Tumors secondary

Ionizing radiation therapy is also a cause of secondary malignancies. These secondary tumors generally develop within or adjacent to the previous radiation field. These cancers often have... 

Is the effect reversible Reversibility of a response is dependent on the drug itself, exposure levels/duration, and factors related to the test animal (metabolic capability, genetic susceptibility, etc.). Most effects produced by immunosuppressive drugs have been shown to be reversible after cessation of therapy, such as those produced during cancer chemotherapy. However, if a tumor develops before the immune system is restored, the effect is not reversible, as is the case of secondary tumors related to chemotherapy. 

Immunosuppression in general is associated with two other unwanted effects. Firstly, there is not only an increased risk of bacterial, viral and fungal infections but also various opportunistic infections occur. The second draw back is the risk for secondary tumors, especially lymphomas. 

Figure 55 Brain images obtained using "mTc-glucoheptonate showing the location of secondary tumors which disrupt the blood brain barrier. (Courtesy of the Nuclear Medicine Department, Queen Elizabeth Hospital, Birmingham, UK)...

TPMT Mercaptopurine, azathioprine Myelosuppression, radiotherapy-related secondary tumors... 

Deposition and adhesion of cells on surfaces play an important part in many biological processes. For example, blood cell deposition and adhesion on surfaces are essential in the vital process of haemostasis and fundamental in the events leading to thrombus formation. Also, malignant cell adhesion on various tissues is responsible for the growth of secondary tumors, after being carried in the blood stream from the primary tumor location. 

Introduction. Cell deposition on various surfaces plays an important part in the initiation of many biological processes, such as hemostasis, thrombosis and growth of secondary tumors. It consists of two main stages (a) the conveyance of cells to the vicinity of the interacting surface, and (b) the adhesion of cells to this surface. In most of the biological systems, the main field which conveys the cells to the surface is a flow field. However, for experimental studies of the process of adhesion per se, it is convenient to use a stagnant solution in which cells are conveyed to the surface by gravity (Weiss and Harlos, 1972) or by a... 

D. Treatment with alkylating agents can induce secondary tumors. 

Alkylating agents kill cells by damaging DNA. Another important consequence of DNA damage is mutagenesis. Not surprisingly, secondary tumor induction as a... 

Niederkorn JY, Streilein JW (1983) hitracamerally induced concomitant immunity Mice harboring progressively growing intraocular tumors are immune to spontaneous metastases and secondary tumor challenge. J hnmunol 131 2670-2674. 

Metastasis is defined as the formation of tumors that are discontinuous from the primary tumor. These secondary tumors can be at nearby or distant sites and can form following dissemination of cells via lymphatic, hematogenous, coelomic cavities or epithelial cavities (Willis, 1973). The most common routes for metastatic spread are lymphatic and hematogenous metastasis so, secondary tumor formation via those routes will be the focus in this chapter. However, it must be noted that these routes are not necessarily the common ones for the spread of some tumor types (e.g. ovary (Cannistra, 1993)). 

Nicolson, G. L., Mascali, J. J. and McGuire, E. J. (1982). Metastatic RAWl 17 lymphosarcoma as a model for malignant-normal cell interactions. Possible roles for cell surface antigens in determining the quantity and location of secondary tumors. Oncodev. Biol. Med. 4, 149-159. 

Alkylating agents have been implicated in the causation of secondary tumors, including acute myeloid leukemia, myelodysplastic syndromes (69), solid tumors (70,71), Hodgkin s disease (72,73), ovarian cancer (74,75), and gastric cancer (69). Survival from the time of diagnosis of secondary malignancies is usually very short (69). 

The biochemical alterations which provide malignant cells with the ability to invade adjacent tissues and to spread to other locations are poorly understood and are undoubtedly complex. This complexity manifests itself clearly in the process of metastasis, in which cells must go through a series of steps including tissue invasion, extravasation into blood vessels, thrombus formation, arrest, penetration through the wall of a lood vessel and growth, all in order to develop a secondary tumor. Each step of this sequence may require the precise temporal expression of specific biochemical functions, and some of these reactions, necessary for a step such as invasion, may be detrimental to other steps, such as the formation of a thrombus and arrest. 

FIGURE 13.16 Anaplastic large cell lymphoma of the skin (A) usually shows reactivity for CD30 (B). Secondary tumors involving the skin as part of systemic disease also may express the ALK-1 protein (C). 

Urinary bladder involvement by a secondary tumor either as a metastasis or by direct extension occurs most commonly from colorectal (33%), prostatic (12%), and cervical (11%) sites.Less common sources include breast, stomach, lung, and melanoma primaries. 

Vang R, Gown AM, Zhao C, et al. Ovarian mucinous tumors associated with mature cystic teratomas Morphologic and immunohistochemical analysis identifies a subset of potential teratomatous origin that shares features of lower gastrointestinal tract mucinous tumors more commonly encountered as secondary tumors in the ovary. Am J Surg Pathol. 2007 31 854-869. 

Khunamornpong S, Siriaunkgul S, Suprasert P, et al. Intrahe-patic cholangiocarcinoma metastatic to the ovary A report of 16 cases of an underemphasized form of secondary tumor in the ovary that may mimic primary neoplasia. Am J Surg Pathol. 2007 31 1788-1799. 

Both primary and secondary tumors require angiogenesis, the formation of new blood vessels, in order to grow to a large mass. 

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