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At least 217 records · Page 12Linked to original sources
PubMed1997

Acute leukaemia during tamoxifen therapy.

Tamoxifen treatment is a proven therapy for breast cancer that produces a survival advantage when used as an adjuvant, and reduces the incidence of recurrences and controlateral tumor evolution. Although this therapy has a very low toxicity profile, an increase in secondary cancers has been reported. Tamoxifen is suggested to be carcinogenic both through direct genotoxic and epigenetic mechanisms. It is activated by cytochrome P450 to form reactive metabolites that bind covalently to DNA to create adducts. We report two cases that developed acute myeloid leukaemia (AML) during tamoxifen therapy for breast cancer.

Antineoplastic Agents, Hormonal↗
PubMed2004

Use of tubed gastro-omental free flap for hypopharynx and cervical esophagus reconstruction after total laryngo-pharyngectomy.

In case of total laryngo-pharyngectomy (TLP), replacement of the pharyngoesophageal segment is more often done with jejunal flap; however, in some cases, this flap doesn't represent the best surgical technique of reconstruction. The tubed gastro-omental free flap (TGO) offers an alternative procedure in selective cases. The objective of the study was to assess the TGO as a method of pharyngoesophageal reconstruction. Our study was based on a literature review and a retrospective study of six consecutive cases of TGO reconstruction after TLP. Six patients aged from 52 to 70 years underwent TGO reconstruction after TLP. Five patients had previously received systemic chemotherapy and external irradiation at curative doses, and three had undergone previous surgery. No abdominal complication occurred. Partial necrosis of the gastric flap occurred in one case. Except for this case, the feeding tube could be removed after 15 days. One patient was successfully treated with pneumatic esophageal dilatation for stricture 2 months after surgery. Four patients died of loco-regional tumor evolution or distant metastatic disease. For both of the patients who survived (mean follow-up, 40 months), a normal diet and an esophageal voice were obtained. The TGO offers a safe method of reconstructing the pharyngoesophageal segment in a surgical field compromised of previous multimodal therapy.

Aged↗
PubMed1996

Clinical significance of LEA-1 expression in adult acute myeloid leukemia.

In this study, we examined expressions of several adhesion molecules (AdMs), i.e. leukocyte function antigen-1 (LFA-1: CD11a/CD18), Hermes homing receptor (CD44) and intercellular adhesion molecule-1 (ICAM-1: CD54), on leukemia cells from 51 adult patients with newly diagnosed acute myeloid leukemias (AMLs) to elucidate clinical significance of these AdM expressions. Those expressions in lymphoid malignancies have been correlated with tumor evolutions, but CD44 was detected in all the AML cases examined and CD54 expression did not associate with their clinical characteristics or outcomes. However, we found that LFA-1 expressions significantly correlated with splenomegaly, resistance to induction chemotherapies and short survival periods in AML patients.

Acute Disease↗
PubMed1989

Nonrandom chromosomal aberrations are associated with sites of tissue involvement in non-Hodgkin's lymphoma.

In an effort to assess the utility of pretreatment cytogenetics as indicators of sites of involvement by lymphoma, clinical and cytogenetic correlations were performed on 133 consecutive specimens derived from 130 patients with non-Hodgkin's lymphoma. Nonrandom chromosomal aberrations detected at the time of diagnosis were associated with sites of clinical involvement presenting initially or during the progression of the lymphoma. Statistically significant associations included translocation breaks involving the chromosomal region 1p32-36 and bone marrow involvement, chromosome 14 abnormalities including breaks at 14q22-24 and splenic involvement, chromosome 9 abnormalities and pulmonary involvement, and monosomy 11 and bone involvement. A significant correlation was also observed between breaks involving the region 6q22-24, detected during the course of disease, and bone marrow involvement by lymphoma. The relationship of the sites of nonrandom chromosomal breakage reported here to known cellular oncogenes and implications to concepts of tumor evolution and spread are discussed.

Bone Marrow↗
PubMed2025

Cloning and validating systems for high throughput molecular recording.

Molecular recording technologies record and store information about cellular history. Lineage tracing is one form of molecular recording and produces information describing cellular trajectories during mammalian development, differentiation and maintenance of adult stem cell niches, and tumor evolution. Our molecular recorder technology utilizes CRISPR-Cas9 barcode editing to generate mutations in genomically integrated, engineered DNA cassettes, which are read out by single-cell RNA sequencing and used to produce high-resolution lineage trees. Here, we describe optimized cloning and validation procedures to construct the molecular recorder lineage tracing system. We include information on considerations of technology design, cloning procedures, the generation of lineage tracing cell lines, and time course experiments to assess their performance.

