的A组和采用含CPT-11方案的B1组组成，两组ORR分别为48.6%和35.3%，DCR分别为68.6%和58.8%，均无明显差异（P值分别为0.264和0.400）；两组二线中位PFS分别为4.0个月和3.0个月，无明显差异（P=0.432）；两组中位OS分别为6.5个月和4.5个月，无统计学差异（P=0.508）。耐药/难治型复发患者由其余含CPT-11方案的B2组、含PTX/DXL方案的C组和含TPT方案的D组组成。组间ORR、DCR、二线中位PFS无明显统计学差异（P值分别为0.521、0.528和0.775）；D组中位OS优于B2组和C组，差异具有统计学意义（P值分别为0.043、0.030）。四个方案组毒副作用相似，Ⅲ度-Ⅳ度血液学毒性组间并无差异；伊立替康组的患者腹泻发生率高于其他三组（P=0.029）。

结论

二线化疗可以给一线治疗失败的小细胞肺癌患者带来生存获益；不同二线化疗方案患者的近期缓解和无进展生存相似；耐药/难治型患者二线化疗采用含TPT的方案可能会给患者带来更好的总生存获益。

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.

Modulation of cyclophosphamide-induced early lung injury by allicin

CONTEXT

Cyclophosphamide (CP) causes lung injury in rats through its ability to generate free radicals with subsequent epithelial and endothelial cell damage.

OBJECTIVE

This study was conducted to assess whether allicin can ameliorate CP-induced early lung injury in rats.

MATERIALS AND METHODS

Male Sprague Dawely rats were divided into four groups. Group I was the control group. Group II received allicin (50 mg/kg/d, p.o.) for 14 consecutive days. Group III was injected once with CP (150 mg/kg, i.p.). Group IV received allicin for seven consecutive days, before and after CP injection (150 mg/kg, i.p.). The parameters of study were serum biomarkers, lung tissue antioxidant profile and histopathological changes in lung tissue.

RESULTS

A single intraperitoneal injection of CP markedly altered the levels of several biomarkers in lung homogenates. Significant increases in lung content of lipid hydroperoxides were seen that paralleled the decreased levels of total reduced glutathione. Superoxide dismutase activity (SOD) was significantly increased. CP increased the level of serum biomarkers; total protein, lactate dehydrogenase (LDH) and tumor necrosis factor-alpha (TNF-α). Pretreatment of rats daily with oral allicin seven days prior to and seven days after CP inject significantly inhibited the development of lung injury, prevented the alterations in lung and serum biomarkers associated with inflammatory reactions, with less lipid peroxidation (LP) and restoration of antioxidants. Moreover, allicin attenuated the secretion of proinflammatory cytokine, TNF-α expression in rat serum. In addition, allicin effectively blunted CP-induced histopathological changes in lung tissue.

DISCUSSION AND CONCLUSION

Our results suggest that allicin is efficient in blunting CP-induced pulmonary damage.

Small-cell lung cancer

The incidence and mortality of small-cell lung cancer worldwide make this disease a notable health-care issue. Diagnosis relies on histology, with the use of immunohistochemical studies to confirm difficult cases. Typical patients are men older than 70 years who are current or past heavy smokers and who have pulmonary and cardiovascular comorbidities. Patients often present with rapid-onset symptoms due to local intrathoracic tumour growth, extrapulmonary distant spread, paraneoplastic syndromes, or a combination of these features. Staging aims ultimately to define disease as metastatic or non-metastatic. Combination chemotherapy, generally platinum-based plus etoposide or irinotecan, is the mainstay first-line treatment for metastatic small-cell lung cancer. For non-metastatic disease, evidence supports early concurrent thoracic radiotherapy. Prophylactic cranial irradiation should be considered for patients with or without metastases whose disease does not progress after induction chemotherapy and radiotherapy. Despite high initial response rates, most patients eventually relapse. Except for topotecan, few treatment options then remain. Signalling pathways have been identified that might yield new drug targets.

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.

New advances in the second-line treatment of small cell lung cancer

Lung cancer is the leading cause of cancer-related death in the U.K., with small cell histology accounting for 15%-20% of cases. Small cell lung cancer (SCLC) is initially a chemosensitive disease, but relapse is common, and in this group of patients it remains a rapidly lethal disease with a particularly poor prognosis. The choice of second-line chemotherapy for patients with relapsed SCLC has been an area of difficulty for oncologists, and until recently there was no randomized evidence for its use over best supportive care (BSC). Topotecan is currently the only drug licensed in Europe and the U.S. for this indication, having been shown in a phase III trial to lead to longer overall survival and better quality of life than with BSC. In this article, we review the current evidence for the use of second-line cytotoxic therapy and also the emerging role of novel agents and targeted therapies in this setting. In particular, we explore the role of the Bcl-2 protein family, which are key regulators of mitochondrial apoptosis and are implicated in resistance to anticancer therapies. SCLC overexpresses antiapoptotic members of the Bcl-2 family in approximately 80% of cases. Several Bcl-2 inhibitors, including obatoclax, are currently entering clinical trials in SCLC and are an exciting area of drug development in the relapsed setting.

