UCLA researchers have identified the incidence and long-term outcomes of patients who develop second, unrelated cancers, resulting in a data set that they say sheds new light on the way cancer survivors may need to be monitored post-disease.

The researchers identified more than 2.1 million patients from the Surveillance, Epidemiology and End Results database, or SEER, with the most common cancers — prostate, breast, lung, colon, rectum, bladder, uterus, kidney and melanoma and non-Hodgkin lymphoma. The team found that 8 percent of patients developed secondary cancers elsewhere, the most common of which was lung cancer, which is often fatal. Among patients who developed a second cancer, 13 percent died of their primary cancer, while 55 percent died of their second cancer, said Dr. Karim Chamie, the study’s lead author and an assistant professor of urology at the David Geffen School of Medicine at UCLA.

“As clinicians, we can become so focused on surveilling our patients to see if a primary cancer recurs that we sometimes may not be aware that patients can be at risk of developing a second, unrelated cancer,” Chamie said, adding that physicians should rethink how they handle follow-up care and monitoring.

► Video: Dr. Chamie on the importance of broadening cancer surveillance

The study, published in the peer-reviewed journal Cancer, found that people diagnosed with bladder cancer had the highest risk of developing a second malignancy — most often lung cancer. Chamie found that 34 percent of bladder cancer patients who were followed for up to 20 years developed a second cancer, and of those, 25 percent developed lung cancer. Routine follow-up care for bladder cancer patients does not include a CT scan of the chest and lungs.

However, Chamie said the findings make a strong case for possibly adding an annual CT scan of the lungs for bladder cancer survivors, particularly those who smoke. The National Lung Screening Trial, headed by Dr. Denise Aberle, a UCLA oncologist, found in 2011 that administering CT scans for high-risk patients saved lives — even more support for the need for CT scans for bladder cancer survivors, Chamie said.

“Lung cancer is a very common and extremely lethal disease, and the national screening trial found CT scans actually saved lives,” Chamie said. “We could make a significant improvement in cancer survivorship, for instance, if we monitored bladder cancer patients annually for second, unrelated lung cancers.”

In additional to bladder cancer, patients with non-Hodgkin lymphoma were also at higher risk of developing second cancers, including lung, prostate and breast cancers.

“The growing number of cancer survivors in the United States, coupled with the observed lethality of second primary cancers in our study suggests that investigation into effective detection and treatment strategies in this population is warranted,” the study states.