CHICAGO — Six years after being diagnosed with colorectal cancer, nearly two-thirds of people tracked in a retrospective longitudinal study of 1,541 elderly survivors relied entirely on their primary care physicians for follow-up care.
Over the same time period, the role of oncology specialists was much smaller and declined significantly, as did the amount of cancer screening that they performed.
With the exception of mammography, primary care physicians provided more preventive services than did oncologists. They ordered more flu shots, Pap smears, cholesterol screening, and bone densitometry tests.
Visits to both types of physician resulted in more of all these measures than did visits to either type alone. “Survivors who see both an oncology specialist and a primary care provider are most likely to receive preventive care,” lead investigator Claire Snyder, Ph.D., reported at the annual meeting of the American Society of Clinical Oncology.
The study, supported in part by an unrestricted grant from Pfizer Inc., explored the growing issue of who takes responsibility for long-term care of cancer survivors in the United States. “The role of oncology specialists and primary care providers during the posttreatment phase is unclear,” said Dr. Snyder, of the division of general internal medicine at Johns Hopkins University, Baltimore.
She and her coauthors linked data from the Surveillance, Epidemiology, and End Results (SEER) registry with Medicare fee-for-services claims to follow patients from 1 year after diagnosis to the end of the sixth year. The study population had an average age of 76 years, included fewer men (42.7%) than women, comprised mostly whites (85.3%), survived stage I or II disease predominantly (82.8%), and had a mean comorbidity index of 1.76.
Initially, 37% of survivors went to both a primary care physician and an oncology specialist, but this fell to 21% by the end of the study. Meanwhile, the proportion seeing only a primary care physician increased from 44% to 62% over the 5-year period, while those seeing only an oncology specialist fell from 8% to 4%.
In any given year, slightly more than 10% of survivors saw neither type of physician, but some visited other specialists, often cardiologists, according to Dr. Snyder.
Additionally, the average number of visits to a primary care physician increased from 4.2 in the first year to 4.7 during the fifth year. Visits to an oncology specialist fell from 1.3 in the first year to 0.5 in the fifth year. Both changes were statistically significant (P = .0001).
“Most primary care provider visits were to internal medicine or family physicians, and most of the oncology specialist visits were to medical oncologists, hematologist/oncologists, or general surgeons,” Dr. Snyder said.
The primary care physician category also included general, ob.gyn., geriatric, and multispecialty practices. The oncology specialist category included colorectal surgery, surgical oncology, and radiation oncology practices.
Who provides care is important, Dr. Snyder said, because survivors have special medical needs. She cited surveillance for recurrence; monitoring for long-term and late treatment effects; general primary and preventive care; and care for comorbid conditions, which can be chronic in these patients.
To assess how the physician mix affected preventive services, her group looked at influenza vaccination and cholesterol screening for the entire population, along with mammography, cervical cancer screening, and bone densitometry in women, with the mammography standard being applied only to women younger than 76 years of age.
The investigators found that the mammography rate fell from 54% in the first year to 43% in the fifth year, and cervical cancer screening from 19% to 11%. “There were no clear trends in flu shots, cholesterol screening, or bone densitometry,” she said.
Cumulative 5-year data on these measures showed statistically significant differences (P less than or equal to .0001) for all based on the medical provider. For example, flu shots were documented for 61.7% of people seen by a primary care physician and an oncologist, for 52.4% of those who visited only a primary care physician, and for 49.2% of those who visited only an oncologist. The rate dropped to 31.4% when survivors saw neither.
Dr. Snyder cautioned that the investigators had no way to ask why some services were not provided. “Did the physician not offer the service? Did the patient refuse it?” she asked, noting that “some question the usefulness of certain screening procedures in the very old.”
The study's main implication, she concluded, is that there is a need for survivorship care plans that clearly delineate the roles and responsibilities of oncologists and primary care physicians in providing future care to cancer survivors.