Sometimes it can hurt. Mine did. I was diagnosed 6 years ago this month with breast cancer. Even having the car seat belt across my chest was uncomfortable until I was able to have surgery.
More often than not, however, if you find an painful lump it is probably a cyst. They can get more painful just before your period. When in doubt its best to get it checked.
Most don't - pain is rarely a sign of breast cancer.
When a breast cancer lump is painful, it's usually because it's advanced. Mine hurt by the time I noticed it, and was stage 3.
I used 'breast cancer lumps don't hurt' as a reason for putting off seeing a doctor for several months.
Most breast lumps aren't cancer; over 80% of lumps considered suspicious enough for biopsy turn out to be benign.
I had seven breast tumors which had metastasized from an ileal primary cancer source. No, they did not hurt - they were painless. Get yourself checked if you have any concerns.
EDIT: Just read Lo_mcg below - I used 'breast cancer lumps aren't easily moveable' as a reason for putting off seeing a doctor for several months. Duh.
All the literature tells you that breast cancer is painless in the early stages.
A painfull lump is much more likely to be a cyst than breast cancer.
Mine, like several other posters here, was quite tender, but then mine was stage 3 .....
No. They don't.
NO not always. By the time I felt the lump in my breast it was too late. My entire breast had to be removed. Also several lymph nodes were taken out and tested positive. I had major chemo.
Get checked asap.