Linkage studies in a Li-Fraumeni family with increased expression of p53 protein but no germline mutation in p53.

We report a family with the Li-Fraumeni syndrome (LFS) in whom we have been unable to detect a mutation in the coding sequence of the p53 gene. Analysis of linkage to three polymorphic markers within p53 enabled direct involvement of p53 to be excluded. This is the first example of a LFS family in whom exclusion of p53 has been possible. Four affected members of the family with sarcoma or premenopausal breast cancer showed increased expression of p53 protein in their normal tissues as detected by immunohistochemistry. It therefore appears that the LFS phenotype has been conferred by an aberrant gene, showing a dominant pattern of inheritance, which may be acting to compromise normal p53 function rather than by a mutation in p53 itself. In order to try to determine the chromosomal location of this putative gene, we have carried out studies of linkage to candidate loci. By these means we have excluded involvement of Rb1 and BRCA1 on chromosomes 13q and 17q respectively. The MDM2 oncogene on chromosome 12q was considered to be the prime candidate as MDM2 is amplified in sarcomas and the MDM2 product binds to p53. Furthermore, p53 mutation and amplification of MDM2 have been shown to be mutually exclusive events in tumour development. Linkage analysis to two polymorphic markers within MDM2 yielded a three-point LOD score of -5.4 at a recombination fraction theta equal to zero. Therefore MDM2 could be excluded. It is possible that the gene which is responsible for cancer susceptibility in this family, possibly via interaction with p53, will be important in the histogenesis of breast cancer in general. We are now carrying out further studies to locate and identify this gene.

Leukemia, lymphoma, and related disorders in families of children diagnosed with Wilms' tumor.

Leukemias and lymphomas occurring in a series of families with Wilms' tumor (WT) are described. One surviving case developed a large cell anaplastic Ki-1 lymphoma at age 20 years, and 23 second- and higher degree relatives were affected. In two instances leukemia/lymphoma occurred in the context of Li-Fraumeni syndrome (LFS) and two other families showed striking clusters of unusual and early-onset malignancies. In several cases, children had genitourinary abnormalities of the type associated with the WT1 gene on chromosome 11p13. Some of these families may provide important subjects for study of WT genes in hematologic disease and lymphomas and for investigation of interaction between different tumor-suppressor genes, e.g., WT1 and other candidate WT genes, and p53.

Malformations in children with soft tissue sarcoma and in their parents and siblings.

The presence of malformations in a population-based series of 181 children diagnosed with soft tissue sarcoma and in the majority of their parents and siblings was ascertained from family interviews and medical records. Five index children (2.8%) had serious anomalies, a figure not in excess of that derived from general population data. Fourteen siblings (4%) were affected, and higher rates of malformations were seen in siblings of female case children (P = 0.06) and siblings of children with visceral tumours (P = 0.03). There was no correlation between site of tumour in the index and specific organ system anomalies in the index or in their respective siblings. The survey indicated that there are unlikely to be strong associations between childhood soft tissue sarcoma and major malformations, a situation distinct from that found in Wilms' tumour.

Rare variant (Glu to Lys) in the leucine zipper region of CHOP (GADD153).

CHOP (GADD153) has been shown to be a dominant negative inhibitor of specific transcription factors. Direct sequencing of the gene, amplified from the DNA of a Li-Fraumeni family index case (liposarcoma, breast cancer) revealed a constitutional variant within the coding region. This alteration, though not responsible for the Li-Fraumeni phenotype, resulted in a glutamic acid to lysine switch within the leucine zipper domain, at a residue conserved between CHOP and its potential target molecules and between the human and hamster sequences. The variant created a Taq I restriction fragment length polymorphism (RFLP) facilitating screening. Analysis of 159 breast tumour DNA samples detected two encoding variant alleles (tumour and constitutional DNA).

Prevalence and diversity of constitutional mutations in the p53 gene among 21 Li-Fraumeni families.

The entire coding sequence of the p53 gene was analysed for the presence of mutations in 12 families conforming to a restricted definition of Li-Fraumeni syndrome (classic LFS) and nine families with features of LFS conforming to a broader definition. Mutations were detected in seven families. Six were point mutations with one each affecting codons 175, 180, and 220 and three affecting codon 248. The seventh was a deletion/insertion mutation in exon 4. Germline mutations in p53 were a feature of families which included children with rhabdomyosarcoma and/or adrenal cortical carcinoma. Germline p53 mutations were detected in six of the nine families with such tumors. An analysis of these 7 mutations, together with 34 published examples, showed that more than one-half were transitions at CpG dinucleotides, suggesting that the majority of germline p53 mutations may arise as a result of spontaneous events. The most common cancers occurring in the 41 families with germline p53 mutations, in common with classic LFS, were bone and soft tissue sarcoma, breast cancer, brain tumors, leukemia, and adrenocortical carcinoma, although less than one-half of the probands with germline p53 mutations came from classic LFS families. More than one-half of the cancers overall and nearly one-third of the breast cancers were diagnosed before 30 years of age. These observations have important implications for asymptomatic carriers of germline p53 mutations, and there is a need for international collaboration in the development of protocols for the management of such families.

