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Primary care providers uninformed of long-term chemotherapy side effects

CHICAGO —   Compared with oncologists, primary care providers were not familiar with the long-term side effects of four chemotherapy drugs commonly used to treat breast and colorectal cancers.

Prior data from the Survey of Physician Attitudes Regarding the Care of Cancer Survivors demonstrated that many PCPs lacked the general knowledge and confidence to care for patients who have been previously treated for cancer.

To assess and better evaluate PCP and oncologist awareness of long-term effects, Larissa Nekhlyudov, MD, MPH, associate professor of population medicine at Harvard Medical School, and colleagues re-examined the survey results for specific knowledge of the most common late effects of treatment, including heart function problems, nerve problems, secondary cancers and premature menopause.

The survey polled 1,072 PCPs and 1,130 oncologists via mail in 2009, requesting that doctors select which of five late effects from each of four widely used breast and colorectal cancer drugs – doxorubicin (Adriamycin, Pharmacia & Upjohn), paclitaxel (Taxol, Corden Pharma), oxaliplatin (Eloxatin, Sanofi-Aventis) and cyclophosphamide (Cytoxan, Baxter Healthcare) – they had most often observed in their practices or had seen reported.

Researchers described and compared the physicians’ responses and, using separate multinomial logistic regression models, determined predictors of their ability to identify the main late effects for all agents, correcting for physician demographics and practice characteristics.

According to the survey results, 95.3% of oncologists identified cardiac dysfunction as a late effect of doxorubicin and peripheral neuropathy as a late effect of both paclitaxel (97.3%) and oxaliplatin (96.6%). In contrast, PCPs were able to identify 55.1% of the late effects of doxorubicin, 26.9% of paclitaxel and 21.8% of oxaliplatin. Most oncologists identified premature menopause (71.4%) and secondary malignancies (62%) as long-term effects of cyclophosphamide vs. only 14.8% and 17.2% of PCPs.

“It is worth noting that pulmonary fibrosis was not identified as a late effect for these agents, although some doctors did point out a possible association with cyclophosphamide, which has been noted in the literature,” Nekhlyudov said during a press conference.

The main late effects for all four chemotherapy drugs were identified by 65% (n=741) of oncologists, yet only 6% (n=60) of PCPs. In adjusted models, oncologists were more likely to identify the main late effects for all chemotherapy drugs if they spent 51% to 90% (OR=1.87; 95% CI, 1.21-2.88) or more than 90% (OR=1.82; 95% CI, 1.08-3.08) of their time on patient care. Oncologists were less likely to identify late effects if they were not board certified (OR=0.58; 95% CI, 0.37-0.89).

“Our study found that while oncologists often identified the main late effects of common cancer drugs, primary care providers did not,” Nekhlyudov said. “This finding is not surprising in that primary care providers have different training and exposure to chemotherapy drugs. The fact that some oncologists were also not aware of the late effects is concerning, suggesting that education of all providers caring for cancer survivors is needed. … However these findings emphasize that in the transition of patients from oncology to primary care settings, primary care providers should be informed about the late effects of cancer treatment so they may be better prepared to recognize and address these among cancer survivors in their care. Whether this will be achieved with the use of survivorship care plans needs to be evaluated.” 

For more information:

Disclosure: The researchers report no relevant financial disclosures.

CHICAGO —   Compared with oncologists, primary care providers were not familiar with the long-term side effects of four chemotherapy drugs commonly used to treat breast and colorectal cancers.

Prior data from the Survey of Physician Attitudes Regarding the Care of Cancer Survivors demonstrated that many PCPs lacked the general knowledge and confidence to care for patients who have been previously treated for cancer.

To assess and better evaluate PCP and oncologist awareness of long-term effects, Larissa Nekhlyudov, MD, MPH, associate professor of population medicine at Harvard Medical School, and colleagues re-examined the survey results for specific knowledge of the most common late effects of treatment, including heart function problems, nerve problems, secondary cancers and premature menopause.

The survey polled 1,072 PCPs and 1,130 oncologists via mail in 2009, requesting that doctors select which of five late effects from each of four widely used breast and colorectal cancer drugs – doxorubicin (Adriamycin, Pharmacia & Upjohn), paclitaxel (Taxol, Corden Pharma), oxaliplatin (Eloxatin, Sanofi-Aventis) and cyclophosphamide (Cytoxan, Baxter Healthcare) – they had most often observed in their practices or had seen reported.

Researchers described and compared the physicians’ responses and, using separate multinomial logistic regression models, determined predictors of their ability to identify the main late effects for all agents, correcting for physician demographics and practice characteristics.

According to the survey results, 95.3% of oncologists identified cardiac dysfunction as a late effect of doxorubicin and peripheral neuropathy as a late effect of both paclitaxel (97.3%) and oxaliplatin (96.6%). In contrast, PCPs were able to identify 55.1% of the late effects of doxorubicin, 26.9% of paclitaxel and 21.8% of oxaliplatin. Most oncologists identified premature menopause (71.4%) and secondary malignancies (62%) as long-term effects of cyclophosphamide vs. only 14.8% and 17.2% of PCPs.

“It is worth noting that pulmonary fibrosis was not identified as a late effect for these agents, although some doctors did point out a possible association with cyclophosphamide, which has been noted in the literature,” Nekhlyudov said during a press conference.

The main late effects for all four chemotherapy drugs were identified by 65% (n=741) of oncologists, yet only 6% (n=60) of PCPs. In adjusted models, oncologists were more likely to identify the main late effects for all chemotherapy drugs if they spent 51% to 90% (OR=1.87; 95% CI, 1.21-2.88) or more than 90% (OR=1.82; 95% CI, 1.08-3.08) of their time on patient care. Oncologists were less likely to identify late effects if they were not board certified (OR=0.58; 95% CI, 0.37-0.89).

“Our study found that while oncologists often identified the main late effects of common cancer drugs, primary care providers did not,” Nekhlyudov said. “This finding is not surprising in that primary care providers have different training and exposure to chemotherapy drugs. The fact that some oncologists were also not aware of the late effects is concerning, suggesting that education of all providers caring for cancer survivors is needed. … However these findings emphasize that in the transition of patients from oncology to primary care settings, primary care providers should be informed about the late effects of cancer treatment so they may be better prepared to recognize and address these among cancer survivors in their care. Whether this will be achieved with the use of survivorship care plans needs to be evaluated.” 

For more information:

Disclosure: The researchers report no relevant financial disclosures.

    Perspective

    This study has a couple of very important messages. On the one hand, there is a very positive message, in that this is really a problem created by our successes. There are now 12 million survivors of cancer in the United States who are a testament to our success in improving cancer care. But these survivors now return to their primary care physicians who may not know what these patents are at risk for. Dr. Nekhlyudov’s study should give us pause.

    It is clear that there is a lot of work to be done. Patients need to be empowered by providing them with treatment summaries and guidelines for follow-up care that they can take to their primary care providers. There is a good case here for the benefit of electronic medical records with effective decision support, which would allow primary care providers to access their patients’ cancer care and understand their ongoing monitoring needs. Obviously, educating primary care providers is essential, but we need to be aware of the needs of our survivors, so the ball does not get dropped. This study is an example of our continuing commitment to our patients, not only as they go through cancer care, but also as they transition to follow-up care as survivors of cancer.

    • Michael P. Link, MD
    • ASCO Immediate Past President Chief, Division of Pediatric Hematology/Oncology Stanford University School of Medicine Director, Bass Center for Cancer and Blood Diseases, Lucile Salter Packard Children's Hospital at Stanford

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