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Query: UMLS:C0598934 (tumor growth)
 58,965 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The morphologic characteristics of a scar may render it an "immunologically privileged site" providing fertile ground for tumor occurrence and growth. We sought to extend this concept and to determine the effect of different stages of wound healing on tumor occurrence. Syngeneic strain-2 guinea pigs and a methylcholanthrene-induced liposarcoma (MCA-2) were used. Incisional flank wounds were created at appropriate intervals such that at the time of tumor inoculation each group of animals had a sequentially aged wound which was a) acute, b) three weeks old, c) nine weeks old, d) 11 weeks old, e) created one week after tumor injection, or f) no wound. Wounds which were three, nine, or 11 weeks old consistently caused a significant increase in tumor growth rate following inoculation of a single cell tumor suspension (<.001). The delayed wounds, or those created following after tumor injection, and the acute wounds did not promote increased tumor growth. This study demonstrates that the ability of a wound to amplify or retard tumor growth may vary with its age. As a postulate we suggest that the relative paucity of lymphatic regeneration within scar tissue may render it an "immunologically privileged site" such that early recognition and destruction of tumor cells within the scar may be delayed long enough for the tumor to grow to a "critical size." Subsequent to this regardless of the host's immunocompetence the tumor can no longer be destroyed by an immune mechanism. The general lack of progressive growth of tumor cells placed in acute wounds suggests that they were not protected from immunocompetent cells and were destroyed by the ongoing inflammatory response to injury. Therefore, different biologic characteristics of a surgical scar are important in potentiating or retarding tumor growth. Variations in such factors may account for the local recurrence of cancer in operative wounds.
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PMID:Biologic determinants of tumor growth in healing wounds. 42 50

A patient with abdominal liposarcoma is described, and the treatment of this in children extremely uncommon tumor is discussed. After complete surgical excision, local irradion with 5000-6000 rad should be considered only if no vital organs are irradiated. Because of the high tendency for local recurrence and for distant metastases of this tumor a primary polychemotherapy beginning immediately after surgical excision is proposed as in cases of other solid tumors in children for instance rhabdomyosarcoma or fibrosarcoma. 18 months after the surgical excision and after the beginning of polychemotherapy our patient is clinically well without demonstrable tumor growth.
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PMID:[Treatment of abdominal liposarcoma in children (author's transl)]. 65 96

Tumors in rats of the Nb strain, arising either spontaneously or after prolonged treatment with s.c. pellets of estrogen, were transplanted to establish whether hormone conditioning was required for their growth. Whereas all spontaneous tumors arising in males and many of those in females were autonomous on transplant, most of those arising in estrogenized rats continued to require hormones for growth after transplantation. The latter included carcinomas of the adrenal cortex, breast, pituitary ectopic tissue, ovary (thecomas), Leydig cells of testis, thymus, pancreas,salivary glands, oribital gland (fibroadenoma), liposarcoma, and lymphoma. Many of the tissues of origin of the tumors have not been considered to be under theinfluence of estrogens. A type of hormone-responsive tumor that was inhibited by estrogen and that grew only in normal rats is described. Ali estrogens tested, including estriol , were interchangeable in action. The incidence of the more common tumors of the adrenal, breast, and pituitary was very low in normal rats, but higher in females. All tumors were more common after estrogenization in both sexes, particularyly in older animals. The secretion of steroids and pitiutary hormones by many tumors led to obvious biological effects. Pituitary secretion led to severe lesions frequently associated with diseases in humans, but the signs of such diseases in the rat apparently were hormone dependent and disappeared if the tumor was removed. The overall results raised the possiblity that estrogens were not carcinogenic per se but stimulated the growth of previously altered cells and that, following their transplantation, this hormone requirement was retained. Irrespective of the mechanism of carcinogenesis, hormone-dependent tumor growth was not irreversible but was controlled in an unexpectedly wide spectrum of organs by exogenous estrogen. Host factors may play a major role in controlling the growth of many tumors and the ultimate course of the disease.
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PMID:Spontaneous and estrogen-produced tumors in Nb rats and their behavior after transplantation. 116 9

Transplantable tumor lines were previously established from a variety of estrogen-induced tumors in Nb rats, including tumors of the adrenal cervix, salivary gland, and pancreas, a lymphoma, and a liposarcoma. Spontaneous tumors, however, were found to arise in untreated females and showed the same characteristics. Tumor growth was dependent upon or influenced by estrogen when assessed in estrogenized and unconditioned hosts. Intermitten estrogenization was effective, but tumor growth took place more slowly. The type of response observed led to a new classification of five types of hormone-responsive tumors including tumors inhibited by estrogen. Estrogen-dependent tumor cells might remain dormant indefinitely and not grow in unconditioned animals until stimulated to grow by estrogen. The growth rate of hormone-dependent adrenal carcinomas was related to the amount of estrogen. Tumor growth started more rapidly in the presence of low estrogen dose levels in old rats used as hosts than it did in young rats. Breast carcinomas required the largest amount of estrogen for growth, whereas ovarian thecomas would grow in normal females but not in males. The growth rate in conditioned hosts of most transplanted tumors (some have maintained hormone dependency over 10 years) increased over successive generations. Progression, however, towards a more autonomous state after repeated transplantations was remarkably slow, and a sudden change to autonomy was rarely noted. In contrast, transplants of 9,12-dimethylbenz(a)anthracene-induced mammary carcinomas progressed rapidly to autonomy. Fould's concept of progression (2, 3) has been discussed but the described classification of tumors under hormone influence apparently allows a more detailed analysis of definition of different types of progression.
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PMID:A classification of transplantable tumors in Nb rats controlled by estrogen from dormancy to autonomy. 118 86

