N,N'-dimethylnitrosourea-induced tumors in mice and Syrian hamsters

Carcinogenic effect of N, N'-dimethylnitrosourea (DMNU) on mice and hamsters was studied. Repeated subcutaneous injections&#12288;of DMNU resulted in the induction of malignant lymphomas with an&#12288;incidence of 100 per cent in adult C3HjBifBjKi mice and induced&#12288;malignant tumors of&#12288;forestomach, mammary gland and uterus with a&#12288;high incidence in adult hamsters. Control animals showed no pathological&#12288;changes. Electron microscopy revealed the presence of murine&#12288;type C virus particles in some of the tissues examined. Many type C&#12288;virus particles were found in a transplant of DMNU.induced malig.&#12288;nant lymphoma. Some type C virus particles were shown in malignant&#12288;lymphomas and lymph nodes of malignant lymphoma-bearing mice.&#12288;A very small number of type C virus particles were observed in thymus&#12288;of control mice and bone marrow of a malignant lymphoma.bearing&#12288;mouse. A few particles, quite similar to murine type C virus particles,&#12288;were detected in&#12288;DMNU.induced mammary adenocarcinoma of hamster.&#12288;No virus-like particles were seen in mammary glands of control hamsters. Whether these particles are merely passengers or are playing&#12288;a significant role in the carcinogenesis of these tumors remains to&#12288;be determined.</p

Chromosome 8-14 translocation in a non-African Burkitt's lymphoma with leukemic conversion.

A specific chromosome translocation, t(8q-; 14q+), was observed in a 43-year-old female with non-African Burkitt's lymphoma in which leukemic conversion had occurred. The chromosome studies used cells from ascites. The ascites was apparently the result of a primary tumor involving the ovaries and contained 68% of lymphoma cells. The frequent occurrence of abnormalities related to chromosomes 1, 8 and 14 in African and non-African Burkitt's lymphomas was emphasized.</p

Absence of C-type virus production in human leukemic B cell, T cell and null cell lines.

Electron microscope observation of cultured human leukemic B cell, T cell and null cell lines and reverse transcriptase assay of the culture supernatants were all negative for the presence of C-type virus. Bat cell line, which propagates primate C-type viruses well, was cocultivated with the human leukemic cell lines, in the hope of amplification of virus if present. Three weeks after mixed culture, the culture supernatants were again examined for reverse transcriptase activity and the cells were tested for syncytia formation by cocultivation with rat XC, human KC and RSb cell lines. All these tests, except for the positive control using a simian sarcoma virus, were negative, suggesting that no C-type was produced from these human leukemic cell lines.</p

Cytological and histological correlation of primary lung cancer: a preliminary study of 106 cases with resectable tumors.

In order to increase the accuracy of diagnosis in lung cancer, analysis concerning cytological and histological correlation was attempted. The present study consists of 106 patients, who were seen during the past approximately five years and underwent radical surgery to remove tumors completely; mere biopsy specimens were excluded. These patients were 63 years old on the average, 78 males and 28 females, 29 cases of the hilar type (H) and 77 of the peripheral type (P), and 27 and 76 cases of the clinical stage I in H and P, respectively. Histologically, there were 53 adenocarcinomas (Ad), 38 squamous cell carcinomas (Sq), 4 adenosquamous cell carcinomas (Ad + Sq), 5 large cell carcinomas (LCC), and 6 small cell carcinomas (SCC); among them, 3 Ad and 21 Sq in H, and 50 Ad and 17 Sq in P. The overall positive percentages were 65.5 (H) and 26.0 (P) by combination of spontaneous, airsol-induced and Saccomanno's methods, against 96.6 (H) and 72.8 (P) with inclusion of brushing method. 94.8% of Sq in H and 66.7% of Ad and 70.6% of Sq in P were positive by the brushing. A comparative study of these four methods, performed at least once on the same patient, also confirmed the superiority of brushing. Cyto- and histological agreement was 21/21 (100%) for Sq in H, whereas 30/34 (88.2%) for Ad and 13/15 (86.7%) for Sq in P. In conclusion, cyto- and histological findings in H and P corresponded well, and as far as cytology of peripheral type is concerned, a combined method, especially with brushing, is strongly recommended.</p

Anticancer drug sensitivity by human tumor clonogenic assay.

The anticancer drug sensitivity of human cancers was tested by the human tumor clonogenic assay (HTCA). Of 152 human cancer specimens tested, 63 (41%) formed more than 30 tumor cell colonies in control plates and could be used to evaluate the drug sensitivity of tumor cells. In 42 (93%) of 45 clinical trials in 24 patients, a parallel correlation was observed between the in vitro anticancer drug sensitivity measured by the HTCA and the clinical response of tumors to anticancer drugs. These results suggest that the HTCA is a good technique for the in vitro test of the anticancer drug sensitivity of human cancers.</p

Heterotransplantation of human leukemic B-cell, T-cell and null-cell lines in hamsters.

