hi,thanks for query.If you have lump in breast with only criteria whether it moves or not,one can not judje the character of the lump.Lump in breast even if one which is cancer or not,readily moves in early stages.Only in advance cases of breast cancer the lump may or may not be fixed to deeper structurer.For complete evaluation you need to undergo mamography and examination by doctor for proper examination.
wishing you good health.

welcome to hcm,
always take a lot of time to examine a lump if u find so..watch out for the changes and consult the surgeon immediately..mobility of lump will not determine if its cancerous or not..if its painless and easily mobile within the breast and if u are under 25, it could probably be a fibroadenoma( not a cancer) which is very common and can be removed..initially all cancerous lumps will be mobile so its advicible to get a FNAC done to rule out cancer..mammogram can be done as a screening for unnoticed pathology...if any of your family members had breasr cancer, or ovarian cancer then chances are high ..so act early and do not delay..take care