{'fraction_non_alphanumeric': 0.026466380543633764, 'fraction_numerical': 0.006437768240343348, 'mean_word_length': 4.90295358649789, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Origins of Human Cancers

There is a general agreement that cancer development in humans as well as in animals in many organs or tissues involves a stepwise process in which new cell populations are regularly seen (9, 10). This overall pattern is seen with different types of carcinogenic stimuli including chemicals, radiations, and some viruses and in cancer development without any known etiologic agents such as in the colon and breast in humans. Some of these new cell populations function as sites of yet another new or aItered noncancerous cell population. With each step, the process shows an increased probability of evolving ultimately into a malignant neoplastic population that, in turn, continues to show this progression until death of the cancer cells or of their host. It is also becoming evident that each of the phenotypic landmarks of malignancy such as (a) relatively autonomous growth, (b) invasion, and (c) metastasis occur quite late in the whole process of carcinogenesis and appear to be acquired seriatum and not as a single “package.” In humans, judging by the evidence in lung, colon, uterus, skin, liver, thyroid, and some other sites, the process often takes 10, 20, or 30 yr before the manifestations of malignancy appear. This is comparable to the one-third to two-thirds of the normal life span often required in experimental animals for the same process to unfold.