A study published on bmj.com today reports that the longer women wait for radiotherapy after breast cancer surgery, the more chance there is of local recurrence.

Starting radiotherapy as soon as possible will minimize this risk according to the authors.

The reasonable generally accepted interval between cancer surgery and radiotherapy is four to six weeks. Evidence on the effect of waiting times in patients with breast cancer is unclear.

In order to find out more, researchers from the United States, Canada and Japan investigated the link between interval to radiotherapy and recurrence of breast cancer.

A total of 18,050 national cancer records were analyzed. The data were from women aged 65 or older who were diagnosed with early stage breast cancer during 1991-2002. All women received breast conserving surgery and radiotherapy, but not chemotherapy.

Data from the 2000 US population census was used to identify demographic information. Women were monitored for an average of five years.

The findings indicated that starting radiotherapy more than six weeks after surgery was linked to a modest but significant increase in local recurrence. In the study, more than one in four women (30 percent) started radiotherapy after this time. A total of 734 (4 percent) experienced a local recurrence at five years.

Additional investigation showed a continuous relation between time to radiotherapy and local recurrence. This suggests that initiating radiation therapy as soon as possible could minimize local recurrence risk.

Longer periods before undergoing radiotherapy were also found among Black and Hispanic women and among women who lived outside the southern states of the US. The rates of breast conserving surgery were higher, suggesting limitations in capacity of radiation delivery.

The continuous relationship between the start of radiotherapy and local recurrence suggests that there is no “secure” threshold in terms of waiting time. Therefore, the authors recommend that radiotherapy should be started as soon as possible.

The researchers comment that the cost of increasing capacity to consistently ensure short waiting times could be important. This would need to be evaluated in return with the small absolute benefit in local recurrence. The authors conclude that it appears appropriate to consider this is a price to pay, given the recognized negative impact of local recurrence on overall survival, and the large numbers of women treated with radiotherapy for breast cancer.

In an associated editorial, Ruth Jack and Lars Holmberg from King’s College London say that minimizing delay improves outcomes; therefore investment and planning are needed.

They comment that healthcare providers need to evaluate where probable delays are occurring. Then they should make certain that these are reduced. In addition, they should ensure equal opportunities in accessing good care. On the other hand, they point out that if significant investment is required, the modest effects seen in this study would have to be weighed against other opportunities and priorities in cancer care.

“Impact of interval from breast conserving surgery to radiotherapy on local recurrence in older women with breast cancer: retrospective cohort analysis”
Rinaa S Punglia, assistant professor, Akiko M Saito, research fellow, chief, Bridget A Neville, programmer, Craig C Earle, associate professor, senior scientist, Jane C Weeks, professor
BMJ 2010; 340:c845
doi:10.1136/bmj.c845

“Waiting times for radiotherapy after breast cancer”
Ruth H Jack, information analyst, Lars Holmberg, professor of cancer epidemiology
BMJ 2010; 340:c1007
bmj.com

Written by Stephanie Brunner (B.A.)