Radiation therapy is often used to destroy or reduce the size of tumors in cases of prostate cancer that have contained only the gland itself. Most men who are treated in this manner have very positive long-term results. Radiation therapy, like other cancer therapies, is not without its risks, one of which is the potential for the development of secondary malignancies.
Specific characteristics determine if a cancer is secondary:
- Distinct from the primary malignancy that prompted treatment.
- It happens because of the radiation in that location.
- Arrived after the radiation therapy had begun.
- Start showing up at least four years after the therapy has ended.
According to records, cancers that develop after the primary tumor are very uncommon. But this finding has been changed because of a large study of men who were treated with modern ways of giving radiation.
The study of prostate cancer
The research team analyzed information from 144,000 men who had treatment for localized prostate cancer at VA hospitals over 15 years. The men’s ages varied from 60 to 71, and they represented a variety of races and ethnicities. Within a year of their diagnosis, 53 thousand of them had radiation therapy. The other 91,000 males either had surgery at the same time or chose to have their cancers checked and treated only if these checks showed that the cancer was getting worse.
Three percent of the radiation-treated males and 2.5 percent of the non-radiation-treated males acquired secondary malignancies after a median follow-up of nine years. Rectal cancer, leukemia, lymphoma, and bladder cancer were the four most frequently diagnosed types of disease. Most of the time, these second cancers show up five to six years after radiation therapy ends.
Cancer Risk Assessment
Radiation therapy increases a man’s chance of developing second cancer, but physicians aren’t very good at pinpointing exactly which men would be at the most risk. If a man smokes, he should think about quitting before beginning treatment. Radiation increases the risk of colorectal cancer in men who have a hereditary predisposition to the disease due to Lynch syndrome. These males have mutations that hinder their ability to repair DNA damage in their cells.
As a result of their increased risk of developing abdominal malignancies, men with a history of inflammatory bowel illnesses such as ulcerative colitis are sometimes discouraged from receiving radiation treatment. Also, doctors suggest that older men who have had radiation therapy for prostate cancer talk to their doctors before stopping regular colorectal screening.
Patients who are considering radiation therapy should be warned that there is a possibility, although a low one, that they might develop secondary cancers years after the treatment has been completed. These cancers most often affect the rectum and the bladder.