Response to thoracic radiotherapy in patients with small cell carcinoma of the lung after failure of combination chemotherapy

1st ESMO Consensus Conference in lung cancer; Lugano 2010: small-cell lung cancer

The 1st ESMO Consensus Conference on lung cancer was held in Lugano, Switzerland on 21st and 22nd May 2010 with the participation of a multidisciplinary panel of leading professionals in pathology and molecular diagnostics and medical, surgical and radiation oncology. Before the conference, the expert panel prepared clinically relevant questions concerning five areas as follows: early and locally advanced non-small-cell lung cancer (NSCLC), first-line metastatic NSCLC, second-/third-line NSCLC, NSCLC pathology and molecular testing, and small-cell lung cancer (SCLC) to be addressed through discussion at the Consensus Conference. All relevant scientific literature for each question was reviewed in advance. During the Consensus Conference, the panel developed recommendations for each specific question. The consensus agreement in SCLC is reported in this article. The recommendations detailed here are based on an expert consensus after careful review of published data. All participants have approved this final update.

Radioimmunotherapy of small-cell lung cancer xenografts using 131I-labelled anti-NCAM monoclonal antibody 123C3

We have studied the therapeutic efficacy of 131I-labelled monoclonal antibody 123C3 in human small-cell lung carcinoma xenografts established from the NCI-H69 cell line in nude mice. Several radiation doses were administered intraperitoneally and different treatment schedules were tested. The maximal tolerated dose, 2 x 500 microCi, resulted in complete remission of tumours smaller than 200 mm3 and long-lasting remission (more than 135 days) of the larger tumours. In control experiments, treatment with unlabelled monoclonal antibody 123C3 did not affect the tumour growth rate, while the effect of radiolabelled non-relevant, isotype-matched, monoclonal antibody M6/1 was minor and transient. Regrowth of the tumours occurred in all cases and could not be attributed to loss of neural cell adhesion molecule (NCAM) expression. Tumour recurrence is probably caused by insufficient radiation dosage. Radiation-induced toxicity was monitored by assessment of weight and bone marrow examination. Weight loss was observed in all treatment groups, but the mice regained their initial weight within 14 days, except for the group receiving the highest radiation dose (3 x 600 microCi). In this group all mice died as a result of radiotoxicity. Of the mice injected with 600 microCi radiolabelled control antibody, 50% died within 2 weeks after administration. Apparently the higher uptake of the radiolabelled monoclonal antibody in the tumour reduced systemic radiation toxicity.

Radiation therapy for chest recurrences following induction chemotherapy in small cell lung cancer

Once small cell lung cancer fails induction chemotherapy, second line drugs are usually ineffective, accounting for mostly partial responses in the order of 0-20% and a median survival of 6-10 weeks. A review of patients with relapsed small cell lung cancer was carried out at the University of Maryland. Of 51 such patients, 44 received thoracic irradiation at the time of relapse. Excluding 8 patients who received insufficient treatment, the series consists of 36 patients (27 with limited and 9 with extensive disease) and represents the largest experience with relapsed small cell lung cancer subjected to radiation alone. Total radiation doses were 60 Gy in 11, 45-55 Gy in 14, and 38-42 Gy in the remaining 11 patients. No second line chemotherapy was given simultaneously with radiation at time of relapse and it was only given subsequently during the course of the disease to four patients. Responses to radiation were seen in 28 (77%) with 9 (25%) complete and 19 (52%) partial. The median survival was 16-40 weeks varying with disease extent, response, and total dose. Subsequent failures occurred in chest (34%) and distant sites (66%). A dose-response curve was attempted; the higher doses achieved as much as 75% local control. A poor response to induction chemotherapy did not predict a poor radiation response at time of relapse. Nearly 2/3 of patients who had not responded to induction chemotherapy responded to radiation at the time of relapse. The post-recurrence survival after radiation therapy was as long as or longer than the recurrence-free interval after induction chemotherapy, and this clearly demonstrates the value of radiation in achieving excellent palliation and good quality of life in these patients. Thoracic irradiation is recommended as a therapeutic alternative for locally recurrent small cell lung cancer after induction chemotherapy.

Accelerated radiotherapy followed by chemotherapy for locally recurrent small-cell carcinoma of the lung. A phase II study of Cancer and Leukemia Group B

Recurrent or persistent small-cell carcinoma of the lung (SCCL) after chemotherapy (CT) alone has shown a poor response to conventional salvage radiotherapy (RT). Accelerated RT is judged more effective than conventional RT for rapidly growing tumors such as SCCL. The objectives of this study were: to determine the tolerability of accelerated RT; and to test the ability of accelerated RT plus CT to achieve local tumor control (LTC) of SCCL recurrent after CT. Patients whose localized tumor was not controlled were selected from Arm III of the Cancer and Leukemia Group B (CALGB) protocol 8083 (Proc. ASCO 2:230, 1984) as eligible for this study. The program of accelerated RT consisted of the delivery of 50.1 Gray (Gy) in 30 fractions over a period of 21 days to the chest. New chemotherapy different from the first began 2 weeks after the completion of RT and was repeated every 3 weeks for 18 months (M). Of 29 potentially eligible patients with locally recurrent SCCL after the first line CT alone from Arm III of the CALBG protocol 8083, 12 were enrolled initially in this study. The analysis of LTC included 11 patients excluding one patient who died 4 weeks after the start of RT from liver metastases. The LTC achieved was as follow: complete remission in 8/11 (72%) and partial remission in 3/11 patients. None of the patients was converted to CR by subsequent chemotherapy. Survival ranged from 2 to 20 M, with a median survival time of 6 M. Tolerance to the subsequent CT, normal tissue reaction to accelerated RT, and the theoretical advantage of accelerated RT over conventional RT for SCCL were evaluated.

