BRAF-driven pancreatic cancer: prevalence, molecular features and therapeutic opportunities

BRAF-altered pancreatic cancer is an important molecular subgroup that activates the mitogen-activated protein kinase pathway and promotes tumorigenesis. This manuscript reviews the prevalence and molecular features of BRAF-driven pancreatic cancer and also explores the published data about targeted approaches for this subgroup. A review of the existing literature was undertaken through the PubMed database using the search terms BRAF mutation, BRAF fusion, BRAF deletion, mitogen-activated protein kinase pathway and pancreatic cancer. Pathogenic BRAF variants are enriched in KRAS wild-type tumors and drive tumorigenesis in in-vitro and experimental animal models. The majority of clinical cases are comprised of V600E mutations, N486-P490 deletions and fusions. Anecdotal evidence is building that KRAS wild-type, BRAF-driven pancreatic cancers are sensitive either to BRAF inhibitors, MEK inhibitors or combination strategies. Precision-medicine has transformed the treatment landscape for several cancers. With increasing knowledge about molecular drivers in pancreatic cancer, it is critical to characterize each distinct subgroup and evaluate targeted approaches to improve clinical outcomes.

Beyond the dermis-high-risk invasive squamous cell carcinoma: a retrospective review

OBJECTIVE

Most cutaneous squamous cell carcinomas (cSCC) are low risk and can be treated with simple excision or ablation. High-risk cSCC require invasive treatment, including radical surgery. We present our experience in treating invasive cSCC of the pelvis and extremities.

METHOD

A retrospective review of the data of patients with invasive cSCC, indicated for surgery between 2014 and 2018, from a single institution was carried out.

RESULTS

A total of 19 patients (nine men, 10 women) were included in the study. Mean age was 62 years; mean tumour size was 8.6cm). Of the 19 patients, five patients with paraplegia with cSCC arising from hard-to-heal ulcers died of infection or bleeding after surgery or systemic therapy. Also, nine patients with localised cSCC underwent margin-negative resection with or without radiation; one patient experienced disease relapse. Of the participants, two patients with previous transplants and multifocal aggressive cSCC underwent numerous resections but succumbed to disease, and two patients who presented with locally recurrent disease after previous positive margin resection and radiation underwent re-resection but developed recurrent disease.

CONCLUSIONS

Prognosis for invasive cSCC largely depends on clinical setting. Tumours arising from ulcers in patients with paraplegia have a poor prognosis regardless of treatment. Invasive cSCC in transplant patients are often multifocal and often recur. Debulking procedures are associated with local recurrence despite radiation. Patients presenting with localised disease have a favourable prognosis with wide resection, flap coverage and adjuvant therapy.

Abstract 3183: Initial safety of AFP SPEAR T-cells in patients with advanced hepatocellular carcinoma

Background: Genetically engineered affinity-enhanced autologous SPEAR T-cells (AFPc332T-cells) directed towards the HLA-A*02-restricted AFP peptide FMNKFIYEI are being tested in an ongoing Phase 1 trial to evaluate safety and antitumor activity in patients with hepatocellular carcinoma (HCC) (NCT03132792).

Methods: This is a first-in-human study in HCC patients not amenable to transplant, resection, or loco-regional therapy and failed/intolerant/refused standard of care treatment. Patients must be HLA-A*02:01+ or 02:642+. Patients must have AFP expression by immunohistochemistry at ≥1+ in ≥20% HCC tumor cells or serum AFP ≥400 ng/ml and ≤5% IHC AFP in non-cancerous liver tissue. Up to 24 patients will be enrolled using a modified 3+3 design. Lymphodepletion is with fludarabine 20 mg/m2/day and cyclophosphamide 500 mg/m2/day on days -7 to -5. The initial transduced cell dose is 0.1×109 cells; additional doses are 1×109 and 5×109. Cohort expansion will occur at maximum tolerated dose and may allow doses up to 10×109 transduced cells. Dose-limiting toxicities (DLTs) are adjudicated by a Safety Review Committee.

