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R Arriagada

Publications and source records attributed to R Arriagada.

At least 73 records · Page 4Linked to original sources
PubMed1994

Early stopping rules and long-term follow-up in phase III trials.

The main advantage of interim analyses is that a randomized trial can be concluded in advance. As a consequence, the cost is reduced and the protection of the individual is increased from an ethical point of view. Formal statistical methods are, however, necessary to control the overall significance level and the power of the trial. Group sequential analysis and triangular test properties are compared in the setting of randomized trials with a long-term follow-up. Potential biases secondary to the conduct of the first analyses on a small number of events are discussed. Conservative methods which employ stringent criteria for the first analyses should be used to avoid loss of power in subsequent comparisons of long-term survival when early stopping occurs. Early stopping leads to less precision in the estimation of the treatment effect as the size of the sample is reduced. Furthermore, the observed effect could be biased upwards when trials are stopped early because the effect is larger than expected and biased downwards because the effect is lower than expected. Finally, as the ultimate goal of a trial is to alter therapeutic strategies, data should always be consistent so that the medical community can be convinced that treatment management should be modified.

Clinical Trials, Phase III as Topic↗
PubMed1994

Radiotherapy alone versus combined chemotherapy and radiotherapy in unresectable non-small cell lung carcinoma.

We report the results observed in a large randomized study comparing radiotherapy alone to combined radiotherapy and chemotherapy in unresectable squamous cell and large cell lung carcinoma. Radiation dose was 65 Gy in both groups and chemotherapy included vindesine, cyclophosphamide, cisplatin and lomustine. One hundred seventy-seven patients received radiotherapy alone, and 176 received the combined treatment. The 2-year survival rate was 14% for patients receiving radiotherapy vs. 21% for patients receiving the combined treatment (P = 0.02). The distant metastasis rate was significantly lower in the group receiving the combined treatment (P < 0.001). Local control at 1 year was poor in both groups (17% and 15%, respectively) and remains a major problem in locally advanced non-small cell lung cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Alternating radiotherapy and chemotherapy in limited small cell lung cancer: the IGR protocols. French FNCLCC Lung Cancer Study Group.

Two-hundred two patients with limited small cell lung cancer were tested by four consecutive alternating radiotherapy and chemotherapy protocols. The alternating schedule consisted of six cycles of chemotherapy (doxorubicin, etoposide, and cyclophosphamide, plus methotrexate in the first protocol; cisplatin replaced methotrexate in the other three protocols) and three courses of thoracic radiotherapy at a total dose of 45, 55, 65 and 61 Gy in the four consecutive protocols, respectively. A 1-week rest followed each chemotherapy cycle and each course of radiotherapy. Seventy-six percent of patients were in complete remission at the end of the induction treatment. Overall results showed a 2-year cumulative incidence rate of failure of 75%. The first cause of failure was local recurrence only, 33%; distant only, 25%; distant and local simultaneously, 9%; and intercurrent death, 8%. Overall survival rate at 5 years was 16%. No significant differences were observed between the four treatment groups. Alternating radio-chemotherapy approaches are feasible and currently included in Phase III trials.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Initial chemotherapeutic doses and survival in patients with limited small-cell lung cancer.

BACKGROUND: Moderate increases in the initial doses of certain chemotherapeutic drugs, such as cisplatin and cyclophosphamide, may prolong overall survival in patients with limited small-cell lung cancer. METHODS: We conducted a prospective study of 105 patients with limited small-cell lung cancer. The patients were randomly assigned to receive higher or lower initial doses of cisplatin (100 or 80 mg per square meter of body-surface area) and cyclophosphamide (300 or 225 mg per square meter daily for four days); all patients received the same doses of doxorubicin and etoposide. The first course of chemotherapy was followed by five additional courses and by three courses of radiotherapy. All patients received the lower doses of cisplatin and cyclophosphamide and the same doses of doxorubicin and etoposide from the second through the sixth cycle of chemotherapy. RESULTS: The median follow-up was 33 months. The two-year survival rate for the 55 patients who received the higher doses of chemotherapy was 43 percent, as compared with 26 percent for the 50 patients who received the lower doses (P = 0.02). The rates of complete response at six months were 67 percent in the higher-dose group and 54 percent in the lower-dose group (P = 0.16). Disease-free survival at two years was 28 percent in the higher-dose group, as compared with 8 percent in the lower-dose group (P = 0.02). Side effects from treatment were not increased in the higher-dose group. CONCLUSIONS: Higher initial doses of cyclophosphamide and cisplatin improve disease-free and overall survival in patients with limited small-cell lung cancer.