Human leukemic B-cell (BALL-1), T-cell (TALL-1) and null-cell (NALL-1) lines have been established from three patients with acute lymphoblastic leukemia (ALL). To study the heterotransplantability and in vivo growth characteristics, attempts were made to transplant these ALL cell lines into newborn Syrian hamsters treated with rabbit anti-hamster thymocyte serum. Intraperitoneal implantation of 1.8-3.5 x 10(7) cells gave rise to invasive tumors in all recipients after 15 to 41 days. In addition to a common in vivo feature of mesenteric and retroperitoneal tumors, BALL-1 line was characterized by infiltration of the skin, massive ascites and bone marrow invasion. TALL-1 cells infiltrated various organs including the lymph nodes, liver, gallbladder, spleen, bone marrow, central nervous system and eyes. NALL-1 line grew slowly, producing the least tumors, although there were distant metastases in the lungs. Tumor cells were detected in the blood of 2 of 3 BALL-1-bearing hamsters and in the blood of 4 of 5 TALL-1-bearing hamsters. Thus, these three ALL cell lines were found to exhibit a characteristic biological behavior in hamsters, which might be related to the different cell lineage.</p

Growth inhibitory effects of antifolates against an adriamycin-resistant human small cell lung cancer cell line

We have established an Adriamycin (ADM) -resistant small cell lung cancer (SCLC) cell line, SBC-3/ADM100, which shows multifactorial mechanisms of resistance to ADM, such as overexpression of P-glycoprotein, an enhanced detoxifying system and a decrease in topoisomerase II activity. In the present study, we confirmed that SBC-3/ADM 100 showed collateral sensitivity to methotrexate and TNP-351, a new antifolate, though this cell line showed a typical multidrug resistance (MDR) pattern. We also demonstrated a faster uptake and higher accumulation (1.3-fold) of TNP-351 in the SBC-3/ADM100 cells than those in the parent SBC-3 cells. These results explain one of the mechanisms for collateral sensitivity in the resistant cells. Furthermore, this cell line was found to have no cross-resistance to edatrexate and minimal cross-resistance to trimetrexate, 254-S (cisplatin analog), 5-fluorouracil and 4-hydroperoxyifosfamide. These drugs will have clinical importance in patients with SCLC who were previously treated with an ADM-containing regimen. Thus, antifolates, especially TNP-351 and edatrexate, can be expected to eradicate residual multidrug resistant SCLC cells selected by ADM.</p

Prognostic factors of small-cell lung cancer in Okayama Lung Cancer Study Group Trials.

In order to elucidate factors influencing the prognosis of small-cell lung cancer (SCLC), we reviewed the records of 253 patients with SCLC and evaluated 20 pretreatment prognostic factors by univariate analysis and Cox's multiple regression analysis. Recursive partitioning and amalgamation (RPA) was employed to identify subgroups with similar survival rates. Cox's multiple regression analysis identified five significant factors: extent of disease, number of metastatic sites, serum albumin, serum lactate dehydrogenase, and presence of weight loss. Among these, extent of disease was the most influential factor. RPA analysis revealed three subgroups predicting significantly different prognoses. The median survival time and 3-year survival rate were 18.4 months and 20.6%, respectively for the good-risk group (limited disease without weight loss), 13.5 months and 9.1%, respectively for the intermediate-risk group (limited disease with weight loss or extensive disease with less than two metastatic sites), and 9.2 months and 0%, respectively for the poor-risk group (extensive disease with two or more metastatic sites). These results will be useful for development of new staging system or subsequent stratification for randomized trials.</p

Mortality and morbidity in two-year disease-free survivors of small cell lung cancer after treatment with combination chemotherapy with or without irradiation.

We evaluated the long-term outcome of 148 patients with small cell lung cancer (SCLC) who had been entered into clinical trials of chemotherapy with or without thoracic and prophylactic cranial irradiation (PCI) between 1981 and 1987. Eighteen patients (12%) survived for 2 or more years. With a minimum follow-up of 4.5 years, 10 of the 18 patients who remained disease-free at 2 years are currently alive and free of SCLC. Seven of these 10 patients currently function as they did before diagnosis. However, three suffer from central nervous system changes of varying degrees in severity which appeared 2-3 years after PCI. Eight of the 18 patients who were disease-free at 2 years have died. Two died of isolated relapse in the brain at 3.6 and 4.2 years after initiation of chemotherapy. Five died of other malignancies while continuing their complete response to SCLC; two of non-small cell lung cancer, two of acute myelogenous leukemia, and one of hepatocellular carcinoma. Another patient died of an unrelated disease without any evidence of SCLC. A small but substantial proportion of patients who underwent intensive treatment will achieve long-term survival; however, these patients remain at higher risk for second cancers and late toxicities. Therefore, attention must be directed to defining the safest way to employ such treatment in the management of SCLC.</p

Pretreatment serum albumin concentration and lactic dehydrogenase activity as prognostic factors in patients with small cell lung cancer.

Pretreatment laboratory parameters were analyzed as prognostic factors in patients with small cell lung cancer. Serum lactic dehydrogenase activity, serum albumin concentration, PPD skin reaction, and peripheral lymphocyte count were of prognostic importance. When these factors were evaluated by multivariate analysis together with performance status and disease extent, lactic dehydrogenase and albumin were the most influential factors related to survival.</p