Results: As of 21Sep18, 2 patients were treated with 0.1×109 AFP SPEAR T-cells. Both had cytopenias related to lymphodepleting chemotherapy. Neither experienced cytokine release syndrome or SAEs during initial hospitalization. Liver chemistries show no AFPc332T-related hepatotoxicity. AFPc332T-cells were detected in both patients. One patient had grade 1 cognitive disturbance on day 8. This patient had SAEs of biliary obstruction at week 9 treated with stenting, and abdominal pain at week 12; neither was considered related to AFPc332T. Post-treatment imaging shows stable disease at week 12 by RECIST v1.1. Serum AFP was 12665 ng/ml at baseline, 29616 ng/ml at week 2, and 16,489 at week 12. Week 8 tumor biopsy showed diffuse tissue necrosis with cholestasis suspicious for necrotic tumor cells. No viable tissue was present. Immunostaining for CD3 showed numerous T-cells and T-cell aggregates within the necrotic tissue. The 2nd patient had no SAEs reported; post-treatment imaging is pending.

Conclusions: AFP SPEAR T-cells at the 0.1×109 cell dose show no evidence of on target or off target toxicity in the first 2 patients. No protocol defined DLTs were reported. Current data support continued investigation of AFPc332T-cells. Updated data will be presented.

Citation Format: Lipika Goyal, Matthew Frigault, Tim Meyer, Lynn G. Feun, Jordi Bruix, Anthony El-Khoueiry, Petr Hausner, Bruno Sangro, Theodore T. Pierce, Elliot Norry, Sulabha Ranganathan, Rafael G. Amado, Richard S. Finn. Initial safety of AFP SPEAR T-cells in patients with advanced hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3183.

Phase I/II trial of hyperfractionated radiation and chemotherapy followed by surgery in stage III lung cancer

BACKGROUND

We have previously demonstrated that high-dose chemoradiotherapy followed by resection for patients selected on the basis of mediastinal sterilization was feasible and resulted in excellent outcomes. This study was designed to determine the ability to intensify our prior approach utilizing hyperfractionated radiation and more aggressive consolidative chemotherapy.

METHODS

Patients with documented stage IIIA/B nonsmall-cell lung cancer, performance status 0 to 2, and adequate organ function were eligible. A phase I portion utilized escalating doses of carboplatin and vinorelbine, commencing with areas under the curve of 1 and 5 mg/m(2), respectively, and concurrent 69.6 Gy hyperfractionated radiotherapy. A phase II portion utilized the identical radiotherapy with carboplatin/vinorelbine at the maximum tolerated dose established in phase I. Patients for whom mediastinal nodal clearance was demonstrated underwent resection. All patients were to receive consolidation chemotherapy consisting of carboplatin/vinorelbine for three cycles, followed by docetaxel for three cycles. Prophylactic cranial irradiation was offered to patients after completion of therapy.

RESULTS

Forty-seven patients participated in the study (33 IIIA, 14 IIIB; 15 men, 32 women; median age, 56 years). The maximum tolerated dose for concurrent carboplatin/vinorelbine and hyperfractionated radiotherapy was established at areas under the curve of 1 and 10 mg/m(2), respectively. Twenty-eight patients completed trimodality treatment including surgery. Median survival time for the entire study cohort (n = 47) is 29.6 months, and it is 55.8 months for patients with mediastinal clearance who underwent resection (n = 28).

CONCLUSIONS

Surgical resection of locally advanced stage IIIA and IIIB nonsmall-cell lung cancer after induction hyperfractionated radiation and concurrent chemotherapy is safe and well tolerated. Whether this approach is superior to less aggressive therapy is uncertain and will require comparative studies.

Phase II trial of gemcitabine/carboplatin (GC) followed by paclitaxel (P) in patients with performance status = 2,3 or other significant co-morbidity (HIV infection or s/p organ transplantation) in advanced non-small cell lung cancer (NSCLC)