Cloning, Molecular↗
PubMed2003

[Nasal angiocentric T cell-natural killer cell lymphoma with pancreatic localisation in a child].

The nasal angiocentric T-cell-natural killer cell lymphoma is an aggressive tumor, exceptional in Tunisia, which is observed especially in Asia, Mexico and South America. We report the case of an 11-year-old boy, presenting with an exuberant and ulcerative tumor of the right nasal pit. Radiological investigation evidenced a right ethmoïdo-frontal tumor. Evolution was characterized by the installation of abdominal pain and fever, the evidenciation of a mass within the head of the pancreas that compressed the extra hepatic biliary duct and Wirsung's canal and was associated to hyperamylasemia. Biopsy under ultrasound revealed a histiocytic nature. Nasal biopsy found histiocytic and lymphocytic cells and led to a diagnosis of rhinoscleroma. The absence of improvement under antibiotic treatment and the development of fever with leuconeutropenia oriented towards the diagnosis of a non-Hodgkinian malignant lymphoma. Medullary biopsy and immunohistochimic study confirmed a T/NK cells lymphoma, with medullary invasion. The child died from acute respiratory distress syndrome. The authors insist on the rarity of this bipolar location, in particular in children, emphasize the difficulty of the diagnosis and review the literature.

Abdominal Pain↗
PubMed2005

A complex translocation (9;22;16)(q34;q11.2;p13) in chronic myelocytic leukemia.

The t(9;22) is present in almost all cases with chronic myelocytic leukemia (CML). Around 5% of these patients show complex translocations involving a third chromosome in addition to chromosomes 9 and 22. All chromosomes have participated in these variants and the BCR-ABL1 hybrid gene is always present. We describe a CML case with a new complex t(9;22;16)(q34;q11.2;p13). Seven months after imatinib treatment a karyotype showed the appearance of a clone with a standard t(9;22) in addition to the clone with the complex translocation. The b3a2 transcript of BCR-ABL1 was detected both at diagnosis and 7 months after therapy. In CML, both complex translocations and standard translocations have the same prognosis. However, these complex variants could contribute to the tumoral evolution by conferring selective advantages that, in turn, cause the preferential manifestation at diagnosis of clones with complex translocations.

Child, Preschool↗
PubMed2004

Telomere length heterogeneity and chromosome instability.

Chromosome aberrations are the hallmark of cancer cells. Although a few specific chromosome aberrations are frequently detected in some types of cancer, the majority of karyotypic abnormalities tend to differ between different histological types and between individuals with the same type of cancer. Recent work indicates that telomeres may be directly involved in shaping the karyotypes of tumor cells. In particular, the heterogeneity of telomere lengths within cells may have direct influence on the frequency with which chromosomes engage in telomeric fusions and in subsequent breakage-fusion-bridge cycles. Since telomere length distribution among chromosome arms is a polymorphic trait, difference in distributions between individuals may account, at least in part, for the karyotypic differences found among tumors of the same type. Conversely, if single telomere lengths happen to be inherited, the segregation of particularly short telomeres in families may increase the incidence of specific chromosome aberrations during tumor evolution, and perhaps contribute, along with other factors, to cancer pre-disposition.

Alleles↗
PubMed2026

Mirror worlds: The shared regulatory architecture of cell fate in development and cancer.

Lineage plasticity has emerged as a central mechanism through which cancer cells adapt to therapeutic pressure, evade immune surveillance, and acquire aggressive phenotypes. Although recognized across tumor types, the regulatory principles governing how cancer cells reprogram cellular identity remain incompletely understood. In this review, we propose that lineage plasticity in cancer reflects the redeployment of regulatory frameworks established during normal development. Rather than representing a stochastic byproduct of genomic instability, cancer plasticity frequently unfolds within gene regulatory architectures that also govern cell fate specification, lineage commitment, and controlled state transitions during embryogenesis and tissue homeostasis. Developmental transcription factors, including members of the SOX family, FOXA1, ASCL1, NKX2-1, and epithelial-mesenchymal transition regulators, function as lineage gatekeepers during development but are repurposed in cancer to destabilize lineage commitment and enable phenotypic switching. Similarly, epigenetic regulators that guide developmental trajectories, including chromatin remodeling complexes, Polycomb group proteins, and DNA methylation machinery, are frequently dysregulated or redistributed in tumors, altering the repression of lineage-stabilizing and alternative lineage programs and thereby weakening epigenetic barriers to lineage transitions. Together, these observations support a model in which development and cancer operate as mirror regulatory systems: one establishing and stabilizing cellular identity, the other exploiting the same regulatory architecture to permit adaptive reprogramming under selective pressure. We further discuss how emerging single-cell and spatial multi-omics technologies, integrated with artificial intelligence-based modeling, enable mapping of cell state landscapes and transitional trajectories, transforming lineage plasticity from a descriptive phenomenon into a measurable and predictable property of tumor evolution.

