Second-line chemotherapy in small cell lung cancer

Chemotherapy for small cell lung cancer: a comprehensive review

Combination chemotherapy is the current strategy of choice for treatment of small cell lung cancer (SCLC). Platinum containing combination regimens are superior to non-platinum regimens in limited stage-SCLC and possibly also in extensive stage-SCLC as first and second-line treatments. The addition of ifosfamide to platinum containing regimens may improve the outcome but at the price of increased toxicity. Suboptimal doses of chemotherapy result in inferior survival. Early intensified, accelerated and high-dose chemotherapy gave conflicting results and is not considered a standard option outside of clinical trials. A number of newer agents have provided promising results when used in combination regimens, for example, gemcitabine, irinotecan and topotecan. However, more studies are required to appropriately evaluate them. There is a definitive role for radiotherapy in LD-SCLC. However, timing and schedule are subject to further research. Novel approaches are currently being investigated in the hope of improving outcome.

Topotecan in the treatment of relapsed small cell lung cancer

Small cell lung cancer (SCLC) represents about 15% to 20% of all lung cancers. Chemotherapy is the cornerstone of the treatment, cisplatin–etoposide combination being the most used combination as first-line therapy. Despite high initial chemosensitivity, most SCLC patients will experience relapse sooner or later. Unfortunately, second-line chemotherapy does not result in a high response rate like first-line therapy, most patients having developed wide chemoresistance. This chemoresistance is far more important in refractory patients, ie, those who never responded to first-line therapy or who relapsed within 3 months after the end of chemotherapy, than in sensitive patients, ie, those who relapse more than 3 months after the end of chemotherapy. Topotecan, a topoisomerase I inhibitor, is the most studied drug in this second-line setting and has proved its efficacy as a single agent and in combination. A phase III trial comparing oral topotecan to best supportive care (BSC) in relapsed SCLC demonstrated a significant survival benefit as well as a better quality of life. Although the usual schedule is 1.5 mg/m², days 1–5 intravenously, it is not convenient for patients with relapsed SCLC, especially those who are refractory because of their short survival expectation. Oral topotecan is of similar efficacy and much more convenient with limited stay in a treatment unit and has a comparable toxicity profile for these patients with short expected survival. Combination of topotecan with platinum salts or taxanes does not seem to improve further the outcome of the patients and thus single-agent therapy with topotecan is the standard treatment for relapsed SCLC.

Combination chemotherapy with paclitaxel and ifosfamide as the third-line regimen in patients with heavily pretreated small cell lung cancer

The efficacy of salvage regimens for small cell lung cancer remains to be established. We evaluated the efficacy and safety of the paclitaxel and ifosfamide (PI) combination chemotherapy salvage regimen in heavily pretreated small cell lung cancer (SCLC) patients. Thirty-five patients who had received more than two prior chemotherapy regimens were treated with PI chemotherapy. Paclitaxel (175 mg/m(2)) was administered on day 1 and ifosfamide (2500 mg/m(2)) on day 1-2 every 3 weeks. Thirty-three patients were available for treatment response evaluation. Median age was 63 years (range, 40-78) and Eastern Cooperative Oncology Group (ECOG) performance scores of 0/1/2 were 29.4%, 61.8%, and 11.8%, respectively. A median of 2 cycles (range, 1-6) of chemotherapy were administered. The overall response rate (RR) in the intent-to-treat population was 20.0% (95% Confidence Interval (CI), 6.7-33.3%) with 7 partial responses (PR) and no complete response (CR). Patients who responded to previous chemotherapy just before PI showed significantly higher RR than non-responders (RR, 57.1% versus 10.7%, P=.023). After a median follow-up of 8.8 months (range, 1.6-14.7), the median time to progression was 3.3 months (95% CI, 2.3-4.4) and the median overall survival was 7.6 months (95% CI, 6.7-8.5). The most common toxicity observed was mild nausea/vomiting and grade 3/4 adverse events were observed in 4 (11.4%) patients. There were no treatment-related deaths in the study. Our findings suggest that salvage PI chemotherapy is a feasible and well tolerated regimen for previously treated SCLC patients. Further studies are warranted to define the effects of PI chemotherapy on quality of life and survival benefits.

Small cell lung cancer

Small cell lung cancer accounts for 13-15% of all lung cancer worldwide. There has been a decrease in the number of cases, with no clear explanation, except probably to changing in smoking habits in the last two decades. In the early eighties, it became clear that SCLC was an extremely sensitive tumor as to radiation as to chemotheraputic agents. With cisplatinum etoposide combinations or cyclophosphamide, anthracycline and vincristine/etyoposide regimens responses were observed in 50-70%, with 20-30% complete remissions in extensive disease. For limited stage patients chemotherapy associated with thoracic radiation was able to produce a cure rate of 10-20%. The addition of prophylactic brain irradiation to limited stage cases has reduced mortality by a factor of nearly 5%. But despite these early good results no breakthrough came later on, and in the last decade or so, we are still facing this plateau. New agents have recently been included in the therapeutic armamentarium, such as gemcitabine, irinotecan, paclitaxel. This fact has allowed many patients to receive a relatively active second line therapy, but the overall survival remains unchanged. Targeted therapies are undergoing some evaluations, but the data are too premature and so far quite discouraging. At the present time there is a urgent need to improve clinical research in this somehow forgotten disease.

