Baseball great Satchel Paige said, “Don’t look back. Something might be gaining on you.” The context is usually humorous, but it can be applied to deadly serious topics such as cancer as well.
A study in Cancer stated that what might be gaining on the growing number of survivors of the disease is a second cancer, unrelated to the first.
One in 12 patients developed a second-site cancer in a U.S. population of more than 2 million people who were diagnosed with the 10 most common types of cancer between 1992 and 2008. The second-site cancer proved to be fatal in 55% of the cases. Of those who developed a second cancer, only 13% died from the initial cancer.
Improving survival rates for cancer over the last few decades has created a situation where patients and oncologists might want to widen their diagnostic focus.
“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 stated.
Karim Chamie, MD, the study’s corresponding author, said in a press release that “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.”
Cancer death rates have fallen by 22% between 1991 and 2011. There were 14 million cancer survivors in the United States in 2012; that number is expected to climb to 20 million by 2024, according to researchers at the University of California–Los Angeles.
This study used data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program to look at the 10 most commonly diagnosed cancers between 1992 and 2008. Of the 2,116,163 patients, 170,865 (8.1%) developed a secondary primary malignancy.
Researchers looked at cancers of the prostate, breast, lung, colon, rectum, bladder, uterus or kidney, or melanoma or non-Hodgkin lymphoma.
Lung cancer was the most likely second-site cancer, representing 18% of all second-site malignancies. It was followed by colorectal cancer (12%), prostate cancer (9%), and bladder cancer (8%). Lung cancer was common among bladder cancer survivors, representing 25% of all second-site cancers, the study stated. Chamie said in the press release that this makes a good case for adding an annual CT scan of the lungs for bladder cancer survivors, particularly for those who smoke. The high rate of second-site prostate, breast, and colorectal cancer may be partly the result of cancer survivors getting more of the cancer screening tests that are already routine, he said in the release.