Alterations in human lung parenchyma after cytostatic therapy

Chemotherapy does not only affect the viability of the tumor cell. It may also cause alterations in normal organs. Thus, tumor-free areas within human lung parenchyma of 63 surgical specimens of intrapulmonary metastases were analyzed to assess the extent of morphologic changes in response to previous cytostatic therapy. The material included 34 cases of sarcoma, 20 cases of germ cell tumors, 6 cases of hypernephroid carcinoma, two cases of mammary carcinoma and one case of metastatic melanoma. All patients had received cytostatic therapy in generally applied regimens for more than two years. Morphologic analysis was carried out by routine procedures. In addition to conventional staining procedures including HE, PAS, and Sirius stain, further tools were employed to extend the array of determined characteristics. To evaluate any changes in the tissue in order to specifically recognized carbohydrate structures, labeled neoglycoproteins or proteoglycans with specificity for endogenous receptors that bind to mannose, maltose, L-fucose, lactose, N-acetyl-D-glucosamine, and heparin were used. A monoclonal antibody binding the HLA-DR receptor was also included in the study. As a control, sections of 20 cases with intrapulmonary metastases without exposure to previous cytostatic therapy were included. To address the further question whether cytostatic therapy may induces changes in tumor-free lung that show similarities to the organ in question, sections from 18 cases with tuberculosis and from 37 cases suffering from sarcoidosis were similarly examined. Focal interstitial fibrosis was seen in 28/63 (44%) of the patients receiving chemotherapy. In contrast, only 2/20 (10%) patients of the untreated group exhibited this alteration. An active fibrosis with proliferating smooth muscle cells was found in two cases, dysplastic pneumocytes in 10 cases (16%) in the group with cytostatic therapy, but in no cases in the untreated group. Expression of the HLA-DR receptor in the pneumocytes was observed in 27/63 cases (43%) of the cytostatic cohort, in 21/37 (57%) patients of the sarcoidosis cohort, in 15/18 (83%) patients of the tuberculosis cohort, and in 1/20 (5%) of the untreated patients. In contrast to sections from treated patients, binding of neoglycoproteins was low in the untreated cohort. Interestingly, similarities between the tuberculosis cohort and the cytostatic cohort were seen for receptors that are specific for fucose and lactose, respectively. The results suggest that long-lasting cytostatic therapy induces focal fibrosis in 40%-50% of the patients, mainly via unspecific interstitial inflammatory infiltrates. A hypersensitivity reaction or direct toxicity may less frequently lead to pathologic alterations.