User:Anthonyhcole/Esophageal cancer

From WHO Cancer Report
Less common than colon or stomach but more lethal due to late diagnosis

"Screening protocols remain poorly developed for oesophageal carcinomas."

"Oesophageal cancer is a malignant, usually epithelial neoplasm most commonly showing squamous, glandular (adenocarcinoma), or neuroendocrine differentiation and arising in the oesophagus. Other, rarer types of malignant neoplasms can be encountered (adenoid cystic carcinoma, adenosquamous carcinoma, muco-epidermoid carcinoma, mixed adenoneuroendocrine carcinoma, various sarcomas, and melanoma). Only squamous cell carcinoma and adenocarcinoma are addressed here as they account for most oesophageal malignant neoplasms."

Epidemiology

 * Oesophageal cancer is the eighth most common cancer worldwide, with an estimated 456 000 new cases (3% of all cancers) and 0.4 million cancer deaths (5% of all cancer deaths) in 2012. About 73% of all new cases occurred in countries at low or medium levels of human development, and 49% of all new cases occurred in China.
 * Incidence and mortality rates are elevated in Central and East Asia as well as in eastern Africa. Incidence rates tend to be relatively low in western Africa and in some Latin American countries.
 * Incidence varies 15-fold between countries worldwide in men and almost 20-fold in women. Incidence and mortality rates are 2–4 times as high in men as in women.
 * Due to the high fatality rate, mortality rates are close to incidence rates, regardless of sex differences and human development levels.
 * Incidence and mortality trends are variable and reflect the changing prevalence and distribution of the underlying risk factors for oesophageal cancer and its main histological subtypes (adenocarcinoma and squamous cell carcinoma). An increasing tendency to classify cancers located at the gastro-oesophageal junction as adenocarcinoma (rather than gastric cardia cancer) may also have had an impact on the overall trends.

" Stomach, liver, and oesophageal cancers are three of the other major cancers in men that, like lung cancer, have relatively poor survival and hence mortality rates that are close to the incidence rates (incidence and mortality of 17.4 and 12.7 per 100 000, respectively, for stomach cancer, 15.3 and 14.3 per 100 000 for liver cancer, and 9.0 and 7.7 per 100 000 for oesophageal cancer). The other major cancer in men is colorectal cancer, which has an incidence rate of 20.6 per 100 000 but a substantially lower mortality rate of 10.0 per 100 000."

" Among men, the most common cancers and causes of cancer death are cancers of the lung, stomach, liver, colorectum, and oesophagus"

" Likewise, in sub-Saharan Africa, the average incidence rate for oesophageal cancer in men is 6 per 100 000, ranging from 25 per 100 000 in Uganda and Malawi to less than 1 per 100 000 in Guinea and Nigeria. The reason for the variation in this case is little understood, which should act as a stimulus for research [19]."

" Chewing tobacco has been proven to cause oesophageal, oral, bladder, and pancreatic cancers."

"The relationship between alcohol consumption and cancer risk has been known since the beginning of the 20th century. Epidemiological and biological research on the association has established that alcohol consumption causes cancers of the mouth, pharynx, larynx, oesophagus, liver, colorectum, and female breast."

" Tumour types caused by drinking alcoholic beverages include cancers of the oral cavity, pharynx, larynx, oesophagus..."

"These meta-analyses establish that a significant positive dose–response association exists between alcohol consumption and cancers of the mouth, pharynx, oesophagus..."

"When epidemiological criteria were examined for causality [12], the association between alcohol consumption and cancers of the mouth, pharynx, oesophagus, colorectum, liver, larynx, and female breast was found to be causal..."

"Evidence suggests a synergistic effect of tobacco smoking and consumption of alcoholic beverages on the risk of cancer of the oral cavity, pharynx, larynx, and oesophagus, with very high risks observed in individuals who are both heavy drinkers and heavy smokers."

"In 2010, the largest contributors to the burden of alcohol-attributable cancer deaths were: overall, liver cancer (responsible for 23.9% of all such deaths); for women, breast cancer (responsible for 42.0% of these deaths); and for men, oesophageal cancer (responsible for 27.4% of these deaths)."

"The biological effects of alcohol intake on the risk of digestive tract cancers are also dependent on the genotype of the consumer; individuals with the ALDH2 Lys487 allele (and therefore a deficiency of ALDH2) experience a higher risk of oesophageal cancer for the same amount of alcohol consumed. The ALDH2 Lys487 allele is thought to modify the risk of all cancers that are caused by the metabolites of alcohol [4,5]."