Phase II study of picoplatin as second-line therapy for patients with small-cell lung cancer

PURPOSE

This study was designed to confirm the efficacy and safety of picoplatin, a cisplatin analog designed to overcome platinum resistance, in patients with small-cell lung cancer (SCLC) with platinum-refractory/-resistant disease.

PATIENTS AND METHODS

All patients received intravenous picoplatin 150 mg/m(2) every 3 weeks. Tumor response, progression-free survival, and overall survival were evaluated. Adverse events were assessed for frequency, severity, and relationship to treatment. Quality of life was assessed with the Lung Cancer Symptom Scale instrument.

RESULTS

Seventy-seven patients were treated with picoplatin (median number of cycles, two; range one to 10). Three patients (4%) had a partial response, 33 (43%) had stable disease (four of these were unconfirmed partial responses), 36 (47%) had progressive disease, and five were not assessable for response. Median progression-free survival was 9.1 weeks (95% CI, 7.0 to 12.1 weeks). Median overall survival was 26.9 weeks (95% CI, 21.1 to 33.4). The most common grade 3 and 4 toxicities were thrombocytopenia (48%), neutropenia (25%), and anemia (20%). The most commonly reported adverse events of any severity included thrombocytopenia (64%), anemia (49%), neutropenia (39%), nausea (27%), fatigue (16%), and dyspnea (16%). No severe neurotoxicity or nephrotoxicity were observed. There were no treatment-related deaths.

CONCLUSION

Picoplatin demonstrated clinical efficacy in platinum-refractory SCLC. The major toxicity was hematologic. These results warrant further evaluation in this patient population.

Small-Cell Lung Cancer: An Unusual Therapeutic Approach with More than 10-year Overall Survival. Case Report and Review of the Literature

Small-cell lung cancer is the most aggressive lung cancer, with a dismal prognosis. The authors present a case report of a patient with limited-stage small-cell lung cancer who underwent a thoracotomy for diagnostic purposes, with the diagnosis being made after surgical excision. Combination chemotherapy remains the cornerstone of treatment for both limited and extensive disease. Radiotherapy has been established as an adjunct to chemotherapy in limited-stage disease, while in extensive-stage disease it is mostly reserved for the treatment of brain metastases. As for surgery, the potential benefits of resection are predominantly seen in patients who present with a solitary pulmonary nodule. Since small-cell lung cancer becomes highly resistant to chemotherapy, second-line chemotherapeutic schemes are used for disease progression, with topotecan being the highlighted agent. Despite the unusual therapeutic approach, where surgery was preferred over the standard diagnostic and staging procedures, the patient's more than ten years’ survival makes this case presentation a very interesting one.

[Small cell lung cancer]

With about 20% of all lung cancers small cell lung cancer (SCLC) represents a major subset of this entity. Although therapeutic improvements did not receive as much attention as in non small cell lung cancer (NSCLC), many small steps of clinical progress have been achieved within the last 20 years. An optimal treatment should be based on an interdisciplinary treatment plan. The standard treatment in localized stages represents combined radiation and chemotherapy. Cisplatin and etoposide are in this concern considered as a gold standard. 3D-planned conformal radiotherapy should start as early as possible and should be applied concomitantly to chemotherapy and in certain cases even in a hyperfractionated treatment protocol. In very early stages surgical resection could be an option in selected cases. In advanced stages a platinum-based doublet offers high response rates. As already established in limited disease prophylactic cranial irradiation is now also indicated in extensive disease in case of any tumor remission. In the second line treatment and in patients with reduced performance status topotecan is recommended. Similar as in NSCLC pemetrexed might become an alternative treatment option in the second line setting. In the field of new targeted therapies bevacizumab achieved the most promising results. The present review highlights historical milestones and up-to-date trends in radiotherapy, chemotherapy and surgery. Furthermore, the role of experimental strategies and the management of certain special clinical situations are discussed.

