Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Accept all cookies Reject all non-essential cookies Find out more

Table 9.1

The main results for overall survival in the randomized controlled trials considered by the Early Breast Cancer Trialists’ Collaborative Group. Standard errors (se) in percent are given in parentheses.

Cycle Data included Main results for overall survival and references
First Trials started before 1985. Follow-up to 1985.

Tamoxifen (28 trials involving 16,500 randomized women): Highly significant (p <0.0001) reduction in mortality in trials of ‘tamoxifen versus no tamoxifen’ over about five years of follow-up (EBCTCG 1988).

Chemotherapy (40 trials involving over 13,000 randomized women): Highly significant (p = 0.003) reduction in mortality in trials of ‘any chemotherapy versus no chemotherapy’, and also (p = 0.001) in trials of ‘polychemotherapy versus single-agent chemotherapy’, both over about five years of follow-up. Chemotherapy for 12–24 months may offer little survival advantage over 6 months (EBCTCG 1988).

Second

Trials started before 1985. Follow-up to 1990.

Tamoxifen (40 trials involving 30,000 randomized women): Highly significant 17% (se 2; p <0.00001) reduction in overall mortality rate in trials of ‘tamoxifen versus no tamoxifen’ over about 10 years of follow-up. Indirect comparisons suggest longer term treatment (∼2–5 years) better than shorter. Polychemotherapy plus tamoxifen clearly better than polychemotherapy alone at ages 50–69 (EBCTCG 1992).

Chemotherapy (31 trials involving 11,000 randomized women): Highly significant 16% (se 3; p <0.00001) reduction in overall mortality rate in trials of ‘polychemotherapy versus no chemotherapy’ over about 10 years of follow-up. No advantage in long-term treatment (∼12 months) over shorter term (∼6 months). Tamoxifen and polychemotherapy may be better than tamoxifen alone at ages 50–69 (EBCTCG 1992).

Ovarian ablation (10 trials involving 3000 randomized women): Highly significant 25% (se 7; p = 0.0004) reduction in overall mortality rate for women treated at age < 50 over at least 10 years of follow-up. No significant effect for those aged 50+ when treated. (EBCTCG 1992).

Immunotherapy (24 trials involving 6300 randomized women): No significantly favourable effects of immunotherapy found (EBCTCG 1992).

Local therapies (64 trials involving 28,500 randomized women): Radiotherapy reduced rate of local recurrence by factor of three and breast conserving surgery involved some risk of recurrence in remaining tissue, but no definite differences in overall survival at 10 years (EBCTCG 1995).

Third

Trials started before 1990. Follow-up to 1995.

Tamoxifen: (55 trials involving 37,000 women): No significantly favourable effect in women with ER-negative tumours, but for 30,000 women with ER-positive or untested tumours highly significant effects with 12% (se 3), 17% (se 3) and 26% (se 4) reductions in the overall mortality rate in trials of 1, 2, and 5 years respectively of tamoxifen versus no tamoxifen, over about 10 years of follow-up. Proportionate benefit applies regardless of nodal status, age, menopausal status, daily tamoxifen dose, and whether or not chemotherapy was given (EBCTCG 1998b). Chemotherapy (69 trials involving 30,000 women): Highly significant reductions in overall mortality rate of 25% (se 5; p <0.00001) in women aged < 50 and 11% (se 3; p = 0.0001) in women aged 50–69 in trials of “polychemotherapy versus no chemotherapy”. Proportionate benefit similar regardless of nodal status, menopausal status (given age), ER-status and whether or not tamoxifen had been given. No advantage of more than about 6 months of treatment (EBCTCG 1998a).

Ovarian ablation (12 trials involving 3500 women): No benefit for women aged over 50, but highly significant improvement in 15-year survival among those aged 50 or under when treated (15-year survival 52% versus 46%; p = 0.001) in trials of “ovarian ablation versus no ablation”. Further evidence needed on effect of ablation in the presence of other adjuvant treatments (EBCTCG 1996).

Radiotherapy (40 trials involving 20,000 women): Substantial reduction in breast cancer mortality largely offset by an increased risk of mortality from cardiovascular disease, so that overall 20-year survival was 37% with radiotherapy and 36% without (p = 0.06) in trials of “radiotherapy versus no radiotherapy”. The ratio of benefit (from reduced mortality from breast cancer) to harm (from increased mortality from cardiovascular disease) was strongly affected by nodal status, age and decade of follow-up (EBCTCG 2000).

Fourth

Trials started before 1995. Follow-up to 2000.

Data on ∼80,000 women randomised in trials of tamoxifen, ∼50,000 women in trials of chemotherapy, 10 000 women in trials of ovarian ablation and ∼38,000 women in trials of local therapies have recently been published (EBCTCG 2005); see page 196.