Only two-thirds of oncologists could identify the major long-term adverse effects of four standard chemotherapy drugs used to treat breast and colorectal cancer, a large survey has showed.
Not surprisingly, primary care physicians (PCPs) did even worse: Only 6% could identify the major late effects associated with the use of cyclophosphamide, paclitaxel, oxaliplatin, and doxorubicin, said Larissa Nekhlyudov, MD, MPH, Assistant Professor of Population Medicine at Harvard Medical School and an internist at Harvard Vanguard Medical Associates.
The findings were highlighted at a media teleconference held in advance of the ASCO Annual Meeting, where she gave her formal presentation of the research (Abstract 6008).
“This is a problem of our own success,” said ASCO 2011–2012 President Michael P. Link, MD, noting that there are nearly 12 million cancer survivors in the U.S., up from three million in the 1970s.
Once active cancer treatment ends, survivors typically receive ongoing follow-up care from PCPs, who may be less familiar with long-term toxicities associated with chemotherapy, said Link, the Lydia J. Lee Professor in Pediatric Cancer at Stanford University School of Medicine and a staff physician at the Lucile Packard Children's Hospital at Stanford.
“As patients transition from oncology to primary-care settings, primary-care providers should be informed about the late effects of cancer treatment so that they may be better prepared to recognize and address them among cancer survivors in their care,” Nekhlyudov said.
Surveys like this are an important step toward better defining problems so that they may be addressed and solved, both agreed.
Doxorubicin Cardiac Toxicity Well Known
For the Survey of Physician Attitudes Regarding the Care of Cancer Survivors (SPARCCS), a representative national sample of 1,072 PCPs and 1,130 oncologists who cared for breast cancer and colorectal cancer patients were mailed the survey in 2009.
Prior results reported at last year's ASCO Annual Meeting by Katherine S. Virgo, PhD, (one of the coauthors of this year's study), suggested that many PCPs feel they lack the general knowledge, skills, and confidence to care for cancer survivors (Abstract CRA9006; OT 8/10/11).
The current analysis, which was funded by the National Cancer Institute and the American Cancer Society, focused on the question in which respondents were asked to select from a list of five late effects of doxorubicin, paclitaxel, oxaliplatin, and cyclophosphamide they had observed in their practices and/or seen reported in the literature.
The primary care providers surveyed were most aware of doxorubicin toxicity, with 55.1 percent correctly identifying cardiac dysfunction as a late effect. Also, 26.9 percent cited peripheral neuropathy as a late effect of paclitaxel, and 21.8 percent reported peripheral neuropathy as a long-term effect of oxaliplatin use. Premature menopause and secondary malignancies were identified as late effects of cyclophosphamide by 14.9 percent and 17.2 percent of PCPs, respectively.
“The figures are weighted percentages of respondents who checked, ‘Yes, this adverse effect is observed most often as a result of this drug,’” Nekhlyudov said.
As for oncologists, 95.4 percent identified cardiac dysfunction as an late effect of doxorubicin, 97.3 percent recognized peripheral neuropathy as a long-term effect of paclitaxel, and 96.6 percent cited peripheral neuropathy as a late effect of oxaliplatin.
But premature menopause and secondary malignancies were identified as late effects of cyclophosphamide by only 71.4 percent and 62.0 percent of oncologists, respectively.
Oncologists and PCPs alike did poorly when it came to recognizing pulmonary fibrosis as a late effect of paclitaxel (5.2% and 6.0%, respectively); oxaliplatin (5.0% and 8.6%, respectively); and cyclophosphamide (20.6% and 13.1%).
Six percent of PCPs identified the main effects of all four drugs versus 65 percent of oncologists—a highly significant difference, Nekhlyudov said.
Survivorship a Relatively New Field
In multinomial logistic regression models, predictors of oncologists' ability to identify the late effects of all the drugs were oncology board certification and time spent on patient care. Age, gender, race, U.S. training, the type of practice, and the percentage of uninsured patients were found to not be associated with awareness of the drugs' toxic long-term effects.
In response to a question, Nekhlyudov said that she was surprised that more oncologists weren't aware of more late toxicities of chemotherapy drugs. “That's what we do,” she said.
Why didn't oncologists do better? she asked rhetorically. “I think I could speculate that the field of survivorship is a relatively new one. Much of the focus has really been on the treatment of cancer patients, and only recently have we become aware of the importance of survivorship and the potential for late effects. I think that as more and more attention is placed on cancer survivorship, oncologists will become more equipped with that information.”
‘Study Should Give Us Pause’
“The study should give us pause,” said Link. “We all need to be aware of the needs of survivors. Patients should be empowered by providing them with treatment summaries and guidelines for follow-up care that they can take to their primary-care providers.”
The findings also make a “good case” for electronic medical records, he added. “Electronic medical records with effective decision reports would allow primary-care providers to access patients' cancer care and understand the ongoing monitoring needs. Obviously, educating primary-care physicians is essential, but we all need to be aware of the needs of our survivors, so the ball does not get dropped.”
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