Available treatment options for the management of Lambert-Eaton myasthenic syndrome

Lambert-Eaton myasthenic syndrome is a rare, but reasonably well-understood, antibody-mediated autoimmune disease that is caused by serum auto-antibodies and results in muscle weakness and autonomic dysfunction. One half of the patients have an idiopathic form, the other half a tumour-associated form of the disease. Three randomised trials and a large number of smaller clinical studies have resulted in a number of drugs becoming available for the treatment of Lambert-Eaton myasthenic syndrome. Several drugs are available for the symptomatic treatment of the disease, including guanidine, aminopyridines or acetylcholinesterase inhibitors. Other therapies aim to deplete the serum autoantibodies or to suppress the immune system. For this purpose, immunomodulating strategies, such as intravenous immunoglobulins or plasmapheresis, or several immunosuppressive agents are available. Chemotherapy has successfully ameliorated the course of disease in Lambert-Eaton myasthenic syndrome patients with an underlying tumour.

Prophylactic cranial irradiation in extensive small-cell lung cancer

BACKGROUND

We conducted a randomized trial of prophylactic cranial irradiation in patients with extensive small-cell lung cancer who had had a response to chemotherapy.

METHODS

Patients between the ages of 18 and 75 years with extensive small-cell lung cancer were randomly assigned to undergo prophylactic cranial irradiation (irradiation group) or receive no further therapy (control group). The primary end point was the time to symptomatic brain metastases. Computed tomography or magnetic resonance imaging of the brain was performed when any predefined key symptom suggestive of brain metastases was present.

RESULTS

The two groups (each with 143 patients) were well balanced regarding baseline characteristics. Patients in the irradiation group had a lower risk of symptomatic brain metastases (hazard ratio, 0.27; 95% confidence interval [CI], 0.16 to 0.44; P<0.001). The cumulative risk of brain metastases within 1 year was 14.6% in the irradiation group (95% CI, 8.3 to 20.9) and 40.4% in the control group (95% CI, 32.1 to 48.6). Irradiation was associated with an increase in median disease-free survival from 12.0 weeks to 14.7 weeks and in median overall survival from 5.4 months to 6.7 months after randomization. The 1-year survival rate was 27.1% (95% CI, 19.4 to 35.5) in the irradiation group and 13.3% (95% CI, 8.1 to 19.9) in the control group. Irradiation had side effects but did not have a clinically significant effect on global health status.

CONCLUSIONS

Prophylactic cranial irradiation reduces the incidence of symptomatic brain metastases and prolongs disease-free and overall survival. (ClinicalTrials.gov number, NCT00016211 [ClinicalTrials.gov].).

Phase III trial comparing supportive care alone with supportive care with oral topotecan in patients with relapsed small-cell lung cancer

PURPOSE

For patients with small-cell lung cancer (SCLC), further chemotherapy is routinely considered at relapse after first-line therapy. However, proof of clinical benefit has not been documented.

PATIENTS AND METHODS

This study randomly assigned patients with relapsed SCLC not considered as candidates for standard intravenous therapy to best supportive care (BSC) alone (n = 70) or oral topotecan (2.3 mg/m2/d, days 1 through 5, every 21 days) plus BSC (topotecan; n = 71).

RESULTS

In the intent-to-treat population, survival (primary end point) was prolonged in the topotecan group (log-rank P = .0104). Median survival with BSC was 13.9 weeks (95% CI, 11.1 to 18.6) and with topotecan, 25.9 weeks (95% CI, 18.3 to 31.6). Statistical significance for survival was maintained in a subgroup of patients with a short treatment-free interval (< or = 60 days). Response to topotecan was 7% partial and 44% stable disease. Patients on topotecan had slower quality of life deterioration and greater symptom control. Principal toxicities with topotecan were hematological: grade 4 neutropenia, 33%; grade 4 thrombocytopenia, 7%; and grade 3/4 anemia, 25%. Comparing topotecan with BSC, infection grade 2 was 14% versus 12% and sepsis 4% versus 1%; other grade 3/4 events included vomiting 3% versus 0, diarrhea 6% versus 0, dyspnea 3% versus 9%, and pain 3% versus 6%. Toxic deaths occurred in four patients (6%) in the topotecan arm. All cause mortality within 30 days of random assignment was 13% on BSC and 7% on topotecan.

CONCLUSION

Chemotherapy with oral topotecan is associated with prolongation of survival and quality of life benefit in patients with relapsed SCLC.

Small cell lung cancer: treatment review

Lung cancer was relatively uncommon at the turn of the 20th century, and has increased in prevalence at alarming rates, particularly because of the augmented trend in smoking, so that it is now the most common cause of cancer death in the world. As almost a quarter of these cancers are of small cell in origin, it seems only appropriate that small cell lung cancer receives ample attention, rather than seemingly to have been overlooked over the last 10-15 years. Despite its generally late presentation and high risk of dissemination, it is exceptionally sensitive to chemo-radiotherapy. This review looks at the diverse options of treatment that have been used over the last few years and tries to highlight the best available. As more than 50% of patients diagnosed with lung cancer are over 70 years of age and various studies have shown that older people respond just as well as their younger counterparts, with similar results in response rates, toxicity and outcomes, it is imperative that the older generation are not disregarded in terms of age being a contraindication to therapy.

