By CAROLE GORNEY

The scourge of cancer has plagued mankind from the earliest times. The first written record of it can be found in an Egyptian papyrus from about 3000 B.C. that described breast cancer. Down through the centuries many incorrect theories developed about the causes and treatments of cancer.

Hippocrates, the father of medicine, believed that cancer was caused by black bile - a notion that went unchallenged for 1,300 years. As recent as the 1920s, trauma was thought by some to cause cancer. At one time it was even believed to be contagious.

Today, we know that cancer is not a single disease. There are more than 100 different types of cancers that affect nearly every part of the body. And while human cancer, itself, is not contagious, we now know that certain viruses, bacteria, and parasites can increase a person’s risk of developing cancer.

Lifestyle choices, such as obesity, poor diet, lack of physical activity and consumption of alcohol are contributing factors. The use of tobacco accounts for more than 1/5 of all cancer deaths. Approximately 5-to-10 percent of cancers are due to inherited genetic defects.

Since the risk of cancer is more common in developed countries, and increases with age, the World Health Organization expects cancer to increase globally as lifestyles change in developing countries and populations live longer.

In the United States, cancer is the second leading cause of death, according to the American Cancer Society, which estimates that one-half of all men and one-third of all women in the U.S. will develop cancer during their lifetimes According to its most recent published report, the ACS projects that in 2016, there will be an estimated 1,685,210 new cancer cases diagnosed, and 595,690 cancer deaths in this country alone.

The Center for Disease Control publishes state-by-state reports of cancer diagnoses and deaths. The latest figures are from 2012, and they show that Pennsylvania ranks in the highest range for incidences of all cancers combined, with a rate of 476 per 100,000. Only six other states are in this top range. Considering only cancer deaths, Pennsylvania falls within the second highest incidence rate, with 174.9 per 100,000. In both incidents and deaths, Pennsylvania rates are slightly higher than the national average.

On the positive side, the National Cancer Institute reports that despite increases in incidences of cancer in the United States, due in part to progress in diagnosis and the aging of the population, the overall cancer death rate has been declining since 1992. At the same time, five-year survival rates, which are commonly used to evaluate and compare different treatment options, have increased dramatically in many cancers. According to the NIH’s most updated statistics, the five-year survival rate among adults for all cancers combined is now approximately 68 percenty; for children it is approximately 81 percent.

Survival rates for some specific cancers are even more dramatic. As of 2006, survival rates for four of the most common cancers were: breast, 90 percent; prostate, 100 percent; colorectal, 67 percent; and bladder, 81 percent.

As the St. Luke’s panel of cancer specialists noted in the pilot of “Health Now,” today there are many different approaches to treating cancer, often in combinations, that are contributing to more positive outcomes, and generating optimism about a potential cure. These are some examples, cited by the National Institute of Health:

• Combination chemotherapy that contains the drug cisplatin has led to cure rates for testicular cancer of approximately 95 percent, while 80 percent of patients with metastatic testicular cancer can now be cured.

• Three cancer prevention vaccines have been approved by the U.S. Food and Drug Administration (FDA). One of these, the hepatitis B virus vaccine, has the potential to prevent some forms of liver cancer. The remaining two vaccines have the potential to prevent approximately 70 percent of cervical cancers.

• Several other cancer treatment vaccines are being tested in large-scale clinical trials, including vaccines for the treatment of non-small cell lung cancer, pancreatic cancer, ovarian cancer, melanoma, and multiple myeloma.

• Therapies that target the specific molecular changes that cause cells to become cancerous and processes that are required for continuous cancer cell growth and survival are now part of the therapeutic arsenal. To date, the FDA has approved approximately 30 molecularly targeted agents for cancer-related indications.

• Radioactive seeds, designed to deliver high doses of radiation to tumors while minimizing the doses delivered to nearby healthy tissue, are now widely used.