Causes of cancer

DOLL R andPETO R (1981) The causes of cancer quantitative estimates of avoidable risks of cancer in the United States today , J Nat Cancer Inst, 66, 1191-308. 

Breast cancer is the most common site of cancer and is second only to lung cancer as a cause of cancer death in American women. It is estimated that 214,640 new cases of breast cancer will be diagnosed and that 41,430 women will die of breast cancer in 2006.1 Whites account for the largest portion of estimated cases (82%) and deaths (80%). In addition to invasive breast cancers, it is estimated that 61,980 cases of in situ cancer will be diagnosed among women in the United States in 2006. The median age for the diagnosis of breast cancer is between the ages of 60 and 65 years.2... 

Though still the second leading cause of cancer death, mortality rates for colon cancer have declined over the last 30 years as a result of better and increasingly used screening programs and more effective and better tolerated treatments. 

Current knowledge suggests that social habits and diet are as much a cause of cancer and cardiovascular diseases, as are exposure to environmental hazards such... 

Because a higher incidence of cancer has been found among workers in the dye industry, at one time exposure to aniline was thought to be a cause of cancer. There has, however, been no evidence to substantiate this assumption. It is now believed that any increase in the incidence of cancer among aniline workers is associated with the presence of other chemicals rather than with aniline. 

Ames, B.N., DNA damage from micronutrient deficiencies is likely to be a major cause of cancer, Mutat. Res., 475, 7, 2001. 

IDEC was interested in NHL, in 1990, because NHL, specihcally the low-grade or follicular type of the disease, remains an incurable tumor for the vast majority of pahents. It has a large and expanding patient base. NHL is the hfth most-frequently diagnosed cancer in the United States, the sixth leading cause of cancer death, and the second fastest-growing cancer (in incident rate). NHL mainly afflicts people over 50 years of age. As with most scien-hfic research, however, there was a fair bit of serendipity involved in our choice of target. 

We shall begin with a little history, and then move to a discussion of cancer statistics and the causes of cancer, and then provide some background on cancer biology and the mechanisms of tumor development. Some of the general characteristics of chemical carcinogens will also be covered. The methods for identifying chemical carcinogens are the subject of Chapter 6. How their risks are estimated is left to later chapters. 

With some exceptions, cancer experts generally cannot determine with high confidence the specific cause of cancer in an individual. At best they can understand the factors that contribute to the cancer rates observed in large populations. Differences in the rates of certain types of cancers in different regions of a country, different countries of the... 

In 1981, two eminent British cancer experts. Sir Richard Doll and Richard Peto published a paper in the Journal of the National Cancer Institute entitled The causes of cancer Quantitative estimates of avoidable risks of cancer in the United States today. The authors drew upon a vast body of literature of the type mentioned above, and attempted to allocate the deaths caused by cancers among various responsible factors. The authors concluded that a certain percentage of human cancer deaths could be avoided if exposure to the responsible factors could be eliminated or controlled in some way, although the appropriate degree and nature of control for some of the lifestyle factors, especially diet, is still highly uncertain. The Doll and Peto estimates are presented in Table 5.2. The factors are listed in a somewhat different order from how they were listed by the original authors, because of our interest in clearly separating lifestyle factors (the first... 

In the beginning, before there is analysis, there must be accurate description. How much cancer is there, and how do rates of occurrence vary geographically, and between sexes, and with age How do rates of different types of cancer vary over time, and what happens to the rates that occur in specific groups of people when they move from one geographic location to another Information describing these types of differences and trends - which can be compiled with accuracy only when cancer registry information is reliable - are enormously beneficial in providing clues to the causes of cancer. The statistical data presented in Chapter 5 arose from these types of studies. 

Shields PG, Harris CC. 1990. Environmental causes of cancer. Med Clin North Am 74 263-277. 

Colorectal cancer is the third most common cancer and the second leading cause of cancer-related deaths in the United States. (77). The incidence is approx. 40 per 100,000 in men and 25-30 per 100,000 in women (78). For those with stage 111 disease with presumed micrometastatic disease, adjuvant chemotherapy is used, typically 5-fluorouracil (5-FU) and leucovorin for 6-8 mo, with a 30% reduction in disease recurrence and 22-32% reduction in mortality (79,80). 

The plot seemed to be getting much simpler. All vertebrate cells seemed to carry a common set of proto-oncogenes. These genes could become converted into potent cancer-causing genes either by retroviruses or by nonviral mutagens. Proto-oncogenes seemed to represent the ultimate root causes of cancer. 

In 1867, Heinrich Wilhelm Waldeyer-Hartz proposed, with remarkable foresight, that cancer cells developed from normal cells during cell division and then spread by the blood or lymph to other sites in the body. He was an anatomist who not only realised the cause of cancer but also identified the basic unit of the nervous system, to which he gave the name neuron. 

The use of information on the mode of action in the assessment of potential carcinogens is a main focus of the revised cancer guidelines because of the significant scientific advances that have developed concerning the causes of cancer induction. 

Exposure to mustard gas was considered to be a possible cause of cancer in bumans, in light of its strong alkylating ability. Two types of exposures have been studied in particular acute exposure resulting from the use of the gas in war and chronic exposure in the course of its manufacmre. 

Toxicology informs us about cancer on two accounts. First, toxicology research provided insight into the causes of cancer and likelihood of developing cancer. Second, many of the treatments for cancer have serious toxicological side effects. Cancer treatment must often balance the need to kill the cancerous cells while limiting the damage to the normal cells of the body. 

Efforts to understand the underlying biology of cancer are ongoing. The genomic sciences are helping to explain why some people are more susceptible to cancer than others. We also know that there are many causes of cancer and that we can reduce the likelihood of developing cancer. 

Site has information on the treatment and causes of cancer in Japan (Japanese or English version available). 

Gastrointestinal cancers are a major problem in oncology. Together they are amongst the most frequently occurring cancers worldwide and because of the difficulties related to early diagnosis and treatment, they are among the major causes of cancer-related death. 

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