7661

Introduction: The role of chemotherapy (Rx) in patients (pts) with advanced NSCLC and poor performance status (PPS) defined as PS = 2 or 3 is unclear. While survival appears to be enhanced, serious toxicity may occur. In addition, no treatment options have been defined for the growing population of pts with HIV infection or post organ transplantation. Based on a prior study (Cancer 2001;92:146–152), we evaluated the efficacy of sequential, dose attenuated GC followed by P in patients with PS=2,3, HIV infection or s/p solid organ transplantation. Patients and Methods: Rx naive patients with PPS and adequate organ function received G: 1,000 mg/m2 d 1,8 C: AUC=5 d 1 q 21d × 2 followed by P 80 mg/m2 q wk × 6 followed by a 2 wk break and then repeated until progression. Results: 47 of a projected 47 pts have been enrolled. Stage IIIb/IV: 8/39, PS 2/3= 26/19, HIV infection=2, solid organ transplantation=2. 12 (25%) had brain metastases. Thirty-nine pts completed two cycles of GC and 29 pts received at least one cycle of P. Overall response rate:19% (95% CI 1.2%-31.7%). Median survival: 5.8 mo. One year survival: 8.4%. Median event free survival: 3.3 months. Toxicity rates for GC: Grade (gr) 3 neutropenia, anemia and thrombocytopenia = 29.8%, 14.9%, 23.4% respectively, gr 4 neutropenia=19% and 10.6% had gr 4 thrombocytopenia. There were 2 gr 1 bleeding episodes, two pts received platelets and 8 pts received red cells. 8.5% had gr 3 fatigue and 10.6% had gr 3 febrile neutropenia, 4.3% had grade 3 nausea, vomiting. Gr 4 nonhematologic toxicities: Thromboembolism = 1 pt (2.1%), Fever = 1 (2.1%). Toxicity rates for P phase: 2.1% had gr 3 neutropenia and anemia. 4.3% had gr 3 neuropathy. There was 1 episode of gr 4 hemoptysis. Two patients received red cells. Conclusions: 1) Sequential GC to P is well tolerated and active in this population. 2) Survival is comparable to that of other regimens utilized in PS = 2 pts with superior tolerability. 3) The prognosis for these pts is very poor even with Rx.4. This is the first trial to prospectively evaluate Rx for pts with HIV disease or organ transplantation and NSCLC. Supported by Bristol Myers Squibb.

No significant financial relationships to disclose.

Current treatment options and biology of peritoneal mesothelioma: meeting summary of the first NIH peritoneal mesothelioma conference

Peritoneal mesothelioma is a rare cancer of the peritoneum with about 250 new cases diagnosed each year in the United States. It is the second most common site for mesothelioma development and accounts for 10-20% of all mesotheliomas diagnosed in the United States. A meeting sponsored by the NIH Office of Rare Diseases was held in Bethesda, Maryland on September 13 and 14, 2004. The objective of this meeting was to review the epidemiology, biology and current surgical and medical management of peritoneal mesothelioma. In addition, the meeting also discussed clinical and pre-clinical evaluation of novel treatments for mesothelioma as well as ongoing laboratory research to better understand this disease. This report summarizes the proceedings of the meeting as well as directions for future clinical and basic research.

Phase II trial of the novel retinoid, bexarotene, and gemcitabine plus carboplatin in advanced non-small-cell lung cancer

PURPOSE

Platinum-based chemotherapy is the standard treatment for advanced non-small-cell lung cancer (NSCLC). Unfortunately, a plateau in efficacy with currently available agents has been reached. Previous studies of the retinoid, bexarotene, a retinoid X receptor-specific ligand, have indicated that it may improve outcome in advanced NSCLC.

PATIENTS AND METHODS

Patients with previously untreated stage IIIB or stage IV disease, a performance status of 0 to 2, and adequate organ status were entered. Treatment consisted of up to six cycles of carboplatin (area under the curve = 5.0 on day 1) and gemcitabine (1,000 mg/m2 on days 1 and 8) administered every 21 days. Bexarotene 400 mg/m2 orally was to be administered continuously beginning on day 1 and until progression of disease. All patients received atorvastatin 10 mg orally beginning before bexarotene. The objective was to demonstrate a 1-year survival rate of more than 50%.

RESULTS

Forty-eight patients were entered; all were assessable for survival, and 47 were assessable for toxicity and response. The therapeutic regimen was well tolerated except for hypertriglyceridemia. The median time to progression was 6.7 months, and overall median survival was 12.7 months. There was a 25% response rate and a 1-year survival rate of 53%. These results were compared with the outcome of 33 patients treated at our institution with two-drug, platinum-based chemotherapy on controlled trials with similar entry criteria in the previous 5 years.

CONCLUSION

Bexarotene can be safely added to platinum-based chemotherapy provided that there is aggressive prophylaxis of hypertriglyceridemia. The median time to progression and overall survival are promising and warrant further evaluation of bexarotene in advanced NSCLC.

High-dose radiotherapy in trimodality treatment of Pancoast tumors results in high pathologic complete response rates and excellent long-term survival

OBJECTIVE

We sought to study the clinical characteristics and outcomes of patients treated with a surgery-inclusive multimodality approach for Pancoast tumors.

