I don't know about what you meant by tip, but if the reference point was a large intestine it's either cecum or anal canal on both entrance and exits. The cecum is also linked to the appendix where the tip is usually where carcinoma arises, maybe that's what you meant?

For the cause, usually hereditary, sporadic mutation, chronic inflammation, metastasis, and acquired mutations over the years. A lot of cancers are caused by multiple factors and only few cancers have a specific causation to pinpoint. 

For cures, if it's benign, resection usually fixes it but when it's malignant, there's no true cure because relapse can happen and it's risk is always present for a lifetime compared to benign tumors. Asking whether the case is benign vs malignant is always one of the first questions we try to answer when looking at the slide.