Research shows variations in time to breast cancer diagnosis across the province

Differing communication procedures, referral patterns and health-care resources across Alberta may be factors.

Nisa Drozdowski - 18 October 2018

About one in eight Canadian women will develop breast cancer in her lifetime and one in 31 will die from it. While still a leading cause of cancer deaths among Canadian women, the breast cancer death rate has been declining since the mid-1980s, reflecting the impact of screening on detection of the disease and improvements in treatment. (Canadian Cancer Society)

Breast cancer screening and diagnostic care is one area of research for Associate Professor Yan Yuan. Her work aims to optimize quality of care, patients' outcome and their health-care experience-including reducing disparity in timeliness of receiving a breast cancer diagnosis.

The timeline for breast cancer diagnosis begins with a visit to a doctor, or a screening mammogram. An abnormal screening requires further testing that includes a diagnostic mammogram, an ultrasound and/or a biopsy. Yuan says that a shorter timeline for receiving a breast cancer diagnosis reduces a patient's anxiety and means that the treatment can begin sooner.

"A timely diagnosis is critical to a woman's prognosis because we know that early treatment improves outcomes, including survival," she says. "We need to understand what contributes to the diagnostic interval, to optimize the process," she said.

Using Alberta's Cancer Registry, Yuan identified more than 12,000 female Albertans who had been diagnosed with a primary breast cancer between 2004 and 2010. She separated the population into two groups: screen-detected and symptom-detected.

Screen-detected patients included women who had a screening mammogram within the six months prior to their diagnosis. The remaining women were considered symptom-detected. "This group most likely received a diagnosis after they experienced symptoms and then visited a doctor," Yuan explained.

Tumour characteristics were considered for each group at the time of their diagnosis. This included histological grade, or the degree of abnormality of the cancer cells compared to healthy breast tissue cells; and, the cancer stage, based on the extent of it in the woman's body. "We also looked at health-care indicators, such as previous continuity of care from a doctor, the health region where they lived and whether a patient lived in a rural or urban setting," said Yuan.

"Where a woman lived and her stage of cancer were strongly associated with time to diagnosis and how her cancer was detected."

The variation for diagnostic interval by health region ranged from a median of seven to 42 days for screen-detected patients, and from 13 to 33 days for those who were symptom-detected.

The number of screen-eligible women whose cancer was detected by a screening mammogram varied between 40 and 50 per cent in eight of the nine regional health authorities (RHA), which existed at the study period. The remaining RHA is a geographically large and remote region in the northern-most part of the province. There, only 10 per cent of the women with breast cancer had been diagnosed through screening.

"Some women in remote communities have limited access to mammograms, because they rely on a mobile unit getting to them," Yuan said. Other studies have reported similar challenges reaching vulnerable populations, and Yuan says the province has since developed programs to improve screening in this region.

The study also showed the median diagnostic interval for women with screen-detected cancer in the Edmonton-area RHA was seven days, compared to women in the Calgary-area RHA receiving a diagnosis in 25 days. Yuan says this could be because in the Edmonton region, radiologists have a role in arranging follow-up tests, such as a biopsy, on the same day a woman has abnormal mammogram results.

As Yuan expected, screen-detected cancers were much more likely to be diagnosed at an early stage. Her findings also echoed other studies which found later stage breast cancers that were symptom-detected were diagnosed more quickly than those of earlier stages.

"The greater variation associated with the symptom-detected cancer could be a result from the time interval from when a woman visited her family doctor to the time she got a diagnostic test," explained Yuan. "A later stage tumour may be more easily detectable through a clinical examination, prompting a family doctor to put in an urgent request for a diagnostic test."

The study didn't show the same for the time it took to get a diagnosis for later-stage cancer among screen-detected patients, however. "There are standard follow up procedures after any abnormal screening result," Yuan explained. "Mammograms cannot definitely determine breast cancer's stage, so those established processes would be followed."

"The variation between health regions of women whose cancer was diagnosed through a screening mammogram, and the variation in the length of time it took to get a diagnosis, regardless of how the cancer was detected, implies there are some important differences in local coordination of resources and services," she said.

"We need to look more closely at the communication procedures, referral patterns and health-care resources to identify how to minimize those variations, so that women can get timely diagnosis, wherever they live in the province."

Should you have a screening mammogram?

The Alberta Health Services Cancer Screening Program offers these guidelines to women to know when to get screened for breast cancer:

  • Women under 40: The risk of breast cancer is low, so generally a mammogram is not needed. If you have concerns, speak to your health-care provider.
  • Women 40-49: The risk of breast cancer increases with age, but it is not clear that the benefits outweigh the risks of screening for women in this age group. Speak to your health-care provider about your own risks and needs for a mammogram.
  • Women 50-74: Breast cancer screening has proven to be most beneficial to women in this age range. Plan to have a mammogram every two years, or as decided between you and your health-care provider.
  • Women 75+: At this age, you may benefit from continued, regular screening. Talk to your health-care provider.

    For more information on cancer screening programs in Alberta, visit