THE QUESTION Might delaying the start of chemotherapy after breast cancer surgery affect the results a woman might expect?
THIS STUDY analyzed data on 6,827 women, 19 to 85 years old, who had chemotherapy after surgery for Stage 1, 2 or 3 invasive breast cancer. About 40 percent started chemotherapy within 30 days of their surgery, 44 percent started within 31 to 60 days and 16 percent waited more than 60 days to initiate treatment. After about five years, 1,437 (21 percent) of the women had died, and the cancer had recurred in 2,135 women (31 percent) and metastasized in 1,924 (28 percent). Women who waited the longest to start chemotherapy were 19 percent more likely to have died within five years than those who started it within 30 days. In general, risks varied by the type and stage of cancer. For instance, women with hormone-receptive positive tumors had a 29 percent greater chance of dying if they delayed chemotherapy for more than 60 days, and those with triple-negative breast cancer raised their risk by 54 percent compared with women who started treatment right away. For women with Stage 2 cancer, starting chemotherapy after 60 days rather than within 30 days corresponded to a 20 percent greater chance of metastasis, and that risk increased by 36 percent for those with Stage 3 cancer. Women with more advanced and more aggressive types of cancers benefited the most from an early start of chemotherapy.
WHO MAY BE AFFECTED? Women with breast cancer. In stages 0 through 3, the cancer has not spread to distant parts of the body; in Stage 4, the cancer has metastasized beyond the breast and nearby lymph nodes. Chemotherapy, which involves the use of very strong drugs, is prescribed to kill any cancer cells remaining after surgery and thus decrease the chance that the cancer will recur or spread. In the United States, about one in eight women develop breast cancer at some point in their lives.
CAVEATS The study did not include, for comparison, women who did not have chemotherapy as part of their breast cancer treatment. Most women in the study (84 percent) had Stage 1 or 2 cancers.
FIND THIS STUDY Jan. 27 online issue of the Journal of Clinical Oncology.
The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.