The cancerous method is a result of
disturbed cell performance. This can be due to excess
genetic and epigenetic changes inside the cell, expressed
within the accumulation of body or molecular
aberrations, that results in genetic instability. It's tough
to assess the validity of individual factors which can
cause a diseased condition; however, it can be suggested
that interaction of various risk factors has the biggest
contribution to cancer development and metastasis.
Environmental and individual factors, together with
genetic makeup contribute to the development of
cancer. Medical research on malignant tumors has
focused on the effects of environmental and genetic
factors on cancer cases occurring and death rate.
According to the information available, 80–90% of
malignant tumors are a result of external environmental
factors i.e. Carcinogens. Medical studies have indicated
that the most factors leading to metastasis of cancer
among humans are due to environmental factors which
develop due to human activities. The studies show that
smoking, excessive alcohol consumption and diet play
an important role in metastasis of preexisting tumors.
According to WHO, there might be ten million deaths
by the end of 2020, out of which 7–8 million will be in
developing countries and 2–3 million in developed
countries. The aim of this study was to accumulate
knowledge regarding the risk factors leading to
metastasis of tumor and providing them with the most
Keywords : Cancer, Metastasis, Environmental factors, Biological Infection and metastasis, Physical factors, Chemical factors.