Humans↗
PubMed2006

Reaction-diffusion approach to modeling of the spread of early tumors along linear or tubular structures.

We consider a system composed of a tubular sheet of early tumor cells, occupying the surface of a structure existing in the organism. We assume that the cells have a potential for proliferation in response to a growth factor. This model can be thought of as representing an early stage (pre-in situ) of tumor evolution. A biomedical example of such process might be the atypical adenomatous hyperplasia in the lung. Destabilization of the equilibrium in such system represents initial invasion of cancer. We are looking for a transition from a slightly perturbed equilibrium state to uncontrolled and irregular growth. We examine a mathematical model of a population of cells distributed over a linear or tubular structure. Growth of cells is regulated by a growth factor, which can diffuse over the structure. Aside from this, production of cells and of the growth factor is governed by a pair of ordinary differential equations. Equation for the cell number follows from an accepted model of cell cycle. Equation for the bounded receptor particle number follows from a time-continuous Markov process. We demonstrate existence of the solutions of the complete model, using the method of invariant rectangles. We find conditions under which diffusion causes destabilization of the spatially homogeneous steady state, leading to exponential growth and apparently chaotic spatial patterns, following a period of almost constancy. This phenomenon may serve as a mathematical explanation of "unexpected" rapid growth and invasion of temporarily stable structures composed of cancer cells.

Animals↗
PubMed1999

[Total pelvic exenteration and rectal cancer. Apropos of 20 cases].

STUDY AIM: The report of a series of 20 patients with the aim of trying to specify the implications of pelvic exenteration for rectal cancer. PATIENTS AND METHODS: From 1986 to 1996, 20 total pelvic exenterations were performed for rectal adenocarcinoma. This retrospective study included locally extended carcinomas (n = 10), and recurrences (n = 10) after anterior resection (n = 7), and after abdominoperineal resection (n = 3). The subjects included 13 men and seven women with a mean age of 54 years (34-74 years). Complaints were major and serious: pain (n = 20), rectal syndrome (n = 17), recto-vesical fistula (n = 5) recto-vaginal fistula (n = 5), urinary infection (n = 13), and hematuria (n = 6). Preoperative radiotherapy was performed in 11 patients and preoperative radio chemotherapy in six. The surgical procedure included a total pelvic exenteration with perinectomy in 12 patients, and a total pelvic exenteration with preservation of levator ani and perineum in eight, associated in two cases with a partial resection of the sacrum, and in two other cases with partial hepatectomy for a single liver metastasis. Urinary diversion was a trans ileal ureterostomy in 17 patients and a direct double ureterostomy in three. RESULTS: The mean duration of surgery was 6 h. The mean preoperative blood loss was 1,200 L. Nine patients received blood transfusion. There was no postoperative mortality but in contrast, the morbidity rate was high with mainly urinary and digestive complications, pelvic sepsis and thromboembolic complications. After pathological examination, tumoral resections were classified R0 in 19 cases, and R1 in one. All tumors were T4 with tumoral invasion of the bladder (n = 15), prostate (n = 6), seminal vesicles (n = 4), ureter (n = 3), vagina (n = 7), urethra (n = 1), and sacrum (n = 1). Lymph node involvement was present in four patients. The 3 and 5 year actuarial survival rate was respectively 47 and 18%. Thirteen patients died of their cancer, nine from metastases, and four from local recurrence with a mean survival of 29 and 32 months respectively. Seven patients were alive at the time of this study, six without actual recurrence. CONCLUSIONS: In spite of its aggressive aspect, total pelvic exenteration seems justified in rectal carcinoma when extended to the urinary tract, when it causes major functional disorders, when there are no detectable metastases, and when the tumor has no posterior or lateral fixation. Local tumoral evolution can usually be controlled by pelvic exenteration but prolongation of survival is not demonstrated.

Adenocarcinoma↗
PubMed2002

[Laparoscopic hepatectomy].

