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Aim: The present study aims to determine effect of chemotherapy on lung function tests.Material and methods: The study was conducted on 35 cancer patients undertaking cancer chemotherapy with healthy lungs.Pulmonary function test parameters FVC,FEV1, FEV1/FVC were recorded using Medspiror. Results: All parameters showed significant decline in the patients after 1st and 2nd cycles of chemotherapy as compared to before chemotherapy.Conclusion:The present study confirms that chemotherapeutic drugs have toxic effect on lungs.
Key words: chemotherapy pulmonary function tests
Incidence of respiratory illnesses has increased in the last 2-3 decades leading to the derangements of lung functions partly due to the increase in smoking,increase in pollution,increase in life span and partly due to the use of various neoplastic drugs. At present, about 50% of patients with cancer can be cured, with chemotherapy contributing to cure in about 17% patients1 .
Ideal anticancer drugs would eradicate cancer cells without harming normal tissues but unfortunately no currently available agents meets this criterion and pulmonary toxicity is usually irreversible and progressive as a result of chemotherapy administration.So the present study was undertaken to estimate the extent of damage done by anticancer drugs on lungs.
Material and methods
The present study included 35 patients of either sex diagnosed with malignancy but with healthy lungs. The study was conducted in the Department of Radiotherapy/Oncology,Shri Guru TegBahadur(S.G.T.B) hospital,attached to Government Medical College,Amritsar.
Patients with pulmonary metastasis,lung disease or who have been previously exposed to radiotherapy during treatment were excluded from the study.
Patients were randomized into the following three groups :
Group I (1st visit) : before start of chemotherapy.
Group II(2nd visit) : 3-4 weeks after 1st visit(1st dose).
Group III (3rd visit) : 3-4 weeks after 2nd visit(2nd dose).
Pulmonary function tests(PFT) were performed on patients of three groups at baseline(before chemotherapy),3-4 weeks after start of chemotherapy and again after next 3-4 weeks. The tests were done on a computerized spirometer MEDSPIROR in standing posture.
The following pulmonary function test parameters were recorded:
1. Forced vital capacity(FVC).
2. Forced expiratory volume in the first second(FEV1)
3. FEV1 / FVC%.
Data was collected,tabulated and analyzed using paired t-test for comparison of means and chi-square test for two-by-two tables. 'pâ€™ value of 0.05 was taken as cut off for the measure of significance.
The patients on which the study has been undertaken were on various chemotherapy regimens.
No of patients
Carcinoma breast(C.M.F regimen)
Carcinoma breast(C.A.F regimen)
Non Hodgkins lymphoma
The mean age of subjects in all Groups was 51.71+9.97years(range 30 to 70 years).The number of male subjects was 13 and female subjects were 22.
Table I showing Mean and Standard deviation of 3 respiratory parameters in Group I Cancer patients (before),Group II (after 1st cycle of chemotherapy) and Group III (after 2nd cycle of chemotherapy).
Group I Cancer patients (before)
Group II (after 1stcycle of chemotherapy)
Group III (after 2ndcycle of chemotherapy)
Forced Vital Capacity(FVC)Litres
Value of FVC was higher in Group I cancer patients (before chemotherapy) in comparison to Group II and Group III cancer patients (after chemotherapy).The t value calculated in comparison of group I and group II was found to be 3.99 i.e highly significant.FVC declined further in group III as compared with group I. t value was calculated to be 6.26 which showed it was statistically highly significant(p <0.001).
Difference in value of FEV1 in the Group I cancer patients and Group II patients was statistically highly significant while between Group I and Group III cancer patients was also statistically highly significant.
The mean value of FEV1 as % of FVC was found to be almost similar in all the three groups.The mean and standard deviation of FEV1/FVC in Group I,GroupII and Group III was 84.32+3.64,85.67+4.48 and 85.11+5.15 respectively. The difference whatsoever was statistically insignificant (p<0.05).The ratio FEV1/FVC was more in favor of restrictive pattern of lung disease.
In the present study it was seen that the value of FVC was high in Group I cancer patients(before chemotherapy) in comparison to Group II and Group III patients(after chemotherapy).FVC is a measure of the stroke volume if lungs and thorax are regarded as a simple air pump2.Any reduction in it will affect the ventilatory capacity. Causes of stroke volume reduction includes pathology in the lung itself such as fibrosis which reduces its distensibility.The usual pulmonary injury with cytotoxic therapy is probably due to progressive pulmonary fibrosis with relatively little of an inflammatory component and with a tendency to cause irreversible lung damage3. Bleomycin and Mitomycin are cytotoxic antibiotics which cause pulmonary fibrosis in upto 5-10% of patients4. Several cytotoxic drugs that act by alkylation of DNA have also been shown to cause alveolitis and pulmonary fibrosis e.g. Busulphan,Chlorambucil,Cyclophoshamide and Melphalan.These effects have also been seen with Methotrexate and with Carmustine5.
Similarly value of FEV1was seen to decline significantly in Group II and Group III patients as compared with Group I patients. This decline is due to the toxic effects of chemotherapeutic drugs on lung functions. Many studies show similar results as that of this study.
The ratio of FEV1/FVC was more in favor of restrictive pattern of lung disorders.
We found a similarity in our findings with those of Jensen et al (6)(1990)who studied that mantle-field irradiation was associated with a primary obstructive and minor restrictive lung function impairment,wheras chemotherapy and combined modality therapy was associated with a restrictive lung function impairment. Also Nysom et al (7)(1998) who studied acute lymphoblastic leukemia patients observed slight restrictive pulmonary disease which developed after the intake of chemotherapy.
Pulmonary toxicity is usually irreversible and progressive as a result of chemotherapy administration.The initial site of damage seems to be the endothelial cells,with an inflammatory type reaction resulting in drug induced pneumonitis.Another type of damage occurs as a result of an immunologic mechanism.Either the lung or the drug may act as antigen in an allergic type reaction.Chronic exposure to chemotherapy causes extensive alteration of the pulmonary parenchyma,with changes in the connective tissue,obliteration of alveoli,and dilatation of air spaces known as honeycombing.Continous lung injury and repair result in restrictive lung disease,increased work of breathing and a functionally reduced lung volume leading to impaired gas exchange.The chest X-ray may be within normal limits,but can show a pattern of diffuse interstitial markings.Pulmonary function tests can show a restrictive pattern when pulmonary fibrosis has occurred before clinical symptoms occur.
The present study highlights observation that most of the spirometric parameters in cancer patients after chemotherapy showed a significant decline.Some drugs may cause direct damage to lung parenchyma like Bleomycin,Cyclophosphamide and Nitrofurantoin which cause generation of toxic oxygen free radicals,others may act on the system wherby the lung matrix repairs itself, interfering with or increasing collagen formation.In some cases this restrictive type of abnormality is associated with an obstructive pattern as well. In case of intrinsic drug induced lung diseases,the physiological effects of diffuse parenchymal disorder reduces all lung volumes probably by the excessive elastic recoil of the lungs,in comparison to the outward recoil of the chestwall.Expiratory airflow is reduced in proportion to lung volumes.This decline after chemotherapy is probably due to toxicity of the various chemotherapeutic drugs.