Aged↗
PubMed1993

Response of small-cell lung cancer xenografts to chemotherapy: multidrug resistance and direct clinical correlates.

BACKGROUND: Patients with small-cell lung carcinomas (SCLCs) initially respond to combination chemotherapy. Only a few benefit in terms of long-term survival because most relapse. Such outcome may be attributable to development of multidrug resistance. PURPOSE: The response of SCLC to chemotherapy was examined in terms of (a) patient survival, (b) drug sensitivity of tumors in patients and of tumor xenografts in nude mice, and (c) expression of multidrug resistance gene MDR1 and GST-pi gene. METHODS: Tumor samples obtained from seven untreated patients and from one patient both before and after chemotherapy were transplanted into nude mice. The patients were treated with a combination of cyclophosphamide (C'), cisplatin (C), doxorubicin (A), and etoposide (V) (C'CAV) or C'AV and radiotherapy. Drug sensitivity of SCLCs was tested in nude mice that had received tumor xenografts from these seven patients. The expression of MDR1 and GST-pi genes was assessed in the mRNA extracted from xenografts by Northern blot analysis. P-glycoprotein was quantified by enzyme immunoassay. RESULTS: The patients' responses to C'CAV closely correlated with those of the corresponding xenografts. The tumors of the two patients who showed long-term survival after C'CAV completely regressed when they were transplanted into nude mice and subsequently treated with C'CAV. Despite initial complete response, the remaining five patients died during year 1. A high percentage of mice receiving the tumor grafts from these five patients showed only partial tumor regression after C'CAV treatment. The MDR1 transcript was detected in all five of these xenografts. Four of five xenografts were from untreated patients, and the fifth was from a treated patient. MDR1 mRNA expression was absent in the tumor of this fifth patient before chemotherapy, but both the mice receiving the corresponding xenograft and the patient showed expression of MDR1 after C'CAV treatment. MDR1 mRNA expression was absent in the tumor xenografts obtained from two patients with long-term survival. Expression of P-glycoprotein correlated with MDR1 mRNA expression. All xenografts except one expressed the GST-pi gene. CONCLUSIONS: The absence of MDR1 gene expression during chemotherapy for SCLC indicates a favorable prognosis, gene expression is often coincident with ineffective chemotherapy, and tumor xenografts can be appropriately used to predict response to chemotherapy. IMPLICATIONS: Failure of chemotherapy to control SCLC seems to be related to an acquired multidrug resistance involving the MDR1-mediated mechanism. Therapeutic benefit could therefore be expected from chemotherapy combined with inhibitors of MDR1.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Meta-analysis.

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Carcinoma, Small Cell↗
PubMed1993

Response of a multidrug-resistant human small-cell lung cancer xenograft to chemotherapy.