Small cell lung cancer: state of the art and future perspectives

Small cell lung cancer accounts for less than 20% of all lung cancer. The management of this distinct tumor entity differs from the more common non-small cell lung cancer. Primary prevention of smoking exposure remains the most important public health measure. Although small cell lung is an exquisitely chemosensitive disease it remains ultimately fatal for the great majority of patients. Combination chemotherapy regimens have improved response rate and survival of the last three decades. The combination of cisplatin and etoposide has been considered the standard therapy for over a decade. More intensive triplet combination chemotherapy and high-dose chemotherapy have shown improved response rates and survival. Early concomitant and accelerated radiotherapy improves survival in limited stage disease. This review summarizes the current state of the art and future perspectives in detection, staging and standard therapy of small cell lung cancer. Particular emphasis is given to the importance of concomitant and accelerated radiotherapy and consideration of dose-intensive combination chemotherapy regimens.

Treatment and outcomes for elderly patients with small cell lung cancer

It is estimated that approximately half of the 500 000 people diagnosed with lung cancer worldwide every year are aged >70 years. Thus, this disease represents a major problem in the elderly and one that will indeed increase as the median age of the population increases. For small cell lung cancer (SCLC), which accounts for approximately 20% of cases of lung cancer, the primary treatment is chemotherapy and in the majority of cases the primary aim is to control the disease which generally would have spread beyond the lungs at the time of presentation. A small number of 'standard' chemotherapy regimens (combined with radiotherapy for patients with limited disease) have been shown to improve survival and quality of life and are widely used. Much of the work investigating the relationship between age and treatment outcomes has been based on clinical trial data and may itself be inherently biased due to trial eligibility criteria excluding elderly patients. However, there is no good evidence that elderly patients fare worse with treatment than their younger counterparts in terms of response rates and survival. Nevertheless with increasing age comes increasing concomitant illnesses which may account for the widely observed increases in drug toxicity, and this may be the primary consideration in selecting the treatment option. Thus for many elderly patients, carboplatin/ etoposide may be the treatment of choice because it is perhaps the least toxic of the standard regimens. Whatever regimen is chosen, the key to treatment effectiveness seems to be to deliver the first 3 or 4 cycles without delay or dosage reduction. Although palliation of symptoms remains a major goal in the treatment of all patients with SCLC there is a dearth of data on whether elderly patients are equally well palliated as their younger counterparts. There is no good evidence that age per se should be a factor in deciding whether patients should receive standard treatment rather than a more gentle approach, and more elderly patients should be included in clinical trials. The key areas where more information is required regarding the treatment and outcomes of elderly patients with SCLC are the assessment of palliation, and comprehensive reviews of all patients diagnosed with the disease, not just those included in trials.

Management of small cell lung cancer: current state of the art

Small cell lung cancer (SCLC) is a common malignancy that is rapidly fatal if left untreated, with most patients surviving < 6 months. Currently, patients with SCLC are treated with chemotherapy with or without thoracic radiotherapy. Randomized trials have demonstrated the superiority of multiagent regimens over single-agent therapies, with the combination of cisplatin and etoposide being the initial regimen of choice for most patients, regardless of stage at presentation. Dose escalation, weekly chemotherapy, alternating noncross-resistant chemotherapy, and maintenance chemotherapy have been evaluated in SCLC, with no convincing data to date demonstrating an advantage for these strategies over conventional treatment strategies. Second-line therapy may be effective in selected patients, depending on the interval between primary treatment and recurrence, response to primary therapy, and the agents used for initial treatment. Radiotherapy is generally accepted as an essential component of optimal management of limited-stage disease, although sequencing, timing, fractionation, dose, and field size remain less than adequately defined. Finally, the routine use of prophylactic cranial irradiation remains controversial, and currently should be reserved for patients in complete remission.

Second-line chemotherapy and its evaluation in small cell lung cancer

The literature on second-line chemotherapy for small cell lung cancer between 1989-1999 is reviewed. The reports consisted mainly of phase II studies and included a total of 1749 patients. The information was frequently incomplete with respect to duration of response on first-line chemotherapy and the length of treatment free interval. The overall second-line response rate was 20%. Obviously, new chemotherapy regimens are needed for relapsed small cell lung cancer. We propose a methodology for future trials based on the distinction between sensitive and refractory patients. The latter group of patients who progress on or within a short time of induction of treatment are candidates for single arm phase II trials with agents with unknown or new mechanisms of action or new combination regimens. The sole endpoint of this type of phase II studies is response rate. For sensitive patients we propose re-induction chemotherapy as the standard against which investigational agents or combination regimens should be tested. Major end-points include response rate, toxicity and quality of life. Regimens with demonstrated therapeutic activity in this setting could be tested as first-line chemotherapy in phase II trials.