" Occupational exposures, occupations, industries, and occupational circumstances classified as definite carcinogenic exposures (Group 1) by the IARC Monographs, Volumes 1–106 ... Ionizing radiation (including radon-222 progeny): Thyroid, leukaemia, salivary gland, lung, bone, oesophagus..."

"Significant radiation- associated increases in incidence occurred for multiple cancers, including those of the oral cavity, oesophagus..."

" Naturally occurring organic chemical carcinogens produced by plants that are used as herbal medicines, food, or food additives or contaminants: Dihydrosafrole and safrole (Sassafras, essential oils, spices) - Food additive, food contaminant - Metabolism to DNA-reactive sulfo-oxy metabolites → mutations - Liver, lung, oesophagus"

" Obesity, which results in major metabolic imbalance, increases the risk of several malignancies, including colon, postmenopausal breast, endometrial, kidney, liver, pancreatic, thyroid, and oesophageal cancers."

Early detection of asymptomatic cancer
" Evidence-based programmes for population-based screening of other major cancers, such as cancers of the ovary, liver, oesophagus, lung, and prostate, have not yet been established."

"Research has indicated the efficacy of mammography and faecal occult blood screening and paved the way for population-based screening programmes. Screening approaches for other tumour types, such as lung, ovarian, oesophageal, stomach, and prostate cancer, are currently being investigated in research settings..."

Stomach cancer
The gastric antrum (distal stomach) is the most common site of gastric carcinoma. Carcinomas of the oesophago-gastric junction have been most commonly reported in populations in North America and Europe, associated with gastrooesophageal reflux disease and other characteristics similar to adenocarcinoma arising in Barrett oesophagus, and are unrelated to H. pylori infection. However, in parts of Asia, for example in China, but also for a subset of tumours diagnosed in North America and Europe, neoplasms of the proximal stomach arise in a setting of chronic atrophic gastritis with H. pylori infection and are similar to distal gastric cancer. Adenocarcinomas located entirely below the oesophago-gastric junction are considered gastric in origin, and for these tumours the use of the ambiguous and often misleading term “carcinoma of the gastric cardia” is discouraged in favour of “carcinoma of the proximal stomach”.

Cancer control in China: preventive policies and accessible health care
"In 2005, China initiated a national programme of early detection and treatment for oesophageal cancer, gastric cancer, colorectal cancer, liver cancer, nasopharyngeal cancer, and lung cancer in high-incidence areas, and in 2009, China started a national screening programme for cervical cancer and breast cancer in rural areas. In both programmes, early detection and treatment has become an effective strategy for cancer control. For example, in some local areas of China, people have had very high rates of oesophageal cancer for a long time. The early detection and treatment programme screens residents in those areas aged 40–69 years by endoscopy with iodine staining and biopsy of early lesions. Patients with early-stage neoplasia, including severe squamous dysplasia, carcinoma in situ, and intramucosal carcinoma, can receive early treatments in a timely manner.

"To accumulate experience and optimize techniques for this plan, the national programme first chose eight high-incidence areas as demonstration sites and screened about 13 000 high-risk adults each year. Now, after a step-by-step expansion, 88 high-incidence areas in 26 provinces are participating in this early detection and treatment programme for oesophageal cancer [2]. From 2006 to 2012, 412 641 adults from high-risk areas were screened by endoscopy, and 4011 patients were diagnosed with severe precancerous lesions or early-stage cancer [2]. Most of these patients received timely treatment, with great benefit to health, and an economic analysis of this programme has shown that it is cost-effective [3].

"In addition to such early detection and treatment programmes, the Chinese government promotes widespread public education about cancer prevention and treatment, and has conducted interventions to control cancer occurrence, including neonatal vaccination against hepatitis B virus, programmes promoting better nutrition, and targeted programmes to improve occupational safety.

"The China National Central Cancer Registry has also improved the national cancer registry system, and since 2008 has reported national cancer registry data annually. In 2012, there were 222 cancer registry sites, covering 200 million people nationwide."

Smoking
" Smoking can cause death not only from lung cancer (the main neoplastic hazard) but also from cancer of the mouth, pharynx, larynx, oesophagus..."