Monitoring tumour cells in the peripheral blood of small cell lung cancer patients

BACKGROUND

Flow cytometry was used to enumerate tumour cells in longitudinal studies of peripheral blood from small cell lung cancer (SCLC) patients, together with magnetic bead selection to isolate and identify these cells. As part of a trial, 11 patients received either standard (four weekly) chemotherapy with ifosfamide, carboplatin, and etoposide (ICE) or accelerated (two weekly) ICE with filgrastim (granulocyte colony-stimulating factor [G-CSF]) and autologous stem cell support.

METHODS

Fresh venous blood was taken throughout treatment and follow-up. Aliquots were stained with a "tumour-specific" antibody against epithelial tissue (Ber EP4), verified as a good marker of SCLC cells by immunohistochemistry. Matched samples labelled with Ber EP4 were separated magnetically by adding a secondary bead-antibody conjugate for confirmation of tumour cell identity.

RESULTS

Circulating tumour cells were detected and monitored throughout treatment periods. An initial rise in circulating cells after the first cycle was followed by a fall in both treatment arms to baseline levels set by normal controls. This was achieved by week 12 in the accelerated treatment arm and by week 24 in the standard arm.

CONCLUSIONS

Flow cytometry and magnetic bead isolation can be used to identify changes in numbers of circulating tumour cells in patients undergoing chemotherapy for SCLC and thereafter during follow-up periods. Absence of tumour cells may indicate a more favourable patient group who would benefit from a more intense course of treatment.

Randomized phase II study of cyclophosphamide, doxorubicin, and vincristine compared with single-agent carboplatin in patients with poor prognosis small cell lung carcinoma

BACKGROUND

Information on the effect of chemotherapy in a group of patients with poor prognosis, poor performance status small cell lung carcinoma (SCLC) is scarce. A randomized study comparing single-agent carboplatin with combination chemotherapy in this largely unreported population of SCLC patients was undertaken.

METHODS

One hundred nineteen patients were allocated to four cycles of either cyclophosphamide, doxorubicin, and vincristine (CAV) or single-agent carboplatin. Patients had either a Karnofsky performance score < or = 50 and/or a prognostic score indicative of a 1-year survival rate < or = 15%.

RESULTS

Grade 3-4 neutropenia and intravenous antibiotic use were significantly more common with the CAV regimen (P < 0.005). Conversely, Grade 3-4 thrombocytopenia was more common (P < 0.0009) and platelet transfusion was more frequent (P < 0.05) with carboplatin therapy. Nonhematologic toxicity was similar in both treatment arms, except for alopecia with CAV therapy (P < 0.0007). Symptom relief occurred in 48% and 41% of patients in the CAV and carboplatin treatment arms, respectively. Dyspnea was improved in 66% and 41% of patients and cough was improved in 21% and 7% of patients in the CAV and carboplatin treatment arms, respectively. CAV therapy produced a higher response rate than carboplatin (38% vs. 25%), but this was not statistically significant (P = 0.15). The median overall survival for patients in the CAV and carboplatin treatment arms was 17 weeks and 15.9 weeks, respectively, with 1-year survival rates of 12% and 6%.

CONCLUSIONS

Single-agent carboplatin is a feasible treatment in patients with poor prognosis SCLC and produces response rates, relief of tumor-related symptoms, and survival similar to what is seen in patients who receive CAV chemotherapy. The lower risk of life-threatening sepsis and less need for hospitalization or intravenous antibiotic courses is advantageous in this susceptible patient population.

Gender and survival in malignant tumours

BACKGROUND

Epidemiological evidence supports the existence of a survival advantage for female patients with melanoma. This survival advantage often persists when other prognostic variables are taken into account. The basis for this female advantage or male disadvantage is not established although female sex steroids can retard melanoma invasion in vitro.

DESIGN

In considering the mechanisms involved, we have examined the literature to establish whether this female survival advantage is shared by other solid tumours. The tumours selected were breast, lung, colorectal, oesophageal, gastric, pancreatic and soft tissue sarcoma. A Medline database search was carried out to identify those studies in which gender was investigated as a prognostic indicator.

