Leukemia childhood cancer

Consider, for example, the drug 6-mercaptopurine, one of the mainstays of treatment for acute lymphoblastic leukemia, a common type of childhood cancer (Rioux, 2000). Researchers have discovered that the reason some... 

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer with a erne rate of approximately 80%. However, despite the generally favorable outeome of ALL treatment, some children relapse or experience severe treatment side effeets. Reeent research eiforts have focused on understanding the patient genetie eharaeteris-ties that underlie treatment response. To date, several studies have demonstrated that... 

Acute lymphoblastic leukemia is the most common childhood cancer with cure rates of approximately 80% of all patients (1). This success rate largely stems from collaborative clinical trials that have developed risk stratification groups. Treatment intensity is proportional to relapse risk, with patients at relapse risks receiving more intensive, and therefore toxic, therapy. Thus, the overall goal of risk stratification is to balance successful treatment against toxicity. 

Leukemia and brain tumors are the most prevalent cancers among children aged 0-14 years of age in the United States. Together, they account for one-half of all childhood cancers, 30% of which are leukemia and 20% of which are brain cancer. M... 

One study demonstrated that parental occupational exposures to chlorinated hydrocarbons are associated with increased risks for leukemia, lymphoma, and urinary tract cancers in offspring. Another study showed associations between maternal exposures to solvents and increased incidences of leukemia. These solvents include 1,1,1-trichloroethane, toluene, and other mononuclear aromatic hydrocarbons, mineral spirits, and alkanes. Childhood brain cancers, the second leading cause of childhood cancer, have been associated with parental occupational exposures to toxic chemicals. Industries for which such associations have been found include 10 ... 

Children are at greater risk than adults for many cancers. Leukemia and brain cancer account for half of all childhood cancers. The causes of these cancers are often obscure, but research has shown that in utero exposures can start the carcinogenic process that becomes fully manifest after birth. Mixtures of chemicals, most notably tobacco smoke and pesticides, are known causative childhood cancer agents. Other chemical mixtures identified as carcinogenic to children are examined in the next chapter on cancer clusters. 

Many of the childhood cancers are hematologic, and great improvements in survival have been achieved. For example, the acute leukemia survival rate in children has risen from 53% in 1970 to 80% by 1989 (American Cancer Society) and new... 

The subcommittee is aware of a suspected cancer cluster in Fallon, Nevada, and that exposure to JP-8, originating from a naval base located in that town, is under investigation as a possible cause of the cluster (exposures to other chemicals are being investigated as well). Since 1997, sixteen persons currently or previously living in Fallon have been diagnosed with acute lymphocytic leukemia (ALL), a type of childhood cancer. One case of ALL would be expected approximately every 5 yr in Churchill County, where Fallon is located, based on the size of the population (Nevada State Flealth Division 2002). No scientific studies were found that examined a potential relationship between ALL and JP-8 exposure therefore, the subcommittee could not reach any conclusion concerning exposure to JP-8 and this suspected cancer cluster. 

An unusual aspect of cancer is that it is very difficult to consider it as a singular disease entity. Some are rapidly fatal some only after prolonged periods of time. The rate of incidence of most malignancies increases with age, rising steeply after the fifth decade of life. Yet certain cancers are peculiar to childhood (acute leukemia) and adolescence (Ewing s sarcoma). 

Many childhood cancers that were rapidly fatal if untreated (e.g., leukemias) today have a high apparent cure rate with suitable therapy, that is, they have remission of symptoms exceeding a decade or more, which may be permanent. Results are less dramatic with older children and adolescents. In the adult population, however, chemotherapy results are not as clear-cut. In fact, in some cases the postsurgical survival rate of patients treated with chemotherapy was the same as that of patients not so treated. 

One of the most thoroughly researched epidemiology studies has been conducted at Eallon, Colorado. There was a belief that the number of childhood cancers (acute lymphocytic leukemia) in that tovm was above expected values. GDC sampled soil, air, water, and many other mediums looking for a cause. They... 

Much of the epidemiological evidence pertaining to parental occupational exposure as a risk factor for childhood cancer and leukemia is inconsistent or even contradictory and this could be explained, at least for some of the data, by the different study designs, different sources of data, poor definition of the level, and period of exposure [3]. 

The present status of knowledge in this field is far from relevant, hence one can neither incriminate nor refute the occupational causative factors for childhood cancer and leukemias. The positive associations of occupations and exposures having a higher risk could be used only in setting priorities for further research. 

As of 1999,. studies of the effects of pesticide exposure on children s health were limited to those of birth defects, childhood cancer, and acute poisoning following ingestion. Some case-control studies have associated parental exposure to pesticides or pesticide use in the home with childhood brain tumors, leukemia and lymphomas, testicular cancers, and other cancers, Other studies have reported that parental exposure to pesticides or application of pesticides in the home are associated with cenain birth defects, including neural tube and other defects (Eskenazi et at., 1999). Evaluation.s iif OP and CM exposures, levels of expasures, and health impacts to children are needed. 

C. Mandal, C. Tringah, S. Mondal, L. Anastasia, S. Chandra, and B. Venerando, Down regulation of membrane-bound Neu3 constitutes a new potential marker for childhood lymphoblastic leukemia and induces apoptosis suppression of neoplastic cells, Int. J. Cancer, 126 (2010) 337-349. 

A distinct relation between parental occupational exposure and childhood cancer was shown for solvents and paints. High parental exposure resulted in higher incidences of childhood cancers. In the same study, however, generally more cancers were found as a result of parental use of alcohol and tobacco smoke. Childhood leukemia and nervous system cancers, in particular, are the types suspected to be caused by parental exposure to paints and solvents. Kishi et al. described an elevated risk for acute lymphatic leukemia in children of mothers with prenatal exposures to benzene and to paints. In former studies with small numbers of children these tendencies could also be shown, mainly in male painters whose children showed a higher incidence of childhood leukemia and brain tumors. 18.3.4.2.4 Respiratory effects... 

In many studies, increased risks were described mainly for Ixmg cancer (about 40% above the national average), leukemia, bladder cancer, liver cancer, and childhood cancers where there has been parental exposme. ... 

Wilms tumor (WT) accounts for 6% of childhood cancers, but for 90% of renal tumors in childhood (Grundy et al. 2002). It is the fourth most common pediatric cancer after acute leukemia, brain tumors and neuroblastoma. The incidence of WT is 8.1/10 in Caucasian children below the age of 15 (Breslow et al. 1994). 

Clusters of childhood cancer have been identified in several locations and suspected in others. Leukemia and brain cancer are the two most prevalent of these cancer clusters in children. The following are examples of these two types of children s cancer clusters. 

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