Thanks for your question on Health Care Magic. I can understand your mother s situation and problem. Yes, a mole can develop into cancer in seven moths time. Skin cancers like malignant melanoma, squamous cell carcinoma etc can present as cancerous mole on skin. Usually prognosis is excellent if early detection and surgical removal of mole is done. So better to get done staging of this cancer. And if it is localised cancer than surgical removal with negative margins is curative. Seven months duration is sufficient for spread of tumour. If she undergone biopsy earlier than early detection was possible. So first get done staging of her cancer and than decide treatment strategy. Hope I have solved your query. Wishing good health to your mother. Thanks.