METHODS

Clinical records of patients with Pancoast lung cancer who were enrolled for multimodality treatment between 1993 and 2003 at our institution were reviewed retrospectively.

RESULTS

Thirty-six patients completed neodjuvant chemoradiation followed by en bloc surgical resection, whereas one patient received high-dose radiation alone followed by surgical intervention. There were 22 men and 15 women. Thirty-four lobectomies and 3 pneumonectomies were performed. Pretreatment non-small cell lung cancer stages were IIB, IIIA, IIIB, and IV (presenting with solitary brain metastasis) in 18, 8, 6, and 5 cases, respectively. R0 resection was achieved in 36 (97.3%) patients. Operative mortality was 2.7% (n = 1). High-dose radiotherapy was successfully tolerated in all but 1 patient. Mean total radiation dose was 56.9 Gy. Pathologic complete response was found in 40.5% (n = 15) of patients. Recurrences were found in 50% (n = 18) of patients. Brain metastasis was the most common recurrence (n = 9), followed by other distant recurrences (n = 4) and local recurrences (n = 5). Median survival time for the group is 2.6 years, and median survival time (pathologic complete response) is 7.8 years. It is noteworthy that median survival time of patients with positive pretreatment lymph nodes (12 patients) was not reached.

CONCLUSIONS

Surgical resection of Pancoast tumors after neoadjuvant high-dose radiation and chemotherapy can be safely performed. High-dose radiation in trimodality treatment is well tolerated and might be beneficial. Similar to other studies, late central nervous system relapse is problematic and indicates a need for assessing the role of prophylactic cranial irradiation in this disease.

[Effects of hip arthroplasty followed by by inpatient rehabilitation on physical function and quality of life]

The aim of the present study was to investigate the effects of hip arthroplasty followed by an inpatient rehabilitation. Moreover, the relationships among functional status, quality of life and satisfaction with life or health status were examined. Patients were assessed before hip arthroplasty, at the start and at the end of the inpatient rehabilitation. Functional status was measured by using the WOMAC questionnaire and quality of life with the Medical Outcome Survey Short Form 36 (SF-36). Satisfaction was determined with a specific questionnaire (FLZ). Hip arthroplasty followed by an inpatient rehabilitation resulted in significant and clinically highly important improvements of functional status, quality of life and satisfaction with health and life.

Phase 2 study of cryptophycin 52 (LY355703) in patients previously treated with platinum based chemotherapy for advanced non-small cell lung cancer

BACKGROUND

Cryptophycin 52 is a novel antitubulin drug with in vitro and in vivo activity in non-small cell lung cancer. Based upon promising Phase 1 data, a multicenter trial was performed to evaluate the drug in previously treated non-small cell lung cancer (NSCLC).

METHODS

Patients with Stage IIIb (pleural effusion) or Stage IV NSCLC and performance status 0-1 with adequate organ function who had received at least one and no more than two prior chemotherapy regimens (one of which must have contained a platinum agent) were eligible. Cryptophycin 52 was administered at a dose of 1.5 mg/m(2) day 1 and 8 every 3 weeks. Patients were reassessed every two cycles.

RESULTS

Twenty-six patients were enrolled of whom 25 are evaluable for toxicity and response. There were no responders, toxicity was predominantly neurologic in the form of peripheral neuropathy and constipation. After the first 12 patients were enrolled, the dose was lowered to 1.125 mg/m(2) day 1 and 8. Toxicity was substantially reduced with this maneuver. Median survival was 4.1 months. The median number of cycles was two, however ten patients received four or more courses of therapy.

CONCLUSION

Cryptophycin 52 failed to produce measurable responses utilizing this schedule. In 40% of patients there was evidence of disease stabilization. Toxicity at 1.5 mg/m(2) was unacceptable. Since activity and toxicity may be dose and schedule dependent, other schedules of cryptophycin 52 should be considered.

