Impact of Radiotherapy in Small Cell Carcinoma of Lung

BACKGROUND

patients had undergone bronochoscopy of which 40(72.7%) had positive diagnostic yield, and 15(27.3%)had negative yield.These 15 patients were diagnosed with the help of trucut biopsy (8 cases), thoracotomy (2) and FNAC of supraclavicular lymph node (5 cases).As per the bronchochospic and chest radiographic findings, 31(56.4%)had lesion in the right lung and 24 (43.6%) had in the left lung.Of the 55 patients, 38 received chemotherapy of which 7 had received six cycles, 10 had received 4 cycles while as 21 patients had received 3 or less cycles of chemotherapy.Grade I and II chemotherapy toxicity was observed in 11 cases and grade III toxicity in 4 cases.Majority of cases did not complete full chemotherapy mainly because of socio-economic reasons.Of the 55 patients 30 patients were planned for radiotherapy and only 22 had completed the prescribed dose of radiation i.e., 45 Gy/20 fractions/4 weeks, (Group-III & IV).Out of the six patients who had undergone surgery, two had inoperable growth at thoracatomy and in 4 patients lobectomy was performed.During the treatment and subsequent follow-up, 7 patients developed metastasis, 5 in bone (dorsal spine), one in brain and one in liver.The overall survival at 1 year, 2 year and 3 years was 15.3%, 13.2% and 7.8% respectively (Table 2).This excludes patients in Group-I, who had not received any specific treatment.As per the treatment, long survival of 5 years was seen in Group-IV followed by Group-III.

Methods
We reviewed the Departmental records of all patients treated at our tertiary care hospital between 1996 and 2000 with the diagnosis of small cell lung cancer.Cases that had full medical records with a minimum follow up of 3 months were included.Patients with incomplete medical records and or incomplete treatment were excluded from the study.All patients had histological or cytological confirmation of small cell lung cancer determined through bronchoscopy, fine needle aspiration or open biopsy.All patients had undergone staging workup in the form of history, physical examination, complete blood count, biochemistry, CT scan of chest and brain, bone scan, ultrasonography besides the chest radiography.A total of 55 patients were included for analysis of outcome of various treatment strategies.Of these 21 patients had extensive stage and 34 had limited stage disease.On the basis of treatment, patients were divided into four groups.Group-I (17 cases) included those patients who had not received any specific treatment and were on symptomatic treatment only.These patients had either extensive stage (9 cases) and or refused treatment (8 cases) because of the poor performance and poor socio-economic status.Group-II (16 patients) included cases who were treated with chemotherapy alone.Group-III (16 cases) were treated with chemoradiotherapy and Group-IV (6 cases) had undergone surgery followed by chemo-radiotherapy.Chemotherapy was given 2 in the form of inj.Cisplatin, 50mg/m i/v infusion over 3 hours per day for 3 days, after adequate hydration and 2 premedication, Inj.Etoposide, 100mg/m i/v infusion over 2 hours for 3 days.Cycle was repeated after 3 weeks.Radiation was delivered on cobalt-60 teletherapy unit (Theratron-780).The radiation field included the gross disease as seen on chest x-ray with 2-3cm margin, the mediastinum and ipsilateral hilum.Supraclavicular areas were included in treatment field in case of the disease in upper lobes.Treatment was delivered by anterio-posterior parallel opposed portals.A radiation dose of 45 Gy was delivered in 20 fractions with five fractions in a week.Surgery was done in the form of open biopsy/lobectomy.The sequence of treatment in this group was surgery followed by 3 cycles of chemotherapy followed by radiotherapy followed by 3 more cycles of chemotherapy.Follow-up of 3 months to 5 years was available.Prophylactic cranial irradiation (PCI) was not used.Patients lost to follow-up were considered dead.

Results
From January 1996 through December 2000, fifty-five patients with small cell carcinoma of the lung were studied retrospectively.Patient characteristics are shown in Table 1.There were 50(90.9%)male and 5(9.1%) female patients in the age group ranging from 30 to 80 years (median 53 years); 31(56.4%)patients were from rural and 24 (43.6%) from urban areas.Out of 55 patients 37(67.3%)were active smokers, and 18(32.7%)had no history of smoking.All

Discussion
This retrospective study was undertaken to find out the role of radiotherapy in patients with small cell lung cancer.Surgery, radiotherapy and chemotherapy are the various options available for the management of lung cancer.Surgery is not considered as a part of standard treatment of small cell 11 lung cancer due to its propensity for early spread.Surgery as an option of treatment was discarded 30 years ago, when randomized study demonstrated better results with radio-2 therapy.In the current study 2 out of 55 patients (3.7%) who had undergone surgery followed by chemo-radiotherapy were alive at 5 years of follow-up.This shows that surgery as a single modality has no role in small cell lung cancer, but when combined with chemo-radiotherapy, it definitely improves survival in a selected group of patients.Although, the chances of cure in small cell lung cancer are small, treatment is indicated in most cases, since the median survival is markedly increased from 2 to 3 months in untreated patients to 8 to 16 9,12 months in patients treated with chemotherapy.We also observed that Group I patients were lost to follow-up within three months and those who had received at least one modality of treatment (Group-II) 62.5% of patients were alive at 6 months (Table -2 Perry et al first reported a survival advantage with addition of thoracic radiotherapy to chemotherapy in limited 15 stage disease.We also observed that addition of radiotherapy in Group-III and IV has definitely improved survival when compared to Group-I and II (Table -2).This strongly justifies the role of radiotherapy in the management of small cell lung cancer irrespective of its stage.Our results are similar with those who reported survival advantage with addition of thoracic radiotherapy to chemotherapy in limited stage 8,16 disease.However, in extensive stage disease, addition of chest irradiation to chemotherapy has reduced frequency of local recurrence, but did not alter the objective response 12,17 rates, medial survival or 2 year disease free survival.With current treatment protocols 5 year survival of 20-23% has been achieved in limited stage disease.However, our overall survival of the whole cohort was 3.7% and we had only 2 cases who survived 5 years.Poor outcome in our study was directly related to the advanced stage of disease, poor performance status, poor socio-economical status which leads to lot of drop outs and inadequate treatment.
In conclusion, Small cell lung cancer is an aggressive disease with a propensity for early dissemination.Radiotherapy plays a pivotal role for major therapeutic programs of this disease.Even with real benefit from radiotherapy, more effective chemotherapy programs need to be developed to deal with the systemic nature of the disease, if the outcome for patients with small cell lung cancer is to improve.
). Randomized trials have established that combination chemotherapy is clearly superior to11,12 single agent chemotherapy in small cell lung cancer.Treatment for limited disease SCLC includes combined modality in the form of thoracic radiation and systemic 13 chemotherapy.Radiation is usually given either sequentially 14 or concurrently with systemic chemotherapy.Pignon et al Collected data on 2140 patients from 16 randomized trials comparing chemotherapy alone versus chemotherapy plus thoracic radiotherapy and found an improvement in absolute 2,8 survival of 5.4% at three years.None of the cases received PCI.Even the 2 long term survivors were not given PCI.In limited stage group only one patient developed brain metastasis.Role of PCI in small cell carcinoma of lung has been controversial though it, no doubt, improves the Disease free survival and as such, at present, most of oncology centers use this in complete responders with early/limited stage 14a disease.