AIM: To report the current indications and techniques of laparoscopic liver resections, and assess the results of this technique by reviewing international literature. REVIEW OF THE LITERATURE: About 200 laparoscopic hepatectomies have been reported from 1991 to 2001. 102 resections were performed for malignant tumours, and 84 for benign tumours. Global conversion rate was 7% (13/186). Morbidity rate was 16.1% with two cases of possible gas embolisms (1.1%). Mortality rate was 0.54% (1/186 patients). Mean hospital stay was 7.7 days. CONCLUSION: Laparoscopic hepatectomy is feasible, with a morbidity and mortality rate comparable to open procedures according to a careful selection of patients. However, prospective randomized trials are still needed to confirm those results, especially for resection of metastasis or malignant tumors. Evolution of laparoscopic hepatectomies will probably depend on the development of new techniques and instrumentations.

Hepatectomy↗
PubMed2001

Chromosomal analyses of 52 cases of follicular lymphoma with t(14;18), including blastic/blastoid variant.

We have identified 52 patients of follicular lymphoma (FL) with t(14;18)(q32;q21). Histologically, the lymphomas were placed into six groups according to their cellular composition and growth pattern. Chromosome analysis revealed that all cases but one had additional secondary chromosomal abnormalities. The most frequent numerical aberrations were gains of chromosomes 7 (38%), X (36%), 5 (15%), 12 (15%), 18/der(18)t(14;18) (25%), and 21 (15%). Structural abnormalities of chromosome 1 were seen in 19 tumors (36%) affecting both arms with breakpoints clustered at 1p36. Other structural abnormalities included partial deletions of 6q, 10q, and 13q. Breakpoint at 8q24 was seen in four cases. The chromosome aberrations were correlated with the morphological subtypes of follicular lymphoma. Gain of chromosome 7 appeared to be associated with follicular large cell lymphoma. The incidence of trisomy 5 and 12, and 13q- was higher in follicular lymphoma with aggressive histological features than in low-grade lymphoma. In addition, complexity of the karyotype and high degree of polyploidy increased with the grade. The most valuable cytogenetic markers in the t(14;18) lymphomas are those involving 8q24 which was found exclusively in the blastic/blastoid variant FL. Therefore, chromosome analysis in relation to histologic pattern of follicular lymphoma can provide additional information in predicting tumor evolution and transformation to a higher-grade malignancy.

Adult↗
PubMed2003

Trisomy 8 as the sole chromosomal aberration in myelocytic malignancies: a multicolor and locus-specific fluorescence in situ hybridization study.

Trisomy 8 is the most common chromosomal aberration in myelocytic malignancies, occurring both as a sole change as well as in addition to other abnormalities. In spite of this, next to nothing is known about its pathogenetic importance or its molecular genetic consequences. Possible mechanisms involved in the transformation process include dosage effects of genes mapping to chromosome 8 and presence of specific mutations or cryptic fusion genes on the duplicated chromosome. In the latter case, +8 would be secondary to a cryptic primary rearrangement and not involved in leukemogenesis as such, but rather in tumor evolution. Although hidden genetic changes have been found in some trisomies, for example, mutations in KIT in acute myelocytic leukemia (AML) with +4 and in MET in hereditary papillary kidney carcinoma with trisomy 7, none associated with +8 have so far been discovered. To address this issue, we have investigated a total of 13 cases of AML, myelodysplastic syndromes, and chronic myeloproliferative disorders with trisomy 8 as the sole chromosomal anomaly. All cases were studied by combined binary ratio multicolor fluorescence in situ hybridization (FISH) and with FISH using locus-specific probes for both arms of chromosome 8, the subtelomeric regions of 8p and 8q, and the leukemia-associated genes FGFR1, MOZ, ETO, and MYC. No cryptic changes were detected, thus excluding the possibility of gross genetic rearrangements or aberrations involving these loci on chromosome 8.

Acute Disease↗
PubMed2025

Modern biology of extrachromosomal DNA: A decade-long voyage of discovery.

Genomic instability is a hallmark of cancer and is a major driving force of tumorigenesis. A key manifestation of genomic instability is the formation of extrachromosomal DNAs (ecDNAs) - acentric, circular DNA molecules ranging from 50 kb to 5 Mb in size, distinct from chromosomes. Ontological studies have revealed that ecDNA serves as a carrier of oncogenes, immunoregulatory genes, and enhancers, capable of driving elevated transcription of its cargo genes and cancer heterogeneity, leading to rapid tumor evolution and therapy resistance. Although ecDNA was documented over half a century ago, the past decade has witnessed a surge in breakthrough discoveries about its biological functions. Here, we systematically review the modern biology of ecDNA uncovered over the last ten years, focusing on how discoveries during this pioneering stage have illuminated our understanding of ecDNA-driven transcription, heterogeneity, and cancer progression. Furthermore, we discuss ongoing efforts to target ecDNA as a novel approach to cancer therapy. This burgeoning field is entering a new phase, poised to reshape our knowledge of cancer biology and therapeutic strategies.

