The ranks of cancer survivors in America are growing and by 2020 there will be almost 18 million of them, a new report from the American Cancer Society and the National Cancer Institute predicts.

The report, titled Cancer Treatment & Survivorship Facts & Figures, was released Thursday and also found that the rate of new cancer cases is decreasing.

It is estimated that there are currently 13.7 million cancer survivors in the United States.

The number of cancer survivors is on the rise because of the growing and aging population. Improvements in treatments that extend the lives of cancer patients have also been credited.  

Many survivors, even among those who are cancer-free, must cope with the long-term effects of treatment, as well as psychological concerns such as fear of recurrence, said Elizabeth R. Ward, national vice president of Intramural Research and senior author of the report. As more people survive cancer, it is vital that health care providers are aware of the special needs of cancer patients and caregivers.