Third-line chemotherapy for small cell lung cancer

Efficacy of third-line chemotherapy treatment for small cell lung cancer (SCLC) is unknown. We present our experience with third-line chemotherapy for recurrent SCLC. Between January 1996 and July 2004 all consecutive patients treated for SCLC were retrospectively studied. We recorded patient characteristics, treatment details for each subsequent regimen, response to chemotherapy and survival. From 191 patients treated with chemotherapy 35 patients (18%) received third-line chemotherapy. At the start of third-line therapy, median age was 58 years (range 36-77), male/female 54%/46%, and ECOG performance score was 0/1/2/3 in 15%/64%/12%/9% of patients. Median time from diagnosis till start of third-line treatment was 15 months (range 5-34). Tumor response to first-line, second-line, and third-line therapy was 91%, 51%, and 26%, respectively. Median survival time estimated from the start of third-line treatment was 5 months (range 1-15). No toxic deaths were observed. Comparison of characteristics of patients who were treated with third-line chemotherapy with patients treated with maximally two lines of chemotherapy revealed that those who received third-line therapy were younger (p<0.001), had a better performance score (p<0.001), and had a better response to first-line treatment (p=0.004). In conclusion, third-line chemotherapy is still active in one in four SCLC patients.

Metabolism and transport of oxazaphosphorines and the clinical implications

The oxazaphosphorines including cyclophosphamide (CPA), ifosfamide (IFO), and trofosfamide represent an important group of therapeutic agents due to their substantial antitumor and immuno-modulating activity. CPA is widely used as an anticancer drug, an immunosuppressant, and for the mobilization of hematopoetic progenitor cells from the bone marrow into peripheral blood prior to bone marrow transplantation for aplastic anemia, leukemia, and other malignancies. New oxazaphosphorines derivatives have been developed in an attempt to improve selectivity and response with reduced toxicity. These derivatives include mafosfamide (NSC 345842), glufosfamide (D19575, beta-D-glucosylisophosphoramide mustard), NSC 612567 (aldophosphamide perhydrothiazine), and NSC 613060 (aldophosphamide thiazolidine). This review highlights the metabolism and transport of these oxazaphosphorines (mainly CPA and IFO, as these two oxazaphosphorine drugs are the most widely used alkylating agents) and the clinical implications. Both CPA and IFO are prodrugs that require activation by hepatic cytochrome P450 (CYP)-catalyzed 4-hydroxylation, yielding cytotoxic nitrogen mustards capable of reacting with DNA molecules to form crosslinks and lead to cell apoptosis and/or necrosis. Such prodrug activation can be enhanced within tumor cells by the CYP-based gene directed-enzyme prodrug therapy (GDEPT) approach. However, those newly synthesized oxazaphosphorine derivatives such as glufosfamide, NSC 612567 and NSC 613060, do not need hepatic activation. They are activated through other enzymatic and/or non-enzymatic pathways. For example, both NSC 612567 and NSC 613060 can be activated by plain phosphodiesterase (PDEs) in plasma and other tissues or by the high-affinity nuclear 3'-5' exonucleases associated with DNA polymerases, such as DNA polymerases and epsilon. The alternative CYP-catalyzed inactivation pathway by N-dechloroethylation generates the neurotoxic and nephrotoxic byproduct chloroacetaldehyde (CAA). Various aldehyde dehydrogenases (ALDHs) and glutathione S-transferases (GSTs) are involved in the detoxification of oxazaphosphorine metabolites. The metabolism of oxazaphosphorines is auto-inducible, with the activation of the orphan nuclear receptor pregnane X receptor (PXR) being the major mechanism. Oxazaphosphorine metabolism is affected by a number of factors associated with the drugs (e.g., dosage, route of administration, chirality, and drug combination) and patients (e.g., age, gender, renal and hepatic function). Several drug transporters, such as breast cancer resistance protein (BCRP), multidrug resistance associated proteins (MRP1, MRP2, and MRP4) are involved in the active uptake and efflux of parental oxazaphosphorines, their cytotoxic mustards and conjugates in hepatocytes and tumor cells. Oxazaphosphorine metabolism and transport have a major impact on pharmacokinetic variability, pharmacokinetic-pharmacodynamic relationship, toxicity, resistance, and drug interactions since the drug-metabolizing enzymes and drug transporters involved are key determinants of the pharmacokinetics and pharmacodynamics of oxazaphosphorines. A better understanding of the factors that affect the metabolism and transport of oxazaphosphorines is important for their optional use in cancer chemotherapy.