(HealthDay) -- Many primary care doctors don't know the long-term side effects of the chemotherapy treatments that cancer survivors under their care may have been given, a new survey found.
On the other hand, most oncologists -- though not all -- are familiar with the side effects of four common treatments used to treat breast and colon cancer, according to the results of the survey being presented at the upcoming annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago.
"While oncologists commonly identify the main late effects of four common cancer drugs, primary care providers did not," study author Dr. Larissa Nekhlyudov said during a Wednesday news conference. "This is not surprising in that primary care providers have different training and exposure to chemotherapy drugs," she noted.
"However, these findings emphasize that in the transition of patients from oncology to primary care settings, primary care providers should be informed of late effects of cancer treatments so they are better prepared to recognize and address these effects," added Nekhlyudov, who is an assistant professor of population medicine at Harvard Medical School.
Advances in cancer treatment have pushed the number of cancer survivors in the United States from 3 million in the 1970s to 12 million today.
Once cancer treatments -- such as chemotherapy or radiation -- are complete, primary care physicians become a critical part of continuing care for cancer survivors.
The new findings are based on a 2009 survey of more than 1,100 primary care doctors and more than 1,100 oncologists (doctors who specialize in cancer) across the United States.
Both types of doctors were asked to identify side effects of four commonly used chemotherapy drugs for breast and colon cancer: Adriamycin (doxorubicin); Eloxatin (oxaliplatin); Cytoxan (cyclophosphamide); and Taxol (paclitaxel).
Fifty-five percent of primary care doctors identified heart problems as a late-occurring effect of Adriamycin, while only 27 percent and 22 percent identified peripheral neuropathy (nerve damage to the arms and legs) as a possible result of Taxol and Eloxatin, respectively.
Only 15 percent to 17 percent of primary care doctors knew that early menopause and second cancers could result from Cytoxan.
Oncologists performed better on the survey, with 62 percent to 97 percent aware of these late effects.
It was "surprising that oncologists were not more aware of late effects," Nekhlyudov said. But she also pointed out that the area of cancer survivorship is relatively new.
"As more and more attention is placed on survivorship, oncologists will become more equipped with that information," she said.
The findings highlight the need for more communication between the different doctors involved in a patient's care, one expert stressed.
The burden of that communication lies not only with doctors (oncologists and primary care physicians) but also with patients, said Dr. Stephanie Bernik, chief of surgical oncology at Lenox Hill Hospital in New York City.
"This study just highlights the importance of communication on everyone's part, including the patient, including the doctors in trying to get that information across," she added. "If an oncologist is discharging a patient, they should make it clear what they need to be looking for in the future and that they need to convey this to their doctor."
The knowledge rates shown here make "a good case for electronic medical records . . . which would allow primary care providers to access patients' cancer care," said ASCO spokesman Dr. Nicholas Vogelzang.
A second study being presented at the ASCO meeting in June found that the antipsychotic drug Zyprexa (olanzapine), used to treat schizophrenia and bipolar disorder, reduced post-chemotherapy nausea and vomiting among patients who had not responded to other therapies.
Eighty patients with chemotherapy-related nausea and vomiting were randomized to receive either Zyprexa or the heartburn drug Reglan (metoclopramide), often used to treat nausea and vomiting in cancer patients.
Over the next three days, 71 percent of patients taking Zyprexa did not vomit, compared with 32 percent of patients receiving Reglan.
About two-thirds of patients on Zyprexa experienced no nausea, compared with only one-quarter of Reglan patients, the study found.
Zyprexa can cause side effects if used for six months or longer, but did not cause significant side effects for the short duration used in this study. Generally, those getting chemotherapy would not need to take Zyprexa for longer than three days.
The data and conclusions of research presented at medical meetings should be viewed as preliminary until published in a peer-reviewed journal.
Explore further: Study: Doctors differ in how best to care for America's 12 million cancer survivors
The U.S. National Cancer Institute has more on chemotherapy.