Cancer metastasis - A molecular insight and the challenges during covid times

The word Metastasis means ‘Meta-transformation, stasisresidence', is stated as the spread of cancer by invasion in a way that is discontinuous to the primary tumor mass and forms secondary tumor masses in a distant area at the site of lodgment. Metastasis is a feature to distinguish malignant from benign tumors [1,2]. Worldwide, 19.3 million new cancer cases arise and about 10.0 millions of cancer deaths has occurred in 2020 [3]. In the year 2020 1,392,179 cases of cancer were reported in India, among which the breast, lung, mouth, cervix uteri, and tongue were the most commonly involved site. The head and neck, stomach, breast cancers are diagnosed in their locally advanced stage whereas, distant metastasis was predominant in lung cancer. Thus metastatic potential differs among the different type of cancer [4]. About 30% of patients with newly diagnosed solid tumors (other than melanomas) presents with clinically evident metastases. About 20% have hidden metastases at the time of diagnosis. It is stated that metastasis is the main cause for 90% of cancer deaths [1,2,5].