Non-ionizing electromagnetic radiation (NIEMR), particularly the magnetic field component, has been implicated in the development of human neoplasia. Research suggests that if these fields are part of the carcinogenic pathway, they may act as a promoter or in the progression of established cancer. Active progression of cancer cells by NIEMR negate the possible early detection of clinically silent neoplasms. We have observed the effect of non-ionizing electromagnetic fields on an established breast carcinoma cell line MCF-7, and found no stimulation of growth when exposed to a low-frequency magnetic field. The same magnetic field has been used as an adjuvant to anti-neoplastic chemotherapeutic agents. The results of this study have shown an improvement in the neoplastic cell kill by antineoplastic chemotherapy when coupled with a low frequency magnetic field. Non-ionizing electromagnetic radiation may be involved in the carcinogenic process; however, the answer to this question awaits further studies. We are exploring new methods of cancer treatment using non-ionizing electromagnetic radiation.