The "comparative growth assay": examining the interplay of anti-cancer agents with cells carrying single gene alterations

We have developed a "comparative growth assay" that complements current assays of drug effects based on cytotoxicity. A co-culture of two cell lines, one of which is fluorescently labeled, is exposed to a cytotoxic agent and the proportion of fluorescent cells is compared with that of a baseline unexposed co-culture. For demonstration purposes, two HCT116 cell lines (an hMLH1 homozygous and an hMLH1 heterozygous mutant), altered by insertion of vector alone or the same vector carrying an insert for the expression of enhanced green fluorescent protein (EGFP), were exposed to numerous "anti-cancer" agents. The assay was further validated in a system of two cell lines differing only in the expression of the breast cancer resistance protein (BRCP). The assay allowed the estimation of the duration of action of a particular agent. Assessment of the agent's differential activity over a given time in culture could be expressed as a selection rate, which we chose to describe on an "average selection per day" basis. We conclude that this assay: 1) provides insight into the differential dynamic effects of chemotherapeutic agents or radiation; and 2) allows, through the use of matched cell lines, the investigation of critical physiologic features that govern cell sensitivity.

Disseminated growth of murine plasmacytoma: similarities to multiple myeloma

Murine plasma cell tumors share a number of common features with human multiple myeloma, suggesting their possible use as a model for this disease. However, one major difference between the two is the peritoneal localization of murine tumors as opposed to bone marrow residence of malignant plasma cells in early stages of multiple myeloma. We have thus examined the ability of murine plasmacytoma to produce disseminated growth similar to that seen in myeloma or other lymphoid neoplasias. Of four murine cell lines evaluated, all were demonstrated to effect highly metastatic disease involving multiple organs, although variation was observed between lines. A temporal analysis was accordingly performed with the S107 line to assess the pattern of cellular localization. Both light microscopy and PCR analysis revealed that engraftment of plasma cells occurs first in the bone marrow, followed by dissemination to other sites including the spleen, lung, and liver. Cells passaged in vivo through the bone marrow display an entirely different metastatic pattern with no homing preference to bone marrow or any other organ, suggesting the occurrence of a phenotypic change. Microscopic osteolytic lesions were observed adjacent to plasma cell tumor masses in the bone marrow, indicating early stages of bone disease. These findings demonstrate previously unrecognized similarities between the murine and human diseases and suggest the use of this in vivo model for experimental approaches to the treatment of human disease.

Mutations in beta-catenin are uncommon in colorectal cancer occurring in occasional replication error-positive tumors

Beta-catenin has been identified as an oncogene in colon cancer and melanoma. Phosphorylation of sites in exon 3 of beta-catenin leads to degradation of this protein. These sites are primary targets for activating mutations. The frequency with which oncogenic mutations at these sites are found in colorectal cancer is unknown, as is the frequency of their occurrence in other malignancies. We analyzed 92 colorectal cancers (CRCs) and 57 cancer cell lines (representing a diversity of tumor types) to determine the frequency of activating mutations in this gene. Mutations in exon 3 of beta-catenin were found in 2 of 92 CRCs and in the colorectal cancer cell line HCT 116. Both tumors with beta-catenin mutations exhibited widespread microsatellite instability, which is indicative of a replication error phenotype, a phenotype known to be present in HCT 116. This suggests that mutations in beta-catenin are infrequent in CRC and miscellaneous cancer cell lines and may occur in association with a replication error phenotype.

Characterization of C57BL/6 plasmacytomas lacking a c-myc translocation

BALB/c peritoneal plasmacytomas induced by a variety of agents are invariably associated with a c-myc translocation. In contrast, naturally arising bone marrow plasma cell tumors in C57BL/KaLwRij mice lack this translocation. This difference has led to the suggestion that these are 2 fundamentally different plasma cell diseases. Herein, we have analyzed 2 rare C57BL/6 peritoneal plasmacytomas in terms of characteristics associated with the bone marrow-derived lines. Like the bone marrow lines, these peritoneal plasmacytomas do not exhibit c-myc translocations, indicating that c-myc translocation is not an obligatory event in the development of all murine extramedullary plasmacytomas. However, myc is dysregulated at the mRNA level, indicating that myc overexpression may be fundamental to most plasma cell diseases but that dysregulation can occur by alternative mechanisms possibly reflecting different genetic backgrounds.

