Older women with node positive (N+) breast cancer (BC) get similar benefits from adjuvant chemotherapy (adj) as younger patients (pts): The Cancer and Leukemia Group B (CALGB) experience

Reviewer: Walter Sall, MD
OncoLink
Last Modified: May 31, 2003

Presenter: H. B. Muss
Presenter's Affiliation: Univ. of Vermont, CALGB
Type of Session: Scientific

Background

This study is an analysis of the benefits and toxicities by age of adjuvant chemotherapy in N+ breast cancer patients.
Little data exists regarding the benefit of cytotoxic chemotherapy in elderly (>65) breast cancer patients.
The prevailing viewpoint is that elderly women do not benefit from chemotherapy, thus most are treated with tamoxifen alone.

Materials and Methods

Retrospective data from four CALGB trials (7581, 8082, 8541 and 9344) were pooled to yield 6,489 patients. These patients had been randomized to various doses and schedules of adjuvant chemotherapy.
Toxicity data were available from all trials.
Patients were randomized in low vs. high dose regimens in the various trials. Variations of CMF, CAF and AC/T chemotherapy were used in all trials.
Information about tamoxifen use was available only for the two most recent trials. Between 50 and 95% of ER(+) patients received tamoxifen in these trials.

Results

Median follow-up was 9.6 years.
34% of patients were T1, 55% T2 and 11% T3
48% had 1-3 positive nodes, 37% had 4-9 and 15% had 10+.
54% were age 50 or younger, 38% were 51-64 and 8% were 65+.
Older patients (65+) had significantly more positive nodes (p<0.05).
T stage, # of nodes, high chemotherapy dose and tamoxifen use all correlated with longer relapse free survival and overall survival.
Age < or > 65 did not correlate with RFS and OS.
A 31% reduction in risk of relapse was seen in older patients when given high vs. low dose adjuvant chemotherapy.
Death rate due to therapy was 1.3% for those >65 vs. 0.2% for those <50 years old

Author's Conclusions

When compared to younger women, older women have similar dose related benefits from adjuvant chemotherapy in reducing breast cnacer related relapse and mortality.
Since 50% of breast cancer diagnoses are in women >65 years old, this age group is significantly under-represented in this study.
Older women in this study had significantly more positive lymph nodes, possibly increasing the liklihood that benefit would be found in this patient group.
Elderly women had a greater risk of breast cancer and non-breast cancer death.

Clinical/Scientific Implications

Though this study was restrospective and examined a very heterogeneous group of patients, is provides compelling new evidence that at least some subsets of elderly women with breast cancer can benefit from cytotoxic chemotherapy. As the population ages, data regarding the chemotherapeutic management of elderly breast cancer patients will become more important. More aggressive enrollment of older women in prospective adjuvant chemotherapy trials is necessary in order to confirm the data found in this study. Since many of the elderly patients in this study had high numbers of positive lymph nodes, it is unclear whether elderly patients with fewer positive lymph nodes will obtain similar benefit.

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