Emergency room visits and hospitalizations are common among patients with early breast cancer receiving chemotherapy, particularly among those receiving a regimen containing docetaxel, according to a study supported by the Ontario Institute of Cancer Research, Toronto. “In this population-based cohort study, emergency room visits and hospitalizations were significantly higher among women with early breast cancer undergoing adjuvant chemotherapy compared with age-matched noncancer controls and compared with themselves 2 years before their cancer diagnosis,” the researchers wrote in the Journal of Oncology Practice.
Patients diagnosed between January 2007 and December 2009 were identified using the Ontario Cancer Registry. “Patient records were linked deterministically to provincial health-care databases to provide comprehensive medical follow-up,” the investigators noted. All patients received one or more cycles of adjuvant chemotherapy.
A total of 8,359 patients with early breast cancer were matched to the same number of noncancer controls on age, comorbidity, and geographic location. The mean age of the study participants was 53.67 years.
“Emergency room visits and hospitalizations within 30 days of chemotherapy were identified. If the primary reason for the visit was a common chemotherapy toxicity, the visit was considered chemotherapy associated. All-cause and chemotherapy-associated visits were compared between patient cases and controls,” the authors explained.
Overall, most visits were for emergency room alone, 68.9% of visits by patients receiving chemotherapy and 82.4% of visits by noncancer controls. “The proportion of patients with at least one emergency room visit and hospitalization was significantly higher in patients with early breast cancer undergoing chemotherapy compared with noncancer controls (43.4% vs 9.4%, P < .001),” the researchers reported. Patients receiving adjuvant chemotherapy for early breast cancer were also more likely to have multiple emergency room visits and hospitalization visits (17.9% vs 2.4%, P <.001).
The most common chemotherapy regimens contained docetaxel (65.8%). Paclitaxel-containing regimens were taken by 13.9% of patients; 20% took anthracyclines alone; and 20.8% used trastuzumab (Herceptin) in combination with chemotherapy.
“Patient characteristics varied significantly by chemotherapy regimen,” the researchers reported. “Compared with both the docetaxel and paclitaxel cohorts, patients in the anthracycline-only cohort were significantly older (P ≤ .001), had a higher comorbidity burden (P = .01), and were more likely to have stage I breast cancer (P ≤ .001).”
Among those receiving chemotherapy for early breast cancer, 62.4% of all their visits were considered chemotherapy related. The primary reasons for emergency room visits by patients receiving chemotherapy were fever or neutropenia, infection, and gastrointestinal complaints. These toxicities were observed in 24% of patients receiving chemotherapy and “were more common with the use of docetaxel (29%) than with paclitaxel (13%) or anthracyclines alone (16%, P < .001),” the investigators reported. “Comorbidities in patients receiving chemotherapy were associated with an increased risk of all-cause emergency room visits and hospitalizations (P < .001) but were not associated with an increased risk of chemotherapy-associated emergency room visits and hospitalizations (P = .13),” the researchers observed.
The rate of emergency room visits and hospitalizations was “significantly higher than in randomized clinical trials of adjuvant chemotherapy, where rates of emergency room visits and hospitalizations are rarely or never reported,” the investigators noted. “The use of adjuvant chemotherapy in patients with early breast cancer outside clinical trials may result in increased toxicities for several reasons. Compared with the general population, patients in clinical trials are younger, have fewer comorbidities, and have more social supports,” the researchers wrote. “Patients enrolled onto clinical trials undergo increased clinical monitoring compared with patients treated off trials, which may result in earlier detection and treatment of chemotherapy-associated toxicities.”
The authors concluded, “Interventions aimed at early detection and intervention for chemotherapy-associated toxicities, particularly in the highest-risk women, have the potential to decrease emergency room visits and hospitalizations in patients with early breast cancer and improve quality of care.”
Enright K, et al: J Oncol Pract. January 20, 2015 (early release online). ■