[Use of flow cytometry in the diagnosis of acute leukemias in childhood]

The authors examined, using the method of flow cytometry, 56 children with acute lymphoblastic leukaemia. Leukaemic cells of the bone marrow aspirate and peripheral blood were examined on a FACS 440 apparatus for establishment of the diagnosis before treatment was initiated. Individual immunological subtypes were differentiated by means of a panel of monoclonal antibodies. 80.5% of acute lymphoblastic leukaemias originated from different developmental stages of B cells, 12.5% were formed by leukaemias from T cells and 7% were non-differentiated leukaemias. The mean follow-up period in the group was 33 months. According to the therapeutic results children with leukaemia ensuing from precursors of B cells had a more favourable prognosis than children with T leukaemia and children with non-differentiated leukaemia. Quantitative examination of nuclear DNA of leukaemic cells revealed in 55% of the patients of the group aneuploidy with clear predominance of hyperdiploidy, 45% of the patients suffered from diploidy. The least number of relapses was recorded in the investigation period in children with hyperploid acute lymphoblastic leukaemia. The proliferating activity of leukaemic blasts was expressed by the number of cells in the S + G2M stage of the cellular cycle and was higher in the bone marrow than in peripheral blood but did not differ in individual immunological subtypes or in diploid leukaemias. The authors were not able to prove its prognostic importance. Flow cytometry is a rapid and sensitive diagnostic method which makes it possible to characterize more satisfactorily the heterogeneous group of acute lymphoblastic leukaemias.

[DNA flow cytometry: perspective prognostic parameters in carcinoma of the uterine cervix]

We studied the relation between the 5-year disease free interval and the flow cytometric DNA content in a group of 55 patients treated by radiation for squamous cell carcinoma of the uterine cervix, stages Ib-IIIb (FIGO). The diploid DNA content was associated with a better prognosis, while prognostically unfavourable tumours tended to be aneuploid. The relation was statistically significant in the whole group (p = 0.016), in stage II disease (p = 0.003) and in the subgroup formed by the combination of stages I and II (p = 0.000). In stage III we did not prove the relation. Analysis of the survival function revealed also a better prognosis of diploid tumours (p = 0.041) in the whole group. The division into clearly diploid and non-diploid tumours seems to be more suitable for evaluation (p = 0.012). The difference between the prognostically favourable and unfavourable groups is expressed more clearly. We consider the flow cytometric DNA content a perspective prognostic parameter in squamous cell carcinoma of the uterine cervix. Its significance is apparent especially in patients treated by radiotherapy, because the size of the tumour cannot be assessed reliably in these cases.

[Cervico-acetabular impingement after femoral neck fracture]

Six cases of femoral neck-acetabular impingement following fracture of the femoral neck are reported. To our knowledge, this complication has not previously been described in the literature. A bony prominence at the level of the former fracture site following primary or secondary valgus position of the femoral head showed a conflict with the acetabular rim causing pain and limited motion. In four patients this impingement was posterior, between the femoral neck and the acetabulum in extension with external rotation, and in two patients it was anterior in flexion with internal rotation. A detailed description of the symptoms, diagnostic procedures and treatment options is presented.

[T-lymphocyte subpopulations in chronic active hepatitis]

In 33 patients with chronic active hepatitis quantitative changes were found in the ratio of different sub-populations of T lymphocytes in the peripheral blood stream which were either associated with treatment or with the presence of HbsAg in serum. A reduction of CD 3 positive lymphocytes was found in patients not treated by immunosuppression. In HbsAg positive patients an increase of CD 4 positive lymphocytes was found, as compared with HBsAg negative patients. Signs of activity of the hepatic process correlated with the presence of sign CD 8.

[Advances in the treatment of acute lymphoblastic leukemia in childhood: experience with intensive protocol treatments]

The authors analyzed a group of 64 children with acute lymphoblastic leukaemia (ALL) treated according to three protocols of different intensity. The best therapeutic results were obtained in children treated according to the most intensive protocol of the West German Multicentre Investigation BFM 83 which is graded as to its intensity with regard to the degree of risk of an adverse course. Successful remission in the entire group of patients was 93%, one third of the children developed during the investigation period a relapse of the basic disease. 12% of the children died during remission from complications of treatment. The surprising agreement of therapeutic results of different protocols after three years' complete remission is apparent from the fact that early relapses during the first two years of treatment, implying resistance to administered therapy, are at present the greatest problem of effective treatment which is not resolved even by the ever increasing intensity of treatment. In the conclusion the authors define the group of patients with a high risk of early relapse for whom new therapeutic procedures must be sought.