Small cell lung cancer: a problem of tumor heterogeneity

Small cell undifferentiated carcinoma represents a subtype of lung cancer that possesses biologic and clinical characteristics that make it significantly distinct from other forms. A major impact on the natural history of this disease has been accomplished during the past 15 years, including the potential for cure by non-surgical treatment modalities. Further progress in the management of this disorder has been impaired by a number of factors that appear to be inherent to the biology of the tumor and its clinical features. Analysis of initial clinical trials and more detailed examination of this tumor in vitro have permitted the elucidation of many barriers to curative outcome presently being evaluated at the laboratory and clinical levels. These include clear biologic and morphologic heterogeneity; problems with chemotherapy responsiveness including drug resistance; the potential for combining chemotherapy and radiation modalities; the re-examination of the role of surgical intervention in selected patients; and the need to deal with central nervous system dissemination of tumor cells. Further advances in this disease will be dependent on the successful integration of laboratory and clinical disciplines.

Impact of tumor control on survival in carcinoma of the lung treated with irradiation

The long-term results in tumor response, intrathoracic tumor control and survival are reported in patients with medically inoperable or unresectable non-oat cell and small cell carcinoma of the lung. In 376 patients with stages T1-3, NO-2 carcinoma of the lung tumors, accessioned to a Radiation Therapy Oncology Group (RTOG) randomized study to evaluate different doses of irradiation, a higher complete response rate (24%), intrathoracic tumor control (67%) and three year survival (15%) was observed with 6000 cGy, compared with lower doses of irradiation (4000 or 5000 cGy). Increased survival was noted in patients with complete tumor response. Three year survival in complete responders was 23%, in partial responders, 10%, and in patients with stable disease, 5%. Patients treated with 6000 cGy had an overall intrathoracic failure rate of 33% at 3 years, compared with 42% for those treated with 5000 cGy, 44% for patients receiving 4000 cGy with split course, and 52% for those treated with 4000 cGy continuous course (p = 0.02). Patients surviving 6 or 12 months exhibited a statistically significant increased survival when the intrathoracic tumor was controlled. Patients treated with 5000-6000 cGy, showing tumor control, had a three year survival of 22%, versus 10%, if they had intrathoracic failure (p = 0.05). In patients treated with 4000 cGy (split or continuous), the respective survival was 20% and 10%, if the intrathoracic tumor was controlled (p = 0.001). In patients surviving 12 months after treatment with 5000-6000 cGy, on whom the intrathoracic tumor was controlled, the median survival was 29 months, in contrast to 18 months, if they developed intrathoracic failure (p = 0.05). In patients treated with 4000 cGy, the median survival was 23 months with control and 18 months without control of the intrathoracic tumor [corrected] (p = 0.008). In another RTOG study for patients with more advanced tumors (T4 or N3), those with local tumor control at 12 months had a three year survival rate of 25%, compared with 5% for those with thoracic failures. These differences are statistically significant (p = 0.006). Higher doses of irradiation yield a greater proportion of complete response, higher intrathoracic tumor control and better survival in non-oat cell medically inoperable or unresectable carcinoma of the lung.(ABSTRACT TRUNCATED AT 400 WORDS)

Patterns of failure in small cell carcinoma of the lung

The initial sites and frequencies of disease progression in 97 patients with small cell carcinoma of the lung treated in a Northern California Oncology protocol were analyzed. Among the extensive disease complete responders (25 patients), the chest was the most frequent initial relapse site (18 patients), followed by the liver (nine patients) and bone (six patients). For those patients who had a partial or no response to treatment, the chest was the most frequent site of persistent disease and the majority progressed in the chest initially. The addition of chest irradiation (5000 rad/5 weeks) to patients with limited disease significantly reduced the incidence of relapse (25%) and prolonged the disease-free interval in the chest in the complete responders, but did not affect the failure pattern in partial and nonresponders. All patients received prophylactic cranial irradiation and three limited disease patients (10%) and three extensive disease patients (4%) progressed in the brain.

Local control of intrathoracic disease with chemotherapy and role of prophylactic cranial irradiation in small-cell carcinoma of the lung

Between 1978 and 1979, 39 consecutive patients at the Medical College of Wisconsin were seen with small-cell carcinoma of the lung; of these, 31 were treated with chemotherapy and prophylactic CNS irradiation (2500 rad/10 fractions) and were evaluable after 22 month median follow-up. The intrathoracic primary was not irradiated unless there was no response to chemotherapy or subsequent recurrence. Of the 31 patients, 12 had limited disease (LD) and 19 had extensive disease (ED). Twenty, including all the patients with LD, had a complete response, eight had a partial response, and three were nonresponders. Of 24 patients with complete response at the primary site, 20 subsequently displayed local failure of the intrathoracic primary tumor, most developing disseminated extrathoracic disease simultaneously with or shortly after primary failure. The median survival time (MST) of the evaluable group was ten months with an actuarial one-year survival of 39%. Patients with LD had a median remission duration of 13 months and a MST of 16 months. Three patients are still alive with no evidence of disease at 14, 20, and 27 months. Of 26 patients receiving prophylactic cranial irradiation, all are free of CNS relapse. Chemotherapy alone appears insufficient to permanently control the bulky intrathoracic tumor, leading to the use of "consolidation" irradiation of moderate dose (3750 rad/15 fractions) to follow chemotherapy. Prophylactic CNS irradiation should be used routinely.