RESULTS

Results from large, mostly retrospective series show that for 5 of these 7 tumour groups, there is evidence for a female survival advantage. In particular, this survival advantage is usually more prominent in early stage disease.

CONCLUSION

Melanoma is not unique in showing a female survival advantage. Although the current literature does not address the mechanisms involved, we suggest that these are worth investigating as they may contribute to new treatment modalities aimed at preventing metastatic spread.

Oestrogenic steroids and melanoma cell interaction with adjacent skin cells influence invasion of melanoma cells in vitro

The invasion of melanoma is complex and multi-staged and involves changes in both cell/extracellular matrix (ECM) and cell/cell interactions. Female steroids and alpha-MSH have also been reported to influence metastatic melanoma progression, but their mechanisms of action are unknown. Accordingly, our aim was to establish in vitro models to examine (a) the influence of sex steroids and alpha-melanocyte-stimulating hormone (alpha-MSH) on tumour invasion and the influence of (b) ECM proteins and (c) adjacent cells on melanoma invasion. In the first model, melanoma cell invasion through fibronectin over 20 hr under serum-free conditions was used to investigate the effects of 17beta-oestradiol and oestrone on the invasion of human melanoma cell lines, A375-SM and HBL. A375-SM, but not HBL cells, proved very susceptible to inhibition by female steroids. However, invasion of the HBL line was inhibited by alpha-MSH. Using the second model of reconstructed human skin based on de-epidermised acellular dermis, we found that the HBL cells on their own failed to invade into the dermis (irrespective of the presence or absence of the basement membrane). However, there was a significant synergistic interaction between keratinocytes, fibroblasts and HBL cells, such that a modest invasion of HBLs into the dermis was seen within 2 weeks when other skin cells were present. In contrast, A375-SM cells showed a significant ability to invade the dermis in the absence of other cells, with less invasion when other skin cells were present. In summary, these models have provided new information on the extent to which melanoma cell invasion is sensitive to oestrogenic steroids and to alpha-MSH and to interaction, not only with adjacent skin cells but also to the presence of basement membrane antigens.

Guidelines for the stratification of patients recruited to trials of therapy for low-risk gestational trophoblastic tumor

OBJECTIVE

The aim of the study was to initiate a search for factors which might independently predict the need for salvage therapy in patients with low-risk gestational trophoblastic tumor.

METHODS

The independent effect of six factors on the need for salvage chemotherapy was assessed in patients with low-risk gestational trophoblastic tumor who were treated with low-dose methotrexate and folinic acid. The accuracies of World Health Organization and Charing Cross Hospital scores were also compared.

RESULTS

Age, pretreatment beta hCG, antecedent pregnancy-treatment interval, and the presence of chest metastases detected on chest X ray were not significantly predictive. The size of tumor (P = 0.001) and the presence of chest metastases on chest computerized tomography (P = 0. 00028) had independent, statistically significant predictive power, and a simple prognostic index was derived from these variables. The World Health Organization score was found to be significantly better than the Charing Cross Hospital score. The accuracy of the simple prognostic index was slightly greater than that of the World Health Organization score, although this was not statistically significant.

CONCLUSIONS

These results confirm that patients entered into studies of different therapies for low-risk gestational trophoblastic tumor should be stratified and that a simple score, derived from the results of tumor size and chest computerized tomography, is potentially as good as the World Health Organization score for predicting the need for salvage therapy.

A randomized phase III study comparing dacarbazine, BCNU, cisplatin and tamoxifen with dacarbazine and interferon in advanced melanoma

The purpose of this study was to compare the response rate, overall and 1-year survival in patients with advanced melanoma treated with a standard therapy, dacarbazine and interferon-alpha (DTIC/IFN), or combination chemotherapy, consisting of dacarbazine, BCNU, cisplatin and tamoxifen (DBCT). Treatment toxicity and time spent in hospital were secondary end points. One hundred and five patients (of whom 100 were eligible) were randomized to receive either DTIC/IFN or DBCT. The trial was designed to detect a 25% absolute difference in response rate or in 1-year survival with 80% power. There was no significant difference in response rate: this was 17.3% with DTIC/IFN and 26.4% with DBCT. Median overall survival was similar at 199 and 202 days respectively. One-year survival rate favoured standard treatment (30.6 vs 22.6%), but did not differ significantly between arms. DBCT was associated with significantly greater haematological toxicity, and a greater need for time spent in hospital (5.75 days/treatment cycle vs 2.29 with dacarbazine and interferon). DBCT combination therapy cannot be recommended as standard treatment for advanced melanoma. Dacarbazine remains the standard chemotherapy for this condition.

