Final answer:
Colorectal cancer is the intestinal cancer of greatest concern due to its high incidence and mortality rates. It is associated with risk factors like family history, smoking, and diet, but dietary fiber and calcium intake have not been proven to significantly reduce the risk.
Step-by-step explanation:
The intestinal cancer of greatest concern is Colorectal cancer (A). This cancer affects the large intestine which comprises the colon and the rectum. It is a major health issue as each year around 140,000 Americans are diagnosed with colorectal cancer, and approximately 49,000 lose their lives to this disease. It is important to know that factors such as a family history of colorectal cancer, smoking, heavy alcohol consumption, and a diet high in animal fat and protein can increase the risk of developing this cancer. Contrary to popular belief, there is no conclusive evidence that dietary fiber and calcium intake significantly reduce the risk of colorectal cancer.