My sun is in both Cancer and Leo. I consider them both as vibrations. I'm affected by both. I feel/see both sides. In ambition I'm Leo. In Love I'm Cancer (70%) and Leo (30%). That is about the Sun.
Mars in Cancer:
I think mars means your mode of action. I guess a typical mars with male energy would mean you just head on straight to your goals. I move differently. I start with the opposition I think I might face when I move towards my goals, and then make plans to tackle all those oppositions one by one, and only then make my move. I am usually emotionally attached with all my goals. I can get lazy in between not because I'm lazy, but because I exert myself too much, and then there is a temporary burn out episode and need to take time off. I'm an initator and starts new things/ventures often. I work hard, and don't show off immediately. I'm faster than my competiton and takes very less resources too, very well planned, but I'll look slower compared to my competition because I'm not going to show all my cards (products) in the beginning itself, but rather wait for the right time or for the plan to play out in order, so you don't see all the products I made in the same time, and this might make you think that I made less products than you, but that's only because I'm hiding them as my backup plan, which I'll bring out eventually, whether I need them as backup or not (hidden strength).
In love I imagine me to be very romantic and likes being chased by the girl I like (I dont know if this is mars in cancer). I prefer for things to happen around me, rather than me make things happen - the important take away is that things should happen.
I'm vey protective of my goals. Mars in cancer gives you a very strong sixth sense about threats to your goals and allows you to be well prepared in advance, and work on your weak points. I'm a perfectionist in my goals. I can sometimes take more time than necessary because I'm not satisfied with the results and keep refining it.