Chemotherapy Plus Tamoxifen Improves Survival of Early Breast Cancer

[Admin]

NEW YORK (Reuters Health) Apr 03 - Adding chemotherapy to tamoxifen improves the survival of early breast cancer, but adding ovarian ablation/suppression seems to offer no benefit in most women, according to the results of two studies conducted by the Adjuvant Breast Cancer (ABC) Trials Collaborative Group.

In the ABC Chemotherapy trial, Dr. Judith Bliss, from The Institute of Cancer Research in Sutton, UK, and colleagues assessed the outcomes of 1991 patients, between 28 and 81 years of age, who were randomized to receive prolonged (5 years) tamoxifen therapy with or without standard chemotherapy. Some of the premenopausal women were also treated with ovarian ablation or suppression.

The chemotherapy group experienced fewer relapse events than the control group--298 vs. 332-but the difference fell short of statistical significance, according to the report in the Journal of the National Cancer Institute for April 4.

After adjusting for nodal status, estrogen receptor status, and age, adding chemotherapy to tamoxifen reduced the risk of death by 17% (p = 0.03). A total of 243 deaths were noted in the chemotherapy group compared with 282 in the control group.

The benefit of chemotherapy on relapse-free survival emerged early, while it took at least 5 years for the overall survival benefit to become apparent, the researchers note.

On subgroup analysis, chemotherapy provided the greatest survival benefit in women younger than 50 years, especially premenopausal women not treated with ovarian ablation or suppression.

To better understand the benefits, if any, of ovarian ablation/suppression, Dr. Bliss' team conducted the ABC Ovarian Ablation or Suppression trial, which involved 2144 pre- and perimenopausal women who were given tamoxifen, with or without chemotherapy, and were randomized to receive or not receive ovarian ablation/suppression.

Ovarian ablation/suppression provided no improvement in overall or relapse-free survival, the report indicates. Moreover, this held true after adjusting for age, nodal status, and estrogen receptor status.

Despite these findings, the authors note that there may be a role for ovarian ablation/suppression in women younger than 40, especially those not given chemotherapy, but further studies are needed.

In a related editorial, Dr. Kathleen I. Pritchard, from Toronto Sunnybrook Regional Cancer Centre, comments that additional useful information could have been provided by these trials if the estrogen receptor status of more of the patients had been known (absent in over 40% of cases).

"These studies stress the importance of establishing processes to ensure availability of archived tumor specimens for all randomized adjuvant trials. The era in which such large important trials should be carried out without the archived correlational tumor samples is over," she concludes.

J Natl Cancer Inst 2007;99:494-495,506-525.

Source: http://www.medscape.com/viewarticle/554645?src=mp