For several authors, DNA tumoral cell content represents an important prognostic factor in colorectal cancer. Samples obtained from 65 human colorectal cancers operated on between 1983 and 1986 were studied. Of 52 cases studied by flow cytometry 60 p. 100 were aneuploid tumors. The proliferative index was calculated in slightly over 50 p. 100 of the cases by DNA histogram analysis. During the same period 30 tumoral karyotypes were established by cytogenetic analysis. In 17 cases a comparison was possible between flow cytometry and cytogenetic results. In all cases a significant correlation was seen between the DNA histogram modal value and the mean number of chromosomes counted by cytogenic analysis. In this study, there was no statistical correlation between flow cytometry results and Dukes classification. Because of the short follow-up in our series, no prognostic value may be attributed to the DNA index.

108 cases of Ewing's Sarcoma are collected at the "Curie Institute" and studied by the authors using the modern Technics of electron microscopy, cytochemistry, immunohistochemistry and cytogenetics. They raise the histogenesis and etiological factors not entirely resolved yet at the light of literature review.

Two children born to myasthenic mothers presented at birth with severe arthrogryposis, hypotonia and respiratory distress which followed a favourable course. A family history in one of these two cases and in another case reported in the literature raises the problem of a possible recurrence.

Breast cancer has generally environmental causes. However numerous investigations among the families of cancer patients have shown the probable role of a genetic factor in a minority of the cases. Those cases are characterized by the early age of the patient, the multicentricity of the tumour and the frequent association with other neoplasms. Progress in molecular genetics should allow in the next future the discovery in the population of high risk subjects.

72 bladder tumors were studied for nuclear DNA content with flow cytometry. A bimodal DNA profile was present in 33 of them (45%). The following findings concerning the aneuploid second peak of these 33 tumors are remarkable. Aneuploid peak DNA index distribution is discontinuous: there is no peak below 1.5 nor between 2.3 and 2.7. Aneuploid peak importance (second peak cell percentage versus all tumor cells in the same sample) increases when its DNA index decreases from 2.0 to 1.5 = this percentage is on average 45% for a DNA index of 2.0 and increases to 75% when DNA index decreases to 1.5. Aneuploid peak mitotic activity increases when DNA index decreases from 2.0 to 1.5 = the percentage of S G2 M cells of the aneuploid peak is in the range of 15% for a DNA index of 2.0 and in the range of 22% for a DNA index of 1.5. These findings are in favor of a dynamics in bladder cancer natural history. Tumors are supposed to share the same clonal evolution, in 3 stages. First stage: transformed tumor cell DNA profile is unimodal with a DNA index in the region of 1; second stage: due to chromosomic non-dysjunction during mitosis, a second peak appears with a DNA index of 2. Third stage: DNA index of this aneuploid second peak progressively decreases from 2 to 1.5 as a consequence of non vital chromosomes loss by tumor cells. It is suggested that DNA index as defined by flow cytometry does not have an absolute prognostic value per se, but in combination with tumors mitotic activity.(ABSTRACT TRUNCATED AT 250 WORDS)

When ultrasound examination of the upper abdomen detects a liver nodule, the malignancy of this lesion must be discussed. If past history of cancer is known, a benign lesion cannot be excluded. Conversely, if the examination is performed without a history of cancer, we must raise the possibility of a malignant lesion. We attempted to demonstrate that the simple clinical and biological findings allow, if well used, a diagnosis of malignancy or benign nature, rather than performing further investigations, sometimes costly or invasive. We therefore compared three different methods: the well known bayesian diagnostic process; the multivariate analysis using logistic regression model; the Decision Theory, constructing a binary discrimination tree. The three methods lead to approximately the same rate of well classified patients (93 to 95%). Advantages and disadvantages are discussed.

Etiological and epidemiological studies of triploid and hydatidiform molar conceptuses were done using HLA polymorphism. The segregation of HLA markers allowed to know the etiology of 25 triploidies and 19 hydatidiform moles. Five other moles and a post molar choriocarcinoma were also studied by molecular hybridization. This confirms that triploidies in about 3/4 of the cases involved two sets of paternal chromosomes mainly by di-sperm. Hydatidiform moles from Algeria, France and Senegal were all of androgenic origin excepted for one case. DNA analysis of the choriocarcinoma demonstrated the presence of a paternal marker suggesting for this case a direct cellular lineage from the mole. Positive associations with HLA A 28 and B 7 were found which could be related to gametogenesis-fecundation dysfunction. A slight excess of antigens shared by parents of triploidies was shown. This was not observed for parents of hydatidiform moles but when they shared HLA antigens a preferential inheritance in the mole of the shared specificities was observed. This relative compatibility of the molar conceptus with the mother may be an element of the process that prevent its early rejection.

In a cytogenetic study of 54 patients with acute monoblastic leukaemias (AML5) two had a (9;11) (p21;q23) translocation. In addition to the clone, with t(9;11), both patients had a second clone with t(9;11) and trisomy 8. These two patients were aged 23 and 35 years at diagnosis and were classified as M5a in the FAB formulation. A complete remission was achieved in each case, persisting after 19 and 18 months respectively (autograft for one patient). Whereas chromosome 11 anomalies are involved in 13% of all AML5 cases, t(9;11) is less frequently encountered (3.7% in our experience).

A rearrangement of the short arm of chromosome #12 with a breakpoint at band 12 was found in 4 out of 15 patients with CMML: two deletions, one simple translocation (9;12)(p21;p12) and one complex t(11;12;13)(p11;p12;q21). Their haematological and clinical characteristics were investigated together with those of 5 other similar published cases. Although this alteration is not very frequent in this myelodysplastic syndrome, and is also found in various other malignant blood disorders, it is clearly a non-random phenomenon, the consequences of which are discussed.

A total of 8% of chronic lymphocytic leukemias (CLL) occur in young people, before the fourth decade, and can be considered as a specific clinical form of CLL. We report 24 cases of young CLL treated since 1975. The clinical course has the same characteristics in young as in old people except for the high tumoral B stage which has a worse prognosis.