Investigation of female survival benefit in metastatic melanoma

Epidemiological studies show female survival benefit in advanced metastatic melanoma. In investigating a possible mechanism for this female survival benefit, we have previously reported that the female steroid 17beta-oestradiol significantly reduces invasion of a human melanoma cell line (A375-SM cells) and ocular melanoma cells through fibronectin. Neither cell type was found to possess oestrogen receptor-alpha. The aim of the current study was to obtain further information on the extent to which progression of cutaneous melanoma might be sex steroid sensitive by (a) examining the relationship between circulating sex steroids, sex hormone binding globulin and disease progression; (b) examining the relationship between sex steroid structure and the ability of steroids to reduce invasion of a melanoma cell line in vitro; and (c) examining the effects of sex steroids on proliferation of these cells in vitro. We report a significant reduction in circulating oestrone with disease progression in male but not female patients. Examining steroids for their ability to inhibit invasion of A375-SM cells through fibronectin in vitro, oestrogenic compounds (17beta-oestradiol and oestrone) were found to inhibit invasion; in this respect, oestrone was approximately 50 times more potent than 17beta-oestradiol; steroids lacking the benzene ring structure did not inhibit invasion, indeed dehydroepiandrosterone (DHEA) which acts as a precursor to androgenic steroids significantly enhanced invasion. Proliferation of A375-SM cells was unaffected by 17beta-oestradiol, oestrone or dihydrotestosterone when cells were cultured on plastic; in contrast, all three steroids induced modest proliferation of cells when grown on fibronectin with dihydrotestosterone the most mitogenic of the three steroids. These data are consistent with sex steroids playing a role in melanoma progression.

MDR-1 expression in non-Hodgkin's lymphomas is unrelated to treatment intensity or response to therapy

Over-expression of the MDR-1 gene, which codes for P-glycoprotein, is thought to be an important mechanism in the drug resistance exhibited by many tumours. A number of chemotherapeutic agents which induce MDR-1 expression are also components of combination chemotherapies that are used in the treatment of high grade non-Hodgkin's lymphomas (NHL). We have therefore examined expression of MDR-1 in a series of NHL by Northern blot analysis as well as investigated the localization of P-glycoprotein by immunohistochemistry. The series included 11 hyperplastic reactive nodes and tonsils, 17 low grade NHL and 15 high grade NHL. The levels of MDR-1 mRNA were quantified by scanning densitometry and comparison with levels of glucose-6-phosphate dehydrogenase (G6PD). The MDR-1 mRNA was observed in both non-malignant and NHL tissues. Immunohistochemical staining revealed that expression of MDR-1 mRNA in reactive nodes was related to the presence of P-glycoprotein in lymphocytes, however, P-glycoprotein was apparent in both the reactive lymphocytes and tumour cells in the NHL samples. Elevated mRNA levels (2-3 fold increase) were observed in some low grade and high grade NHL relative to those observed in reactive lymphoid tissue. There appeared to be little correlation, however, between expression of the MDR-1 gene and either treatment intensity or response to therapy. The drug resistance that is often encountered in NHL patients is therefore likely to involve mechanisms other than over-expression of P-glycoprotein.

