Both are water signs, and are highly empathetic and emotionally sensitive. Each woman should be able to easily tune into the others feelings. Cancer and Pisces are inclined to pick up psychic impressions very readily and are therefore able to sense what the other is experiencing.
Cancer requires a lot of emotional stability.
Pisces can sense the continuity between herself and another person to the point where, at times, it is hard to distinguish her own identity. If anything, these two women can be almost too emotionally intertwined with each other. This relationship can be a very strong one but some problems can arise due to subtle differences in the way these two women approach life. The Pisces woman tends to find her identity through everything she is involved with, and sees many facets of herself in all other people. The Cancer woman may find this nebulous quality in her Piscean partner disorienting, as she needs somthing more definitive in order to feel secure.