TL;DR: This review deals with environmental origin, occurrence, episodes, and impact on human health of arsenic, a metalloid occurs naturally, being the 20th most abundant element in the earth's crust.
TL;DR: Reports on the presence of HPV infections in cancers of the oral cavity, the larynx, and the esophagus further emphasize the importance of this virus group as proven and suspected human carcinogens.
TL;DR: Various affections of the skin such as tuberculosis, syphilis and various benign new growths, that may be followed by cancer, are touched upon, together with the forms of keratoses.
Abstract: THE various cutaneous conditions that may precede the development of cancer have been sometimes grouped, more or less loosely, under the title "Precancerous Conditions," "Precancerous Keratoses," etc. Thus, Dubreuilh1 in his paper "Des hyperkeratoses circonscrites," read at the International Congress of Dermatology in London, 1896, discusses under the heading "precancerous keratoses," the following affections: cornu cutaneum, keratoma senile, xeroderma pigmentosum, arsenical cancer, chimneysweep's cancer, cancer in workers in paraffine and tar, and leucokeratoses. Keratosis follicularis (Darier's disease) and Paget's disease, are cited as affections which, although not strictly coming under the head of keratoses, have a distinct analogy with the precancerous keratoses. Hartzell 1 , in a paper read at a meeting of the American Dermatological Association in Washington in 1903, touches upon various affections of the skin such as tuberculosis, syphilis and various benign new growths, that may be followed by cancer, together with the forms of keratoses just mentioned.
TL;DR: The limitations of the epidemiological data available and the state of the science on the mode-of-action of arsenic toxicity are inadequate to support the conclusion that there are adverse health effects in the United States from arsenic in drinking water at or below the limit of 50 microg/L.
TL;DR: Clinical features of actinic keratoses that provide a practical guide to practitioners in the treatment of AK are found, including IDRBEU, which is the most common premalignant lesion in humans.
Abstract: Our objective was to obtain practical clinical parameters to indicate those actinic keratoses (AK) that are at risk of becoming invasive. A systematic review of the literature, with focus on randomized trials, retrospective studies and reviews was undertaken. The main outcome measure was the rates and clinical features of AK that transformed into SCC. This study reviewed randomized and retrospective studies and reviews of AK and their risk of becoming SCC. We reviewed a total of 875 studies and identified 62 useful prospective, retrospective studies and reviews. Finally 15 studies covering percentage and/or clinical parameters of malignant transformation were found to be useful: a total of 9 reviews, 4 randomized controlled trials and 2 retrospective studies. Only 1 study (meta-analysis) examined the percentage of malignant transformation and found a rate between 0.025% and 20% per year/per lesion. Clinical parameters found were: induration (3 studies), bleeding (3 studies), enlargement in diameter (3 studies), erythema (2 studies) and ulceration (2 studies). Other minor clinical criteria were pain, palpability, hyperkeratoses, pruritic lesions and pigmentation. The amount of quality research on the most common premalignant lesion in humans is disappointing. The only longitudinal study looking at the incidence of malignant transformation of AK to SCC dates from 1988.Besides the known risk factors (skin type, photodamage, immunosuppression etc), based on this review we found clinical features that provide a practical guide to practitioners in the treatment of AK. Although not prospectively studied, clinical parameters indicating those AK with an increased risk of malignancy are IDRBEU. I (Induration /Inflammation), D (Diameter > 1 cm), R (Rapid Enlargement), B (Bleeding), E (Erythema) and U (Ulceration). In future prospective studies, these parameters should be included.