WASHINGTON — The focus on short-term goals during cancer treatment can overshadow care for diabetes and other endocrine disorders that patients may have or acquire as they undergo treatment.
When cancer patients return to the community after successful treatment at a cancer center, it's easy for their primary care physicians “to lose focus on their other medical problems, because cancer becomes the focus when they're at the cancer center,” Robert F. Gagel, M.D., said at a consensus conference on patient safety and medical system errors in diabetes and endocrinology.
A similar situation can develop when patients receive cancer treatment in the community or at a university hospital where oncology is not a major part of the hospital's services, said Dr. Gagel of the division of internal medicine at the M.D. Anderson Cancer Center, Houston.
Dr. Gagel and his colleagues convinced administrators at the center that intensive control of diabetes was important enough to merit building a diabetes section there. That “is quite an amazing thing if one understands how resources are allocated” in a cancer center, he said.
Patients with impaired glucose tolerance who were in the Second National Health and Nutrition Examination Survey Mortality Study had a higher cumulative mortality from cancer than did patients who had normal glucose tolerance (Am. J. Epidemiol. 2003;157: 1092–100). Similarly, in a study of colon cancer mortality, diabetic patients had lower survival than did nondiabetic patients (J. Clin. Oncol. 2003;21:433–40).
Another study showed that the development of two or more episodes of hyperglycemia (blood glucose level of 200 mg/dL or higher) during the first 30 days of induction chemotherapy for acute lymphocytic leukemia was associated with a significant reduction in the median duration of complete remission and median survival, compared with patients who did not have hyperglycemia (Cancer 2004; 100:1179–85).
The reason for higher mortality among patients with hyperglycemia is unknown, Dr. Gagel noted, although it might be due to higher rates of infection. The hyperglycemic patients in the leukemia study developed sepsis or any complicated infection at higher rates than did patients without hyperglycemia.
Many cancer patients, especially those with breast cancer, have a high risk for osteoporosis. The major contributor to bone loss in patients with breast cancer is hypogonadism in the 50% or more of women who develop ovarian failure after chemotherapy. Of 49 women in a study who had early-stage breast cancer treated with adjuvant chemotherapy, 35 developed ovarian failure and had a rapid progression of bone loss 6 and 12 months later (J. Clin. Oncol. 2001;19:3303–5). About 14% of breast cancer survivors in the Women's Health Initiative study had a fracture during less than 5 years of follow-up.
The introduction of aromatase inhibitors in the last 2 years has contributed to the risk of osteoporosis in breast cancer patients, Dr. Gagel said. Aromatase inhibitors block conversion of androstenedione to estrone, or testosterone to estradiol, thereby lowering estrogen levels further.
In a recent trial comparing the aromatase inhibitor anastrozole (Arimidex) with tamoxifen, anastrozole significantly decreased spinal and hip bone mass after a median follow-up of 33 months, compared with tamoxifen. The rate of fractures also was significantly higher with anastrozole than with tamoxifen (Lancet 2002;359:2131–9). Follow-up at 47 months did not show continued worsening of bone mass or fracture risk (Cancer 2003;98:1802–10).
The conference was cosponsored by the American College of Endocrinology and the American Association of Clinical Endocrinologists.