Continuous infusion of 5-fluorouracil with alpha 2b interferon for advanced colorectal carcinoma

Thirty patients with symptomatic colorectal carcinoma were commenced on treatment with 5-fluorouracil (2.5 g week-1) administered by continuous intravenous infusion and alpha 2b interferon (3 x 10(6) U s.c. three times a week). Six out of 30 patients (20%) achieved a partial response. Three patients (10%) had stable disease and 21 patients (70%) progressed on treatment. Twenty patients (67%) completed ten or more weeks of treatment. In nine patients, treatment was withdrawn after 2-9 weeks because of disease progression or death. One patient's treatment was interrupted by emergency surgery. The median survival for all patients was 210 days (7 months). The principal side-effects were oral mucositis (12/30 patients), nausea (8/30 patients) and transient diarrhoea (4/30 patients), and initial constitutional symptoms due to alpha 2b interferon. The combination of low-dose continuous infusional 5-fluorouracil and low-dose alpha 2b interferon is well tolerated but has no obvious advantage over alternative infusional regimens using 5-fluorouracil as a single agent.

Chemotherapy with vincristine/ifosfamide/carboplatin/etoposide in small cell lung cancer

Although chemotherapy is considered the cornerstone of treatment for small cell lung cancer (SCLC), the majority of SCLC patients relapse and die of their disease within 2 years of diagnosis. Until newer, more effective drugs are developed, both optimization of available chemotherapeutic regimens and the use of combined chemotherapy/radiotherapy will be required to improve the survival of SCLC patients. Combining ifosfamide, carboplatin, and etoposide, among the most active single agents against SCLC, into the ICE regimen was a logical move that has resulted in improved response and survival rates. In limited and extensive SCLC, respectively, ICE and ICE administered with vincristine (VICE) have achieved overall response rates of 79% to 94% and 77% to 100% and 2-year survival rates of 24% to 33% and 9% to 25%, respectively. Treatment-related toxicities, especially myelosuppression, have hindered efforts to accelerate the administration of ICE and VICE regimens and to incorporate them into combined-modality treatments. However, the use of hematologic support measures, including growth factors and peripheral blood progenitor cells, may pave the way for maximizing the effectiveness of these regimens.

Therapy for small cell lung cancer using carboplatin, ifosfamide, etoposide (without dose reduction), mid-cycle vincristine with thoracic and cranial irradiation

The aim of this study was to assess the efficacy and toxicity of intensive chemotherapy, administered without dose reduction, with cranial and thoracic radiotherapy given when possible as a single fraction in small cell lung cancer. 87 patients were eligible on the basis of good performance status, normal or near normal biochemistry and clinical staging, 73 limited and 14 extensive stage, computed tomography scanning was not mandatory. Six cycles of carboplatin, ifosfamide and etoposide with vincristine on day 15 at 4 weekly intervals were planned. Dosages were not reduced in response to myelosuppression. Prophylactic cranial irradiation (PCI) as a single fraction after the first cycle and thoracic irradiation (when possible as a single fraction) following the third cycle were delivered. Seventy-two per cent of patients completed the protocol. Complete response rate was 55% and 26% of patients had a partial response. The median nadirs of neutropenia were 0.5 x 10(9)/l and thrombocytopenia 14 x 10(9)/l, with 6% probable treatment-related deaths. Performance status and dyspnoea improved markedly to normal or near normal levels following the second course. Brain metastases occurred in 13% of patients. The median survival was 16.2 months with a 2-year survival of 31% (95% confidence interval, 24-41%) for a minimum follow-up of 26 months. These results compare favourably with other combined modality studies, using multiple radiotherapy fractions with cisplatin-based combinations and dosage reduction for patients staged in more anatomical detail. The toxicity spectrum and efficacy data could lead to the use of this chemotherapy regimen with haematopoietic growth factors and, in the future, peripheral blood progenitor cell rescue.

Asthma in pregnancy complicated by iatrogenic pulmonary oedema

We report a unique case of near fatal acute pulmonary oedema developing with intravenous ritodrine, given in an attempt to suppress premature labour. The novel aspect of the case is that the patient had also been treated in the previous week with high dose nebulized beta-agonists for an episode of acute severe asthma, demonstrating that this idiosyncratic reaction to beta-adrenergic agents only occurs with the intravenous route of administration. The management of acute severe asthma occurring in pregnancy is discussed with a review of previous literature regarding possible mechanisms of beta 2-agonist-induced pulmonary oedema.