Breast reduction v. Liposuction for C cup to A cup?

Thank you for the question.
Very few patients who present with breast hypertrophy are good candidates for breast reduction through liposuction surgery, in my opinion. Liposuction surgery will  remove adipose tissue but does not address the excess breast parenchymal tissue and/or ptotic skin that is present. Therefore, the degree of breast reduction possible through liposuction surgery alone is relatively small.  
Skin elasticity is another factor that needs to be taken into consideration;  most patients with large breasts have  loss some skin elasticity…  My best advice: select your plastic surgeon carefully. Make sure that he/she has significant experience achieving the types of outcomes you will be pleased with. Then, communicate your goals carefully, as  well. Working together you will come up with a good plan to achieve your goals.  
Best wishes. 

Liposuction is limited as it can only remove fat. Breast reduction is appropriate if you need to address glandular tissue and fibrous tissue. Consult in person with an experienced and expert board certified plastic surgeon to understand your options.

There are limits to what can be achieved by liposuction and you are best to ask you PS to show you examples of what can be achieved by liposuction only so that you can decide whether this would give you the sort of volume reduction you are after.