Chemotherapy and breast cancer - side effects underestimated

Researchers believe that the side effects of chemotherapy treatment for breast cancer are probably higher than thought.

New research by the Dana-Farber Cancer Institute, in Boston and Harvard Medical School, has found that the side effects of chemotherapy along with related costs are possibly underestimated.

Study author Dr. Michael Hassett says when the rates of side effects commonly associated with chemotherapy were examined they found women experienced more hospitalizations or emergency room visits for these side effects than was previously estimated.

Doctors often prescribe chemotherapy to eliminate residual cancer cells in women who have undergone surgery for breast cancer.

The study was carried out to find out how chemotherapy-related serious adverse effects affected a population of younger women with breast cancer as it is the most common reason why American women receive chemotherapy.

According to the researchers hospitalizations due to chemotherapy side effects are thought to be rare, but only one study has previously been done to measure the side effects of chemotherapy on the general population.

Hassett says they wanted to find out how frequently side effects occurred in the general community, because what happens in the community may be different from what is seen in clinical trials.

To better assess the incidence of side effects, Hassett and his team collected data from a pool of 12,239 women who had been recently diagnosed with breast cancer, all were under the age of 63 and 4,075 of which had received chemotherapy.

The researchers examined hospitalization and emergency room visits in the year following the initial diagnosis for both women who received chemotherapy and those who did not and found that women on chemotherapy were much more likely to visit the emergency room or be hospitalized for any cause than women who had not had chemotherapy; 61 percent compared to 42 percent.

Women who received chemotherapy were found to be more likely to be hospitalized or visit emergency rooms for problems that are typically related to chemotherapy, including fever or infection, low white blood cell or platelet count, nausea, diarrhea, malnutrition or dehydration.

For the women who received chemotherapy this equated to more than $1,200 in additional health-care expenditures related to chemotherapy and more than $17,000 in additional costs for ambulatory care than women who did not receive chemotherapy.

Hassett believes there are a number of possible explanations for these events; clinical trials may not detect all of the side effects that occur and people enrolled in clinical trials may be less likely than those treated in the general community to experience serious side effects of chemotherapy.

Also clinical trials may not have enough power to detect rare side effects.