Can i have a lower risk of cancer if small breasts?

No: Size of the breast has no bearing on the risk of breast cancer.

Probably not always.: Sometimes mammograms are harder to do in small women, and so a cancer may be harder to detect. If breast tissue gets fibrosed, that may make it harder also.

Small Breast>cancer?: According to a study in the danish breast cancer study, breast reductions resulted in a reduction in breast cancer risk by nearly 50% in women over 40 years old (cancer causes control. 1997 mar;8(2):253-8) the reduction in risk was less clear in younger women. This would suggest that increased breast mass is associated with a higher breast cancer risk and smaller breasts are less prone.