Small-cell lung carcinomas (SCLC) are highly responsive to various chemotherapies. However only a minority of patients benefit from long survival. SCLC patients treated at the Institut Gustave Roussy received a combined chemotherapy (CCAV) including cisplatin, cyclophosphamide (Cpa), Adriamycin (doxorubicin; Adm) and vepeside (VP16). We report here the intrinsic sensitivity of a small-cell lung carcinoma, designated SCLC-6, grafted in nude mice. This xenografted tumour was derived from an untreated patient. The CCAV regimen given to the patient donor of the tumour sample resulted in a complete response followed by recurrence and death, 8 months after the initial cure. The expression of P-glycoprotein encoded by the MDR1 gene was detected with the C219 antibody on the membrane of SCLC-6 tumour cells. When given to SCLC-6-tumour-bearing nude mice, CCAV induced a strong inhibition of tumour growth (84% of growth inhibition, 20 days after start of the treatment), but no cure. Intensification of CCAV doses did not improve the response. The efficacy of individual agents of the CCAV, given at maximal tolerated doses was analysed. Only cisplatin (10 mg/kg) and Cpa (3 x 50 mg/kg) inhibited SCLC-6 growth (79% and 100% inhibition respectively), VP16 (3 x 24 mg/kg) was poorly efficient (42%) and Adm (10 mg/kg) not at all. Two-drug combinations such as cisplatin plus VP16 or cisplatin plus Cpa inhibited tumour growth (81% and 70%, respectively). Curiously, the efficacy of Cpa, given in combination with cisplatin was less than that of Cpa alone. Repeated treatments with CCAV administered to mice at each in vivo passage of the tumour induced a loss of chemosensitivity, which was observed until the ninth passage. An improvement of the therapeutic response was obtained by adding a headline reverser of multi-drug resistance, verapamil (25 mg/kg), to CCAV (81% versus 63% inhibition). MDR1-related resistance appeared to play a role in the failure of SCLC-6 chemotherapy; frequent recurrences after treatment with cisplatin and Cpa, two drugs that are not recognized by the P-glycoprotein, indicated that other modes of resistance were simultaneously active.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Radiotherapy alone in breast cancer. Analysis of tumor and lymph node radiation doses and treatment-related complications. The experience of the Gustave-Roussy Institute and the Princess Margaret Hospital.

This retrospective analysis was conducted on breast cancer patients treated by radiotherapy alone at The Princess Margaret Hospital and at the Institut Gustave-Roussy. These patients had either operable tumors, but were unfit for general anesthesia, or had inoperable tumors due to local contraindications to surgery. Previous results showed that a radiation dose increase of 15 Gy can decrease the relative risk of tumor or lymph node recurrence twofold. In this third report, the same data were analyzed to determine the treatment-related complication rates and to correlate these to the radiation dose levels. Overall results were analyzed on 453 patients, but detailed analyses on complications were conducted on 372 patients not developing local recurrence in the first 6 months of follow-up. Each complication was graded on a 3-level previously defined scale. Most frequent complications were skin changes of different degrees, which were usually asymptomatic. More disabling complications were arm edema, impaired shoulder mobility, rib fractures and brachial plexopathy. The incidence of disabling complications was low. The only factor significantly increasing the risk of complications was the radiation dose level to the tumor and axilla. Technical factors such as overlapping fields should also be taken into account. As the more effective control of tumor and lymph nodes obtained in patients treated with higher radiation doses is counterbalanced by an increase in the complication rate, the dose to be delivered for each patient should be carefully chosen according to individual risk factors.

Arm↗
PubMed1993

Results of a randomized clinical trial comparing two radiation schedules in the palliative treatment of brain metastases.

In 216 patients with brain metastases two schedules of brain irradiation were compared in a randomized trial: one course of 18 Gy/3 fractions/3 days versus the same fractionation followed by a second course of radiotherapy with a one-month time interval. The second course was identical to the first one or delivered 25 Gy/10 fractions/14 days. No difference in overall survival, nor in the neurologic response or in the incidence of complications was demonstrated. Two clinical factors appeared to be prognostic of the overall survival: the presence of multiple brain metastases and the presence of extracerebral metastases.

Brain Neoplasms↗
PubMed1992

A meta-analysis of thoracic radiotherapy for small-cell lung cancer.

BACKGROUND: In spite of 16 randomized trials conducted during the past 15 years, the effect of thoracic radiotherapy on the survival of patients with limited small-cell lung cancer remains controversial. The majority of these trials did not have enough statistical power to detect a difference in survival of 5 to 10 percent at five years. This meta-analysis was designed to evaluate the hypothesis that thoracic radiotherapy contributes to a moderate increase in overall survival in limited small-cell lung cancer. METHODS: We collected individual data on all patients enrolled before December 1988 in randomized trials comparing chemotherapy alone with chemotherapy combined with thoracic radiotherapy. Trials that included only patients with extensive disease were excluded. RESULTS: The meta-analysis included 13 trials and 2140 patients with limited disease. A total of 433 patients with extensive disease were excluded. Overall, 1862 of 2103 patients who could be evaluated died; the median follow-up period for the surviving patients was 43 months. The relative risk of death in the combined-therapy group as compared with the chemotherapy group was 0.86 (95 percent confidence interval, 0.78 to 0.94; P = 0.001), corresponding to a 14 percent reduction in the mortality rate. The benefit in terms of overall survival at three years (+/- SD) was 5.4 +/- 1.4 percent. Indirect comparison of early with late radiotherapy and of sequential with non-sequential radiotherapy did not reveal any optimal time for treatment. There was a trend toward a larger reduction in mortality among younger patients: the relative risk of death in the combined-therapy as compared with the chemotherapy group ranged from 0.72 for patients less than 55 years old (95 percent confidence interval, 0.56 to 0.93) to 1.07 (0.70 to 1.64) for patients over 70. CONCLUSIONS: Thoracic radiotherapy moderately improves survival in patients with limited small-cell lung cancer who are treated with combination chemotherapy. Identification of the optimal combination of chemotherapy and radiotherapy will require further trials.

