Many Unknowns With Surveillance After Cancer Treatment

HOLLYWOOD, Florida — Monitoring cancer patients with a slew of tests to detect the spread or return of disease is a common medical practice in the United States, according to speakers here at the National Comprehensive Cancer Network (NCCN) 19th Annual Conference.
However, this "intensive surveillance" has rarely been shown to prolong patients' lives in randomized controlled trials, said one presenter, Crystal Denlinger, MD a medical oncologist from the Fox Chase Comprehensive Cancer Center in Philadelphia.
"For the majority of cancers, intensive surveillance has not been proven to improve survival," she said. In fact, reasonable evidence of the effectiveness of surveillance after definitive curative treatment exists for only a few tumor types, she noted.
There are not a lot of data supporting surveillance, "except in colorectal cancer, breast cancer, and maybe ovarian cancer," she declared.
Dr. Denlinger went on to review data on surveillance testing in those 3 and other cancers. She explained that this is an area of cancer care that is understudied and, therefore, must be considered with "a grain of salt."
For instance, the few randomized trials performed mostly date from the 1990s. Furthermore, a lack of effective therapy for recurrent cancers can influence that fact that surveillance does not improve survival, Dr. Denlinger explained.
There are pros and cons of the testing that need to be considered. Clinicians should sit down with patients and discuss recommended surveillance tests for individual cancers, she emphasized.
On the plus side, surveillance might detect a recurrent tumor when it is small and potentially curable. A testing program might also assure patients that they are "disease free," which would be a psychological boon. Indeed, surveillance is a considered a mark of "good practice" by patients and families, Dr. Denlinger said.
But on the negative side, patients need to realize that testing can "induce anxiety," she reminded attendees. Also, false-positive results can lead to a cascade of further testing, including invasive procedures. And further testing can increase cost, radiation exposure, and the expenditure of time.
Patients have "unrealistic expectations" about surveillance tests, said Michael Buchholtz, MD, from the Cancer Institute of the North Shore-LIJ School of Medicine in Huntington, New York.
Dr. Buchholtz was pleased to see post-treatment surveillance on the NCCN meeting agenda. "I would like to see programs on surveillance become a priority," he told Medscape Medical News after Dr. Denlinger's talk.

 

The major oncology organizations, such as ASCO and NCCN, have been delinquent.

 

"The major oncology organizations, such as ASCO and NCCN, have been delinquent in giving us better direction as to what is appropriate in terms of surveillance," he said.
As a general rule, less is more in surveillance testing, said Dr. Denlinger, who is panel chair of the NCCN Clinical Practice Guidelines in Oncology for Survivorship.
The majority of cancer recurrences are picked up after the development of symptoms or when a patient has a physical exam, she explained. In other words, the majority of recurrences are not detected with common surveillance methods such as imaging or disease-marker blood tests.
In general, the risk for recurrence is greatest in the first 5 years after diagnosis, she said. However, even when recurrences are caught with testing, a cure is improbable.
"Cure with treatment after recurrence is highly unlikely in many diseases," said Dr. Denlinger.
Breast Cancer Considered
The NCCN recommends that breast cancer patients receive annual mammograms and physical exams after their treatment; this combination has been shown to improve survival.
However, the organization does not recommend more "intensive" surveillance. The basis of this recommendation is rooted in 2 randomized controlled trials from 1994, both conducted in Italy.
One of these studies followed 1320 women after stage I to III unilateral breast cancer, all of whom received an annual mammogram and physical exam (JAMA. 1994;271:1587-1592). The women were randomized to either intensive surveillance (with bone scan, liver ultrasound, chest x-ray, and lab tests) or no additional special testing.