A new study from the American Cancer Society has found that people who have survived cancer in adulthood have a greater risk of developing and dying from new cancers than people in the general population.
The research looked at data from over 1.5 million cancer survivors in the United States, aged between 20 and 84, finding that around 10% of them were diagnosed with a “subsequent primary cancer (SPC),” a cancer thought to be unrelated to their original diagnosis.
“The number of cancer survivors who develop new cancers is projected to increase, but, until now, comprehensive data on the risk of subsequent primary cancers among survivors of adult-onset cancers has been limited,” said Hyuna Sung, PhD, Principal Scientist, Cancer Surveillance Research at the American Cancer Society and lead author of the study. “These findings highlight the importance of ongoing surveillance and efforts to prevent new cancers among survivors,” Sung added.
It is well-known that people who have survived cancer typically have a greater risk of being diagnose with the disease again, even if their first cancer has been successfully treated. In many cases, this is recurrence of the original cancer or metastatic disease related to the original cancer. It is also not uncommon for treatments for the primary cancer to unfortunately cause another cancer, but in many cases this link is hard to definitively prove. The American Cancer Society study looked at new cancers thought to be unrelated to the first cancer diagnosis.
Of the cancer survivors diagnosed with another subsequent primary cancer, over half died from their disease. But the risk of developing and dying from a SPC varied widely between different cancer types and even the sex of the individuals. Men who survived laryngeal cancer and Hodgkin lymphoma had the greatest risk of developing a SPC, whereas women who had survived laryngeal or esophageal cancer had the greatest risk of SPCs.
Although it is frequently not possible to pinpoint the exact “cause” of cancers, many can be linked to lifestyle factors such as obesity and smoking. Among people who had first cancers that were smoking-related, such as lung, oral cavity and esophageal – their risk of also developing a smoking-related SPC was also increased. Similar trends were observed with people who had both first and SPCs related to obesity.
The study authors suggest that some of these SPCs in cancer survivors may be preventable by addressing the lifestyle factors that increase risk of cancer development.
“These findings reinforce the importance of coordinated efforts by primary care clinicians to mitigate the risks of SPCs through survivorship care, with greater focus on lifestyle factors, including smoking cessation, weight management, physical activity, and healthy eating, as receipt of counseling or treatment (tobacco only) to aid in the adoption of healthy habits,” said Ahmedin Jemal, PhD, senior author of the paper and Senior Vice President of the Data Science Department of the American Cancer Society.