It is good to know that many sizes are interchangeable. If women wears size wears size 80C, it is worth to try sizes 85B and 75D. It is possible that these sizes will have even better fit then usual ones. These sizes are are called parallel (below there is a table with examples of parallel sizes).
Women’s underwear and homewear
Men’s underwear and homewear
* Size may be slightly different for different brands and product models.