Background

The management of breast cancer among older patients places major and growing demands on NHS resources. Just over half the cases of breast cancer occur in older patients (65 years or older) with the peak incidence rate occurring in women in their ninth decade of life . The incidence of the disease is set to rise due to an increase in the age-specific incidence of the disease and demographic changes in the population. In Scotland a 12% rise in breast cancer between 1996-2006 is predicted in women 75 years or older. Additional cases are likely to be detected as the age limit of the UK breast screening programme is extended up to the age of 70 in 2001/2. The Scottish Executive predicts a 41% rise in the annual number of cases of breast cancer, from 3312 per annum in 1995-7 to 4831 per annum by 2010-14.

The differences between older and younger women in response to standard treatments are poorly defined since patients over 70 are frequently excluded from trials on the basis of age or comorbidity. The National Institute of Health Consensus Development Conference Statement (2000) on adjuvant therapies in breast cancer identified the need for trials of adjuvant therapies in older patients. It is also reported for many malignancies that patients aged 65 and older are underrepresented in clinical trials. Addressing the particular needs of older patients with cancer is one of the priorities of the Scottish National Cancer Plan. The conduct of randomised trials of cancer therapy among older patients in general and for breast cancer in particular is therefore an important priority of the NHS.

Breast conserving surgery, adjuvant postoperative breast radiotherapy and systemic therapy has become standard treatment for increasing numbers of women with early breast cancer. In Scotland in 1993 44% of women 70 years or older with axillary node negative operable breast cancer underwent breast conserving surgery. Nonetheless there is evidence of wide variation in the receipt of breast irradiation among older patients undergoing breast conserving surgery. Ballard-Barbash et al (1996) found among a cohort of 18,704 women aged 65 or older that the receipt of postoperative radiotherapy declined substantially with age, irrespective of comorbidity and disease stage. For the age groups 65-69 and 80 years or older, the use of irradiation fell from 77% to 24% in women with no comorbid conditions and 50% to 12% with two or more comorbid conditions. The reasons for the lower rates of breast irradiation with age are often not related to the stage of the disease. They may reflect the patient's, carer's or oncologist's belief that breast irradiation will not be well tolerated or is not worthwhile. Selecting older patients for irradiation is often made more difficult by the presence of comorbidity which may increase the risk of treatment complications and can influence survival.

Postoperative radiotherapy has been shown in a number of randomised trials to reduce the risk of breast cancer recurrence following breast conserving surgery. A four fold reduction in risk of breast recurrence was shown in the Scottish Conservation trial. No compromise in survival was demonstrated in these trials by the omission of breast radiotherapy. The addition of adjuvant tamoxifen would be expected to further reduce the risk of local recurrence. While distant metastases may develop in patients who develop local recurrence, it remains unclear whether or not these events are causally related or coincidental.