Paclitaxel and carboplatin in the treatment of small-cell lung cancer patients resistant to cyclophosphamide, doxorubicin, and etoposide: a non-cross-resistant schedule

PURPOSE

To evaluate the efficacy of paclitaxel and carboplatin (PC) in small-cell lung cancer (SCLC) patients resistant to cyclophosphamide, doxorubicin, and etoposide (CDE).

PATIENTS AND METHODS

We performed a phase II study with PC in SCLC patients who relapsed within 3 months after first-line treatment with CDE. Paclitaxel administration (175 mg/m2 by a 3-hour intravenous infusion) was followed by a 30-minute infusion of carboplatin (area under the curve 7; Chatelut formula) once every 3 weeks for five cycles. Dexamethasone, clemastine, and ranitidine were standard premedication before every cycle.

RESULTS

Included were 35 patients (median age, 59 years; 16 with limited disease and 19 with extensive disease; Eastern Cooperative Oncology Group performance status of < or = 1; median time off treatment 6 weeks) who were previously treated with CDE (n = 33), oral etoposide (n = 2), and reinduction CDE (n = 15); only one patient had received three CDE treatments of five cycles. The CDE regimen was followed by local thoracic radiotherapy in seven patients. Hematologic toxicity of grade 3 or 4, for leukopenia was 27% and 6%, for thrombocytopenia 21% and 13%, and for anemia 17% and 0%, respectively, for a total of 132 cycles. Two patients had neutropenic fever; no toxic death occurred. Nonhematologic toxicity was paresthesia CTC grade 3, diarrhea grade 4, and myalgia grade 3 in one patient each. Reversible paresthesia (CTC grade 1 and 2) in toes and fingers was reported in 69% of patients. Thirty-four patients were assessable for response: complete response in two patients, partial response in 23 patients, stable disease in eight patients, and progressive disease in one patient (response rate, 73.5%; 95% confidence interval, 59% to 88%). One patient was found to have atypical carcinoid at pathologic review and was excluded. Median time to progression was 21 weeks (range, 3 to 40 weeks). Median survival was 31 weeks (range, 6 to 112 weeks). One-year survival was 9%.

CONCLUSION

Second-line PC in CDE-resistant SCLC patients yields a high response rate and seems non-cross-resistant to CDE. Toxicity was mild in these poor-prognosis patients.

A phase II study of paclitaxel in heavily pretreated patients with small-cell lung cancer

The purpose of the study was to delineate the efficacy and toxicity of paclitaxel (Taxol, Bristol Myers Squibb) in the treatment of drug resistant small-cell lung cancer (SCLC). Patients with SCLC relapsing within 3 months of cytotoxic therapy received paclitaxel 175 mg m(-2) intravenously over 3 h every 3 weeks. The dose of paclitaxel was adjusted to the toxicity encountered in the previous cycle. Of 24 patients entered into the study, 24 and 21 were assessable for response and toxicity respectively. There were two early deaths and two toxic deaths. No complete and seven partial responses (29%) (95%CI 12-51%) were observed and five patients had disease stabilization. The median survival (n = 21) was 100 days. Life-threatening toxicity occurred in four patients; in others (non)-haematological toxicity was manageable. Paclitaxel is active in drug-resistant SCLC. Further investigation in combination with other active agents in this poor prognosis group is appropriate.

Fucosyl-GM1 in small-cell lung cancer. A comparison with the tumour marker neuron-specific enolase

BACKGROUND

Recently, the ganglioside Fucosyl-GM1 (FucGM1) has been described as a possible new tumour marker for small-cell lung cancer (SCLC). FucGM1 has been detected in 75% to 90% of SCLC tumours by immunohistochemical analysis and in about 50% of sera from SCLC patients. Neuron-specific enolase (NSE) is a glycolytic enzyme which is expressed in the majority of SCLC tumours and patient sera.

PATIENTS AND METHODS

Sera from 156 patients with SCLC were analyzed for FucGM1 with a scintillation proximity assay (SPA), which is a simple and sensitive analysis. Sera were analyzed before the initiation of chemotherapy, and twenty patients were monitored during and after treatment. The concentration of FucGM1 was compared to the tumour marker NSE and related to clinical data and survival.

RESULTS

Sixty-three per cent of the patients were positive for FucGM1. The concentrations did not correlate with NSE or clinical data including stage of disease, organ site of metastases or ABO blood group status. Nor did the expression of FucGM1 correlate with survival. As a monitor of clinical response, a correlation was found in 8 out of 20 patients. Eighty-four per cent of the patients were positive for NSE; and 97% were positive for either FucGM1 or NSE.

CONCLUSION

We conclude that FucGM1 does not have a clinical role as a tumour marker for patients with SCLC at diagnosis or during treatment.