[Immunologic profile in patients with acute anterior uveitis]

The authors investigated 52 patients (22 men and 30 women) with acute anterior uveitis where they ruled out systemic autoimmune disease, metabolic disease and focal or chronic infection. At the time of the infection the patients had not been treated for several months by any immunosuppressive treatment. The authors investigated in these patients serum concentrations of immunoglobulins G, A and M, the concentration of the C3 component of complement and the concentration of circulating immune complexes. Before the onset of therapy they investigated the response to antigens of the Immunoskin test. They assessed also the ratio of transplantation antigens class I by the microlymphocytotoxic test. They compared furthermore immunological indicators in subjects with a first attack and relapse of the disease and in groups, classified by the severity of the inflammatory symptoms. The authors detected significantly more frequently (p = 0.0005) the incidence of HLA-B27 antigen. Those where it was present were more frequently affected with a severe inflammation, as compared with subjects who did not have this phenotype (p less than 0.04). The relapse of the disease was more frequent in women (p = 0.1). The immunological laboratory findings did not differ in the first attacks and relapses of the disease, differences were, however, found in groups which differed as to the severity of inflammatory symptoms. In these groups the response rate to tests of skin sensitivity differed also. Based on these findings the authors assume that the ratio of immune processes in the development of acute idiopathic anterior uveitis cannot be ruled out.

[Factors affecting the prognosis of acute lymphoblastic leukemia in childhood]

The authors tried to test the value of some clinical and laboratory characteristics for the prognosis of acute lymphoblastic leukaemia (ALL) in a group of 69 children treated according to three different protocols. The results were evaluated by methods of one-dimensional and multidimensional analysis. The absolute number of blasts in the peripheral blood stream and initial leucocytosis during establishment of the diagnosis proved to be the most important risk factors influencing the prognosis of the patients. Other adverse signs for the prognosis of ALL in the group were a mediastinal tumour, L2 type of leukaemic blasts according to the morphological FAB classification and age above 10 years when the diagnosis was established. The patient's sex, immunophenotype of the leukaemic blasts, chromosomal abnormality of the karyotype in the leukaemic cells, marked hepatosplenomegaly, thrombocytopenia, haemoglobin values and PAS reaction in the blasts, did not affect the therapeutic results in the author's group of patients.

Common variable immunodeficiency and malignancy: a report of two cases and possible explanation for the association

Two patients with common variable immunodeficiency (CVID) and malignant tumours are reported. The first patient developed myelogenous leukaemia soon after the myelodysplastic syndrome has been diagnosed. The undifferentiated gastric lymphoma found in the second patient suggests that an increased risk of gastrointestinal malignancies in CVID could partly be due to lymphomas. We hypothesize that the tissue- or site-specific risk of lymphomas and gastrointestinal cancer can be explained by an increased chromosomal or genomic instability with a higher mutation rate and genomic disorganization, and that this instability could be related to viral carcinogenesis. The primary immunodeficiency per se may not be responsible for the cancer susceptibility in CVID patients.

The Thy-1 glycoprotein is expressed in mouse embryonal carcinoma cells P19

Thy-1 is a well characterized glycoprotein known to be variably expressed on the surface of different cell types. Serological analysis of a limited number of teratocarcinoma-derived cell lines suggested that mouse embryonal carcinoma cells do not express Thy-1 and that its expression is associated with the appearance of differentiated cells. In this report we show that monoclonal antibody 1aG4, recognizing Thy-1.2 epitope, binds specifically to P19 embryonal carcinoma cells and their undifferentiated subclones. A number of control experiments confirmed that 1aG4 antibody binds to the Thy-1.2 glycoprotein expressed on the surface of P19 embryonal carcinoma cells and not to the antigen expressed on differentiated derivatives of these cells or to a cross-reactive epitope. Transcriptional activity of the Thy-1 gene in undifferentiated P19 cells was shown by transfection experiments in which transfer of the Thy-1.1 gene into P19 cells resulted in stable expression of the Thy-1.1 antigen on the surface of recipient cells. Direct evidence for the presence of Thy 1 mRNA in P19 cells was obtained by Northern blot analysis with a Thy-1-specific cDNA probe. Treatment of P19 cells with retinoic acid resulted in a decrease in the expression of Thy-1 antigen which preceded changes in morphology of the cells. These data indicate that Thy-1 is a developmentally regulated surface marker of P19 embryonal carcinoma cells which is amenable to direct genetic analysis.