Foetal loss and infant deaths in families of children with soft-tissue sarcoma.

Distribution of miscarriages, stillbirths and infant deaths in the families of a population-based series of children with soft-tissue sarcoma was examined in relation to index case histology (rhabdomyosarcoma or other soft-tissue sarcoma) and to the possible presence of genetic predisposition to cancer in the families (Li-Fraumeni syndrome or neurofibromatosis). Reproductive loss was not related to index histology (miscarriages, p = 0.3; all losses, p = 0.6) but was significantly higher in "genetic" rather than "sporadic" families (miscarriages, p = 0.02; all losses, p = 0.01). However, excess reproductive loss was not a feature of families with the Li-Fraumeni syndrome, but appeared to be concentrated in the families affected by neurofibromatosis.

Genitourinary tumors in the families of children with renal tumors.

The occurrence of genitourinary tumors in the relatives of a population-based series of 218 children diagnosed with renal tumors was investigated. Family data on 92% (176 of 192) of Wilms' tumor (WT) patients and 77% (20 of 26) of other renal tumor patients were obtained. In all, 21 genitourinary tumors in first-degree relatives in 19 families were ascertained, together with 30 such tumors in second-degree relatives. Ten families were diagnosed with multiple genitourinary tumors, although none of these manifested familial WT. It is proposed that a small proportion of families of children with renal tumors has a genetic predisposition to develop genitourinary tumors and that these tumors may represent further manifestations of the pleiotropic effects of the WT1 gene or of other genes involved in WT predisposition.

Second primary neoplasms in a population-based series of patients diagnosed with renal tumours in childhood.

Eight second malignant tumours developed in a population-based series of 218 patients diagnosed with renal tumours in childhood: renal cell carcinoma of the contralateral kidney, hepatocellular carcinoma, Hodgkin's disease, and 4 basal cell and 1 squamous cell carcinomas of skin. Excess risk of developing a second malignancy (excluding skin carcinomas but including a registrable spinal neurofibroma) was 14.7 (95% CI 4.0-37.7, P = 0.0003) for Wilms' tumour patients. Cumulative incidence of second malignant neoplasms (excluding skin carcinoma) was zero at 10 years, 5.0% at 20 years, and 10.2% at 30 years. The most common second neoplasms seen were benign osseous/chondromatous tumours and 4 of the 7 Wilms' tumour patients with malignant tumours had previous or synchronous tumours of this kind. Development of bony exostoses may be a marker for those patients at particularly high risk of subsequent malignancy.

Multiple primary tumours in a population-based series of patients with histopathologically peer-reviewed sarcomas.

Multiple primary tumours occurring in a three-year population-based series of patients with histopathologically peer-reviewed sarcomas from North West England were ascertained in order to look at the patterns of neoplasms seen. A total of 30 out of the 310 patients entered in the study had additional primary tumours. Very few patients were aged under 60 years at diagnosis of both their malignancies. The youngest was a known case of neurofibromatosis and, although seven patients were diagnosed with a sarcoma and carcinoma of the breast--a combination of cancers characteristic of the Li-Fraumeni cancer family syndrome--no other patients could directly be identified as suffering from any other cancer predisposition syndrome.

Patterns of cancer in the families of children with soft tissue sarcoma.

BACKGROUND: Childhood soft tissue sarcomas are known to occur in a number of genetic syndromes. This study assesses the proportion of soft tissue sarcoma diagnosed in childhood associated with genetic predisposition to cancer. METHODS: Information on the occurrence of neoplastic disease was collected for 151 of 179 families of a population-based series of children with soft tissue sarcoma. RESULTS: Considering the index child as the proband, 5 of the 151 families manifested the classic Li-Fraumeni cancer family syndrome according to standard criteria and a further 10 families showed features consistent with the syndrome. One proband had double primary syndrome cancers. One other family had a sibling pair of childhood cancers, seven families had cancer which had occurred in childhood in other relatives, and three families had adult-onset sarcomas in more distant relatives. In another 16 families, one parent or the other had developed a possible syndrome cancer, or had developed cancer when younger than 60 years of age. Two families showed striking clusters of stomach cancer. Five case children were thought to have been affected with neurofibromatosis. CONCLUSIONS: Genetic predisposition to cancer was thought to be present in 7% to 33% of families interviewed.

Congenital abnormalities in children with cancer and their relatives: results from a case-control study (IRESCC).

