Is there a genetic problem in my family maybe with genes that are yet to be discovered?

This essay is for my college application. Several members of my family got cancer and some of them passed away. None of them had any known cancer causing genes. Is there a genetic problem in my family maybe with genes that are yet to be discovered? Were they exposed to anything in particular? Or it was maybe their habits what caused their illness? All these questions inspired me to go to college to learn and then investigate a scientific explanation, that way, I may save lives in the future.
Instructions given to me by my english teache:r:
1- Pose a question the reader wants answered, but not literally. Keep the reader wondering, “How is that going to turn out?” “What does she mean by that?” “How is this all going to tie back together?” To accomplish that, begin your essay with a hook that encourages the reader to want to find out more.
2- Don’t focus exclusively on the past. Highlight my growth and introspection, so my essay should focus on me learning and growing as a person. Don’t just brag or describe. It should have a moment of revelation: what did I learn from my experience? How did it make me the person I am today?
3- Open up. Include how it made me feel, how it changed the way I think, and whether it had an impact on my priorities and/or values.
4- Experiment with the unexpected
If possible, include something readers wouldn’t have necessarily thought I’d do, think, or care about.
5- Don’t summarize
Avoid explicitly stating the point of my essay. It’s far less effective when I spell it out for someone. Delete every single “That’s when I realized,” “I learned,” and “The most important lesson I learned was”.
My actions can be small, but they should be loaded with meaning, It just needs to represent that I’ve made a decision, change, or risk.