We carried out DNA cytofluorometry with propidium iodide stain on the 17 cases of soft tissue tumors including giant cell tumor of the tendon sheath, pigmented villonodular synovitis, 2 hemangiomas, 3 lipomas, 5 schwannomas, 3 neurofibromas, liposarcoma and synovial sarcoma. The benign tumors were characterized by regular polyploidization with very few S-phase cells, indicating slow tumor growth. Most of the malignant soft tissue tumors were associated with remarkable polyploidization with an increase in S-phase cells. However, some malignant tumors did not show polyploidization. We concluded, therefore, that an increase in S-phase cells is an important, cytofluorometric criterion for malignancy of soft tissue tumors.
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PMID:[DNA cytofluorometry of soft tissue tumors]. 609 47

A spontaneous non-immunogenic transplantable liposarcoma in BN rats was found to be sensitive to the antitumor effects of rat fibroblast interferon (RIF) when it was administered from the day of tumor implantation onwards. Treatment with RIF starting at 7 days after implantation was not effective. Tumor growth was markedly inhibited by cyclophosphamide (Cyclo). At the time and dose schedules used, Cyclo was more effective than RIF. When the growth of the tumor was inhibited by Cyclo, subsequent treatment with RIF did not lead to an additional retardation of tumor growth. Administration of RIF interfered with the beneficial effect of Cyclo when both agents were given concomitantly. RIF and Cyclo gave similar results to those obtained with RIF alone and these were inferior to those obtained with Cyclo alone.
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PMID:Effect of treatment with interferon and cyclophosphamide on the growth of a spontaneous liposarcoma in rats. 618 16

Sixty-three patients with malignant and benign tumors of soft tissues were examined making use of magnetic resonance computer-aided tomography (MRT). This method was found effective in the diagnosis of soft tissue tumors, permitting the detection of tumor connection with the adjacent structures. In some cases MRT helped differentiate between malignant and benign soft tissue tumor growth, e.g. liposarcoma, malignant fibrous histiocytoma, lipoma, desmoid, hematoma. MRT may be effectively used in the diagnosis of soft tissue formations.
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PMID:[Magnetic resonance computerized tomography in the diagnosis of soft tissue neoplasms]. 780 81

Local recurrence of tumor is a common phenomenon in soft tissue sarcoma (STS) and may be accompanied by an increase in malignant potential. In the present study, an increase of proliferative activity in recurrent tumors compared to primary tumors was observed using a silver stain for nucleolar organizer regions (AgNOR), and its implication for predicting prognosis is assessed. 44 patients with STS showing local tumor recurrence were selected. Local recurrence was defined as new tumor growth more than 2 months after the initial surgery in the same region where the primary tumor occurred. All patients received surgery, followed in 11 patients by adjuvant radiotherapy and/or chemotherapy. The histologic subtype was malignant fibrous histiocytoma in 22 cases, synovial sarcoma in 5, leiomyosarcoma in 4, liposarcoma in 3, malignant schwannoma in 3, and others in 7. The interval between initial surgery and local recurrence ranged from 2 to 72 months. No patients changed from one histological subtype to another. Histological changes included an increase in mitosis, cellularity, and sclerosis in 43.2, 31.8, and 27.3%, respectively. The AgNOR count (mean +/- SD) in recurrent tumors (7.22 +/- 2.59) was significantly higher than that in primary tumors (5.58 +/- 2.28; p < 0.0057), clearly showing a tendency for an increase in proliferative activity during recurrence. The 5-year survival rate of patients with a marked increase (> 4) in AgNOR count (16.7%) was worse than with minor to moderate increases (60.0%; p < 0.02). Marked AgNOR increase was more frequently observed in the tumors located in the head and neck and retroperitoneum (40%) than in other sites (9%). Irrespective of the primary site of tumors, a marked AgNOR increase resulted in an unfavorable prognosis. Multivariate analysis of change in histologic factors including AgNOR, cellularity, mitotic counts, pleomorphism, myxoid change, necrosis, sclerosis, and tumor size showed that increase of AgNOR counts was significant (p < 0.05). The present findings suggest that AgNOR counts can be used as a prognostic factor in recurrent STS.
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PMID:Usefulness of argyrophilic nucleolar organizer staining for predicting prognosis of patients with recurrent soft tissue sarcoma. 819 7

Mediastinal liposarcoma are of rare entity; there are less than one hundred cases published worldwide. Because of the equivocal and inapparent symptomatology clinical signs often are falsely estimated, and in time of surgery there is generally seen a wide spread tumor growth, so that a radical resection often is impossible. Radiotherapy and chemotherapy are of limited value and mean no chance for curative therapy. The case of a 46 years old patient with an extensive primary liposarcoma of the mediastinum and the results of the review of the literature will be discussed.
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PMID:[Diagnosis and treatment of primary mediastinal liposarcoma]. 1252 64

A 22-year-old woman with a newly detected chondroid liposarcoma located in the iliac muscle was diagnosed as having bilateral pulmonary embolism. Gadolinium-enhanced MRI further revealed a long distance thrombus reaching from the iliac vein to the right atrium. The thrombus was attributed to a hypercoagulability state which has been described for chondroid liposarcoma. High-dose chemotherapy with autologous stem cell support reduced the tumor burden and led to a symptom-free interval of 6 months. Despite therapeutic anticoagulation, repeated imaging showed no reduction or remodeling of the thrombus. However, when the thrombus progressed again, the patient underwent cardiac surgery and histology revealed the intravascular growth of the known chondroid liposarcoma. We conclude that in sarcoma patients intravascular tumor growth must be kept in mind when imaging is suggestive for thrombosis.
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PMID:Thrombectomy discloses intravascular growth of chondroid liposarcoma mimicking a long distance vena cava thrombosis. 1536 85


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