Age Factors↗
PubMed1992

Risk factors for failure of immediate breast reconstruction with prosthesis after total mastectomy for breast cancer.

BACKGROUND: Immediate breast reconstruction (IBR) after mastectomy represents a clear improvement in the quality of life of patients with breast cancer, but prosthesis removal is relatively frequent. Therefore, it is important to identify risk factors related to this removal. METHODS: A series of 142 patients treated with mastectomy and IBR at the Institut Gustave-Roussy between January 1976 and December 1988 were studied. Forty-seven had an in situ carcinoma, 93 an infiltrating carcinoma, and 2 a fibrosarcoma. IBR failures were defined as removal of the prosthesis, and early failures as removal during the first 7 weeks after IBR. RESULTS: The early failure rate was significantly higher in patients with invasive carcinomas or fibrosarcomas than patients with in situ carcinomas (12% versus 0%, P = 0.04). The risk of late IBR failure was significantly higher in patients who had received postoperative radiation therapy than patients who did not (P = 0.0002). However, this increased risk applied only to women in whom the chest wall was exposed to radiation because of a high risk of recurrence. CONCLUSION: It might be preferable to postpone breast reconstruction for patients with infiltrating breast carcinoma because early complications are not infrequent and could delay adjuvant chemotherapy. Late complications associated with chest wall irradiation could be avoided with the use of alternative techniques such as the transverse rectus abdominis myocutaneous (TRAM) flap procedure.

Breast↗
PubMed1992

Prognostic factors and natural history in lymph node-negative breast cancer patients.

The prognostic significance of clinical and histological factors as well as hormone receptors was analyzed in a population of 3,064 lymph node-negative breast cancer patients operated in the Stockholm region between 1976 and 1988. None of these patients received systemic adjuvant treatment. Multivariate analysis showed that only histological tumor size, number of examined axillary lymph nodes, and progesterone receptors were independent prognostic factors in terms of recurrence-free interval. An individual risk of recurrence was calculated taking into account these three factors to discriminate between three groups of patients with a risk of less than 15%, 15-25%, and more than 25% of recurrence at 5 years. Similar results were obtained taking into account only the first two factors. The prognostic information added by the knowledge of progesterone receptors only changed the recurrence rate in approximately 3%. This study showed that conventional prognostic factors permit the identification of high risk lymph node-negative breast cancer patients. Results obtained by the use of new more sophisticated factors should be compared with those obtained analyzing strong conventional prognostic factors.

Breast Neoplasms↗
PubMed1992

Phase I-II study of vinorelbine (Navelbine) plus cisplatin in advanced non-small cell lung cancer.

32 patients with advanced non-small cell lung cancer previously untreated by chemotherapy were included in a phase I-II study in order to determine the feasibility of the combination of vinorelbine and cisplatin, each administered at its optimal dose, i.e. 30 mg/m2 weekly and 120 mg/m2 every 4-6 weeks, respectively. There were 27 males and 5 females with a mean age of 55 years and a median performance status of 80%. 13 had locally advanced disease and 19 had distant metastases at the time of inclusion. Our study demonstrated the feasibility of this protocol. Dose intensities could be maximised by adapting vinorelbine doses rather than by postponing treatment in the event of neutropenia. Both response rate (33%) and overall survival of the population (median 11 months) justify further studies.

Adult↗