Tumor Suppressors and Oncogenes

June 6, 2007 | by

The cell cycle is a series of ordered events that occur in a cell between it’s initial formation and eventual duplication and division into two daughter cells. Cells in the human body normally reproduce up to ~50 times [1], doubling their number with each cell cycle. Stem cells provide a pool of dividing cells to replace those that have died.

Interphase, the period between cell divisions, is where most cells remain for at least 90% of the cell cycle. Interphase consists of three phases: G1 (for gap 1), S phase (for synthesis) and G2 (for gap 2). During G1, the cell undergoes rapid growth and metabolic activity, including production of RNA and synthesis of protein. For the cell to divide and produce an identical copy of itself, its genome must be duplicated. DNA replication occurs in S phase. During G2, cell growth continues and the cell prepares for division. Cell division or mitosis occurs in M phase.

In normal cells, during G1 there are specific genes that control the speed of the cell cycle. These genes, called tumor suppressors and oncogenes, are mutated (meaning damaged) in cancer cells and can result in uncontrolled reproduction. Additionally, unlike normal cells, cancer cells do not stop reproducing after ~50 divisions. Thus, a cancer is an uncontrolled proliferation of cells.

March is National Colorectal Cancer Awareness Month

March 8, 2007 | by

The goal of the annual National Colorectal Cancer Awareness Month is to make people aware of colorectal cancer and to encourage people to learn more about how to reduce their risk of colorectal cancer (CRC) through regular screening and a healthy lifestyle. The results of the National Health Interview Survey (NHIS) administered to 32,374 adults 18 years of age or older in 2000 showed that colorectal cancer screening is underused [1]. Just over 60% of adults had ever had colorectal cancer testing. Only 44% of men and 37% of women greater than 75 years of age were current for testing. Colorectal cancer screening is very important. If colorectal cancer is allowed to metastasize (meaning to spread to other parts of the body), the 5-year survival rate is less than 10%. However, if colorectal cancer is found early, the 5-year survival rate is greater than 90% [2].

Cancer Prevention

February 5, 2007 | by

As much as 70% of all cancers are preventable through diet and lifestyle [1]. Cancer is the leading cause of death in the U.S. for people between the ages of 45 and 74, taking more than 550,000 lives a year. The Center for Disease Control (CDC) estimates that 20% of all cancer cases are related to obesity [2]. Highlight HEALTH is taking this opportunity to provide information about choosing healthy lifestyle alternatives to reduce your risks for developing cancer.

Decrease in US Cancer Deaths

January 22, 2007 | by

In 2003, cancer deaths in the United States decreased by 369 deaths compared to 2002, the first drop seen since 1930. In 2004, the decrease in cancer deaths was eight times greater – 3,014 deaths – than in 2003, according to a report published in the latest issue of the American Cancer Society (ACS) journal CA: A Cancer Journal for Clinicians [1].

Experts are attributing the decreases to declines in smoking, earlier detection and more effective treatment of tumors. The three most common cancers — breast cancer, prostate cancer and colorectal cancer – show a decrease in death rates, with the largest change from colorectal cancer. Experts attribute much of the credit for the reduction in colorectal cancer to screening exams and the early detection of polyps that can be removed before they become cancerous.