Several studies have revealed an excess of malformations in children with certain malignancies. A few environmental causes have been identified which may damage the foetus and lead to malformation and cancer. However, most of the numerous recognised cancer/malformation syndromes are genetically determined. This report describes a case-control study of 555 newly diagnosed children with cancer and 1,110 matched controls, chosen from general practitioner lists (GP controls) and hospital admissions (H controls). Their parents were interviewed on topics of possible aetiological significance and medical records were checked to confirm reports at interview. The numbers of congenital malformations in the index and GP control children, and the relatives of the index children, the GP and H controls are described. There were more children with malformations among the cases (60/555) than among the GP controls (27/555), P < 0.001. The abnormalities in the cases included eight with specific chromosomal/genetic conditions (e.g. Down's syndrome, XY gonadal dysgenesis, Von Recklinghausen's neurofibromatosis, Goldenhar's syndrome) whereas only one GP control child had a chromosomal defect (P < 0.05). Five case children but no GP controls had neural tube defects; this is not statistically significant. No excess of malformations was found in the siblings of cases compared with GP and H control siblings. Case mothers had a small excess of malformations (22/555) compared with GP controls (8/555), P < 0.05. Among more distant relatives the results were difficult to interpret because of the relatively small numbers in the diagnostic subgroups and because of apparent under reporting in grandparents, but no striking differences were seen between case and control relatives. The excess of malformations found in children with cancer, compared with controls, without a similar excess of malformations in their close relatives may indicate that in some (perhaps very roughly one in 20) cases antenatal events may lead both to the malformation and the malignancy.

Wilms' tumor in the Li-Fraumeni cancer family syndrome.

Scrutiny of the family pedigrees of a population-based series of 176 children diagnosed with Wilms' tumor between 1954 and 1990, along with a review of the literature on the Li-Fraumeni cancer family syndrome, indicate that Wilms' tumor may be an uncommon component of the syndrome and that a small proportion of children with Wilms' tumor may be members of Li-Fraumeni syndrome (LFS) families.

Sarcomas in north west England: III. Survival.

Survival data on a population-based series of bone, soft tissue and visceral sarcomas diagnosed in the North West of England between 1982-84 and subjected to histopathological peer review are presented. Five-year crude survival for all cases was 34%. Survival in males and females did not differ significantly (P = 0.6, 5-year survival 32% vs 36%) but was markedly worse for patients diagnosed over the median age of 60 years, even when allowance was made for underlying mortality (P = 0.03, 34% vs 44%). Five-year survival rates for the major site groups were: bone 44%; soft tissues of head, neck and trunk 36%; soft tissues of extremities 35%; female genital tract 35%; retroperitoneum 15%; gastro-intestinal tract 13%. Analysis by the major histological types revealed the following survival rates: leiomyosarcoma--female genital tract 25%, gastro-intestinal tract 14%, non-visceral soft tissue 21%; malignant fibrous histiocytoma of soft tissue 29%; liposarcoma 52%; osteosarcoma of bone 46%; and chondrosarcoma of bone 50%.

p53 germline mutations in Li-Fraumeni syndrome.

Germline mutations within a defined region of the p53 gene have recently been found in families with the Li-Fraumeni syndrome (LFS). In the present study this region of p53 was sequenced in affected individuals from 8 families with LFS. In only 2 of them were such mutations detected. Our findings suggest that the p53 mutation could be the primary lesion in some but not all families with LFS, and confirm that there is a "hot spot" for these mutations at the CpG dinucleotide moiety of codon 248. Assigning risks and counselling families on the basis of presence of p53 mutations should be approached with caution.

Sarcomas in north west England: II. Incidence.

Incidence data on a population-based series of bone, soft tissue and visceral sarcomas from the North West of England are presented. The data are derived mainly from a total of 429 cases registered with the North Western Regional Cancer Registry and diagnosed during the period 1982-84, 76% of which were confirmed as sarcomas by a panel of five pathologists. Overall incidence of confirmed sarcomas per million person years was slightly higher in females (26.81) than in males (24.71) but there was no sex difference when 38 non-reviewed cases were taken into consideration (females 29.07, males (28.83). After exclusion of tumours of female genital tract, incidence of soft tissue tumours was very similar in both sexes (females 18.25, males 18.70). Bone tumours were almost twice as frequent in males (6.01) as in females (3.55).

Sarcomas in north west England: I. Histopathological peer review.

A total of 468 cases of bone, soft tissue and visceral sarcomas (and certain other tumours) diagnosed during the years 1982-84 in North West England were entered in a study of histopathological peer review, incidence and survival. This paper describes the effects of peer review. Material was reviewed by a panel of five pathologists for 413 of the 450 cases originally registered as sarcomas with the Regional Cancer Registry. The diagnosis of sarcomas was confirmed in 76% cases and and there was agreement on sub-type for 53% cases. Measures of agreement were lowest for the two sub-types most commonly diagnosed i.e. malignant fibrous histiocytoma and leiomyosarcoma. Degree of agreement between individual pathologists and final panel diagnosis was also very variable but never less than 65%. It is concluded that second opinion is essential in cases of presumed sarcomas for studies of incidence and aetiology and to ensure that appropriate treatment is selected.

Cancer risk in second degree relatives of children with soft tissue sarcoma.

The risk of cancer in the second degree relatives of a population-based series of children with soft tissue sarcoma was studied in relation to (i) various characteristics in these relatives, (ii) certain clinical features in the index children previously identified as risk factors for cancer in their first degree relatives. Overall there was a non-significant deficit of cancers in the second degree relatives (RR = 0.88) and cancer risk was unrelated to type or site of cancer, type of relative, or to risk factors in the index case. The findings indicate that although the families investigated may include a proportion with the Li-Fraumeni cancer family syndrome, the increased cancer risk already reported in the first degree relatives does not extent to second degree relatives in general.