Humans↗
PubMed2026

Methylation profiling of normal tissue adjacent to breast tumors reveals two distinct groups with divergent tumor microenvironment features.

We previously identified diverse genetic evolutionary patterns in whole-genome sequencing of paired normal tissue adjacent to tumor (NAT) and tumor tissues from Hong Kong breast cancer (HKBC) patients. Here, we investigated whether DNA methylation (DNAm) contributes to NAT heterogeneity and shapes the tumor microenvironment (TME). Genome-wide DNAm profiling was performed on paired NAT and tumor tissues from 188 HKBC patients using the Infinium 850 K array. RNA-seq data were available for 76 NATs and 177 tumors. Cellular composition was inferred using MethylCIBERSORT, CIBERSORTx, and EpiDISH, and histopathologic features were assessed on 115 H&E-stained sections. Unsupervised clustering identified two distinct NAT subtypes with divergent TME characteristics. Cluster 1 (N = 139) showed higher epithelial and fibroblast content and enrichment of estrogen response pathways. Cluster 2 (N = 49) exhibited an immune-metabolic phenotype characterized by increased fat and immune cells, stromal disruption, inflammatory pathway activation, and greater macrophage infiltration. Cluster 2 patients also demonstrated significantly younger epigenetic age estimated using multiple epigenetic clocks. These DNAm-defined NAT subtypes and associated TME features were validated in 97 NAT samples from TCGA breast cancer patients. Overall, our findings identify DNAm-driven NAT heterogeneity with distinct TME landscapes, providing new insights into field cancerization and tumor evolution in breast cancer.

Journal Article↗
PubMed2003

Genome-wide-array-based comparative genomic hybridization reveals genetic homogeneity and frequent copy number increases encompassing CCNE1 in fallopian tube carcinoma.

Fallopian tube carcinoma (FTC) is a rare, poorly studied and aggressive cancer, associated with poor survival. Since tumorigenesis is related to the acquisition of genetic changes, we used genome-wide array comparative genomic hybridization to analyse copy number aberrations occurring in FTC in order to obtain a better understanding of FTC carcinogenesis and to identify prognostic events and targets for therapy. We used arrays of 2464 genomic clones, providing approximately 1.4 Mb resolution across the genome to map genomic DNA copy number aberrations quantitatively from 14 FTC onto the human genome sequence. All tumors showed a high frequency of copy number aberrations with recurrent gains on 3q, 6p, 7q, 8q, 12p, 17q, 19 and 20q, and losses involving chromosomes 4, 5q, 8p, 16q, 17p, 18q and X. Recurrent regions of amplification included 1p34, 8p11-q11, 8q24, 12p, 17p13, 17q12-q21, 19p13, 19q12-q13 and 19q13. Candidate, known oncogenes mapping to these amplicons included CMYC (8q24), CCNE1 (19q12-q21) and AKT2 (19q13), whereas PIK3CA and KRAS, previously suggested to be candidate driver genes for amplification, mapped outside copy number maxima on 3q and 12p, respectively. The FTC were remarkably homogeneous, with some recurrent aberrations occurring in more than 70% of samples, which suggests a stereotyped pattern of tumor evolution.

Carcinoma↗
PubMed2002

A phylogenetic analysis identifies heterogeneity among hepatocellular carcinomas.

Primary hepatocellular carcinoma (HCC) is a significant cause of cancer morbidity and mortality on the global scale. Although epidemiologic studies have identified major risk factors for HCC, the sequence of oncogenic events at the molecular level remains poorly understood. While genetic allele loss appears to be a common event, the significance of the loss is not clear. In order to determine whether allele loss appears to be a random event among HCCs or whether patterns of loss cluster in groups of tumors, a phylogenetic approach was used to examine 32 tumors for genome-wide loss of heterozygosity employing 391 markers. Clusters identified by the phylogenetic analysis were then contrasted to compare candidate locus variation among individuals and to determine whether certain clusters exhibited higher loss rates than other clusters. The analysis found that 3 major and 1 minor cluster of loss could be identified and, further, these clusters were distinguished by variable rates of loss (cluster 1, 29%; cluster 2, 21%; cluster 3, 16%). The analyses also indicated that the allele loss rates in HCC were not insignificant and that the patterns of allele loss were complex. In addition, the results indicated that an individual's constitutional genotype at the EPHX1 locus may be a critical factor in determining the path of tumor evolution. In conclusion, it appears that in HCC, allele loss is not random, but clusters into definable groups that are characterized by distinctive rates of loss.

Adult↗